Revascularization Benefits in Ischemic Cardiomyopathy With Nonviable Myocardium

Patients with ischemic cardiomyopathy with a nonviable myocardium may still benefit from revascularization vs medical therapy alone, according to a meta-analysis published in Cardiovascular Revascularization Medicine.

Among patients with ischemic cardiomyopathy and nonviable myocardium, investigators aimed to compare those who received revascularization vs those who received medical therapy alone. All-cause mortality was the primary outcome.

The investigators initiated a meta-analysis and systematic review using MEDLINE database to search for studies published to December 2021. Inclusion criteria were patients with nonviable myocardium, patients with coronary artery disease amenable to percutaneous coronary intervention or coronary artery bypass grafting, and studies assessing revascularization impact vs medical therapy alone after myocardial viability evaluation.

They found 12 studies assessing nonviable myocardium in 1363 patients. Among these patients, 501 received revascularization and 862 received medical therapy alone (control group). All the included studies were of high quality, and were either randomized studies (n=1) or nonrandomized studies with a Newcastle-Ottawa scale greater than 6 (n=11). Using a Funnel plot and Egger’s linear regression test, the investigators found no significant publication bias.

The range for all-cause mortality was similar for the revascularization group (0.0%-70.4%) vs the control group (2.9%-66.7%). Investigators noted the revascularization group saw a significant reduction in all-cause mortality (risk ratio [RR], 0.76; 95% CI, 0.62-0.93; I²= 0) compared with the control group in pooled analysis.

They found no association between the risk of all-cause mortality and the type of viability imaging method used (P-interaction =.58). The intervention group had a lower all-cause mortality rate regardless of imaging method used (echocardiography RR, 0.75 [95% CI, 0.59-0.96]; single-photon emission computed tomography RR, 0.95 [95% CI, 0.05-18.73]; positron emission tomography RR, 0.47 [95% CI, 0.2-1.1]).

Meta-analysis limitations include that 11 of the 12 studies are nonrandomized and are subject to selection bias. Additionally, most of the observational studies are underpowered for nonviable myocardium patients who receive revascularization and the individual-level participant data is lacking.

“The findings of this meta-analysis suggest a benefit from revascularization compared to medical therapy alone in patients with ischemic cardiomyopathy even with non-viable myocardium,” the study authors wrote. “Future prospective trials of revascularization in patients with ischemic cardiomyopathy, regardless of viability status, should be considered to search for mechanisms of benefit of revascularization distinct from mitigation of ischemia.”