Value of negative predischarge exercise testing in identifying patients at low risk after acute myocardial infarction treated by systemic thrombolysis.

Although thrombolytic therapy reduces mortality in patients with acute myocardial infarction (AMI), it is associated with a greater incidence of successive coronary events, and there is still no ideal diagnostic and therapeutic strategy for such patients. The present study verifies the value of negative predischarge exercise testing in identifying low-risk patients treated with thrombolysis after AMI. One hundred fifty-seven consecutive patients with an uncomplicated clinical course underwent maximal or symptom-limited exercise testing (Bruce treadmill protocol) within 15 days of AMI in the absence of therapy. The location of the AMI was anterior in 51 patients, inferior in 85 and non-Q-wave in 21. All of the patients were followed for 6 months. Death and nonfatal reinfarction were considered as major coronary events, and the recurrence of angina as a minor event. Exercise test results were negative in 105 patients (group 1) and positive for angina or ST depression greater than or equal to 0.1 mV in 52 (group 2). No deaths occurred during follow-up; there were 3 reinfarctions (3%) and 7 cases (7%) of postinfarction angina in group 1, and 2 reinfarctions (4%) and 21 cases (40%) of postinfarction angina in group 2. By the end of follow-up, 90% of the patients with negative exercise test results were event-free (97% in the case of major events). These results show that thrombolytic therapy does not affect the value of negative postinfarction exercise testing in identifying low-risk patients.