Long-term survival and freedom from reintervention after off-pump coronary artery bypass grafting: A propensity-matched study.

Journal article

Background

The long term outcomes following off-pump coronary artery bypass grafting (CABG) are the subject of speculation. Our institution has over 15 years of experience performing CABG both off-pump (OPCAB) and on cardiopulmonary bypass (CPB). Our null hypothesis was that there would be no difference in a long-term composite of death and revascularisation between the two methods.

Methods

We performed a retrospective cohort study of all isolated CABG at our institution from 2001 - 2015. We used an intention to treat analysis, performing risk-adjustment using adjustment for and matching to propensity score. In total, 13226 patients had CABG: 5,882 had OPCAB and 7,344 had CPB with a median follow-up of 6.2 years.

Results

Of the 5,882 OPCAB, 76 (1.3%) converted to CPB. One, five and ten year survivals in each group were similar (OPCAB vs CPB: 96.7%, 87.9%, 72.1% vs 96.2%, 87.4%, 72.8%). There was no difference in long-term survival (adjusted hazards ratio [HR] 1.03; 95%CI: 0.94, 1.11 for OPCAB vs CPB; p=0.56) or freedom from death and re-intervention (HR 0.98; 95% CI: 0.92 – 1.06 for OPCAB vs CPB; p=0.23). Patients receiving OPCAB had higher EuroSCOREs (median [quartiles]: 2.81 [1.53-5.57] vs 2.73 [1.51-5.22], p=0.01), fewer grafts (mean ± SD: 3.0 ± 0.9 vs 3.3 ± 0.9, p<0.001) but more total arterial grafting (45.9% v 8.4%, p<0.001). OPCAB also had more trainee 1st operators (15.3% v 12.5%), lower cardiac enzyme rise, shorter length of stay and fewer complications (such as MI).

Conclusions

Off-pump coronary artery bypass grafting is associated with similar long term outcomes to CABG performed on cardiopulmonary bypass in our institution. Our low conversion rate to cardiopulmonary bypass, whilst training junior surgeons, demonstrates that OPCAB can be taught safely. 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 re-intervention as on-pump CABG.

Authors: Kirmani, B; Holmes, M; Muir, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Heart Association
• Journal: Circulation
• Volume: 134
• Issue: 17
• Pages: 1209-1220
• Publication date: 2016-10-01
• Acceptance date: 2016-09-13
• DOI: 10.1161/CIRCULATIONAHA.116.021933
• ISSN: 1524-4539 and 0009-7322
• Language: English
• Keywords: outcome; coronary artery bypass graft; off-pump surgery; cardiopulmonary bypass