Impact of Body Mass Index on Short- and Long-Term Outcomes After Isolated First-Time Surgical Aortic Valve Replacement for Aortic Stenosis

Objective: To ascertain whether body mass index (BMI) has a clinical effect on short- and long-term postoperative outcomes after surgical aortic valve replacement in patients with severe aortic stenosis. Design: Single-center, retrospective study. Setting: Tertiary referral hospital. Participants: The study comprised 1,561 patients who underwent isolated first-time aortic valve replacement between 2005 and 2012. Interventions: Fourteen underweight patients were removed from the analysis. The remaining patients were divided into the following 4 groups according to their BMI: 418 as normal weight (>= 18.5 to <25 kg/m(2)), 629 as overweight (>= 25 to <30 kg/m(2)), 342 as obese (>= 30 to <35 kg/m(2)), and 158 as very obese (>= 35 kg/m(2)). Early mortality and postoperative complications were compared, and long-term survival rates were investigated. Measurement and Main Results: Thirty-day mortality was higher in the normal weight group but did not reach statistical significance = 0.054), and the incidence of postoperative complications was not different for cerebrovascular accident (p = 0.70), re-sternotomy for bleeding (p = 0.17), sternal wound infection (p = 0.07), and dialysis (p = 0.07). With a mean follow-up time of 4.92 +/- 2.82 years, survival rate was better in the overweight group. A Cox proportional hazard model found BMI inversely correlated with long-term mortality when analyzed in a univariable fashion (hazard ratio 0.95; p = 0.009), but this apparent protective effect disappeared when adjusted for preoperative covariates (hazard ratio 0.98, 95% confidence interval 0.96-1.004; p = 0.12). Conclusion: Once adjusted for preoperative characteristics, obesity does not represent an independent predictor for long-term survival rates. There was a higher incidence of 30-day mortality in the normal weight group compared with the overweight and very obese groups. The incidence of deep sternal wound infection was higher in very obese patients. (C) 2019 Elsevier Inc. All rights reserved.