Long-term value of exercise testing after acute myocardial infarction: influence of thrombolytic therapy.

Abstract

OBJECTIVES: To evaluate the long-term predictive value of exercise testing performed early after acute myocardial infarction (AMI) in patients receiving thrombolytic therapy. DESIGN: Nonblinded prospective follow-up study. SETTING: Cardiac rehabilitation unit in a 900-bed university hospital. SUBJECTS: Four hundred forty-three patients allowed to perform exercise testing 3 weeks after AMI were followed for a median of 75 months; 183 received IV thrombolysis and 263 did not. RESULTS: Cardiac death hazard ratios were significantly increased in the presence of reduced physical working capacity on exertion, left ventricular dysfunction, and > or = 1-mm (but < 2-mm) ST-segment depression on exertion. In the group receiving thrombolytic therapy, no patient with > or = 2-mm ST-segment depression on exercise died; this group was characterized by a high rate of revascularization, whereas the group with > or = 1-mm but < 2-mm ST-segment depression was not. No parameter related to clinical or exercise testing predicted recurrent infarction in the group receiving thrombolytic therapy. Among patients not receiving thrombolysis, cardiac death was significantly related to > or = 2-mm ST-segment depression on exertion, to reduced physical working capacity, and to the lack of revascularization during follow-up. CONCLUSION: Exercise test-derived parameters have variable value in predicting long-term survival of patients performing exercise test after AMI depending on the following: (1) whether thrombolytic therapy was given or not; (2) the degree of ST-segment depression during exercise testing; and (3) the rate of revascularization.