Prognostic value of exercise EKG testing in asymptomatic normotensive subjects. A prospective matched study.

We prospectively studied 135 asymptomatic normotensive subjects with exercise-induced ST ischemic depression of 1 mm or more and compared them with 379 controls. At least two controls with negative responses on the exercise electrocardiographic (EKG) test were selected for each case and were matched for age, sex, work, community, and coronary-risk-factors index. The end points considered were the following coronary events: angina pectoris, myocardial infarction, and sudden death. After a median follow-up period of 6.0 years for the cases and 6.4 years for the controls, the relative risk was 5.55 (95 per cent confidence limits, 2.75 to 11.22). Coronary events occurred significantly earlier in the cases than in the controls. Our data also suggest that the exercise EKG response is a particularly good prognostic indicator for myocardial infarction. In addition, our analysis has confirmed the predictive roles of age, smoking, blood pressure, and the coronary-risk-factors index and suggests that the exercise EKG response is an additional independent risk indicator for coronary events.