Conversion in off pump coronary artery bypass grafting: a retrospective analysis

Background: Intraoperative conversion of off-pump coronary artery bypass grafting (OPCAB) to on-pump coronary artery bypass grafting (ONCAB) has been associated with adverse outcomes. Inspite of several preoperative risk factors reported in the literature, conversion still remains an unpredictable event. This study aims to determine the incidence and predictors of conversion and attempts to evaluate strategies to prevent the same. Methods: Between June 2011 to May 2012, out of 994 patients who were planned for elective OPCAB by 8 different surgical teams at our institution, 127 patients underwent intraoperative conversion to ONCAB. We conducted a retrospective analysis of these patients under two groups—ONCAB (n = 127) and OPCAB (n = 867). Patients undergoing elective ONCAB and emergency OPCAB were excluded from the study. Results: The incidence of intraoperative conversion was 12.77 %. Those who underwent conversion had a significantly higher rate of postoperative complications including hospital mortality (9.44 versus 2.42 %). Left ventricular dysfunction, history of myocardial infarction, and left main disease emerged as independent predictors of conversion. Conclusion: Association of certain preoperative risk factors can predict the occurrence of intraoperative conversion. Planned and smooth conduct of OPCAB plays a key role to avoid higher mortality and morbidity associated with conversion. If at all unavoidable, a timely conversion can prevent hazards of emergency conversion. © 2015, Indian Association of Cardiovascular-Thoracic Surgeons.