Off-Pump CABG Safer Than On-Pump for STEMI

SAN DIEGO — Patients with ST segment elevation MI who underwent off-pump coronary artery bypass grafting had significantly lower morbidity and mortality compared with patients who underwent on-pump CABG, results from a randomized, single-center Italian study showed.

Between February 2002 and October 2007, 127 patients underwent CABG at the University of Palermo, Italy, within 48 hours from onset of symptoms. Patients were included in the study if they had evolving myocardial ischemia refractory to medical therapy; presence of left main stenosis and/or three-vessel disease; ongoing ischemia despite successful or failed percutaneous coronary intervention (PCI); or complicated PCI; or if they were in cardiogenic shock and had complex coronary anatomy.

Of the 127 patients, 65 were assigned to receive on-pump therapy while 62 received off-pump therapy, Dr. Khalil Fattouch reported at the annual meeting of the American Association for Thoracic Surgery.

The mean age of patients was 62 years and 22% were older than age 70. The only statistically significant preoperative differences between the two groups were related to gender (77% in the on-pump group were men vs. 61% in the off-pump group), and history of a previous myocardial infarction (19% in the on-pump group vs. 39% in the off-pump group), said Dr. Fattouch of the department of cardiac surgery at the university.

The mean number of grafts used per patient was 2.8 in the on-pump group vs. 2.6 in the off-pump group, a difference that was not statistically significant. The mean follow-up was 22 months.

Dr. Fattouch reported that the overall in-hospital mortality was 4.7%. In-hospital mortality was significantly higher for the on-pump group compared with the off-pump group (7.7% vs. 1.6%, respectively). More on-pump group patients in cardiac shock died in the hospital compared with their off-pump counterparts (27% vs. 7.5%) as did on-pump patients who underwent CABG in less than 6 hours from onset of symptoms (23% vs. 7.5%).

Intraoperatively, the use of catecholamines, time of inotrope support, time of intra-aortic balloon pump use, and length of mechanical ventilation were significantly greater in the on-pump group compared with the off-pump group.

Postoperatively, the incidence of low cardiac output syndrome, reoperations for bleeding, and lengths of ICU and hospital stays were significantly greater in the on-pump group compared with the off-pump group.

In addition, the serum levels of troponin I and creatine kinase MB were higher during the first 48 hours after surgery in the on-pump group compared with the off-pump group, said Dr. Fattouch, who disclosed that he had no conflicts of interest.