Limitations
There are several limitations to this study. It is a retrospective single-centre analysis in a limited cohort. The allocation of patients to the study group was by surgeon’s expertise, and this might have led to undetected difference in risk profile between groups. The study is from an Institution with historical high interest and expertise in OPCAB surgery, and this might limit the applicability of the findings to Institutions with less interest and proficiency in OPCAB surgery. The study included a patient cohort treated over a long time period, hence with possible confounding factors due to changes in clinical practice overtime. Finally, the evaluation of long-term impact of redo-OPCAB surgery was limited to all-cause mortality as no data were available on cardiac-related mortality or late graft patency.