Myocardial viability for decision-making concerning revascularization in patients with left ventricular dysfunction and coronary artery disease: a meta-analysis of non-randomized and randomized studies.

Myocardial viability tests have been proposed as a key factor in the decision-making process concerning coronary revascularization procedures in patients with left ventricular dysfunction and coronary artery disease (LVD-CAD).We performed a systematic review and meta-analysis of studies that compared medical treatment with revascularization in patients with viable and non-viable myocardium and recorded mortality as outcome.Thirty-two non-randomized (4328 patients) and 4 randomized (1079 patients) studies were analyzed. In non-randomized studies, revascularization provided a significant mortality benefit compared with medical treatment (p<0.05). Since the heterogeneity was significant (p<0.05) a viability subgroup analysis was performed, showing that revascularization provided a significant mortality benefit compared with medical treatment in patients with viable myocardium (p<0.05) but not in patients without (p=0.34). There was a significant subgroup effect (p<0.05) related to the intensity of the effect, but not to the direction. In randomized studies, revascularization did not provide a significant mortality benefit compared with medical treatment in either patients with viable myocardium or those without (p=0.21). There was no significant subgroup effect (p=0.72). Neither non-randomized nor randomized studies demonstrated any significant difference in outcomes between patients with and without viable myocardium.The available data are inconclusive regarding the usefulness of myocardial viability tests for the decision-making process concerning revascularization in LVD-CAD patients. Patients with viable myocardium appear to benefit from revascularization, but similar benefits were observed in patients without viable myocardium. Moreover, a neutral or adverse effect of revascularization cannot be excluded in either group of patients.