The real-world outcomes of off-pump coronary artery bypass surgery in a public health care system

Abstract

The population-based results of off-pump coronary artery bypass surgery (OPCAB) in a public health care system have not been reported. The study objective was to compare the one-year outcomes of OPCAB with those of the standard on-pump coronary artery bypass surgery (ONCAB) in the province of Ontario. The present study was a retrospective, population-based study (n=15,172, with 1660 OPCAB patients) undertaken in fiscal years 2000 and 2001 using clinical and administrative data. Multivariate regression modelling for risk adjustment and propensity matching were used to compare OPCAB with ONCAB for one-year outcomes, including death, repeat revascularization and cardiac readmission. The rate of OPCAB was 11%, with institutional rates ranging from 3% to 51%. OPCAB patients were more likely to be female and older than 79 years of age, with peripheral vascular disease and higher socioeconomic status. OPCAB patients were less likely to have surgically significant coronary disease, poor left ventricular function, an urgent status, congestive heart failure and diabetes. The risk-adjusted one-year composite outcome was higher for OPCAB (11.8%, 95% CI 10.40% to 13.29%) than ONCAB (10.8%, 95% CI 10.23% to 11.27%); however, this difference was eliminated with propensity matching. OPCAB patients had shorter hospital lengths of stay and lower blood product transfusion rates than ONCAB patients. Despite the minimal use of OPCAB in Canada's public health care system, outcome rates are similar to those of ONCAB. The benefits of OPCAB observed in randomized trials, including shorter hospital lengths of stay and lower transfusion rates, remained true in the investigators' real-world experience. The results OPCAB were at least equivalent to those of ONCAB.