Isolated coronary artery bypass grafting in obese individuals: a propensity matched analysis of outcomes.

BACKGROUND: There is conflicting data regarding the impact of obesity on morbidity and mortality in patients undergoing isolated coronary artery bypass grafting (CABG). METHODS AND RESULTS: Retrospective cohort analysis of patients who underwent CABG from January 1, 1995, through July 31, 2010 was performed. Patients were classified as obese or non-obese (body mass index ≥ 30.0 kg/m(2) and <30.0 kg/m(2), respectively). The primary outcome was in-hospital mortality. Secondary outcomes included postoperative respiratory failure, postoperative stroke, postoperative myocardial infarction, sternal and leg wound infections, postoperative atrial fibrillation, postoperative ventricular tachycardia, postoperative renal failure and length of hospital stay. Propensity-matched stepwise multivariable logistic regression was performed. Of 13,115 patients, 4,619 (35.2%) were obese. In the propensity-matched logistic regression models (n = 8,442), obesity was not associated with postoperative mortality (odds ratio = 1.13, 95% confidence interval 0.86-1.48). However, obesity was associated with postoperative respiratory failure, postoperative renal insufficiency, sternal wound infection, and leg wound infection. Obesity was also associated with a decreased risk of postoperative bleeding and re-operation from bleeding. CONCLUSIONS: Obesity was associated with an increased risk of postoperative respiratory failure, postoperative renal failure, and surgical site infections. However, obesity was not associated with in-hospital mortality in patients undergoing CABG.

Association of gender with morbidity and mortality after isolated coronary artery bypass grafting. A propensity score matched analysis.

INTRODUCTION: There is conflicting evidence about the impact of gender on outcomes after coronary artery bypass grafting (CABG). METHODS: We performed a multivariate logistic regression and propensity score matched analyses in 13,115 patients (75% men) who underwent CABG between January 1, 1995 and December 31, 2009. The primary outcome was in-hospital mortality. Secondary outcomes included post-operative respiratory failure, stroke, myocardial infarction, sternal and leg wound infections, atrial fibrillation (AF), renal failure, need for postoperative intra-aortic balloon pump (IABP) support, and length of hospital stay. RESULTS: A higher proportion of women (184; 5.6%) suffered in-hospital death compared to men (264; 2.7%), p<0.0001. After propensity score matching (n=3600 total, 1800 in each group), female gender was an independent predictor of mortality after isolated CABG (odds ratio [OR]=1.84; 95% confidence interval [CI] 1.22-2.78). Women also experienced a higher incidence of postoperative complications including stroke (3.8% vs. 2.3%, OR 1.37; 95% CI 1.08-1.73) and leg wound infection (3.4% vs. 1.7%, OR 1.75; 95% CI 1.36-2.54) on multivariate regression analyses. However, these differences were not significant after propensity score matching. We also observed a lower risk of post-operative AF (21.2% vs. 22.1%, OR 0.78; 95% CI 0.70-0.86) in women that remained significant after propensity matching (O.R. 0.76; 95% C.I. 0.65-0.90). Length of hospital stay was longer in women compared with men (11.9 ± 9.0 vs. 10.4 ± 9.2 days, p<0.0001). CONCLUSIONS: Female gender is an independent predictor of increased mortality and a lower incidence of post-operative AF after isolated CABG.