Obesity in Heart Failure with Preserved Ejection Fraction: Insights from the REDUCE LAP-HF II Trial

BACKGROUND AND AIMS: Obesity is causally related to the development of HFpEF but complicates the diagnosis and treatment of this disorder. We aimed to determine the relationship between severity of obesity and clinical, echocardiographic and hemodynamic parameters in a large cohort of patients with documented HFpEF. METHODS: The REDUCE LAP-HF II trial randomized 626 patients with EF =40% and exercise pulmonary capillary wedge pressure (PCWP) =25?mmHg to atrial shunt or sham procedure. We tested for associations between body mass index (BMI), clinical characteristics, cardiac structural and functional abnormalities, physical limitations, quality of life and outcomes with atrial shunt therapy. RESULTS: 60.9% of patients had BMI =30?kg/m . As the severity of obesity increased, symptoms (KCCQ score) and 6-min walk distance worsened. More severe obesity was associated with lower natriuretic peptide levels despite more cardiac remodeling, higher cardiac filling pressures, and higher cardiac output. Lower cut points for E/e' were needed to identify elevated PCWP in more obese patients. Strain measurements in all 4 chambers were maintained as BMI increased. Pulmonary vascular resistance at rest and exercise decreased with higher BMI. Obesity was associated with more first and recurrent HF events. However, there was no significant interaction between obesity and treatment effects of the atrial shunt. CONCLUSIONS: Increasing severity of obesity was associated with greater cardiac remodeling, higher right and left ventricular filling pressures, higher cardiac output and increased subsequent HF events. Despite significant obesity, many HFpEF patients have preserved right heart and pulmonary vascular function and thus, may be appropriate candidates for atrial shunt therapy. This article is protected by copyright. All rights reserved.