Outcomes of reoperative versus primary cardiac surgery: a systematic review and meta-analysis

Background: Cardiovascular diseases are lifelong and progressive conditions that can recur after primary surgery. The procedural risks and prognosis of patients requiring reoperations are not well-defined. Materials and Methods: We searched MEDLINE, EMBASE, and the Cochrane Library for eligible studies. Analysis was performed using a random-effects meta-analysis for the main (short-term mortality) and additional (short-term adverse events and long-term mortality) endpoints. Binary endpoints were pooled using odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs). A two-tailed P -value < 0.05 was considered statistically significant. We used R Studio for all analyses. Results: We included 34 studies ( n = 148 149). Reoperative surgery was associated with higher odds of in-hospital mortality in coronary bypass grafting (OR 2.45; 95% CI 1.90–3.15; P < 0.001) and in valve surgery (OR 2.08; 95% CI 1.84–2.35; P < 0.001), but not in aortic surgery (OR 1.40; 95% CI 0.94–2.14; P = 0.13). Long-term mortality was higher in the subgroups of valve surgery (HR 1.88; 95% CI 1.52–2.32; P < 0.001) and aortic surgery (HR 1.50; 95% CI 1.20–1.86; P < 0.001), but not in coronary bypass (HR 1.30; 95% CI 0.82–2.05; P = 0.32). Redo valve surgery was associated with more adverse events, while findings in coronary bypass and aortic surgery were borderline. Conclusion: Redo cardiac surgery is generally associated with worse in-hospital outcomes and worse long-term mortality.