The relationship between severity of obesity and outcomes in heart failure (HF) has long been under debate. We studied index HF admissions from the 2013-14 National Readmission Database. Admissions were separated into three weight-based categories: non-obese (Non-Ob), obese (Ob), and morbidly obese (Morbid-Ob) to analyze hospital mortality and readmission at 30 days and 6 months. We investigated etiologies and predictors of 30-day readmission among these weight categories. We studied a total of 578,213 patients of whom 3.0% died during index hospitalization (Non-Ob 3.3% vs. Ob 1.9% vs. Morbid-Ob 1.9%; p < 0.01). Non-Ob comprised 79.5%, Ob 9.9%, and Morbid-Ob 10.6% of patients. Morbid-Ob patients were the youngest among age categories and more likely to be female. In-hospital mortality during readmission at 30 days and 6 months was significantly lower among Morbid-Ob and Ob compared with Non-Ob patients (all p < 0.01). Thirty-day readmission among Morbid-Ob was lower than Non-Ob and higher than Ob patients (19.6% vs. 20.5% vs. 18.6%, respectively; p < 0.01). Morbid-Ob patients were less likely to be readmitted for cardiovascular etiologies compared with both Ob and Non-Ob (45.0% vs. 50.3% vs. 50.6%; p < 0.01). Multivariable regression analysis revealed that Ob (adjusted odds ratio 0.84, 95% confidence intervals 0.82-0.86) and Morbid-Ob (aOR 0.83, 95% CI 0.81-0.85) were independently associated with lower 30-day readmission. Readmission at 6 months was highest among Morbid-Ob followed by Non-Ob and Ob (51.1% vs. 50.2% vs. 49.1%, p < 0.01). Morbid-Ob and Ob patients experience lower in-hospital mortality during index HF admission and during readmission with 30 days or 6 months compared with Non-Ob. Morbid-Ob patients experience greater readmission at 6 months despite the lower rate at 30 days post discharge. Morbid-Ob patients are most likely to be readmitted for non-cardiovascular causes.
Keywords: Etiologies; Heart failure; Morbid obesity; Mortality; Obese; Readmission.