Exercise-Induced Ischemia in Mildly Symptomatic Patients with Coronary-Artery Disease and Preserved Left Ventricular Function

Abstract

To determine prospectively whether the severity of reversible left ventricular ischemia provides prognostic information in mildly symptomatic patients with coronary-artery disease and preserved left ventricular function at rest (ejection fraction greater than 40 per cent), we studied 117 patients by means of exercise electrocardiography and radionuclide angiography. No patient had stenosis of the left main coronary artery. Mortality during subsequent medical therapy was significantly associated (by univariate life-table analysis) with three-vessel coronary-artery disease and the magnitude of the ejection fraction during exercise. In patients with three-vessel disease who had both ST-segment depression of 1 mm or more and a decrease in ejection fraction during exercise, in association with an exercise tolerance of 120 W or less, the probability of survival at four years was only 71 +/- 11 per cent (S.E.). All deaths occurred in this subgroup. Thus, objective evidence of left ventricular ischemia during exercise and exercise capacity identify one subgroup of minimally symptomatic patients with three-vessel disease with an excellent prognosis and another subgroup at relatively high risk of dying during subsequent medical therapy.

Prognostication in 3-Vessel Coronary Artery Disease Based on Left Ventricular Ejection Fraction During Exercise

“…Our results are consistent with previous reports of prognostic value of the LV exercise response (⌬LVEF 1,6 or absolute exercise LVEF 3 ) in this population 1,3,6 and also among medically treated patients with 1-or 2-vessel CAD and LV dysfunction at rest 32,33 and those not stratified for CAD severity. [2][3][4][5] Most previous studies of 3-vessel disease have dichotomized patients, 1,6,7,32,33 although some also analyzed exercise LVEF as a continuous variable; the majority demonstrated that those with ischemia have poorer outcomes than those without. 1,6,7,32 Our results confirm these findings by demonstrating a direct relation between the magnitude of LVEF exercise response and likelihood of cardiac events, including cardiac death.…”

“…[2][3][4][5] Most previous studies of 3-vessel disease have dichotomized patients, 1,6,7,32,33 although some also analyzed exercise LVEF as a continuous variable; the majority demonstrated that those with ischemia have poorer outcomes than those without. 1,6,7,32 Our results confirm these findings by demonstrating a direct relation between the magnitude of LVEF exercise response and likelihood of cardiac events, including cardiac death. Thus, our observations indicate that for a patient with 3-vessel disease whose LV performance is normal or near normal at rest, prognosis can be inferred relatively precisely from the direction and magnitude of ⌬LVEF.…”

“…[1][2][3][4][5] However, few studies have assessed the predictive value of exercise LVEF among patients with disease specifically involving all 3 major coronary systems, 1,3,6 -8 and none has examined the independent prognostic value of change (⌬) in LVEF with exercise in this population. Moreover, the relative effects of CABG and of nonsurgical therapy on long-term outcome among subpopulations with equivalent pretherapy LVEF exercise responses are poorly understood, precluding optimal application of test results in patient management.…”

Efficacy of Anti-anginal Drugs in the Treatment of Angina Pectoris Associated with Silent Myocardial Ischemia. Importance of Quantitative Holter ECG Data for Patient Activity.

“…Patients with ischemic heart disease associated with episodes of silent myocardial ischemia (SMI) are known to have a poor prognosis similar to, or in some cases rather worse than, that associated with angina pectoris syndrome (1,3,4,8,10,16,25,27,30). Treatment for SMI should be implemented in the case of such patients, and nitrates are expected to be efficacious in this respect (2, 4-6, 8, 10, ll, 16, 22, 31).…”

Current review of exercise testing: applicatiOn and interpretation

“…A greaterthan 50% decline in specificity has been demonstrated during 1978 to 1982 from 78 % to 3 1 % which is attributed to a pre/posttest r e f e d bias (Rozanski et al, 1983). However, because radionuclide ventriculography is less expensive than thallium, it has been utilized: (1) to evaluate asymptomatic or atypically symptomatic patients with positive exercise ECG tests; (2) to screen typical anginal patients with positive exercise ECGs to determine if at high risk; and (3) to distinguish patients with known CAD at high and low risk for future cardiac events (Bonow et al, 1984;Campbell and Tavel, 1985). Thallium studies, on the other hand, may be employed when radionuclide ventriculography is likely to be falsely positive (as in conditions causing left ventricular dysfunction other than ischemic coronary artery disease), in evaluating the significance of known anatomic lesions, or in assessing efficacy of medical treatment, bypass revascularization or coronary angioplasty (Campbell and Tavel, 1985).…”