Low-dose dobutamine testing using contrast left ventriculography in the same session as coronary angiography predicts the improvement of left ventricular function after coronary angioplasty in postinfarction patients

The role of percutaneous transluminal coronary angioplasty (PTCA) in the subacute or chronic phases of myocardial infarction remains controversial. This study investigates the usefulness of dobutamine contrast left ventriculography in a single session with coronary angiography for predicting the improvement of ventricular function after PTCA. The study group consisted of 30 patients in whom a contrast left ventricular angiogram and PTCA were performed after a first myocardial infarction. The centerline method was used to calculate dysfunction extent at baseline and its variation during dobutamine infusion at 7.5 mu g/kg/min; contractile reserve was defined as a significant (greater than or equal to 15%) reduction of dysfunction extent. A second ventricular angiogram was performed 6 months later in all patients. Abnormal wall motion extent decreased at 6 months after PTCA (84 +/- 21% vs 70 +/- 29%, p = 0.0001). Wall motion improvement after PTCA correlated with the response to dobutamine (r = 0.54, p = 0.002). Ten patients showed a significant reduction (greater than or equal to 15%) of dysfunction extent at 6 months; dobutamine testing had a 80% sensitivity, 84% specificity, 67% positive predictive value, and 89% negative predictive value in detecting regional function improvement. In the subgroup of 21 patients without restenosis, both the correlation between dysfunction improvement after PTCA and response to dobutamine (r = 0.72, p = 0.0001) and the accuracy of dobutamine testing (sensitivity 88%, specificity 92%, positive predictive value 88%, and negative predictive value 92%) increased. The election fraction significantly increased (>5%) after PTCA in 6 patients; dobutamine testing had a 67% sensitivity, 74% specificity, 44% positive predictive value, and 88% negative predictive value in predicting the increase in the election fraction. In the subgroup without restenosis the improvement of the election fraction correlated with the response to dobutamine (r = 0.63, p = 0.007), and the sensitivity of dobutamine testing was 80%, specificity 83%, positive predictive value 67%, and negative predictive value 91%. In conclusion, dobutamine contrast left ventriculography testing in the same session as coronary angiography predicts regional function and ejection fraction improvement after PTCA in postinfarction patients, particularly when restenosis does not develop. (C)1999 by Excerpta Medica, Inc.