Coronary heart disease without angina pectoris: silent ischemia

Myocardial ischemia without symptoms (= silent ischemia = Sl) has become a well known clinical entity in subjects with heart disease and in apparently healthy subjects. Detection of Sl is easiest and least expensively done with exercise ECG-testing (X-ECG). Data on the significance of Sl in the present report is derived from long-term follow-up of 2014 men aged 40-59 yrs, studied 1972-75, restudied in 1979-81 and 1986-88. The sources of information are: 1) 50 men with Sl detected with X-ECG/coronary angiography in 1972-75; 2) subjects with positive X-ECG in 1979-81 (but not in 1972-75); 3) preliminary data from the last follow-up study; and 4) complete data on cardiovascular mortality by Aug. 1987. The survey data indicate: a) Sl detected with X-ECG, confirmed with angiography is an indicator of later severe CHD-complications over 12-15 yrs; b) positive X-ECGs (not validated invasively) increase the risk of future CHD events and death from CHD 2-4 fold compared with subjects with normal X-ECG of similar age; c) limited isotope studies from the 1986-88 study indicate a very high specificity of a positive X-ECG in CHD, and d) cardiovascular mortality is very accurately predicted by factors known to be associated with the development of CHD. In accordance with the world literature, Sl is frequently observed in apparently healthy middle-aged and old men, and increases the risk of future CHD considerably when encountered.