Prognostic significance of silent exertional myocardial ischaemia in symptomatic men without previous myocardial infarction.

Abstract

A total of 360 consecutive male patients with complaints of chest pain and documented coronary artery disease underwent a maximal exercise test combined with thallium myocardial scintigraphy. Patients with a history of previous myocardial infarction were excluded. During follow-up (46 months; from 12 to 96) 27 patients died and 26 had a first non-fatal myocardial infarction. The 6-year survival rate and the 6-year event-free rate were 81 and 71%. Four variables contributed independently to the prognosis (Cox Model): the number of diseased vessels, the angiographic ejection fraction, the age and a multivariate score of the exercise test. From these patients, 227 had an abnormal response to exercise (ST-segment depression greater than or equal to 0.1 mV); in 138 patients, angina pectoris was induced during exercise while 89 patients had no pain during exercise (silent ischaemia). These 89 patients with silent exertional ischaemia were matched to 89 patients with exertional angina pectoris, according to the above-mentioned four prognostic predictors. The two groups of patients had similar signs of ischaemia during exercise (ST-segment depression and thallium perfusion score). The 6-year survival rates (81 and 81.5%) and the 6-year event-free rates (71 and 70.5%) were similar in the two groups. Thus, in men without previous myocardial infarction, silent exertional ischaemia bears the same prognosis as exertional ischaemia attended by angina pectoris.