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 (p = 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.
(Copyright © 2019 Elsevier Inc. All rights reserved.)