The Obesity Paradox: Obese Patients with HFpEF and HFrEF are Equally at Higher Risk of Readmission

• Published in: Heart & lung 2020-03, Vol.49 (2), p.216-216
• Main Authors: Cox, Zachary, Lai, Pikki, Lewis, Connie, Lindenfeld, JoAnn
• Format: Article
• Language: English
• ISSN: 0147-9563
• DOI: 10.1016/j.hrtlng.2020.02.022

The term Obesity Paradox is used to describe the consistent finding that obese patients with HF have a lower mortality rate than patients with HF at normal body-mass indexes (BMI). However, the impact obesity has on HFpEF versus HFrEF re-hospitalization risks following an index HF hospitalization is unknown. We hypothesize that increasing obesity, quantified by BMI, will increase the rate of 30-day all cause hospital readmissions following an index HF hospitalization compared to the normal BMI range in both HFpEF and HFrEF. We analyzed all patients (n - 2252) age greater than 65 years or older with Centers of Medicare Services (CMS) benefits and a primary discharge diagnosis of HF from an academic medical center who were included in the hospital CMS Hospital Readmission Reduction Program report over a 8-year period (July 2009 - June 2017). We classified obesity using BMI according to the World Health Organization: Underweight (BMI less than 18.5 kg/m2), Normal (18.5-24.9 kg/m2), Overweight (25.0-29.9 kg/m2), Class I Obesity (30.0-34.9 kg/m2), Class II Obesity (35.0-39.9 kg/m2), and Morbid Obesity (greater than 40.0 kg/m2). We classified HFpEF (LVEF greater than 50%) and HFrEF (LVEF less than 40%). The primary outcome was 30-day all-cause readmission to any hospital after a HF admission. Mortality was assessed using the CMS in hospital Quality Reports IQRs and the medical center's electronic medical records. Readmission reasons were classified by primary discharge diagnosis using Clinical Classification Software from the Agency for Healthcare Research and Quality. Morbid Obese were more likely to be readmitted in both HFpEF (22.7%) and HFrEF (24.4%) cohorts than Normal in either, 19.3% and 18.8% respectively. The Obesity Paradox prevails in the overall cohort: mortality rate is lower (5%) and readmission rate is higher (23%) in Overweight/Obese than the Normal (8.5% and 19% respectively) groups. Regarding LVEF subgroups, Overweight/Obese patients of HFrEF had significant higher readmission rate (24.6%) and mortality rate (6.4%) than Normal peers (P less than 0.05). Yet the HFpEF the Overweight/Obese patients had similar readmission and mortality as the Normal peers.Mortality was lower in Morbid Obese in both HFpEF (3.4%) and HFrEF (6.7%) cohorts then in Normal in either, 8.1% and 10% respectively. In contrast to the general paradoxical effects on mortality and readmission, elevated BMI with HFrEF increased the rate of re-hospitalization within 30 days of a