Routine off-pump coronary artery bypass: reasons for on-pump conversion

: To assess the feasibility of routine off-pump coronary artery bypass (OPCAB) and investigate risk factors for on-pump conversion.

: Between July 1, 2002, and June 30, 2004, OPCAB was attempted for all patients who required isolated coronary artery bypass in our institution. The perioperative results of patients were prospectively entered into a structured database, and the results were analyzed to identify the risks of requirement for cardiopulmonary bypass.

: Off-pump coronary artery bypass was successfully performed in all but 9 patients, giving an OPCAB success rate of 97.3% (329/338). The reason for cardiopulmonary bypass was hemodynamic instability occurring during reoperative surgery in 7, and cardiogenic shock in 2. The OPCAB success rate was significantly higher in primary coronary artery bypass grafting (99.3%, 314/316) than in reoperative coronary artery bypass grafting (68.1%, 15/22; P < 0.0001), and higher in patients without cardiogenic shock (97.9%, 329/336) than in those with cardiogenic shock (0%, 0/2; P = 0.0005). Mean number of distal anastomoses performed under OPCAB was 3.5 ± 1.4. There were 2 hospital deaths (0.6%). During a mean follow-up period of 1.0 ± 0.4 years, 7 patients developed angina, which was treated with catheter intervention; there were no other cardiac events.

: Routine OPCAB is feasible with acceptable short-term results. Patients undergoing reoperation or in persistent cardiogenic shock are more likely to require conversion to on-pump coronary artery bypass grafting.