Re-exploration for bleeding and long-term survival after adult cardiac surgery: a meta-analysis of reconstructed time-to-event data

Background: Postoperative bleeding requiring re-exploration is a serious complication that occurs in 2.8-4.6% of patients undergoing cardiac surgery. Re-exploration has previously been associated with a higher risk of short-term mortality. However, a comprehensive analysis of long-term outcomes after re-exploration for bleeding has not been published. Materials and methods: The authors performed a systematic, three databases search to identify studies reporting long-term outcomes in patients who required re-exploration for bleeding after cardiac surgery compared to patients who did not, with at least 1-year of follow-up. Long-term survival was the primary outcome. Secondary outcomes were operative mortality, myocardial infarction, stroke, renal and respiratory complications, and hospital length of stay. Random-effects models was used. Individual patient survival data was extracted from available survival curves and reconstructed using restricted mean survival time. Results: Six studies totaling 135 456 patients were included. The average follow-up was 5.5 years. In the individual patient data, patients who required re-exploration had a significantly higher risk of death compared with patients who did not [hazard ratio (HR): 1.21; 95% CI: 1.14-1.27; P<0.001], which was confirmed by the study-level survival analysis (HR: 1.32; 95% CI: 1.12-1.56; P<0.01). Re-exploration was also associated with a higher risk of operative mortality [odds ratio (OR): 5.25, 95% CI: 4.74-5.82, P<0.0001], stroke (OR: 2.05, 95% CI: 1.72-2.43, P<0.0001), renal (OR: 4.13, 95% CI: 3.43-4.39 P<0.0001) respiratory complications (OR: 3.91, 95% CI: 2.96-5.17, P<0.0001), longer hospital length of stay (mean difference: 2.69, 95% CI: 1.68-3.69, P<0.0001), and myocardial infarction (OR: 1.85, 95% CI: 1.30-2.65, P=0.0007). Conclusion: Postoperative bleeding requiring re-exploration is associated with lower long-term survival and increased risk of short-term adverse events including operative mortality, stroke, renal and respiratory complications, and longer hospital length of stay. To improve both short-term and long-term outcomes, strategies to prevent the need for re-exploration are necessary.