Early exercise testing after stabilization of unstable angina: correlation with coronary angiographic findings and subsequent cardiac events.

To evaluate the safety and diagnostic use of exercise testing in patients with unstable angina, 78 patients underwent submaximal exercise testing and diagnostic cardiac catheterization early after stabilization of their pain. Thirty-six patients (46%) had a positive exercise test manifested as angina or ST segment depression of greater than or equal to 0.1 mV during or immediately after exercise. Thirty-three of 36 patients (92%) with a positive exercise test had multivessel coronary disease compared to 18 of 42 patients (43%) with a negative exercise study (p less than 0.001). Twenty-two of 36 patients (61%) with a positive exercise test had three-vessel disease compared to 12 of 42 patients (29%) with a negative test (p = 0.004). The sensitivity of exercise testing in detecting multivessel disease was 65%, specificity 89%, predictive value of a positive test 92%, predictive value of a negative test 57%, and overall accuracy 73%. When the 42 patients taking beta blockers were examined, these values were essentially unchanged. Ventricular arrhythmias during exercise testing were associated with a lower ejection fraction, 61.1 +/- 12.5%, compared to 67.9 +/- 11.1% in patients without ventricular arrhythmias (p less than 0.05). Submaximal exercise testing after stabilization of patients with unstable angina is safe and useful in evaluating patients for the presence of multivessel coronary artery disease.