Prognostic implications of ambulatory myocardial ischemia and arrhythmias and relations to ischemia on exercise in chronic stable angina pectoris (the Angina Prognosis Study in Stockholm [APSIS])

The prognostic significance of ambulatory ischemia, alone and in relation t o ischemia during exercise was assessed in 686 patients (475 men) with chro nic stable angina pectoris taking part in the Angina Prognosis Study In Sto ckholm (APSIS), who had 24-hour ambulatory electrocardiographic registratio ns and exercise tests at baseline (n = 678) and after 1 month (n = 607) of double-blind treatment with metoprolol or verapamil. Ambulatory electrocard iograms were analyzed for ventricular premature complexes and ST-segment de pression. During a median follow-vp of 40 months, 29 patients died of cardi ovascular (CV) causes, 27 had a nonfatal myocardial infarction, and 89 unde rwent revascularization. Patients with CV death had more episodes (median 5 vs 1; p < 0.01) and longer median duration (24 vs 3 minutes; p < 0.01) of ST-segment depression than patients without events. For those who had under gone revascularization, the duration was also longer (12 vs 3 minutes; p < 0.05). In a multivariate Cox model including sex, history of previous myoca rdial infarction, hypertension, and diabetes, the duration of ST-segment de pression independently predicted CV death. When exercise testing was includ ed, ambulatory ischemia carried additional prognostic information only amon g patients with ST-segment depression greater than or equal to 2 mm during exercise. When the treatment given and treatment effects on ambulatory isch emia were added to the Cox model, no significant impact on prognosis was fo und. Ventricular premature complexes carried no prognostic information. Thu s, in patients with stable angina pectoris, ischemia during ambulatory moni toring showed independent prognostic importance regarding CV death. Ambulat ory electrocardiographic monitoring and exercise testing provide complement ary information, but only among patients with marked ischemia during exerci se. Treatment reduced ambulatory ischemia, but the short-term treatment eff ects did not significantly influence prognosis. (C) 1999 by Excerpta Medica , Inc.