Dobutamine- vs exercise-induced ST segment elevation early after Q wave myocardial infarction. Prediction of functional recovery after revascularization

Abstract

Aims. The association between stress-induced ST elevation and functional recovery following revascularization after myocardial infarction remains unclear. We assessed the relative accuracy of dobutamine- and exercise-induced ST elevation in Q wave leads in predicting functional recovery following revascularization, and we investigated the relationship of ST elevation to different wall motion responses to dobutamine. Methods and Results. Thirty-nine patients underwent dobutamine stress echo and exercise test 8 ± 2 days after Q wave myocardial infarction. All patients underwent angiography and subsequent revascularization. Follow-up echocardiograms were obtained 7 ± 4 weeks after revascularization. Functional recovery was assessed by the difference between the baseline and the follow-up asynergy index. Nineteen patients (48%) developed dobutamine- and exercise-induced ST elevation. There was significant agreement between the tests (k = 0.58, P < 0.001). We found a significant correlation between dobutamine and exercise-induced ST elevation with functional recovery following revascularization (r = 0.45, P < 0.005 and r = 0.7, P < 0.001, respectively). The parameters with the highest predictive value for functional recovery were: (a) the biphasic response during dobutamine infusion, (b) the development of ST elevation in both tests, and (c) the development of exercise-induced ST elevation in more than three leads. Conclusion. There is a strong association between dobutamine- and exercise-induced ST elevation with functional recovery following revascularization. Exercise-induced ST elevation in more than three leads and a biphasic response during dobutamine infusion accurately predict functional recovery.