麻豆传媒

Outcomes after off-pump coronary artery bypass grafting (CABG) matched those of standard on-pump surgery in two separate studies.

Published in the New England Journal of Medicine, the first reported that the of death, stroke, myocardial infarction, renal failure, and repeat coronary revascularization was similar between patients who had off- versus on-pump surgery (23.1% versus 23.6%, HR 0.98, 95% CI 0.87-1.10). Individual components of the primary endpoint also occurred at comparable frequencies among patients.

Neither group had a disadvantage in healthcare cost during the trial either ($15,107 versus $14,992, between-group difference $115, 95% CI -$697 to $927), according to , of McMaster University in Canada, and collaborators on the CABG Off or On Pump Revascularization Study (CORONARY).

Individuals with diabetes did experience fewer adverse events with off-pump CABG, however (22.7% versus 26.1% for on-pump surgery, HR 0.85, 95% CI 0.72-1.00).

"Our results should stimulate a systematic analysis of data from all other trials on the relative long-term effect of the two techniques according to diabetes status," the researchers said. "Therefore, until further confirmation is available from other trials, caution should be exercised in interpreting this subgroup result."

The study randomized 4,752 patients from 19 countries to off- or on-pump CABG for their coronary artery disease, and then followed for an average of 4.8 years.

For now, "our trial results indicate that both procedures are equally effective and safe," the authors wrote.

A separate single-center study also found that off-pump CABG was tied to long-term outcomes similar to those after cardiopulmonary bypass.

On propensity-matched analysis, between patients who had CABG off-pump and those who received cardiopulmonary bypass (adjusted HR 1.03, 95% CI 0.94-1.11), as was freedom from death and re-intervention (HR 0.98, 95% CI 0.92-1.06), reported , of Liverpool Heart and Chest Hospital in the U.K., and colleagues in Circulation.

Just 1.3% of off-pump CABG procedures were converted to cardiopulmonary bypass.

The off-pump group had a higher EuroSCORE to begin with (median 2.81 versus 2.73, P=0.01) and fewer grafts placed (average 3.0 versus 3.3, P<0.001). These patients, however, had more total arterial grafting performed (45.9% versus 8.4%, P<0.001) and by more trainee first operators (15.3% versus 12.5%, P<0.001). Off-pump CABG was associated with lower cardiac enzyme rise, a shorter length of stay, and fewer complications.

"Our low conversion rate to cardiopulmonary bypass, while training junior surgeons, demonstrates that off-pump CABG can be taught safely," Kirmani et al wrote. "The number of grafts performed between the two approaches is clinically comparable, if statistically different, and appears to provide equal benefits to survival and freedom from reintervention as on-pump CABG."

The retrospective study incorporated data from patients undergoing CABG at Liverpool Heart and Chest Hospital from 2001 to 2015 (n=13,226), of whom 5,882 had off-pump CABG. Follow-up lasted for a median of 6.2 years.

Writing in an to Kirmani’s study, , and , both of Cleveland Clinic, noted that the study had plenty of room for confounders -- for example, surgeons individually performed on- or off-pump CABG exclusively, and the investigators did not adjust for surgical ability.

Nevertheless, the study "serves as further evidence that off-pump CABG can be associated with excellent outcomes when performed by experienced surgeons," as the literature suggests that programs with greater off-pump CABG experience have better results than programs that perform the procedure less frequently.

"Intuitively, the benefits of off-pump CABG may be realized in selected high-risk patients, especially those at increased risk for cardiopulmonary bypass, such as patients with severe chronic obstructive pulmonary disease, hepatic insufficiency, or advanced atheromatous disease of the ascending aorta," the editorial continued.

"Tailoring the operation to the patient is always the best thing to do."