Myocardial viability testing and impact of revascularization on prognosis in patients with coronary artery disease and left ventricular dysfunction: a meta-analysis

Objectives This study pools data from published series examining late survival with revascularization versus medical therapy after myocardial viability testing in patients with severe coronary artery disease (CAD) and left ventricular (LV) dysfunction. Background Previous observational studies have suggested survival benefit in such patients if they are revascularized when myocardial viability is detected on imaging tests. Methods A MEDLINE database search returned 24 viability studies reporting patient survival using thallium perfusion imaging, F-18 fluorodeoxyglucose metabolic imaging or dobutamine echocardiography. Annual death rates were extracted, pooled and analyzed with a random effects model. The risk-adjusted relationship between severity of LV dysfunction, presence of viability and survival benefit associated with revascularization was assessed by meta-regression. Results There were 3,088 patients (2,228 men), ejection fraction 32 ± 8%, followed for 25 ± 10 months. In patients with viability, revascularization was associated with 79.6% reduction in annual mortality (16% vs. 3.2%, CHI-SQUARE = 147, p < 0.0001) compared with medical treatment. Patients without viability had intermediate mortality, trending to higher rates with revascularization versus medical therapy (7.7% vs. 6.2%, P = NS). Patients with viability showed a direct relationship between severity of LV dysfunction and magnitude of benefit with revascularization (p < 0.001). There was no measurable performance difference for predicting revascularization benefit between the three testing techniques. Conclusions This meta-analysis demonstrates a strong association between myocardial viability on noninvasive testing and improved survival after revascularization in patients with chronic CAD and LV dysfunction. Absence of viability was associated with no significant difference in outcomes, irrespective of treatment strategy.