The prognostic value of myocardial viability assessment on left ventricular (LV) aneurysms remains undetermined. We aimed, first, to evaluate the long-term survival benefit of assessing the viability of the aneurysmal myocardium in patients with ischemic cardiomyopathy and, second, in the revascularization subgroup, to compare the short-term effects on LV function and clinical symptoms in patients treated by revascularization alone or by revascularization plus aneurysmectomy. METHODS: Seventy consecutive patients with an LV aneurysm who underwent 99mTc-sestamibi SPECT and 18F-FDG PET were followed up for a median of 6.8 y (range, 0.1-8.8 y). Only cardiac death during follow-up served as the endpoint. Patients were classified into 4 groups by aneurysmal viability and by treatment strategy (medical or surgical). Further, the effects of aneurysmectomy on LV function at 3 mo were evaluated by an analysis of revascularized patients grouped by aneurysmal viability and by aneurysmectomy. RESULTS: Twenty-four patients were assigned to medical therapy, and 46 patients were assigned to surgery (18 revascularization alone and 28 revascularization plus aneurysmectomy). The annual cardiac mortality rate in patients with a viable aneurysm treated medically (n = 10) was significantly higher than that in patients with a viable aneurysm treated surgically (n = 23) (11.6% vs. 1.5%, chi2 = 12.87, P < 0.0001) and was also significant higher than that in patients with a nonviable aneurysm treated medically (n = 14) (chi2 = 4.13, P < 0.05) or surgically (n = 23) (chi2 = 10.46, P = 0.001). Multivariate analysis showed that the aneurysmal mismatch score (P = 0.003) and surgical therapy (P = 0.001) were independent predictors of cardiac death. Improvement of LV function and symptoms after revascularization (P < 0.05) was observed in patients with revascularization plus aneurysmectomy and in patients with a viable aneurysm and revascularization only. CONCLUSION: Viability in LV aneurysm in patients with ischemic cardiomyopathy was a negative independent predictor of survival. Compared with medical therapy, coronary revascularization was associated with improved long-term survival, symptoms, and LV function in patients with a viable aneurysm. These findings warrant further prospective investigations.