Current guidelines do not recommend routine cardiac stress testing in patients with stable coronary heart disease (CHD) unless they report symptoms of angina. Our objective was to compare the prognosis of self-reported angina symptoms, inducible ischemia, or both in patients with stable CHD.
We measured self-reported angina by questionnaire and inducible ischemia using treadmill stress echocardiography in 937 outpatients with stable CHD. We used Cox proportional hazard models, adjusted for traditional cardiovascular risk factors, to evaluate the independent association of angina and inducible ischemia with CHD events (myocardial infarction or CHD death) during a mean of 3.9 years of follow-up.
Of the study participants, 129 (14%) had angina alone, 188 (20%) had inducible ischemia alone, and 40 (4%) had both angina and ischemia. Recurrent CHD events occurred in 7% of participants without angina or inducible ischemia, 10% of those with angina alone, 21% of those with inducible ischemia alone, and 23% of those with both angina and inducible ischemia (P < .001). The presence of angina alone was not associated with recurrent CHD events (adjusted hazard ratio, 1.4; 95% confidence interval, 0.7-2.9) (P = .31). However, the presence of inducible ischemia without self-reported angina strongly predicted recurrent CHD events (adjusted hazard ratio, 2.2; 95% CI, 1.4-3.5) (P = .005).
We found that 24% of patients with stable CHD had inducible ischemia, and more than 80% of these patients did not report angina. The presence of inducible ischemia without self-reported angina is associated with a greater than 2-fold increased rate of recurrent CHD events.