Abstract 3404: Malnutrition, Not Morbid Obesity, Confers Greater Short- and Long-Term Mortality for Patients Undergoing Cardiac Valve Surgery
Objective: Limited data exist on patients (pts) with malnutrition or morbid obesity presenting for valvular heart surgery. The objective of this study is to investigate the relationship between body mass index (BMI) and outcomes following valvular surgery.
Methods: A retrospective review of 4247 pts undergoing valvular surgery (1996–2008) at a US academic center was performed. Pts were divided into 3 groups: BMI<25 (Group 1,n=1527), BMI 25–35 (Group 2,n=2284), and BMI>35 (Group 3,n=436). Data were analyzed using univariable and multivariable regression analysis, adjusted for 13 pre-operative covariates. A smooth kernel regression curve was generated using BMI and in-hospital mortality as variables.
Results: Pts in Group 3 were younger (Group 1:61.7±16.1 yrs, Group 2:61.9±13.6, Group 3:57.5±13.0; p<0.001) and more likely female (778/1527 (50.9%); 912/2284 (39.9%); 240/436 (55.1%); respectively, p<0.001). Pts in Group 3 had longer CPB and aortic crossclamp times (p<0.001); with higher rates of postoperative mediastinitis (p<0.001) and renal failure (p<0.01). Group 1 had the highest in-hospital mortality (111/1527 (7.3%), Group 2:110/2284 (4.8%), and Group 3:24/436 (5.5%); p=0.006). The smooth kernel regression curve (Figure⇓) illustrates the BMI/in-hospital mortality relationship. One, five, and ten year survival was significantly lower in Group 1 (p<0.001) and lower BMI was an independent predictor for short- and long-term mortality.
Conclusions: Pts with BMI<25, not those >35, are at significantly increased risk of short and long-term mortality following valvular surgery and warrant careful risk stratification.