Effect of revascularization on long-term survival in patients with ischemic left ventricular dysfunction and a wide range of viability

Abstract

Short-term survival in patients with viability and ischemic left ventricular dysfunction appears improved by revascularization, but no randomized studies have shown a long-term benefit of revascularization in patients with a wide range of viability. Propensity analysis was used as a substitute for randomization in a study comparing the survival of revascularized and medically treated patients with ischemic dysfunction. Dobutamine echocardiography was performed in 274 patients with ischemic left ventricular dysfunction (mean ejection fraction 32%), with 32% having viability in > or =25% of the myocardium. Clinical, angiographic, and echocardiographic characteristics were comparable between treatment groups except for multivessel disease, hyperlipidemia, and the percentage of nonviable myocardium. A propensity score, reflecting the probability of receiving revascularization, was derived for each patient from baseline variables. After stratification by propensity scores, there were no differences between groups. Patients were followed for cardiac death. Revascularization was performed in 130 patients, and 144 were medically treated. There were 114 cardiac deaths (42%) over 4.5 years of follow-up. After propensity score adjustment, survival was better with revascularization (mean survival 5.9 vs 3.3 years, hazard ratio 0.42, 95% confidence interval 027 to 0.65, p <0.0001). Medical and device therapy during follow-up was similar between treatment groups, except that beta-blocker use was more common in revascularized patients. After adjustment for beta-blocker use and propensity score, survival remained better in revascularized patients (hazard ratio 0.47, 95% confidence interval 0.30 to 0.72, p = 0.0006). In conclusion, revascularization improves long-term survival in patients with ischemic left ventricular dysfunction and a wide range of viability.