ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundAmong apparently healthy men, elevated levels of C-reactive protein (CRP), a marker for systemic inflammation, predict risk of myocardial infarction and thromboembolic stroke. Whether increased levels of CRP are also associated with the development of symptomatic peripheral arterial disease (PAD) is unknown.Methods and Results-Using a prospective, nested, case-control design, we measured baseline levels of CRP in 144 apparently healthy men participating in the Physicians' Health Study who subsequently developed symptomatic PAD (intermittent claudication or need for revascularization) and in an equal number of control subjects matched on the basis of age and smoking habit who remained free of vascular disease during a follow-up period of 60 months. Median CRP levels at baseline were significantly higher among those who subsequently developed PAD (1.34 versus 0.99 mg/L; P = .04). Furthermore, the risks of developing PAD increased significantly with each increasing quartile of baseline CRP concentration such that relative risks of PAD from lowest (referent) to highest quartile of CRP were 1.0, 1.3, 2.0, and 2.1 (Ptrend= .02). Compared with those with no clinical evidence of disease, the subgroup of case patients who required revascularization had the highest baseline CRP levels (median = 1.75 mg/L; P = .04); relative risks from lowest to highest quartile of CRP for this end point were 1.0, 1.8, 3.8, and 4.1 (Ptrend= .02). Risk estimates were similar after additional control for body mass index, hypercholesterolemia, hypertension, diabetes, and a family history of premature atherosclerosis.ConclusionsThese prospective data indicate that among apparently healthy men, baseline levels of CRP predict future risk of developing symptomatic PAD and thus provide further support for the hypothesis that chronic inflammation is important in the pathogenesis of atherothrombosis. (Circulation. 1998;97:425-428.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundRestenosis remains the major limitation of coronary angioplasty. Coronary stents have reduced the incidence of restenosis in selected patients with relatively large vessels. No strategies to date have demonstrated a beneficial effect in vessels < 3.0 mm in diameter. We have shown in the MultiVitamins and Probucol (MVP) Trial that probucol, a potent antioxidant, reduces restenosis after balloon angioplasty. The purpose of this study was to determine whether the benefit of probucol therapy is maintained in the subgroup of patients with smaller coronary vessels.Methods and Results-We studied a subgroup of 189 patients included in the MVP trial who underwent successful balloon angioplasty of at least one coronary segment with a reference diameter < 3.0 mm. One month before angioplasty, patients were randomly assigned to one of four treatments: placebo, probucol (500 mg), multivitamins (beta-carotene 30 000 IU, vitamin C 500 mg, and vitamin E 700 IU), or probucol plus multivitamins twice daily. The treatment was maintained until follow-up angiography was performed at 6 months. The mean reference diameter of this study population was 2.49 +/- 0.34 mm. Lumen loss was 0.12 +/- 0.34 mm for probucol, 0.25 +/- 0.43 mm for the combined treatment, 0.35 +/- 0.56 mm for vitamins, and 0.38 +/- 0.51 mm for placebo (P = .005 for probucol). Restenosis rates per segment were 20.0% for probucol, 28.6% for the combined treatment, 45.1% for vitamins, and 37.3% for placebo (P = .006 for probucol).ConclusionsProbucol reduces lumen loss and restenosis rate after balloon angioplasty in small coronary arteries. (Circulation. 1998;97:429-436.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundA high plasma homocysteine concentration is a risk factor for atherosclerosis, and circulating concentrations of homocysteine are related to levels of folate and vitamin B6. This study was performed to explore the interrelationships between homocysteine, B vitamins, and vascular diseases and to evaluate the role of these vitamins as risk factors for atherosclerosis.MethodsIn a multicenter case-control study in Europe, 750 patients with documented vascular disease and 800 control subjects frequency-matched for age and sex were compared. Plasma levels of total homocysteine (before and after methionine loading) were determined, as were those of red cell folate, vitamin B12, and vitamin B6.ResultsIn a conditional logistic regression model, homocysteine concentrations greater than the 80th percentile for control subjects either fasting (12.1 micro mol/L) or after a methionine load (38.0 micro mol/L) were associated with an elevated risk of vascular disease independent of all traditional risk factors. In addition, concentrations of red cell folate below the lowest 10th percentile (< 513 nmol/L) and concentrations of vitamin B6below the lowest 20th percentile (<23.3 nmol/L) for control subjects were also associated with increased risk. This risk was independent of conventional risk factors and for folate was explained in part by increased homocysteine levels. In contrast, the relationship between vitamin B6and atherosclerosis was independent of homocysteine levels both before and after methionine loading.ConclusionsLower levels of folate and vitamin B6confer an increased risk of atherosclerosis. Clinical trials are now required to evaluate the effect of treatment with these vitamins in the primary and secondary prevention of vascular diseases. (Circulation. 1998;97:437-443.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundAlthough the stratification of patients with myocardial infarction into ECG subsets based on the presence or absence of new Q waves has important clinical and prognostic utility, systematic evaluation of the impact of thrombolytic therapy on the subsequent development and prognosis of non-Q-wave infarction has been limited to date.Methods and Results-We examined 12-lead ECG, coronary anatomy, left ventricular function, and mortality among 2046 patients with ST-segment elevation infarction from the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries angiographic subset to gain further insight into the pathophysiology and prognosis of Q- versus non-Q-wave infarction in the thrombolytic era. Non-Q-wave infarction developed in 409 patients (20%) after thrombolytic therapy. Compared with Q-wave patients, non-Q-wave patients were more likely to present with lesser ST-segment elevation in a nonanterior location. The infarct-related artery in non-Q-wave patients was more likely to be nonanterior (67% versus 58%, P = .012) and distally located (33% versus 39%, P = .021). Early (90-minute, 77% versus 65%, P = .001) and complete (54% versus 44%, P < .001) infarct-related artery patency was greater among the non-Q-wave group. Non-Q-wave patients had better global (ejection fraction, 66% versus 57%; P < .0001) and regional left ventricular function (10 versus 24 abnormal chords, P = .0001). In-hospital, 30-day, 1-year, and 2-year (6.3% versus 10.1%, P = .02) mortality rates were lower among non-Q-wave patients.ConclusionsThe excellent prognosis among the subgroup of patients who develop non-Q-wave infarction after thrombolysis is related to early, complete, and sustained infarct-related artery patency with resultant limitation of left ventricular infarction and dysfunction. (Circulation. 1998;97:444-450.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe effects of pregnancy on women with the hereditary long QT syndrome are currently unknown. The appropriate medical management of pregnant patients with the long QT syndrome has not been established.0.47), borderline (QTc = 0.45 to 0.47), and unaffected (QTc < 0.45). Cardiac events were defined as the combined incidence of long QT syndrome-related death, aborted cardiac arrest, and syncope. The incidence of cardiac events was compared during equal prepregnancy, pregnancy, and postpartum intervals (40 weeks each). Multivariate logistic regression analysis was performed by use of a mixed-effects model to identify independent predictors of cardiac events among probands. The pregnancy and postpartum intervals were not associated with cardiac events among first-degree relatives. The postpartum interval was independently associated with cardiac events among probands (odds ratio [OR], 40.8; 95% confidence interval [CI], 3.1 to 540; P = .01); the pregnancy interval was not associated with cardiac events. Treatment with beta-adrenergic blockers was independently associated with a decrease in the risk for cardiac events among probands (OR, 0.023; 95% CI, 0.001 to 0.44; P = .01).ConclusionsThe postpartum interval is associated with a significant increase in risk for cardiac events among probands with the long QT syndrome but not among first-degree relatives. Prophylactic treatment with beta-adrenergic blockers should be continued during the pregnancy and postpartum intervals in probands with the long QT syndrome. (Circulation. 1998;97:451-456.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundFive years ago, we described a specific ECG pattern of right bundle-branch block and ST-segment elevation in leads V1through V3associated with sudden death in patients without demonstrable structural heart disease. Information on long-term outcome has become available due to pooled data on a large cohort of patients with this syndrome who are followed at 33 centers worldwide.Methods and Results-Data on 63 patients (57 men; mean age, 38 +/- 17 years) with the described ECG pattern were analyzed in terms of arrhythmic events and sudden death. Events were analyzed for patients with at least one episode of aborted sudden death or syncope of unknown origin before recognition of the syndrome (symptomatic patients, n = 41) and for patients in whom the ECG pattern was recognized by chance or because of screening related to sudden death of a relative (asymptomatic patients, n = 22). During a mean follow-up of 34 +/- 32 months, all arrhythmic event occurred in 14 symptomatic patients (34%) and 6 asymptomatic patients (27%). An automatic defibrillator was implanted in 35 patients, 15 received pharmacological therapy with beta-blockers and/or amiodarone, and 13 did not receive treatment The incidence of arrhythmic events was similar in all therapy groups (log-rank 0.86); however, total mortality was 0% in the implantable defibrillator group, 26% in the pharmacological group, and 31% in the no therapy group (log-rank 0.0005). All mortality was due to sudden death.ConclusionsPatients without demonstrable structural heart disease and an ECG pattern of right bundle-branch block and ST-segment elevation in leads V1through V3are at risk for sudden death. Amiodarone and/or beta-blockers do not protect them against sudden death, and an implantable defibrillator seems to be the present treatment of choice. (Circulation. 1998;97:457-460.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundImprovement in the left ventricular outflow tract (LVOT) gradient has been used as a means of assessing response to therapy in patients with hypertrophic obstructive cardiomyopathy (HOCM). To our knowledge, no data exist regarding the spontaneous day-to-day variability of the LVOT gradient in patients with HOCM. Defining the magnitude of such variability is critical to properly understand how much improvement in LVOT gradient must be present to invoke a therapeutic response.Methods and Results-We studied the spontaneous variation in the continuous-wave, Doppler-derived pressure gradient on 5 consecutive days in 12 HOCM patients and 5 aortic stenosis control subjects. While in some patients the day-to-day variability in resting gradient was small, in others it varied markedly. The 95% confidence interval for attributing a change in LVOT gradient to factors other than random variation is +/- 32 mm Hg for resting gradient and +/- 50 mm Hg for provoked gradient. The mean coefficient of variation for gradient across 5 days for the group was 0.52 +/- 0.33 for resting gradient and 0.46 +/- 0.16 for provoked gradient. The day-to-day variability in pressure gradient could not be explained by changes in heart rate, blood pressure, or left ventricular end-diastolic dimension, each of which had a coefficient of variation < .11. Moreover, technical factors related to the performance or interpretation of the studies did not account for it because the coefficient of variation for gradient in aortic stenosis was < 10% and interobserver and intraobserver agreement was excellent (r = .96 and .98, respectively).ConclusionsThe LVOT pressure gradient varies considerably from day to day in stable patients with HOCM. A single measurement of pressure gradient is not adequate to define the severity of dynamic LVOT obstruction in HOCM. (Circulation. 1998;97:461-466.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID