Background: There is evidence that after uncomplicated acute myocardial infarction, T wave positivization during stress testing may unveil myocardial viability. We evaluated in a prospective study the clinical value of T wave positivization during dobutamine stress echocardiography in patients with recent, first uncomplicated acute myocardial infarction.
Methods: Two hundred twenty-nine patients, who underwent dobutamine stress echocardiography within 10 days of uncomplicated acute myocardial infarction, were selected for exhibiting negative T waves in the infarct area. A mean follow-up of 2.1 +/- 1 years (up to 6 years) was obtained.
Results: T wave positivization appeared during dobutamine test in 76 (33%) patients. The agreement of T wave positivization for myocardial viability was 65% (95% confidence interval 59-71). Compared to myocardial viability during dobutamine stress echocardiography, the combination with T wave positivization was more sensitive (55 vs 24%, 95% confidence interval 46-64 vs 17-33) for predicting cardiac events, albeit less specific. Kaplan-Meier survival curves showed 47 (62%) cardiac events in patients with T wave positivization and 70 (46%) cardiac events in the remaining patients (p < 0.05). Soft (n = 91) prevailed over hard (n = 26) cardiac events.
Conclusions: T wave positivization during dobutamine stress echocardiography after uncomplicated acute myocardial infarction identifies patients at higher cardiac risk, and is more sensitive, albeit less specific, for cardiac events than viability alone. T wave positivization is helpful in the case of inconclusive stress echocardiography. The pathophysiology of T wave positivization and its relative value among other variables warrant further analysis.