Copyright © 1994 by the European Society of Cardiology.
© 1994 The European Society of Cardiology
Early and late exercise capacity after acute myocardial infarction treated with recombinant tissue-plasminogen activator



*Institute of Cardiology Krakow, Poland
Department of Cardiology, UZ Gasthuisberg, Leuven Belgium
Nuclear Medicine and Medical Statistics, UZ Gasthuisberg, Leuven Belgium
Received 10 August 1993; revised 7 December 1993; .
Correspondence: Hilaire De Geest, MD, Department of Cardiology, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
Abstract
Thrombolytic therapy salvages jeopardized myocardium and preserves left ventricular function. Therefore, a beneficial effect on exercise tolerance and haemodynamic adaptation to exercise can be anticipated. In the present study the results of bicycle exercise tests, performed at 10 to 14 days and at more than 1 year after infarction, were compared between patients randomized double blindly to recombinant tissue plasminogen activator (rt-PA) or placebo. At 2 weeks, the maximal heart rate (140 vs 130 beats. min1 P=0.017), systolic blood pressure (169 vs 161 mmHg, P=0.018) and pressure-rate product (22907 vs 20865 beats. min-1mmHg, P=0.0025) were higher in rt-PA treated patients (n=145) than in controls (n=142). At a mean follow-up of 16 months, rt-PA patients (n=126) performed a higher total and peak work load (733 vs 600 Watts. min, P=0.027 and 133 vs 100 Watts, P=-0.036, respectively) than control patients (n=122). During both exercise tests the incidence of clinical or electrocardiographic signs of ischaemia was similar. Multiple regression analysis indicated that age and end-systolic volume were predictors of peak pressure-rate product at 2 weeks (R2=0.11, P=0.0001). Age, sex and left ventricular ejection fraction at discharge were independent predictors of peak work load at 2 weeks (R2=0.32, P=0.0001) and the square root of peak work load at 16 months (R2=0.39, P=0.001). These findings suggest that an improved left ventricular function in the thrombolysis group plays a role in the better exercise capacity observed in rt-PA treated patients.
Key Words: Exercise test thrombolysis recombinant tissue plasminogen activator myocardial infarction