Long-term outcome of isolated coronary artery bypass surgery in blacks

Abstract

Objective: There are conflicting data on the influence of race and gender on the outcome of patients undergoing coronary artery bypass graft surgery (CABG), with blacks and females showing higher operative mortality (OM) in some series and not others. Materials and Methods: The medical records of 176 black patients undergoing isolated CABG by a single surgeon from 2000 to 2014 were retrospectively reviewed. The mean age was 61.9 ± 11.2 years and majority 93 (52.8%) were males. Identified risk profiles were peripheral vascular disease 53 (30.1%) patients, insulin-dependent diabetes mellitus 49 (27.8%), end-stage renal disease (ESRD) 27 (15.3%), chronic obstructive pulmonary disease 27 (15.3%), cerebrovascular disease 24 (13.6%), and HIV/AIDS 5 (2.8%). One hundred and forty (79.5%) had severe triple vessel disease, 30 (17.0%) left main disease, and ejection fraction mean 43.0 ± 14.3. Results: One hundred and twenty-eight patients (72.7%) underwent on-pump and 48 patients (27.3%) off-pump coronary artery bypass graft (OPCAB), with 150 (85.2%) urgent surgeries. EuroSCORE-II (ES-II) score was 3.86 ± 3.18 while observed OM was 6.81% (12/176). There was no difference in OM between males and females 6.45% versus 7.22% (P = 0.924) and on-pump and OPCAB 7.81% versus 4.16% (P = 0.604). Univariate analysis identified ESRD and ES as predictors but on multivariate analysis only ESRD with odds ratio 4.630 (95% CI: 1.321-16.229, P = 0.017). The society of thoracic surgeons (STS) quality measurement task force major complications were acute kidney injury 6.81%, prolonged ventilation 6.81%, stroke 3.40%, deep sternal wound infection 2.27%, and reoperation 1.70%. Overall 1 and 5 years survival was 90.0% and 73.9%, respectively, with no significant difference between males and females 92.4% and 75.0% versus 86.4% and 70.9%, respectively, when P = 0.764. Conclusion: The observed/expected 1.76 ratio may partly be due to higher number of urgent and ESRD patients of 85.2% and 15.3% compared to 27.9% and 2.36-7.90%, respectively, in the STS database. Our ESRD patients had 4΍ times odds of death than non-ESRD. Despite males having slightly higher risk profiles, long-term survival was similar with females and overall 1 and 5 years survival comparable to blacks in other series.