Reoperation for Coronary Artery Bypass Grafting Surgery: Outcomes and Considerations for Expanding Interventional Procedures

Background: Owing to an inevitable degeneration of grafts over time, patients may require consideration for repeat coronary artery bypass graft (CABG) surgery. As our understanding of preoperative risks associated with redo CABG surgery is limited and availability of data is limited to historical cohorts, we sought to evaluate our contemporary 20-year experience with this challenging patient population.

Methods: Between January 1993 and June 2014, 748 patients underwent redo CABG surgery at our institution. Median age at reoperation was 69 years (range, 36 to 88), and 644 (86%) were male. Median follow-up was 15.1 years and was 100% complete. Preoperatively, 191 patients (26%) had diabetes mellitus, 562 (75%) had hypertension, 206 (28%) had peripheral vascular disease with 121 (16%) having a history of cerebrovascular disease, and 459 (61%) had prior myocardial infarction. Number of prior CABG operations was 1 in 682 patients (91%), 2 in 62 patients (8%), and 3 in 4 patients (1%).

Results: All patients underwent isolated redo CABG surgery; all 748 (100%) procedures were performed using cardiopulmonary bypass, with median time on pump of 95 minutes (maximum, 378) and cross-clamp time of 48 minutes (maximum, 176). There were 47 early deaths (6%); early nonfatal morbidity included renal failure in 51 patients (7%), stroke in 15 (2%), and pneumonia in 22 (3%). Overall 1-, 5-, and 10-year survival was 89%, 77%, and 51%, respectively. Age (hazard ratio [HR] 1.74, p < 0.001), diabetes (HR 1.51, p < 0.001), peripheral vascular disease (HR 1.51, p < 0.001), and end-stage renal disease with dialysis (HR 11.85, p < 0.001) were associated with increased long-term mortality, whereas higher left ventricular ejection fraction (per 10% increase) was protective (HR 0.78, p < 0.001).

Conclusions: Redo CABG can be performed safely with low early and late morbidity and mortality. Important predictors of long-term mortality such as age, diabetes, renal disease, and peripheral vascular disease were identified and should guide the treatment strategy chosen for this challenging group of patients.