Clinical utility of low dose dobutamine echocardiography in regional myocardial viability detection before and after...

Seventy-eight consecutive patients (mean 63 +/- 10 years, 79.5% men) with a history of myocardial infarction and indication of coronary artery bypass grafting (CABG) were studied with low dose dobutamine stress echocardiography (DSE) before (DSE 1) and at 3-month follow-up (DSE 2) to evaluate its clinical utility in the detection of viable myocardium. We determined the expected utilities of global patients (P; n = 67) and coronary territories (T; n = 126) with the classic strategy: DSE 1 and results of a rest follow-up echocardiogram (REST 2) and applying them to a complementary strategy that submitted false positives (Fp) and false negatives (Fn) results to DSE 2. Assigned utilities in each node of the decision tree were maximal (1.0), submaximal ( 0.75), and intermedium (0.50) using the folding method as a mathematical model.

Global P and T expected utilities when performing DSE 1 were 0.84 and 0.89, respectively for positive viability; 0.85 and 0.82, respectively; and for negative viability 0.83 and 0.82, respectively. The expected utilities with the decision of performing a DSE 2 to Fp were 0.74 and 0.76, respectively (viability was detected in 66% of P and in 58% of T) and 0.47 and 0.45, respectively, as applied to Fn.

Low dose DSE results in high clinical utility by finding viable or scar myocardium before CABG as well as when discordant results are found in follow-up, particularly with Fp.