Risk-Adjusted Outcomes of Reoperative vs Primary Coronary Artery Bypass Grafting

Coronary artery bypass grafting (CABG) is a mainstay of therapy for advanced coronary artery disease. The proportion of reoperative CABG has declined to ∼3% to 7% of all CABG procedures; however, redo operations remain essential for patients with recurrent or refractory ischemia. Redo CABG involves greater technical complexity and risk, highlighting the need for risk-adjusted analyses.

We conducted a single-center retrospective review of all isolated CABG procedures from January 2009 to December 2023. After excluding emergent cases and missing data, 12,120 first-time CABG and 341 redo-CABG patients were analyzed. We used risk-score matching, inverse probability of treatment weighting, and multivariable-adjusted approaches to assess in-hospital mortality, perioperative complications, and mortality and revascularization risks at up to 10 years of follow-up.

Crude in-hospital mortality was 1.0% in CABG vs 1.8% in redo CABG. After risk-score matching (258 pairs), in-hospital mortality was not statistically significantly different between the 2 groups (1.2% vs 1.9%; relative risk, 1.68; 95% CI, 0.40-7.10). Major perioperative complications, including stroke, myocardial infarction, hemofiltration, and extracorporeal membrane oxygenation use, were similar. However, the need for cardiopulmonary resuscitation tended to be higher in redo CABG, and repeat revascularization at up to 10 years was significantly greater in redo CABG. Both groups demonstrated comparable survival at up to 10 years of follow-up. Sensitivity analysis using the inverse probability of treatment weighting approach resulted in in-hospital mortality rates of 1.0% (CABG) and 0.8% (redo CABG), with a relative risk of 0.75 (95% CI, 0.60-0.94).

In this risk-adjusted analysis, redo CABG achieved similar in-hospital mortality and 10-year survival compared with CABG.