Prognostic significance of transient myocardial ischaemia in patients with stable chronic angina pectoris

ABSTRACT

Data on the prognostic value of transient myocardial ischemia in stable patients with coronary artery disease are as yet, very scarce. This study was designed to assess the prognostic significance of transient ischemic episodes [silent and symptomatic] during daily activities in patients with chronic stable angina. Seventy eight patients attending the cardiac out patient clinic were studied by exercise treadmill testing and 24-hours of ambulatory Holter monitoring and followed for prognostic purposes for up to 24 months [mean of 17 months]. Patients inclusion depend on the clinical diagnosis of stable coronary artery disease which necessitated out patient review and it was not dependent on objective evidence of reversible ischemia. Events recorded during the follow-up period included death, non-fatal myocardial infarction, unstable angina and requirements for revascularization. Twenty four patients [31%] had transient ischemic episodes during their daily activities and 45 [58%] patients had a positive exercise test for ischemia with 19 patients [24%] had evidence of ischemia on both investigations and 21 patients [27%] had no documented evidence of ischemia on either investigation. Thee were 16 patient events [20.5%] recorded over a mean of 17 months follow-up including one cardiac death [1.3, 4 non-fetal MI [5.1%], 4 admissions with unstable angina [5.1%] and 7 patients were referred for revascularisation because of symptoms. Of the 5 cases of cardiac death and non-fatal Ml only 2 had evidence of ischemia in both investigations and 2 had no ischemia on either Investigation. As a whole 6 of recorded events occurred in 19 patients [31%] with both investigations positive for ischemia, 6 in 21 patients [29%] with both in investigations negative and 4 in patients who had one test positive for ischemia. We could conclude that in an unselected group of patients with stable angina, 17 months outcome was favorable and over this time the results of ambulatory ST segment monitoring seemed to contribute little to the identification of patients liable to have non-fatal myocardial infarction or cardiac death