Emergency conversion in off-pump coronary artery bypass grafting

Emergency conversion to cardiopulmonary bypass in off-pump coronary artery bypass grafting is recognized to increase operative mortality and morbidity. We conducted a retrospective review of 616 consecutive patients who were planned for off-pump coronary artery bypass grafting from April 2001 to July 2004. Fourteen patients (2.3%) required emergency conversion to cardiopulmonary bypass. Operative mortality was 13.3% in the conversion group and 1.2% in the non-conversion group (P<0.001). The incidence of reoperation for bleeding was 7.1% and 1.0%, respectively (P=0.032) and that of respiratory failure was 35.7% and 3.3%, respectively (P<0.001). Multivariable analysis showed that mitral regurgitation and chronic obstructive pulmonary disease were predictors of emergency conversion with all causes except for bleeding, and that mitral regurgitation and no use of a heart positioning device were predictors of emergency conversion due to hemodynamic compromise during distal anastomosis of the circumflex artery territory. In conclusion, emergency conversion in off-pump coronary artery bypass grafting increases operative mortality and morbidity. Mitral regurgitation and chronic obstructive pulmonary disease are risk factors for emergency conversion. Use of a heart positioning device decreases hemodynamic compromise during anastomosis of the circumflex artery territory.