The prognostic value of pre-discharge exercise testing after myocardial infarction treated with either primary PCI or fibrinolysis: A DANAMI-2 sub-study

Abstract

Aims: To evaluate the prognostic importance of pre-discharge maximal symptom-limited exercise testing (ET) following acute myocardial infarction (AMI) in the era of aggressive reperfusion. Methods and results: In the DANAMI-2 (the second DANish trial in AMI) study, patients with ST-elevation AMI (STEMI) were randomized to primary angioplasty (PCI) or fibrinolysis. Of 1462 patients discharged alive, 1164 (79.6%) performed an ET. Primary endpoint was a composite of death and re-infarction. Patients randomized to fibrinolysis developed ST-depression to a greater extent than patients randomized to primary PCI (21.7 vs. 15.3%, P = 0.007). Multivariable predictors of death and re-infarction included age, gender, diabetes, previous stroke, anterior AMI, randomization to fibrinolysis, and exercise capacity [risk ratio (RR) 0.82 (0.72-0.93); P < 0.001]. ST-depression was predictive of the clinical outcome [RR 1.57 (1.00-2.48); P < 0.05] in multivariable analysis, but stratified according to treatment groups there was a significant association between ST-depression and outcome in the fibrinolysis group [RR 1.95 (1.11-3.44); P < 0.05], but not in the primary PCI group [RR 1.06 (0.47-2.36); P = ns]. However, the P-value for interaction was 0.15. Conclusion: Exercise testing after contemporary reperfusion therapies for STEMI confers important prognostic information. Exercise capacity is a strong prognostic predictor of death and re-infarction irrespective of treatment strategy, whereas the prognostic significance of ST-depression seems to be strongest in the fibrinolysis-treated patients.