Specific phenotypes of heart failure with preserved/reduced ejection fraction according to Body Mass Index

The relationship between Body Mass Index (BMI) and acute heart failure (HF) remains ill-defined. This study aimed to compare the influence of BMI on in-hospital mortality between patients with acute HF with preserved ejection fraction (HFpEF) and those with acute HF with reduced ejection fraction (HFrEF) and to examine the specific phenotypes of HFpEF/HFrEF according to BMI.

This multicenter retrospective study included 5313 and 6332 consecutive patients with acute HFpEF and HFrEF, respectively. Low, normal, and high BMIs were defined as BMI <18.5, 18.5 ≤BMI <25.0, and BMI ≥25.0, respectively. Overweight/obesity was defined as BMI ≥25.0. Kaplan-Meier survival curves and log-rank tests were used for between-group comparisons of in-hospital mortality. Univariable and multivariable Cox regression analyses were performed to identify significant prognostic factors.

A paradoxical association between overweight/obesity and survival benefits, the so-called obesity paradox exists in HFpEF (log-rank P<0.05 in low BMI vs. normal BMI, low BMI vs. high BMI, and normal BMI vs. high BMI). In HFrEF, a trend towards lower in-hospital mortality was observed in patients with higher BMI. However, the obesity paradox in patients with HFrEF was not as evident as that in patients with HFpEF. Significant differences in the clinical characteristics and prognostic factors for in-hospital mortality were observed among the groups according to BMI.

The obesity paradox was more evident in patients with HFpEF than in those with HFrEF. Specific phenotypes of HFpEF and HFrEF according to BMI were revealed.