Associations of Obesity and Prognostic Nutritional Index on 1-Year Mortality in Patients with Acute Heart Failure.

Background: Increased BMI is paradoxically associated with improved survival among patients with acute heart failure (AHF). However, the impact of different nutritional status on this obesity paradox on 1-year mortality is underreported. The prognostic nutritional index is a simple tool to assess nutrition status.

Methods: From 10,027 emergency department admissions at the Amager and Hvidovre Hospital, Copenhagen University Hospital in Denmark, all patients with AHF were identified. Patients were categorised by BMI (normal: 18.5-24.9 kg/m², overweight: 25-29.9 kg/m², obese: ≥30 kg/m²) and nutritional status using the prognostic nutritional index (malnourished: <38, well-nourished: ≥38). Kaplan- Meier curves analysed cumulative survival, and Cox regression examined associations between BMI, nutritional status and outcomes, expressed as HR and 95% CI.

Results: Among 383 AHF patients (median age 76 years), 41.3% were malnourished and 58.7% well nourished. In the well-nourished group, obesity was inversely associated with 1-year mortality (adjusted HR 0.48; 95% CI [0.24-0.95]; p=0.035). However, this correlation disappeared in the malnourished group (adjusted HR 1.08; 95% CI [0.59-2.00]; p=0.798). Mortality rates were significantly lower in the well-nourished group among patients with overweight and obesity.

Conclusion: Obesity was associated with reduced 1-year mortality only in AHF patients with good nutritional status, while in malnourished patients, obesity was not associated with 1-year mortality. The prognosis in patients with AHF depends on both the presence of obesity and their nutritional status, highlighting the need for nutritional assessment for risk stratification.