How safe is it to train residents to perform coronary surgery with multiple arterial grafting? Nineteen years of training at a single institution

Objective The learning curve of coronary artery bypass grafting (CABG) with multiple arterial grafting (MAG) is perceived to be associated with increased surgical morbidity and potentially poorer long term outcomes. We compared short term outcomes and long term survival in patients who underwent CABG with MAG performed by attending surgeons or resident trainees at a single institution over a period of 19 years. Methods Using our institutional database, we identified 3039 patients undergoing MAG from 1996 to 2015. Of those, 958 (32%) were operated by residents and 2081 (68%) by attending surgeons. Propensity score matching and mixed effect models were used to compare the two groups. Results Operative mortality was 0.3% and 0.4% among patients operated by residents and attending surgeons respectively (P=0.71) with no significant differences between the groups in postoperative complications. After a mean follow-up time of 11±4 years, survival probability at 5,10 and 15 years was 95.1%±0.7% versus 96.4%±0.6%, 87.0%±1.1% versus 87.8%±1.1% and 76.6.%±1.8% versus 77.6%±1.8% in the resident and attending surgeon group respectively. Resident and attending surgeon cases showed comparable risk of death (HR 1.01; 95%CI 0.80–1.28; P=0.92). The equipoise between the two groups was confirmed among cases receiving bilateral internal thoracic arteries only (HR 0.88; 95%CI 0.54–1.43; P=0.61), radial artery (HR 1.22; 95%CI 0.92–1.61; P=0.15) or their combination (HR 0.74; 95%CI 0.33–1.65; P=0.47). Conclusions The present analysis confirms that adequately supervised trainees can perform CABG with multiple arterial grafting without compromising patient safety and long term survival.