543 Beneficial effects of coronary revascularization on left ventricular remodelling in patients with ischemic cardiomyopathy: the role of viable myocardium

Background: In patients (pts) with left ventricular (LV) dysfunction due to chronic coronary artery disease, preserved myocardial viability not always implies left ventricular function recovery after revascularization. However, additional benefits may be present. Aim: To test the hypothesis that myocardial viability may prevent LV remodeling after revascularization, independently of the effect on functional recovery. Methods: Dobutamine stress echocardiography (DSE) was performed in 88 pts with ischemic cardiomyophaty, already scheduled for revascularization, to detect the presence of viable myocardium. Resting 2D-echocardiography was performed at a mean of 4,5 months and 2,8 years after revascularization. LV volumes and the LV sphericity index (LVSI: D/L) were measured to evaluate LV remodeling (LV volumes and LVSI increase). Radionuclide ventriculography was performed before and at a mean of 4,5 months after revascularization to assess LV function. Results: After revascularization, progressive remodeling was observed in overall 35 pts (40%). In these pts, the end-diastolic volume increased from 173 ± 42 to 207 ± 56 (at 4,5 months, p<0.01) and to 242 ± 55 ml (at 2,8 years, p<0.05). The end-systolic volume increased from 109 ± 39 to 142 ± 24 (at 4,5 months, p<0.01) and to 169 ± 58 ml (at 2,8 years, p<0.05). The LVSI increased over the follow-up in 23 pts (66%) with LV volume increase. Clinical characteristics were similar in pts with and without remodeling, however, a substantial amount of viable myocardium (major or equal to 25%) was more often present in pts with no remodeling (81% vs 9%, p<0.0001). The number of viable segments was a strong predictor of no remodeling (OR 3, p<0.0001). The likelihood of no remodeling increased proportionally with the number of viable segments. The predictive value remained even after correction for LV function recovery after revascularization(OR 3.1, p<0.0001). After revascularization, LV ejection fraction increased significantly (major or equal to 5%) in 28 of 46 pts (61%) with substantial amount of viable myocardium. However, LV remodeling did not occur (preserved LV volumes and LVSI) in 17 of 18 pts (94%) with viable myocardium that did not recover in function. Conclusions: The presence of viable myocardium in pts with ischemic cardiomyopathy strongly prevents progressive LV remodeling. This benefit is independent of functional recovery after revascularization.