Coronary heart disease morbidity and mortality in hypercholesterolemic men predicted from an exercise test: The lipid research clinics coronary primary prevention trial

Abstract

A positive exercise electrocardiogram (ECG) has been proved to predict cardiovascular events in asymptomatic normolipidemic men. To study whether it is also predictive for hypercholesterolemic men, data from 3,806 asymptomatic hypercholesterolemic men in the Lipid Research Clinics Coronary Primary Prevention Trial were analyzed. All the men had performed a submaximal treadmill exercise test at baseline, before they were assigned to the cholestyramine or placebo treatment group. Because of missing or inconclusive data, 31 men were excluded from the analyses. A test was positive if the ST segment was displaced by greater than or equal to 1 mm (visual code) or there was greater than or equal to 10 microV-s change in the ST integral (computer code), or both. The prevalence of a positive test was 8.3%. During the 7 to 10 year (mean 7.4) follow-up period, the mortality rate from coronary heart disease was 6.7% (21 of 315) in men with a positive test and 1.3% (46 of 3,460) in men with a negative test (placebo and cholestyramine groups combined). The age-adjusted rate ratio for a positive test, compared with a negative test, was 6.7 in the placebo group and 4.8 in the cholestyramine group. With use of Cox's proportional hazards models, it was found that the risk of death from coronary heart disease associated with a positive test was 5.7 times higher in the placebo group and 4.9 times higher in the cholestyramine group after adjustment for age, smoking history, systolic blood pressure, high density lipoprotein cholesterol and low density lipoprotein cholesterol. A positive test was not significantly associated with nonfatal myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Severity of Coronary Artery Calcification by Electron Beam Computed Tomography Predicts Silent Myocardial Ischemia

“…Our results support previous studies demonstrating that asymptomatic subjects with cardiac risk factors generally have normal ETT and perfusion scans. [7][8][9] In the Lipid Research Clinics trial, 9 only 8.3% of 3775 asymptomatic men with hyperlipidemia had exercise-induced ECG ischemia. In a study of middle-aged siblings of patients with premature CAD, the stress ECG was abnormal in only 10% and thallium imaging in 22%.…”

“…1,2 Although the presence and extent of left ventricular ischemia can accurately identify individuals at high risk for cardiac events, [3][4][5][6][7][8] the low prevalence of a positive test result among asymptomatic subjects with cardiac risk factors mitigates against this approach. [7][8][9] Electron beam computed tomography (EBCT) is a new noninvasive technique that can detect coronary atherosclerosis even at its earliest stages on the basis of the presence and severity of coronary artery calcification. 10 Although calcification severity predicts the presence of significant anatomic CAD, 11,12 there is little information as to whether the coronary artery calcium score (CACS) can identify asymptomatic individuals at high risk for having myocardial ischemia among a larger, asymptomatic, heterogeneous population with cardiac risk factors.…”

Maximal Exercise Electrocardiographic Responses and Coronary Heart Disease Mortality Among Men With Metabolic Syndrome

“…They reported that the risk of CHD mortality in association with a positive E-ECG test was 5.7-and 4.9-fold higher in the cholestyramine and placebo groups, respectively. 8 Their results suggested that E-ECG responses are a valuable and independent predictor of CHD mortality risk in men with hypercholesterolemia. Bigi et al 10 evaluated the importance of E-ECG for predicting mortality in hypertensive individuals with angina.…”

“…Few studies have reported on the efficacy of E-ECG stress testing for its ability to predict CHD in persons with MetS or the components of MetS. A double-blinded, placebo-controlled clinical trial was conducted by Ekelund et al 8 in an effort to determine if positive findings on E-ECG are predictive of CVD events in hypercholesterolemic men. They observed 3806 asymptomatic, hypercholesterolemic men for an average of 7.4 years.…”

“…Although sparse, some studies have examined the association between E-ECG responses and CHD risk in men with components of MetS. Ekelund et al 8 reported that positive findings on E-ECG was an independent predictor of CVD events in men with hypercholesterolemia. Laukkanen et al 9 reported that exercise-induced ischemia was associated with a higher risk of adverse outcomes in persons at high risk of CHD.…”