Comparison of invasive treatment strategies in patients with non-ST elevation acute coronary syndrome: A systematic review and meta-analysis.

Objective: To compare the mortality associated with percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with non-ST elevation acute coronary syndrome (NSTE-ACS).

Methods: We searched publications from PubMed, Embase, Web of Science, and the Cochrane Library from inception until December 23, 2020. All randomized clinical trials (RCTs) and observational studies comparing all-cause mortality after treatment with CABG versus PCI for patients with NSTE-ACS with minimum follow-up of 6 months were included. Restricted mean survival time (RMST) differences from RCTs and adjusted RMST differences from observational studies were computed by reconstructing time-to-event data from published Kaplan-Meier curves. Extracted hazard ratios (HRs) were also assessed as a secondary analysis.

Results: Our systematic review included an individual participant data analysis of 3 RCTs and 8 observational studies. A meta-regression showed a significant association between log-transformed HRs and duration of follow-up (-0.009 [95% confidence interval (CI), -0.002 to -0.016] log-HR per 1-year longer follow-up;  = .037), suggesting a violation of the proportional hazard assumption. Analysis of 6 studies with available RMST data showed a significant inverse association between adjusted RMST differences and cutoff years (slope, -0.028 [95% CI, -0.042 to -0.013] year difference per 1-year longer cutoff;  < .005), suggesting a longer survival benefit in the CABG arm compared with the PCI arm with longer follow-up.

Conclusions: There was a trend toward a benefit of CABG compared with PCI in the longer follow-up in patients with NSTE-ACS. A large, well-designed RCT with longer follow-up is needed to obtain definitive evidence on this topic.