Context: Compared with bare metal stents, sirolimus-elut-ing and paclitaxel-eluting stents have been shown to markedly improve angiographic and clinical outcomes after percutaneous coronary revascularization, but thei...Context: Compared with bare metal stents, sirolimus-elut-ing and paclitaxel-eluting stents have been shown to markedly improve angiographic and clinical outcomes after percutaneous coronary revascularization, but their performance in the treatment of de novo coronary lesions has not been compared in a prospective multicenter study. Objective: To compare the safety and efficacy of sirolimus-eluting vs paclitaxel-eluting coronary stents. Design: Prospective, randomized comparative trial(the REALITY trial) conducted between August 2003 and February 2004, with angiographic follow-up at 8 months and clinical follow-up at 12 months. Setting: Ninety hospitals in Europe, Latin America, and Asia. Patients: A total of 1386 patients(mean age, 62.6 years; 73.1% men; 28.0% with diabetes)with angina pectoris and 1 or 2 de novo lesions(2.25-3.00 mm in diameter) in native coronary arteries. Intervention: Patients were randomly assigned in a 1 ∶ 1 ratio to receive a sirolimus-eluting stent(n=701) or a paclitaxel-eluting stent(n=685). Main Outcome Measures: The primary end point was in-lesion binary restenosis(presence of a more than 50% luminal diameter stenosis) at 8 months. Secondary end points included 1-year rates of target lesion and vessel revascularization and a composite end point of cardiac death, Q-wave or non-Q-wave myocardial infarction, coronary artery bypass graft surgery, or repeat target lesion revascularization. Results: In-lesion binary restenosis at 8 months occurred in 86 patients(9.6% ) with a sirolimus-eluting stent vs 95(11.1% ) with a paclitaxel-eluting stent(relative risk [RR], 0.84; 95% confidence interval [CI], 0.61-1.17; P=.31). For sirolimus- vs paclitaxel-eluting stents, respectively, the mean(SD) in-stent late loss was 0.09(0.43) mm vs 0.31(0.44) mm(difference,-0.22 mm; 95% CI,-0.26 to-0.18 mm; P<.001), mean(SD) in-stent diameter stenosis was 23.1% (16.6% ) vs 26.7% (15.8% )(difference,-3.60% ; 95% CI,-5.12% to-2.08% ; P< .001), and the number of major adverse cardiac events at 1 year was 73(10.7% ) vs 76(11.4% )(RR, 0.94; 95% CI, 0.69-1.27; P=.73). Conclusion: In this trial comparing sirolimus- and paclitaxel-eluting coronary stents, there were no differences in the rates of binary restenosis or major adverse cardiac events. Clinical Trial Registration: ClinicalTrials.gov Identifier:展开更多
The purpose of this study was to explore whether dysglycemia, and/or an increased body mass index, and/or an increased waist/hip ratio increased the risk of hypertension in a lean population of South China. The associ...The purpose of this study was to explore whether dysglycemia, and/or an increased body mass index, and/or an increased waist/hip ratio increased the risk of hypertension in a lean population of South China. The association among dysglycemia, obesity, and hypertension has been well documented in Western populations. A stratified cluster sampling method was used according to the National Diabetes Mellitus Epidemiology Survey Program in 1998. Blood pressure, fasting plasma glucose, and plasma glucose were measured 2 hours after 75-g oral glucose consumption using the enzymatic method in the morning. Body height, weight, and waist and hip measurements were also collected for the survey. The criteria for the diagnosis of hypertension and diabetes mellitus, including impaired glucose tolerance(IGT), were those published by the World Health Organization in 1999. A total of 11,402 participants were included in the investigation(5,195 men and 6,207 women; age 20 to 74 years). A total of 1,775 cases of hypertension were confirmed in the survey. The prevalence of hypertension was significantly higher in those with diabetes mellitus than in those with a normal blood glucose level, in those with IGT than in those with normal glucose tolerance test findings, and in obese participants than in those with a normal weight(45.5% vs 14.4% , 32.2% vs 14.5% , and 20.6% vs 12.1% , respectively). Multiple logistic regression analysis indicated that age and gender-adjusted odds ratio of hypertension was 2.24(95% confidence interval 1.88 to 2.68) with IGT compared with those without IGT. The odds ratio for hypertension associated with an increased body mass index and waist/hip ratio was 1.19(95% confidence interval 1.17 to 1.21) and 1.08(95% confidence interval 1.07 to 1.09), respectively. In conclusion, the data from an epidemiologic study in South China demonstrated that dysglycemia and increased body mass index and/or waist/hip ratio increase the risk of hypertension even in a lean Chinese population.展开更多
Background: Patients who develop fulminant myocarditis often die of sudden car diac arrest, arrhythmia, or severe heart failure soon after onset if they do not receive percutaneous cardiopulmonary support in time. The...Background: Patients who develop fulminant myocarditis often die of sudden car diac arrest, arrhythmia, or severe heart failure soon after onset if they do not receive percutaneous cardiopulmonary support in time. The purpose of this study was to identify the risk factors of clinical symptoms/signs or laboratory findi ngs that could predict the fulminant course of acute myocarditis. Methods and re sults: Thirty-five patients(mean age 28±8 years, 17 males) who had been admitt ed to intensive care unit with the diagnosis of acute myocarditis by clinical pr esentations were retrospectively recruited. They were divided into the fulminant group(n=11) and the non-fulminant group(n=24). Clinical features, laboratory d ata, and images on admission were analyzed. Overall in-hospital mortality was 1 7%(6/35). Mortality was higher in the fulminant group(45%vs. 4%, p=0.027). Mu ltivariate analysis revealed that prolongations of the QRS complex(118±27 vs. 8 8±10 ms, p=0.048) and depressed left ventricular ejection fraction(41±7%vs. 5 7±7%, p=0.027) were the only independent factors significantly associated with the fulminant course of acute myocarditis. Conclusion: The in-hospital mortali ty of acute fulminant myocarditis was high. Prolongations of the QRS complex and depressed left ventricular ejection fraction on admission were independent posi tive predictors for the development of acute fulminant myocarditis.展开更多
Aims: The addition of trimetazidine to standard treatment has been shown to improve left ventricular(LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo ...Aims: The addition of trimetazidine to standard treatment has been shown to improve left ventricular(LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo 31P-magnetic resonance spectroscopy(31P-MRS), the effects of trimetazidine on LV cardiac phosphocreatine and adenosine triphosphate(PCr/ATP) ratio in patients with heart failure. Methods and results: Twelve heart failure patients were randomized in a double-blind, cross-over study to placebo or trimetazidine(20 mg t.i.d.) for two periods of 90 days. At the end of each period, all patients underwent exercise testing, 2D echocardiography, and MRS. New York Heart Association(NYHA) class, ejection fraction(EF), maximal rate-pressure product, and metabolic equivalent system(METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P-MRS. On trimetazidine, NYHA class decreased from 3.04±0.26 to 2.45±0.52(P=0.005), whereas EF(34±10 vs. 39±10%, P=0.03) and METS(from 7.44±1.84 to 8.78±2.72, P=0.03) increased. The mean cardiac PCr/ATP ratio was 1.35±0.33 with placebo, but was increased by 33%to 1.80±0.50(P=0.03)with trimetazidine. Conclusion: Trimetazidine improves functional class and LV function in patients with heart failure. These effects are associated to the observed trimetazidi ne-induced increase in the PCr/ATP ratio, indicating preservation of the myocar dial high-energy phosphate levels.展开更多
Background: Elevated coagulative molecular markers could reflect the prothromb otic state in the cardiovascular system of patients with non-valvular atrial fi brillation(NVAF). A prospective, cooperative study was con...Background: Elevated coagulative molecular markers could reflect the prothromb otic state in the cardiovascular system of patients with non-valvular atrial fi brillation(NVAF). A prospective, cooperative study was conducted to determine wh ether levels of coagulative markers alone or in combination with clinical risk f actors could predict subsequent thromboembolic events in patients with NVAF. Met hods: Coagulative markers of prothrombin fragment 1 +2, D-dimer, platelet fact or 4, and β-thromboglobulin were determined at the enrollment in the prospecti ve study. Results: Of 509 patients with NVAF(mean age, 66.6±10.3 years), 263 pa tients were treated with warfarin(mean international normalized ratio, 1.86), an d 163 patients, with antiplatelet drugs. During an average follow-up period of 2.0 years, 31 thromboembolic events occurred. Event-free survival was significa ntly better in patients with D-dimer level< 150 ng/ml than in those with D-dim er level ≥150 ng/ml. Other coagulative markers, however, did not predict thromb oembolic events. Age(≥75 years), cardiomyopathies, and prior stroke or transien t ischemic attack were independent, clinical risk factors for thromboembolism. T hromboembolic risk in patients without the clinical risk factors was quite low(0 .7%/year) when D-dimer was< 150 ng/ml, but not low(3.8%/year) when D-dimer w as ≥150 ng/ml. It was > 5%/year in patients with the risk factors regardless o f D-dimer levels. This was also true when analyses were confined to patients tr eated with warfarin. Conclusions: D-dimer level in combination with clinical ri sk factors could effectively predict subsequent thromboembolic events in patient s with NVAF even when treated with warfarin.展开更多
Context: Restenosis within bare-metal stents is often treated with repeat percutaneous coronary intervention, although subsequent recurrence rates are high, with vascular brachytherapy(VBT) affording the best results....Context: Restenosis within bare-metal stents is often treated with repeat percutaneous coronary intervention, although subsequent recurrence rates are high, with vascular brachytherapy(VBT) affording the best results. The effectiveness of drug-eluting stents in this setting has not been established. Objective: To investigate the safety and efficacy of the polymer-based, slow-release paclitaxel-eluting stent in patients with restenotic lesions after prior stent implantation in native coronary arteries. Design, Setting, and Patients: Prospective, multicenter, randomized trial conducted between June 6, 2003, and July 16, 2004, at 37 North American academic and community-based institutions in 396 patients with in-stent restenosis of a previously implanted bare-metal coronary stent(vessel diameter, 2.5-3.75 mm; lesion length, ≤ 46 mm). Interventions: Patients were randomly assigned to undergo angioplasty followed by VBT with a β source(n=201) or paclitaxel-eluting stent implantation(n=195). Clinical and angiographic follow-up at 9 months was scheduled in all patients. Main Outcome Measure: Ischemia-driven target vessel revascularization at 9 months. Results: Diabetes mellitus was present in 139 patients(35.1% ). Median reference vessel diameter was 2.65 mm and median lesion length was 15.3 mm. In the VBT group, new stents were implanted in 22 patients(10.9% )and in the paclitaxel-eluting stent group, multiple stents were required in 57 patients(29.2% ), with median stent length of 24 mm. Follow-up at 9 months was complete in 194 patients in the VBT group and 191 patients in the paclitaxel-eluting stent group(96.5% and 97.9% , respectively). For VBT and paclitaxel-eluting stents, respectively, the number of events and 9-month rates for ischemic target lesion revascularization were 27(13.9% ) vs 12(6.3% )(relative risk [RR], 0.45; 95% confidence interval [CI], 0.24-0.86; P=.01); for ischemic target vessel revascularization, 34(17.5% ) vs 20(10.5% )(RR, 0.60; 95% CI, 0.36-1.00; P=.046); and for overall major adverse cardiac events, 39(20.1% ) vs 22(11.5% )(RR, 0.57; 95% CI, 0.35-0.93; P=.02), with similar rates of cardiac death or myocardial infarction(10 [5.2% ] vs 7 [3.7% ]; RR, 0.71; 95% CI, 0.28-1.83; P=.48) and target vessel thrombosis(5 [2.6% ] vs 3 [1.6% ]; RR, 0.61; 95% CI, 0.15-2.50; P=.72). Angiographic restenosis at 9 months was 31.2% (53 of 170 patients) with VBT and 14.5% (25 of 172 patients) with paclitaxel-eluting stents(RR, 0.47; 95% CI, 0.30-0.71; P< .001). Conclusion: Treatment of bare-metal in-stent restenotic lesions with paclitaxel-eluting stents rather than angioplasty followed by VBT reduces clinical and angiographic restenosis at 9 months and improves event-free survival. Trial Registration: ClinicalTrials. gov Identifier: NCT00287573.展开更多
Background: We conducted a randomized, controlled trial of circumferential pulmonary-vein ablation for the treatment of chronic atrial fibrillation. Methods: A total of 146 patients with a mean(± SD) age of 57...Background: We conducted a randomized, controlled trial of circumferential pulmonary-vein ablation for the treatment of chronic atrial fibrillation. Methods: A total of 146 patients with a mean(± SD) age of 57± 9 years who had chronic atrial fibrillation were randomly assigned to receive amiodarone and undergo two cardioversions during the first three months alone(the control group) or in combination with circumferential pulmonary-vein ablation. Cardiac rhythm was assessed with daily telephonic transmissions for one year. The left atrial diameter and the severity of symptoms were assessed at 12 months. Results: Among the 77 patients assigned to undergo circumferential pulmonary-vein ablation, ablation was repeated because of recurrent atrial fibrillation in 26 percent of patients and atypical atrial flutter in 6 percent. An intention-to-treat analysis showed that 74 percent of patients in the ablation group and 58 percent of those in the control group were free of recurrent atrial fibrillation or flutter without antiarrhythmic-drug therapy at one year(P=0.05). Among the 69 patients in the control group, 53(77 percent) crossed over to undergo circumferential pulmonary-vein ablation for recurrent atrial fibrillation by one year and only 3(4 percent) were in sinus rhythm without antiarrhythmic-drug therapy or ablation. There were significant decreases in the left atrial diameter(12± 11 percent, P< 0.001) and the symptom severity score(59± 21 percent, P< 0.001) among patients who remained in sinus rhythm after circumferential pulmonary-vein ablation. Except for atypical atrial flutter, there were no complications attributable to circumferential pulmonary-vein ablation. Conclusions: Sinus rhythm can be maintained long term in the majority of patients with chronic atrial fibrillation by means of circumferential pulmonary-vein ablation independently of the effects of antiarrhythmic-drug therapy, cardioversion, or both. The maintenance of sinus rhythm is associated with a significant decrease in both the severity of symptoms and the left atrial diameter.展开更多
Context: Previous studies have suggested that subclinical abnormalities in thyroid-stimulating hormone levels are associated with detrimental effects on the cardiovascular system. Objective: To determine the relations...Context: Previous studies have suggested that subclinical abnormalities in thyroid-stimulating hormone levels are associated with detrimental effects on the cardiovascular system. Objective: To determine the relationship between baseline thyroid status and incident atrial fibrillation, incident cardiovascular disease, and mortality in older men and women not taking thyroid medication. Design, Setting, and Participants: A total of 3233 US community-dwelling individuals aged 65 years or older with baseline serum thyroid-stimulating hormone levels were enrolled in 1989-1990 in the Cardiovascular Health Study, a large, prospective cohort study. Main Outcome Measures: Incident atrial fibrillation, coronary heart disease, cerebrovascular disease, cardiovascular death, and all-cause death assessed through June 2002. Analyses are reported for 4 groups defined according to thyroid function test results: subclinical hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism. Results: Individuals with overt thyrotoxicosis(n=4) were excluded because of small numbers. Eighty-two percent of participants(n=2639) had normal thyroid function, 15% (n=496) had subclinical hypothyroidism, 1.6% (n=51)had overt hypothyroidism, and 1.5% (n=47) had subclinical hyperthyroidism. After exclusion of those with prevalent atrial fibrillation, individuals with subclinical hyperthyroidism had a greater incidence of atrial fibrillation compared with those with normal thyroid function(67 events vs 31 events per 1000 person-years; adjusted hazard ratio, 1.98; 95% confidence interval, 1.29-3.03). No differences were seen between the subclinical hyperthyroidism group and euthyroidism group for incident coronary heart disease, cerebrovascular disease, cardiovascular death, or all-cause death. Likewise, there were no differences between the subclinical hypothyroidism or overt hypothyroidism groups and the euthyroidism group for cardiovascular outcomes or mortality. Specifically, individuals with subclinical hypothyroidism had an adjusted hazard ratio of 1.07(95% confidence interval, 0.90-1.28) for incident coronary heart disease. Conclusion: Our data show an association between subclinical hyperthyroidism and development of atrial fibrillation but do not support the hypothesis that unrecognized subclinical hyperthyroidism or subclinical hypothyroidism is associated with other cardiovascular disorders or mortality.展开更多
Exercise is an important behavior for long-term weight control in overweight and obese patients. However, little evidence exists confirming such findings in patients with advanced heart failure(HF). Using a prospectiv...Exercise is an important behavior for long-term weight control in overweight and obese patients. However, little evidence exists confirming such findings in patients with advanced heart failure(HF). Using a prospective, experimental design, the effects of 24 weeks of a low-level, home-based walking program on weight loss were studied in overweight and obese(body mass index≥ 27 kg/m2) patients with advanced HF who were randomized to exercise(n=48) and control(n=51) groups. Weight changes between the 2 groups at baseline and 6 months were compared using repeated-measures analysis of variance. Patients were on average aged 53.3± 10.1 years and predominantly male(75% ), Caucasian(57% ), and married(55% ). Most patients were in New York Heart Association class III or IV(67% ), with a mean ejection fraction of 25% . Patients in the exercise group showed significant weight reduction from baseline to 6 months compared with those in the control group(-6.37± 11.7 vs -0.33± 9.3 kg, p=0.002). No significant differences were noted between the 2 groups in 6-minute walk distance or depression, although the changes were in the anticipated direction. Modest weight losses of >5% were associated with cardiopulmonary exercise test-documented workload levels at 6 months(r=0.331, p=0.006), as well as decreased depression(r=-0.315, p=0.01) and hostility(r=-0.355, p=0.005). The number of hospital admissions was significantly smaller for patients in the exercise group compared with those in the control group(0.63± 0.94 vs 1.07± 0.95, p< 0.05). In conclusion, the findings demonstrate the beneficial effects of a low-level, home-based walking program on weight loss in overweight and obese patients with advanced HF.展开更多
Context: Although vascular brachytherapy is the only approved therapy for restenosis following bare-metal stent implantation, drug-eluting stents are now being used. Data on the relative merits of each are limited. Ob...Context: Although vascular brachytherapy is the only approved therapy for restenosis following bare-metal stent implantation, drug-eluting stents are now being used. Data on the relative merits of each are limited. Objective: To determine the safety and efficacy of the sirolimus-eluting stent compared with vascular brachytherapy for the treatment of patients with restenosis within a bare metal stent. Design, Setting, and Patients: Prospective, multicenter, randomized trial of 384 patients with in-stent restenosis who were enrolled between February 2003 and July 2004 at 26 academic and community medical centers. Data presented represent all follow-up as of June 30, 2005. Interventions: Vascular brachytherapy(n=125) or the sirolimus-eluting stent(n=259). Main Outcome Measure: Target vessel failure(cardiac death, myocardial infarction, or target vessel revascularization)at 9 months postprocedure. Results: Baseline patient characteristics were well matched. Lesion length was similar between vascular brachytherapy and sirolimus-eluting stent patients(mean [SD], 16.76 [8.55] mm vs 17.22 [7.97] mm, respectively; P=.61). Procedural success was 99.2% (124/125) in the vascular brachytherapy group and 97.3% (250/257) in the sirolimus-eluting stent group(P=.28). The rate of target vessel failure was 21.6% (27/125) with vascular brachytherapy and 12.4% (32/259) with the sirolimus-eluting stent(relative risk [RR], 1.7; 95% confidence interval [CI], 1.1-2.8; P=.02). Target lesion revascularization was required in 19.2% (24/125) of the vascular brachytherapy group and 8.5% (22/259) of the sirolimus-eluting stent group(RR, 2.3 [95% CI, 1.3-3.9]; P=.004). At follow-up angiography, the rate of binary angiographic restenosis for the analysis segment was 29.5% (31/105) for the vascular brachytherapy group and 19.8% (45/227) for the sirolimus-eluting stent group(RR, 1.5 [95% CI, 1.0-2.2]; P=.07). Compared with the vascular brachytherapy group, minimal lumen diameter was larger in the sirolimus-eluting stent group at 6-month follow-up(mean [SD], 1.52 [0.63] mm vs 1.80 [0.63] mm; P< .001), reflecting greater net lumen gain in the analysis segment(0.68 [0.60] vs 1.0 [0.61] mm; P< .001) due to stenting and no edge restenosis. Conclusion: Sirolimus-eluting stents result in superior clinical and angiographic outcomes compared with vascular brachytherapy for the treatment of restenosis within a bare-metal stent. Trial Registration: ClinicalTrials.gov Identifier: NCT00231257.展开更多
The inferior atrial extensions of the atrioventricular(AV) node have been related to the anatomic substrate of the slow pathway, but their role in AV nodal reentrant tachycardia(AVNRT) is unknown. Ten patients with sl...The inferior atrial extensions of the atrioventricular(AV) node have been related to the anatomic substrate of the slow pathway, but their role in AV nodal reentrant tachycardia(AVNRT) is unknown. Ten patients with slow-fast AVNRT were studied before and after successful slow pathway ablation. Simultaneous His bundle recordings from the right and left sides of the septum were made during right and left inferoparaseptal pacing. Longer stimulus to His(St-H) intervals were measured during right inferoparaseptal pacing than during left inferoparaseptal pacing(284± 55 vs 246± 46 ms, p=0.005 for right His recordings and 283± 56 vs 244± 46 ms, p=0.005 for left His recordings) at similar coupling intervals during AVNRT induction. After ablation, the St-H intervals at the maximum AV nodal conduction decrement were similar during right inferoparaseptal and left inferoparaseptal pacing(217± 32 vs 207± 21 ms, p=0.10 for right His and 215± 32 vs 206± 20 ms, p=0.13 for left His) at similar coupling intervals. The difference(Δ St-H) between St-H intervals during AVRNT induction or at the maximum conduction decrement and during constant pacing for right His recordings with right inferoparaseptal pacing were significantly greater than Δ St-H measured with left His during left inferoparaseptal pacing(173± 64 vs 137± 55 ms, p=0.005) before ablation, but not after(117± 39 vs 100± 40 ms, p=0.44). Resetting of AVNRT with delivery of left inferoparaseptal extrastimuli was achieved in 7 of 10 patients. In conclusion, the electrophysiologic characteristics of the right and left inferior atrial inputs to the human AV node in patients with AVNRT and their response to slow pathway ablation provide further evidence that the inferior nodal extensions represent the anatomic substrate of the slow pathway.展开更多
Aims: Non- compliance in patients with heart failure(HF)contributes to worsening HF symptoms and may lead to hospitalization. Several smaller studies have examined compliance in HF, but all were limited as they only s...Aims: Non- compliance in patients with heart failure(HF)contributes to worsening HF symptoms and may lead to hospitalization. Several smaller studies have examined compliance in HF, but all were limited as they only studied either the individual components of compliance and its related factors or several aspects of compliance without studying the related factors. The aims of this study were to examine all dimensions of compliance and its related factors in one HF population. Methods and results: Data were collected in a cohort of 501 HF patients. Clinical and demographic data were assessed and patients completed questionnaires on compliance, beliefs, knowledge, and self- care behaviour. Overall compliance was 72% in this older HF population. Compliance with medication and appointment keeping was high(>90% ). In contrast, compliance with diet(83% ), fluid restriction(73% ), exercise(39% ), and weighing(35% ) was markedly lower. Compliance was related to knowledge(OR=5.67; CI 2.87- 11.19), beliefs(OR=1.78; CI 1.18- 2.69), and depressive symptoms(OR=0.53; CI 0.35- 0.78). Conclusion: Although some aspects of compliance had an acceptable level, compliance with weighing and exercise were low. In order to improve compliance, an increase of knowledge and a change of patient’ s beliefs by education and counselling are recommended. Extra attention should be paid to patients with depressive symptoms.展开更多
OBJECTIVES: We studied the acute effect of caffeine on myocardial blood flow(MBF) at rest and exercise in healthy volunteers at normoxia and during acute exposure to simulated altitude. BACKGROUND: Caffeine is a widel...OBJECTIVES: We studied the acute effect of caffeine on myocardial blood flow(MBF) at rest and exercise in healthy volunteers at normoxia and during acute exposure to simulated altitude. BACKGROUND: Caffeine is a widely consumed stimulant, although its cardiovascular safety remains controversial and its effect on MBF is unknown. METHODS: 15O-labeled H2O and positron emission tomography(PET) were used to measure regional MBF at rest and immediately after supine bicycle exercise in healthy volunteers at normoxia(n=10; mean workload, 175 W; 98% predicted; mean age, 27± 6 years) as well as during hypoxia, simulating an altitude of 4,500 m by inhalation of a mixture of 12.5% oxygen(n=8; 148 W; 78% predicted; mean age, 29± 4 years). Measurements were repeated 50 min after oral ingestion of caffeine(200 mg). Myocardial flow reserve(MFR) was calculated as the ratio of hyperemic to resting MBF. RESULTS: Resting MBF was not affected by caffeine at normoxia(1.05± 0.36 ml/min/g vs. 1.17± 0.27 ml/min/g; p=NS), although it was significantly increased at hypoxia(1.71± 0.41 ml/min/g vs. 2.22± 0.49 ml/min/g; p < 0.001). By contrast, exercise-induced hyperemic MBF decreased significantly at normoxia(2.51± 0.58 ml/min/g vs. 2.15± 0.47 ml/min/g; p< 0.05) and hypoxia(5.15± 0.79 ml/min/g vs. 3.98± 0.83 ml/min/g; p< 0.005 vs. baseline; p< 0.005 vs. normoxia). The MFR decreased by 22% at normoxia(2.53± 0.69 to 1.90± 0.49; p< 0.01) and by 39% at hypoxia(3.13± 0.60 to 1.87± 0.45, p< 0.005; p< 0.05 vs. normoxia). CONCLUSIONS: In healthy volunteers, a caffeine dose corresponding to two cups of coffee(200 mg)signif icantly decreased exercise-induced MFR at normoxia and was even more pronounced during exposure to altitude.展开更多
This study sought to establish the practice patterns of a diverse group of academic physicians, in the management of periprocedural anticoagulation for patients with mechanical heart valves, to study adherence to Amer...This study sought to establish the practice patterns of a diverse group of academic physicians, in the management of periprocedural anticoagulation for patients with mechanical heart valves, to study adherence to American College of Cardiology/ American Heart Association(ACC/AHA) guidelines. Physicians(n=140) were surveyed to assess strategies for the periprocedural anticoagulation of patients with bileaflet mechanical heart valves undergoing 2 common outpatient procedures. Six patient scenarios with graded risk profiles were presented for each valve location(mitral and aortic). In >90% of high-risk patient scenarios, for which the ACC/AHA guidelines recommend periprocedural anticoagulation, anticoagulation was recommended, with minimal differences between physician specialties. However, periprocedural anticoagulation was also recommended in >70% of non-high-risk scenarios, for which the ACC/AHA guidelines recommend no periprocedural anticoagulation. Noncardiologists recommended anticoagulation more often in non-high-risk patients(p< 0.01), especially for patients with aortic valve prostheses. Thus, academic physicians appropriately recommend periprocedural anticoagulation for high-risk patients with mechanical heart valves who undergo elective procedures. However, these data specifically suggest variability in practice for non-high-risk patients that are discordant with current ACC/AHA guidelines, with differences by treating specialty especially notable in this risk subset.展开更多
Objective: To derive a risk score for the combination of death from all causes, myocardial infarction, and disabling stroke in patients with stable symptomatic angina who require treatment for angina and have preserve...Objective: To derive a risk score for the combination of death from all causes, myocardial infarction, and disabling stroke in patients with stable symptomatic angina who require treatment for angina and have preserved left ventricular function. Design: Multivariate Cox regression analysis of data from a large multicentre trial. Setting: Outpatient cardiology clinics in western Europe, Israel, Canada, Australia, and New Zealand. Participants: 7311 patients with all required data available. Main outcome measure: Death from any cause or myocardial infarction or disabling stroke during a mean follow-up of 4.9 years. Results: 1063 patients either died from any cause or sustained myocardial infarction or disabling stroke. The five year risk of this composite ranged from 4% for patients in the lowest tenth of risk to 35% for patients in the highest tenth. The risk score combines 16 routinely available clinical variables(in order of decreasing contribution): age, left ventricular ejection fraction, smoking, white blood cell count, diabetes, casual blood glucose concentration, creatinine concentration, previous stroke, at least one angina attack a week, coronary angiographic findings(if available), lipid lowering treatment, QT interval, systolic blood pressure ≥ 155 mm Hg, number of drugs used for angina, previous myocardial infarction, and sex. Fitting the same model separately to all cause death, myocardial infarction, and stroke gave similar results. The risk score did not seem to predict the nature of the event(death in 39% , myocardial infarction in 46% , and disabling stroke in 15% ) or the incidence of angiography or revascularisation, which occurred in 29% of patients. Conclusion: This risk score is an objective aid in deciding on further management of patients with stable angina with the aim of reducing serious outcome events. The score can also be used in planning future trials.展开更多
Although statins are effective lipid-lowering agents, the phenotypic and demographic predictors of such lowering have been less well examined. We enrolled 944 African-American and white men and women who completed an ...Although statins are effective lipid-lowering agents, the phenotypic and demographic predictors of such lowering have been less well examined. We enrolled 944 African-American and white men and women who completed an open-label, 6-week pharmacogenetics trial of 40 mg of simvastatin. The phenotypic and demographic variables were examined as predictors of the change in lipids and lipoproteins using linear regression analysis. On average, treatment with simvastatin lowered low-density lipoprotein(LDL) cholesterol by 54 mg/dl and increased high-density lipoprotein(HDL) cholesterol by 2 mg/dl. Compared with African-Americans, whites had a 3-mg/dl greater LDL reduction and a 1-mg/dl higher HDL elevation, independent of other variables, including baseline lipoprotein levels(p< 0.01). Multivariate analyses revealed moderate subgroup differences, with older participants having a larger decrease in LDL cholesterol and apolipoprotein B levels compared with younger participants(p< 0.001),women having larger increases in HDL than men(p< 0.01),nonsmokers having larger decreases in LDL and triglyceride levels compared with smokers(p< 0.05), those with hypertension having smaller decreases in apolipoprotein B than those without hypertension(p< 0.05), and those with a larger waist circumference having a diminished lowering of triglycerides in response to treatment with simvastatin(p< 0.01). In conclusion, treatment with simvastatin produced favorable lipid and lipoprotein changes among all participants. The magnitude of the lipid and lipoprotein responses, however, differed among participants according to a number of phenotypic and demographic characteristics.展开更多
OBJECTIVES: We investigated whether plasma nitros(yl)ated species(RXNOs) that mediate systemic nitric oxide(NO) bioactivity are depleted in individuals with cardiovascular risk factors and endothelial dysfunction. BAC...OBJECTIVES: We investigated whether plasma nitros(yl)ated species(RXNOs) that mediate systemic nitric oxide(NO) bioactivity are depleted in individuals with cardiovascular risk factors and endothelial dysfunction. BACKGROUND: Endothelium- derived NO acts not only as a regional messenger but exerts significant systemic effects via formation of circulating RXNOs delivering NO to sites of impaired production. METHODS: Endothelial function was assessed in 68 patients with one to four major cardiovascular risk factors(RF) and 39 healthy control subjects(C) by measurement of flow- mediated dilation(FMD) of the brachial artery using high- resolution ultrasound. In parallel, plasma RXNOs were determined by reductive gas phase chemiluminescence. RESULTS: Increasing numbers of risk factors were accompanied by a progressive decrease in FMD: 6.5± 0.4% (C); 4.7± 0.5% (one RF); 2.8± 0.4% (two RF); 2.2± 0.4% (three RF); and 1.0± 0.3% (four RF). Progressively impaired vascular function was associated with a concomitant decrease in plasma RXNOs(p< 0.01): 39± 2 nmol/l(C); 30± 2 nmol/l(one RF); 24± 3 nmol/l(two RF); 22± 3 nmol/l(three RF); and 15± 2 nmol/l(four RF), with univariate correlation between FMD and RXNO(r=0.41, p< 0.001). In a multivariate regression model, RXNO was an independent predictor of endothelial function. CONCLUSIONS: Endothelial dysfunction in patients with cardiovascular risk factors is associated with decreased levels of circulating RXNOs. Plasma RXNOs may be diagnostically useful markers of NO bioavailability and a surrogate index of endothelial function. Whether the observed decrease in concentration reflects impaired NO formation, accelerated decomposition, and/or consumption of RXNOs and whether these processes play a causal role in the pathophysiology of arteriosclerosis remain to be investigated.展开更多
Background: Patients with heart failure(HF)face challenges complying with multidrug regimens. Objectives: To examine the impact of a compliance enhancing intervention on medication compliance and morbidity in HF. Desi...Background: Patients with heart failure(HF)face challenges complying with multidrug regimens. Objectives: To examine the impact of a compliance enhancing intervention on medication compliance and morbidity in HF. Design: Patients were randomized to either usual care or an inhospital educational intervention delivered by a multidisciplinary team(Intervention). Setting: Acute medical and surgical units at a teaching hospital. Patients: One hundred thirty four patients with a clinical diagnosis of HF and a left ventricular ejection fraction of< 40% requiring long-term medical treatment. Main Outcome Measures: A validated HF-specific instrument provided a measure of knowledge. We characterized patients as noncompliant if pharmacy refill data suggested they had taken ≤ 0.80 of their medication. We measured quality of life using the Minnesota Living with Heart Failure Questionnaire and the Short Form 36 and conducted a time to first event analysis of a composite end point including mortality, readmissions, and emergency department visits. Results: The Intervention group showed higher knowledge scores at discharge and 1 year(P=.05). The risk of noncompliance in Intervention patients varied from 0.78(95% CI 0.33- 1.89)for ACE-I(13% Intervention, 17% Control) to 1.02(0.49- 2.12)for diuretics(23% Intervention, 23% Control). Quality of life improved in both groups over time; the only difference between groups favored the Intervention(Minnesota Living with Heart Failure Questionnaire, P=.04). The composite end point occurred in 67% of control and 60% of Intervention patients(hazard ratio 0.85, 95% CI 0.55- 1.30). Conclusions: An inhospital educational intervention improved knowledge and, possibly, quality of life and may be useful as part of a comprehensive compliance enhancing strategy in patients with HF.展开更多
文摘Context: Compared with bare metal stents, sirolimus-elut-ing and paclitaxel-eluting stents have been shown to markedly improve angiographic and clinical outcomes after percutaneous coronary revascularization, but their performance in the treatment of de novo coronary lesions has not been compared in a prospective multicenter study. Objective: To compare the safety and efficacy of sirolimus-eluting vs paclitaxel-eluting coronary stents. Design: Prospective, randomized comparative trial(the REALITY trial) conducted between August 2003 and February 2004, with angiographic follow-up at 8 months and clinical follow-up at 12 months. Setting: Ninety hospitals in Europe, Latin America, and Asia. Patients: A total of 1386 patients(mean age, 62.6 years; 73.1% men; 28.0% with diabetes)with angina pectoris and 1 or 2 de novo lesions(2.25-3.00 mm in diameter) in native coronary arteries. Intervention: Patients were randomly assigned in a 1 ∶ 1 ratio to receive a sirolimus-eluting stent(n=701) or a paclitaxel-eluting stent(n=685). Main Outcome Measures: The primary end point was in-lesion binary restenosis(presence of a more than 50% luminal diameter stenosis) at 8 months. Secondary end points included 1-year rates of target lesion and vessel revascularization and a composite end point of cardiac death, Q-wave or non-Q-wave myocardial infarction, coronary artery bypass graft surgery, or repeat target lesion revascularization. Results: In-lesion binary restenosis at 8 months occurred in 86 patients(9.6% ) with a sirolimus-eluting stent vs 95(11.1% ) with a paclitaxel-eluting stent(relative risk [RR], 0.84; 95% confidence interval [CI], 0.61-1.17; P=.31). For sirolimus- vs paclitaxel-eluting stents, respectively, the mean(SD) in-stent late loss was 0.09(0.43) mm vs 0.31(0.44) mm(difference,-0.22 mm; 95% CI,-0.26 to-0.18 mm; P<.001), mean(SD) in-stent diameter stenosis was 23.1% (16.6% ) vs 26.7% (15.8% )(difference,-3.60% ; 95% CI,-5.12% to-2.08% ; P< .001), and the number of major adverse cardiac events at 1 year was 73(10.7% ) vs 76(11.4% )(RR, 0.94; 95% CI, 0.69-1.27; P=.73). Conclusion: In this trial comparing sirolimus- and paclitaxel-eluting coronary stents, there were no differences in the rates of binary restenosis or major adverse cardiac events. Clinical Trial Registration: ClinicalTrials.gov Identifier:
文摘The purpose of this study was to explore whether dysglycemia, and/or an increased body mass index, and/or an increased waist/hip ratio increased the risk of hypertension in a lean population of South China. The association among dysglycemia, obesity, and hypertension has been well documented in Western populations. A stratified cluster sampling method was used according to the National Diabetes Mellitus Epidemiology Survey Program in 1998. Blood pressure, fasting plasma glucose, and plasma glucose were measured 2 hours after 75-g oral glucose consumption using the enzymatic method in the morning. Body height, weight, and waist and hip measurements were also collected for the survey. The criteria for the diagnosis of hypertension and diabetes mellitus, including impaired glucose tolerance(IGT), were those published by the World Health Organization in 1999. A total of 11,402 participants were included in the investigation(5,195 men and 6,207 women; age 20 to 74 years). A total of 1,775 cases of hypertension were confirmed in the survey. The prevalence of hypertension was significantly higher in those with diabetes mellitus than in those with a normal blood glucose level, in those with IGT than in those with normal glucose tolerance test findings, and in obese participants than in those with a normal weight(45.5% vs 14.4% , 32.2% vs 14.5% , and 20.6% vs 12.1% , respectively). Multiple logistic regression analysis indicated that age and gender-adjusted odds ratio of hypertension was 2.24(95% confidence interval 1.88 to 2.68) with IGT compared with those without IGT. The odds ratio for hypertension associated with an increased body mass index and waist/hip ratio was 1.19(95% confidence interval 1.17 to 1.21) and 1.08(95% confidence interval 1.07 to 1.09), respectively. In conclusion, the data from an epidemiologic study in South China demonstrated that dysglycemia and increased body mass index and/or waist/hip ratio increase the risk of hypertension even in a lean Chinese population.
文摘Background: Patients who develop fulminant myocarditis often die of sudden car diac arrest, arrhythmia, or severe heart failure soon after onset if they do not receive percutaneous cardiopulmonary support in time. The purpose of this study was to identify the risk factors of clinical symptoms/signs or laboratory findi ngs that could predict the fulminant course of acute myocarditis. Methods and re sults: Thirty-five patients(mean age 28±8 years, 17 males) who had been admitt ed to intensive care unit with the diagnosis of acute myocarditis by clinical pr esentations were retrospectively recruited. They were divided into the fulminant group(n=11) and the non-fulminant group(n=24). Clinical features, laboratory d ata, and images on admission were analyzed. Overall in-hospital mortality was 1 7%(6/35). Mortality was higher in the fulminant group(45%vs. 4%, p=0.027). Mu ltivariate analysis revealed that prolongations of the QRS complex(118±27 vs. 8 8±10 ms, p=0.048) and depressed left ventricular ejection fraction(41±7%vs. 5 7±7%, p=0.027) were the only independent factors significantly associated with the fulminant course of acute myocarditis. Conclusion: The in-hospital mortali ty of acute fulminant myocarditis was high. Prolongations of the QRS complex and depressed left ventricular ejection fraction on admission were independent posi tive predictors for the development of acute fulminant myocarditis.
文摘Aims: The addition of trimetazidine to standard treatment has been shown to improve left ventricular(LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo 31P-magnetic resonance spectroscopy(31P-MRS), the effects of trimetazidine on LV cardiac phosphocreatine and adenosine triphosphate(PCr/ATP) ratio in patients with heart failure. Methods and results: Twelve heart failure patients were randomized in a double-blind, cross-over study to placebo or trimetazidine(20 mg t.i.d.) for two periods of 90 days. At the end of each period, all patients underwent exercise testing, 2D echocardiography, and MRS. New York Heart Association(NYHA) class, ejection fraction(EF), maximal rate-pressure product, and metabolic equivalent system(METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P-MRS. On trimetazidine, NYHA class decreased from 3.04±0.26 to 2.45±0.52(P=0.005), whereas EF(34±10 vs. 39±10%, P=0.03) and METS(from 7.44±1.84 to 8.78±2.72, P=0.03) increased. The mean cardiac PCr/ATP ratio was 1.35±0.33 with placebo, but was increased by 33%to 1.80±0.50(P=0.03)with trimetazidine. Conclusion: Trimetazidine improves functional class and LV function in patients with heart failure. These effects are associated to the observed trimetazidi ne-induced increase in the PCr/ATP ratio, indicating preservation of the myocar dial high-energy phosphate levels.
文摘Background: Elevated coagulative molecular markers could reflect the prothromb otic state in the cardiovascular system of patients with non-valvular atrial fi brillation(NVAF). A prospective, cooperative study was conducted to determine wh ether levels of coagulative markers alone or in combination with clinical risk f actors could predict subsequent thromboembolic events in patients with NVAF. Met hods: Coagulative markers of prothrombin fragment 1 +2, D-dimer, platelet fact or 4, and β-thromboglobulin were determined at the enrollment in the prospecti ve study. Results: Of 509 patients with NVAF(mean age, 66.6±10.3 years), 263 pa tients were treated with warfarin(mean international normalized ratio, 1.86), an d 163 patients, with antiplatelet drugs. During an average follow-up period of 2.0 years, 31 thromboembolic events occurred. Event-free survival was significa ntly better in patients with D-dimer level< 150 ng/ml than in those with D-dim er level ≥150 ng/ml. Other coagulative markers, however, did not predict thromb oembolic events. Age(≥75 years), cardiomyopathies, and prior stroke or transien t ischemic attack were independent, clinical risk factors for thromboembolism. T hromboembolic risk in patients without the clinical risk factors was quite low(0 .7%/year) when D-dimer was< 150 ng/ml, but not low(3.8%/year) when D-dimer w as ≥150 ng/ml. It was > 5%/year in patients with the risk factors regardless o f D-dimer levels. This was also true when analyses were confined to patients tr eated with warfarin. Conclusions: D-dimer level in combination with clinical ri sk factors could effectively predict subsequent thromboembolic events in patient s with NVAF even when treated with warfarin.
文摘Context: Restenosis within bare-metal stents is often treated with repeat percutaneous coronary intervention, although subsequent recurrence rates are high, with vascular brachytherapy(VBT) affording the best results. The effectiveness of drug-eluting stents in this setting has not been established. Objective: To investigate the safety and efficacy of the polymer-based, slow-release paclitaxel-eluting stent in patients with restenotic lesions after prior stent implantation in native coronary arteries. Design, Setting, and Patients: Prospective, multicenter, randomized trial conducted between June 6, 2003, and July 16, 2004, at 37 North American academic and community-based institutions in 396 patients with in-stent restenosis of a previously implanted bare-metal coronary stent(vessel diameter, 2.5-3.75 mm; lesion length, ≤ 46 mm). Interventions: Patients were randomly assigned to undergo angioplasty followed by VBT with a β source(n=201) or paclitaxel-eluting stent implantation(n=195). Clinical and angiographic follow-up at 9 months was scheduled in all patients. Main Outcome Measure: Ischemia-driven target vessel revascularization at 9 months. Results: Diabetes mellitus was present in 139 patients(35.1% ). Median reference vessel diameter was 2.65 mm and median lesion length was 15.3 mm. In the VBT group, new stents were implanted in 22 patients(10.9% )and in the paclitaxel-eluting stent group, multiple stents were required in 57 patients(29.2% ), with median stent length of 24 mm. Follow-up at 9 months was complete in 194 patients in the VBT group and 191 patients in the paclitaxel-eluting stent group(96.5% and 97.9% , respectively). For VBT and paclitaxel-eluting stents, respectively, the number of events and 9-month rates for ischemic target lesion revascularization were 27(13.9% ) vs 12(6.3% )(relative risk [RR], 0.45; 95% confidence interval [CI], 0.24-0.86; P=.01); for ischemic target vessel revascularization, 34(17.5% ) vs 20(10.5% )(RR, 0.60; 95% CI, 0.36-1.00; P=.046); and for overall major adverse cardiac events, 39(20.1% ) vs 22(11.5% )(RR, 0.57; 95% CI, 0.35-0.93; P=.02), with similar rates of cardiac death or myocardial infarction(10 [5.2% ] vs 7 [3.7% ]; RR, 0.71; 95% CI, 0.28-1.83; P=.48) and target vessel thrombosis(5 [2.6% ] vs 3 [1.6% ]; RR, 0.61; 95% CI, 0.15-2.50; P=.72). Angiographic restenosis at 9 months was 31.2% (53 of 170 patients) with VBT and 14.5% (25 of 172 patients) with paclitaxel-eluting stents(RR, 0.47; 95% CI, 0.30-0.71; P< .001). Conclusion: Treatment of bare-metal in-stent restenotic lesions with paclitaxel-eluting stents rather than angioplasty followed by VBT reduces clinical and angiographic restenosis at 9 months and improves event-free survival. Trial Registration: ClinicalTrials. gov Identifier: NCT00287573.
文摘Background: We conducted a randomized, controlled trial of circumferential pulmonary-vein ablation for the treatment of chronic atrial fibrillation. Methods: A total of 146 patients with a mean(± SD) age of 57± 9 years who had chronic atrial fibrillation were randomly assigned to receive amiodarone and undergo two cardioversions during the first three months alone(the control group) or in combination with circumferential pulmonary-vein ablation. Cardiac rhythm was assessed with daily telephonic transmissions for one year. The left atrial diameter and the severity of symptoms were assessed at 12 months. Results: Among the 77 patients assigned to undergo circumferential pulmonary-vein ablation, ablation was repeated because of recurrent atrial fibrillation in 26 percent of patients and atypical atrial flutter in 6 percent. An intention-to-treat analysis showed that 74 percent of patients in the ablation group and 58 percent of those in the control group were free of recurrent atrial fibrillation or flutter without antiarrhythmic-drug therapy at one year(P=0.05). Among the 69 patients in the control group, 53(77 percent) crossed over to undergo circumferential pulmonary-vein ablation for recurrent atrial fibrillation by one year and only 3(4 percent) were in sinus rhythm without antiarrhythmic-drug therapy or ablation. There were significant decreases in the left atrial diameter(12± 11 percent, P< 0.001) and the symptom severity score(59± 21 percent, P< 0.001) among patients who remained in sinus rhythm after circumferential pulmonary-vein ablation. Except for atypical atrial flutter, there were no complications attributable to circumferential pulmonary-vein ablation. Conclusions: Sinus rhythm can be maintained long term in the majority of patients with chronic atrial fibrillation by means of circumferential pulmonary-vein ablation independently of the effects of antiarrhythmic-drug therapy, cardioversion, or both. The maintenance of sinus rhythm is associated with a significant decrease in both the severity of symptoms and the left atrial diameter.
文摘Context: Previous studies have suggested that subclinical abnormalities in thyroid-stimulating hormone levels are associated with detrimental effects on the cardiovascular system. Objective: To determine the relationship between baseline thyroid status and incident atrial fibrillation, incident cardiovascular disease, and mortality in older men and women not taking thyroid medication. Design, Setting, and Participants: A total of 3233 US community-dwelling individuals aged 65 years or older with baseline serum thyroid-stimulating hormone levels were enrolled in 1989-1990 in the Cardiovascular Health Study, a large, prospective cohort study. Main Outcome Measures: Incident atrial fibrillation, coronary heart disease, cerebrovascular disease, cardiovascular death, and all-cause death assessed through June 2002. Analyses are reported for 4 groups defined according to thyroid function test results: subclinical hyperthyroidism, euthyroidism, subclinical hypothyroidism, and overt hypothyroidism. Results: Individuals with overt thyrotoxicosis(n=4) were excluded because of small numbers. Eighty-two percent of participants(n=2639) had normal thyroid function, 15% (n=496) had subclinical hypothyroidism, 1.6% (n=51)had overt hypothyroidism, and 1.5% (n=47) had subclinical hyperthyroidism. After exclusion of those with prevalent atrial fibrillation, individuals with subclinical hyperthyroidism had a greater incidence of atrial fibrillation compared with those with normal thyroid function(67 events vs 31 events per 1000 person-years; adjusted hazard ratio, 1.98; 95% confidence interval, 1.29-3.03). No differences were seen between the subclinical hyperthyroidism group and euthyroidism group for incident coronary heart disease, cerebrovascular disease, cardiovascular death, or all-cause death. Likewise, there were no differences between the subclinical hypothyroidism or overt hypothyroidism groups and the euthyroidism group for cardiovascular outcomes or mortality. Specifically, individuals with subclinical hypothyroidism had an adjusted hazard ratio of 1.07(95% confidence interval, 0.90-1.28) for incident coronary heart disease. Conclusion: Our data show an association between subclinical hyperthyroidism and development of atrial fibrillation but do not support the hypothesis that unrecognized subclinical hyperthyroidism or subclinical hypothyroidism is associated with other cardiovascular disorders or mortality.
文摘Exercise is an important behavior for long-term weight control in overweight and obese patients. However, little evidence exists confirming such findings in patients with advanced heart failure(HF). Using a prospective, experimental design, the effects of 24 weeks of a low-level, home-based walking program on weight loss were studied in overweight and obese(body mass index≥ 27 kg/m2) patients with advanced HF who were randomized to exercise(n=48) and control(n=51) groups. Weight changes between the 2 groups at baseline and 6 months were compared using repeated-measures analysis of variance. Patients were on average aged 53.3± 10.1 years and predominantly male(75% ), Caucasian(57% ), and married(55% ). Most patients were in New York Heart Association class III or IV(67% ), with a mean ejection fraction of 25% . Patients in the exercise group showed significant weight reduction from baseline to 6 months compared with those in the control group(-6.37± 11.7 vs -0.33± 9.3 kg, p=0.002). No significant differences were noted between the 2 groups in 6-minute walk distance or depression, although the changes were in the anticipated direction. Modest weight losses of >5% were associated with cardiopulmonary exercise test-documented workload levels at 6 months(r=0.331, p=0.006), as well as decreased depression(r=-0.315, p=0.01) and hostility(r=-0.355, p=0.005). The number of hospital admissions was significantly smaller for patients in the exercise group compared with those in the control group(0.63± 0.94 vs 1.07± 0.95, p< 0.05). In conclusion, the findings demonstrate the beneficial effects of a low-level, home-based walking program on weight loss in overweight and obese patients with advanced HF.
文摘Context: Although vascular brachytherapy is the only approved therapy for restenosis following bare-metal stent implantation, drug-eluting stents are now being used. Data on the relative merits of each are limited. Objective: To determine the safety and efficacy of the sirolimus-eluting stent compared with vascular brachytherapy for the treatment of patients with restenosis within a bare metal stent. Design, Setting, and Patients: Prospective, multicenter, randomized trial of 384 patients with in-stent restenosis who were enrolled between February 2003 and July 2004 at 26 academic and community medical centers. Data presented represent all follow-up as of June 30, 2005. Interventions: Vascular brachytherapy(n=125) or the sirolimus-eluting stent(n=259). Main Outcome Measure: Target vessel failure(cardiac death, myocardial infarction, or target vessel revascularization)at 9 months postprocedure. Results: Baseline patient characteristics were well matched. Lesion length was similar between vascular brachytherapy and sirolimus-eluting stent patients(mean [SD], 16.76 [8.55] mm vs 17.22 [7.97] mm, respectively; P=.61). Procedural success was 99.2% (124/125) in the vascular brachytherapy group and 97.3% (250/257) in the sirolimus-eluting stent group(P=.28). The rate of target vessel failure was 21.6% (27/125) with vascular brachytherapy and 12.4% (32/259) with the sirolimus-eluting stent(relative risk [RR], 1.7; 95% confidence interval [CI], 1.1-2.8; P=.02). Target lesion revascularization was required in 19.2% (24/125) of the vascular brachytherapy group and 8.5% (22/259) of the sirolimus-eluting stent group(RR, 2.3 [95% CI, 1.3-3.9]; P=.004). At follow-up angiography, the rate of binary angiographic restenosis for the analysis segment was 29.5% (31/105) for the vascular brachytherapy group and 19.8% (45/227) for the sirolimus-eluting stent group(RR, 1.5 [95% CI, 1.0-2.2]; P=.07). Compared with the vascular brachytherapy group, minimal lumen diameter was larger in the sirolimus-eluting stent group at 6-month follow-up(mean [SD], 1.52 [0.63] mm vs 1.80 [0.63] mm; P< .001), reflecting greater net lumen gain in the analysis segment(0.68 [0.60] vs 1.0 [0.61] mm; P< .001) due to stenting and no edge restenosis. Conclusion: Sirolimus-eluting stents result in superior clinical and angiographic outcomes compared with vascular brachytherapy for the treatment of restenosis within a bare-metal stent. Trial Registration: ClinicalTrials.gov Identifier: NCT00231257.
文摘The inferior atrial extensions of the atrioventricular(AV) node have been related to the anatomic substrate of the slow pathway, but their role in AV nodal reentrant tachycardia(AVNRT) is unknown. Ten patients with slow-fast AVNRT were studied before and after successful slow pathway ablation. Simultaneous His bundle recordings from the right and left sides of the septum were made during right and left inferoparaseptal pacing. Longer stimulus to His(St-H) intervals were measured during right inferoparaseptal pacing than during left inferoparaseptal pacing(284± 55 vs 246± 46 ms, p=0.005 for right His recordings and 283± 56 vs 244± 46 ms, p=0.005 for left His recordings) at similar coupling intervals during AVNRT induction. After ablation, the St-H intervals at the maximum AV nodal conduction decrement were similar during right inferoparaseptal and left inferoparaseptal pacing(217± 32 vs 207± 21 ms, p=0.10 for right His and 215± 32 vs 206± 20 ms, p=0.13 for left His) at similar coupling intervals. The difference(Δ St-H) between St-H intervals during AVRNT induction or at the maximum conduction decrement and during constant pacing for right His recordings with right inferoparaseptal pacing were significantly greater than Δ St-H measured with left His during left inferoparaseptal pacing(173± 64 vs 137± 55 ms, p=0.005) before ablation, but not after(117± 39 vs 100± 40 ms, p=0.44). Resetting of AVNRT with delivery of left inferoparaseptal extrastimuli was achieved in 7 of 10 patients. In conclusion, the electrophysiologic characteristics of the right and left inferior atrial inputs to the human AV node in patients with AVNRT and their response to slow pathway ablation provide further evidence that the inferior nodal extensions represent the anatomic substrate of the slow pathway.
文摘Aims: Non- compliance in patients with heart failure(HF)contributes to worsening HF symptoms and may lead to hospitalization. Several smaller studies have examined compliance in HF, but all were limited as they only studied either the individual components of compliance and its related factors or several aspects of compliance without studying the related factors. The aims of this study were to examine all dimensions of compliance and its related factors in one HF population. Methods and results: Data were collected in a cohort of 501 HF patients. Clinical and demographic data were assessed and patients completed questionnaires on compliance, beliefs, knowledge, and self- care behaviour. Overall compliance was 72% in this older HF population. Compliance with medication and appointment keeping was high(>90% ). In contrast, compliance with diet(83% ), fluid restriction(73% ), exercise(39% ), and weighing(35% ) was markedly lower. Compliance was related to knowledge(OR=5.67; CI 2.87- 11.19), beliefs(OR=1.78; CI 1.18- 2.69), and depressive symptoms(OR=0.53; CI 0.35- 0.78). Conclusion: Although some aspects of compliance had an acceptable level, compliance with weighing and exercise were low. In order to improve compliance, an increase of knowledge and a change of patient’ s beliefs by education and counselling are recommended. Extra attention should be paid to patients with depressive symptoms.
文摘OBJECTIVES: We studied the acute effect of caffeine on myocardial blood flow(MBF) at rest and exercise in healthy volunteers at normoxia and during acute exposure to simulated altitude. BACKGROUND: Caffeine is a widely consumed stimulant, although its cardiovascular safety remains controversial and its effect on MBF is unknown. METHODS: 15O-labeled H2O and positron emission tomography(PET) were used to measure regional MBF at rest and immediately after supine bicycle exercise in healthy volunteers at normoxia(n=10; mean workload, 175 W; 98% predicted; mean age, 27± 6 years) as well as during hypoxia, simulating an altitude of 4,500 m by inhalation of a mixture of 12.5% oxygen(n=8; 148 W; 78% predicted; mean age, 29± 4 years). Measurements were repeated 50 min after oral ingestion of caffeine(200 mg). Myocardial flow reserve(MFR) was calculated as the ratio of hyperemic to resting MBF. RESULTS: Resting MBF was not affected by caffeine at normoxia(1.05± 0.36 ml/min/g vs. 1.17± 0.27 ml/min/g; p=NS), although it was significantly increased at hypoxia(1.71± 0.41 ml/min/g vs. 2.22± 0.49 ml/min/g; p < 0.001). By contrast, exercise-induced hyperemic MBF decreased significantly at normoxia(2.51± 0.58 ml/min/g vs. 2.15± 0.47 ml/min/g; p< 0.05) and hypoxia(5.15± 0.79 ml/min/g vs. 3.98± 0.83 ml/min/g; p< 0.005 vs. baseline; p< 0.005 vs. normoxia). The MFR decreased by 22% at normoxia(2.53± 0.69 to 1.90± 0.49; p< 0.01) and by 39% at hypoxia(3.13± 0.60 to 1.87± 0.45, p< 0.005; p< 0.05 vs. normoxia). CONCLUSIONS: In healthy volunteers, a caffeine dose corresponding to two cups of coffee(200 mg)signif icantly decreased exercise-induced MFR at normoxia and was even more pronounced during exposure to altitude.
文摘This study sought to establish the practice patterns of a diverse group of academic physicians, in the management of periprocedural anticoagulation for patients with mechanical heart valves, to study adherence to American College of Cardiology/ American Heart Association(ACC/AHA) guidelines. Physicians(n=140) were surveyed to assess strategies for the periprocedural anticoagulation of patients with bileaflet mechanical heart valves undergoing 2 common outpatient procedures. Six patient scenarios with graded risk profiles were presented for each valve location(mitral and aortic). In >90% of high-risk patient scenarios, for which the ACC/AHA guidelines recommend periprocedural anticoagulation, anticoagulation was recommended, with minimal differences between physician specialties. However, periprocedural anticoagulation was also recommended in >70% of non-high-risk scenarios, for which the ACC/AHA guidelines recommend no periprocedural anticoagulation. Noncardiologists recommended anticoagulation more often in non-high-risk patients(p< 0.01), especially for patients with aortic valve prostheses. Thus, academic physicians appropriately recommend periprocedural anticoagulation for high-risk patients with mechanical heart valves who undergo elective procedures. However, these data specifically suggest variability in practice for non-high-risk patients that are discordant with current ACC/AHA guidelines, with differences by treating specialty especially notable in this risk subset.
文摘Objective: To derive a risk score for the combination of death from all causes, myocardial infarction, and disabling stroke in patients with stable symptomatic angina who require treatment for angina and have preserved left ventricular function. Design: Multivariate Cox regression analysis of data from a large multicentre trial. Setting: Outpatient cardiology clinics in western Europe, Israel, Canada, Australia, and New Zealand. Participants: 7311 patients with all required data available. Main outcome measure: Death from any cause or myocardial infarction or disabling stroke during a mean follow-up of 4.9 years. Results: 1063 patients either died from any cause or sustained myocardial infarction or disabling stroke. The five year risk of this composite ranged from 4% for patients in the lowest tenth of risk to 35% for patients in the highest tenth. The risk score combines 16 routinely available clinical variables(in order of decreasing contribution): age, left ventricular ejection fraction, smoking, white blood cell count, diabetes, casual blood glucose concentration, creatinine concentration, previous stroke, at least one angina attack a week, coronary angiographic findings(if available), lipid lowering treatment, QT interval, systolic blood pressure ≥ 155 mm Hg, number of drugs used for angina, previous myocardial infarction, and sex. Fitting the same model separately to all cause death, myocardial infarction, and stroke gave similar results. The risk score did not seem to predict the nature of the event(death in 39% , myocardial infarction in 46% , and disabling stroke in 15% ) or the incidence of angiography or revascularisation, which occurred in 29% of patients. Conclusion: This risk score is an objective aid in deciding on further management of patients with stable angina with the aim of reducing serious outcome events. The score can also be used in planning future trials.
文摘Although statins are effective lipid-lowering agents, the phenotypic and demographic predictors of such lowering have been less well examined. We enrolled 944 African-American and white men and women who completed an open-label, 6-week pharmacogenetics trial of 40 mg of simvastatin. The phenotypic and demographic variables were examined as predictors of the change in lipids and lipoproteins using linear regression analysis. On average, treatment with simvastatin lowered low-density lipoprotein(LDL) cholesterol by 54 mg/dl and increased high-density lipoprotein(HDL) cholesterol by 2 mg/dl. Compared with African-Americans, whites had a 3-mg/dl greater LDL reduction and a 1-mg/dl higher HDL elevation, independent of other variables, including baseline lipoprotein levels(p< 0.01). Multivariate analyses revealed moderate subgroup differences, with older participants having a larger decrease in LDL cholesterol and apolipoprotein B levels compared with younger participants(p< 0.001),women having larger increases in HDL than men(p< 0.01),nonsmokers having larger decreases in LDL and triglyceride levels compared with smokers(p< 0.05), those with hypertension having smaller decreases in apolipoprotein B than those without hypertension(p< 0.05), and those with a larger waist circumference having a diminished lowering of triglycerides in response to treatment with simvastatin(p< 0.01). In conclusion, treatment with simvastatin produced favorable lipid and lipoprotein changes among all participants. The magnitude of the lipid and lipoprotein responses, however, differed among participants according to a number of phenotypic and demographic characteristics.
文摘OBJECTIVES: We investigated whether plasma nitros(yl)ated species(RXNOs) that mediate systemic nitric oxide(NO) bioactivity are depleted in individuals with cardiovascular risk factors and endothelial dysfunction. BACKGROUND: Endothelium- derived NO acts not only as a regional messenger but exerts significant systemic effects via formation of circulating RXNOs delivering NO to sites of impaired production. METHODS: Endothelial function was assessed in 68 patients with one to four major cardiovascular risk factors(RF) and 39 healthy control subjects(C) by measurement of flow- mediated dilation(FMD) of the brachial artery using high- resolution ultrasound. In parallel, plasma RXNOs were determined by reductive gas phase chemiluminescence. RESULTS: Increasing numbers of risk factors were accompanied by a progressive decrease in FMD: 6.5± 0.4% (C); 4.7± 0.5% (one RF); 2.8± 0.4% (two RF); 2.2± 0.4% (three RF); and 1.0± 0.3% (four RF). Progressively impaired vascular function was associated with a concomitant decrease in plasma RXNOs(p< 0.01): 39± 2 nmol/l(C); 30± 2 nmol/l(one RF); 24± 3 nmol/l(two RF); 22± 3 nmol/l(three RF); and 15± 2 nmol/l(four RF), with univariate correlation between FMD and RXNO(r=0.41, p< 0.001). In a multivariate regression model, RXNO was an independent predictor of endothelial function. CONCLUSIONS: Endothelial dysfunction in patients with cardiovascular risk factors is associated with decreased levels of circulating RXNOs. Plasma RXNOs may be diagnostically useful markers of NO bioavailability and a surrogate index of endothelial function. Whether the observed decrease in concentration reflects impaired NO formation, accelerated decomposition, and/or consumption of RXNOs and whether these processes play a causal role in the pathophysiology of arteriosclerosis remain to be investigated.
文摘Background: Patients with heart failure(HF)face challenges complying with multidrug regimens. Objectives: To examine the impact of a compliance enhancing intervention on medication compliance and morbidity in HF. Design: Patients were randomized to either usual care or an inhospital educational intervention delivered by a multidisciplinary team(Intervention). Setting: Acute medical and surgical units at a teaching hospital. Patients: One hundred thirty four patients with a clinical diagnosis of HF and a left ventricular ejection fraction of< 40% requiring long-term medical treatment. Main Outcome Measures: A validated HF-specific instrument provided a measure of knowledge. We characterized patients as noncompliant if pharmacy refill data suggested they had taken ≤ 0.80 of their medication. We measured quality of life using the Minnesota Living with Heart Failure Questionnaire and the Short Form 36 and conducted a time to first event analysis of a composite end point including mortality, readmissions, and emergency department visits. Results: The Intervention group showed higher knowledge scores at discharge and 1 year(P=.05). The risk of noncompliance in Intervention patients varied from 0.78(95% CI 0.33- 1.89)for ACE-I(13% Intervention, 17% Control) to 1.02(0.49- 2.12)for diuretics(23% Intervention, 23% Control). Quality of life improved in both groups over time; the only difference between groups favored the Intervention(Minnesota Living with Heart Failure Questionnaire, P=.04). The composite end point occurred in 67% of control and 60% of Intervention patients(hazard ratio 0.85, 95% CI 0.55- 1.30). Conclusions: An inhospital educational intervention improved knowledge and, possibly, quality of life and may be useful as part of a comprehensive compliance enhancing strategy in patients with HF.
