Strain Rate Analysis and Levosimendan Improve Detection of Myocardial Viability by Dobutamine Echocardiography in Patients With Post-Infarction Left Ventricular Dysfunction: A Pilot Study

Abstract

The assessment of myocardial viability by wall motion (WM) analysis on dobutamine echocardiography is subjective and provides suboptimal results. The aim of this study was to test the hypothesis that the prediction of functional recovery after revascularization can be improved by combining strain rate (SR) imaging, an objective method to quantify regional function, and levosimendan, a positive inotropic and vasodilator agent with no adrenergic effects. Thirty postinfarction patients (mean age, 65 +/- 13 years) underwent, off drug, dobutamine (5-40 mug/kg/min) and then levosimendan (24 mug/kg in 10 minutes) echocardiography before percutaneous coronary intervention. WM score, peak systolic SR (SRs), end-systolic strain (Ses), and postsystolic strain (Sps) were assessed in all segments. Regional left ventricular functional recovery was identified by >/=1-point improvement in WM as assessed using the standard 16-segment model. Of 215 segments with abnormal resting function, 102 (47%) showed improvement in WM 8 months after revascularization. Functional recovery was predicted in 60 segments with dobutamine and in 76 segments with levosimendan (sensitivity, 59% vs 75%; P = .026), while failure to recover was identified in 93 segments with dobutamine and 90 segments with levosimendan (specificity, 82% vs 80%, P = NS). Overall there was significant agreement between the 2 tests (kappa = 0.73; P < .0001). Peak SRs in segments with functional recovery improved significantly (P = .001) with both dobutamine and levosimendan (from -1.36 +/- 0.41 to -1.87 +/- 0.59 and -1.99 +/- 0.49, respectively) but did not change in regions with unchanged WM at follow-up. There were no significant differences in Ses and Sps between rest and pharmacologic tests, with either dobutamine or levosimendan. Of note, an increment in peak SRs > -0.29 s(-1) after levosimendan had the highest specificity (93%) for predicting segmental functional recovery at follow-up (P = .001). The combination of a newer quantitative echocardiographic technique (SR analysis) and a newer pharmacologic agent (levosimendan) improves the sensitivity of viability assessment compared with conventional dobutamine echocardiography.