Conversion from off-pump to on-pump coronary artery bypass grafting: impact of surgeon and anaesthetist experience.

Objectives: Intraoperative conversion from off-pump to on-pump coronary artery bypass grafting (CABG) is associated with increased postoperative morbidity and mortality. The aim of this study is to assess the impact of surgeon and anaesthetist experience on the conversion rate.

Methods: We performed a retrospective analysis of the data of all patients who underwent planned off-pump CABG in a single centre in 2007-2021, some of whom were non-electively converted to on-pump. Surgeon and anaesthetist experience were assessed by the number of off-pump bypass procedures per year. Multivariable logistic regression analysis was used to assess the impact of surgeon and anaesthetist experience on conversion rate.

Results: A total of 2742 patients met the inclusion criteria. Ninety-four (3.4%) patients underwent non-elective conversion to on-pump surgery. Converted patients had significantly higher mortality [11 (11.7%) vs 35 (1.3%), P < 0.0001] in comparison to non-converted patients. Anaesthetist experience was found to be a risk factor for conversion (P = 0.011). Surgeon experience did not significantly affect conversion rate (P = 0.51). Other risk factors for conversion were female gender [odds ratio 2.65 (95% confidence interval 1.65-4.26), P = 0.0001] and left ventricular ejection fraction ≤35% [odds ratio 1.91 (95% confidence interval 1.05-3.49), P = 0.040].

Conclusions: Conversion from off-pump to on-pump CABG is associated with worse postoperative outcomes. Limited experience of anaesthetists in off-pump bypass surgery is associated with a higher conversion rate.