Off-pump versus on-pump bypass surgery for left main coronary artery disease (EXCEL study) - is experience the unknown variable?

A post hoc analysis of the Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization (EXCEL) data compared off-pump coronary artery bypass (OPCAB) technique with conventional coronary artery bypass grafting (CABG). It was reported that OPCAB was associated with lower rate of revascularization especially in the inferolateral wall and carried increased risk of 3-year all-cause mortality compared to on-pump CABG. However, the study does not provide any information on the experience of participating surgeons which is a key determinant of outcomes in OPCAB surgery. In the absence of this key variable, the extrapolation and applicability of this finding to the wider surgical practice, especially in countries like India and Japan, may not be accurate.