On-pump and off-pump coronary artery bypass grafting for patients needing at least two grafts: comparative outcomes at 20 years.

OBJECTIVES: Despite evidence from several randomized controlled trials and observational studies validating short-term safety and efficacy of off-pump coronary artery bypass grafting (CABG), concerns persist regarding the impact of off-pump CABG on long-term survival and freedom from reintervention. This persistent scepticism regarding off-pump CABG prompted us to review our practice of CABG over the last 20 years with a view to comparing the impact of off-pump and on-pump CABG on short-term and long-term outcomes in a high-volume off-pump coronary surgery centre.

METHODS: We retrospectively analysed prospectively collected data from the Patients Analysis and Tracking System database (Dendrite Clinical Systems, Oxford, UK) for all isolated first-time CABG procedures with at least 2 grafts performed at our institution from January 1996 to September 2017. Over the study period, 5995 off-pump CABG and 4875 on-pump CABG were performed by surgeons with exclusive off-pump and on-pump practices, respectively. Multivariable logistic regression and the Cox model were used to investigate the effect of off-pump versus on-pump procedures on short-term outcomes and long-term survival. Propensity score matching was used to compare the 2 matched groups.

RESULTS: Off-pump CABG was associated with a lower risk for 30-day mortality [odds ratio (OR) 0.42, 95% confidence interval (CI) 0.32-0.55; P < 0.001], reintubation/tracheostomy (OR 0.58, 95% CI 0.47-0.72; P < 0.001) and re-exploration for bleeding (OR 0.48, 95% CI 0.37-0.62; P < 0.001). The benefit in terms of operative deaths from off-pump was significant in those with Society of Cardio-Thoracic Surgery logistic EuroSCORE >2 (interaction P = 0.04). When compared with on-pump CABG, off-pump CABG did not significantly reduce the risk of stroke (OR 0.96, 95% CI 0.88-1.12; P = 0.20) and postoperative haemofiltration (OR 0.98, 95% CI 0.86-1.20; P = 0.35). At the median follow-up of 12 years (interquartile range 6-17, max 21), off-pump CABG did not affect late survival [log rank P = 0.24; hazard ratio (HR) 0.95, 95% CI 0.89-1.02] or the need for reintervention (log rank P = 0.12; HR 1.19, 95% CI 0.95-1.48).

CONCLUSIONS: This large volume, single-centre study with the longest reported follow-up confirms that off-pump CABG performed by experienced surgeons, who perform only off-pump procedures in a high-volume off-pump coronary surgery centre, is associated with lower risk of operative deaths, fewer postoperative complications and similar 20-year survival and freedom from reintervention rates compared with on-pump CABG.