Left Ventricular Function Recovery After Coronary Revascularization and Medical Therapy: A Systematic Review and Meta-Analysis

Background:  The prevalence of coronary artery disease (CAD) with reduced left ventricular ejection fraction (LVEF) is rising, but the optimal treatment remains unclear. The present study aims to investigate the impact of revascularization (coronary artery bypass grafting (CABG), or percutaneous coronary intervention (PCI)) and medical therapy (MT) on LVEF recovery in patients with CAD and LVEF ≤ 40%. Methods:  All clinical studies which reported LVEF in patients with CAD and LVEF ≤ 40% undergoing either revascularization or MT were included. A systematic literature search up to May 11, 2017 was performed on MEDLINE, EMBASE and the Cochrane Library in Ovid. Studies were assessed for eligibility and data were extracted by independent reviewers in duplicate with disagreements resolved by a third reviewer. Bias assessment was performed using the Newcastle-Ottawa Scale. Random effect meta-analysis was performed on included studies. The primary outcome was change in LVEF after intervention as compared to baseline. Results:  83 cohort studies with a total of 7,157 patients were included. We observed a statistically significant increase in LVEF following revascularization with CABG (MD 7.76; 95% CI: 6.81 to 8.70; p<0.00001;  I 2 =99%) and PCI (MD 6.70; 95% CI: 4.71 to 8.70; p<0.00001;  I 2 =94%) but not after MT (MD 4.06; 95% CI: -2.12 to 10.24; p=0.20;  I 2 =98%). Conclusion:  In patients with CAD and LVEF ≤ 40%, revascularization leads to LVEF recovery as compared to MT. There is continued need for RCT level evidence to enable optimization of treatment selection in this difficult population.