Association of body composition with clinical variables and mortality in heart failure patients with preserved and reduced systolic function

Abstract Introduction Obesity and heart failure are among the major public health challenges of our time. Heart failure is characterized by impaired cardiac pump function, which affects blood flow and consequently the delivery of oxygen and nutrients to the tissues. In advanced stages, cardiac cachexia may develop. In this context, excess body weight may provide a survival benefit due to higher metabolic reserves - a phenomenon known as the obesity paradox. Purpose Our aim was to identify the clinical parameters that differ between HFrEF and HFpEF patients and to determine which parameters have the greatest impact on mortality. Methods We enrolled 54 compensated (NYHA I, II) heart failure patients in our study. Participants were divided into two groups: those with preserved ejection fraction (EF ≥45%; HFpEF) and those with reduced ejection fraction (EF 45%; HFrEF). EF was determined by echocardiography. Nutritional status was assessed using BMI and bioimpedance-based body composition analysis, which allows for the assessment of muscle and fat mass as well as intra- and extracellular fluid volumes. Routine laboratory tests and NT-proBNP were obtained from blood samples. Data were analysed using the Mann–Whitney U test and Pearson correlation. Results BMI values were significantly higher in HFpEF patients (26.548 ± 3.912 vs. 31.839 ± 8.992; p=0.026), and also higher total body fat mass and trunk fat. Conversely, NT-proBNP levels were significantly higher in HFrEF patients (5295.930 ± 5890.349 vs. 1813.870 ± 3156.359; p=0.008). Among the variables examined, decreases in BMI (r = –0.343; p=0.032) and total body fat mass (r = –0.324; p=0.039) showed a significant correlation with the overall mortality. Conclusion Obesity is a major risk factor for HFpEF; however, in HFpEF patients, NT-proBNP levels may often be lower, partly due to reduced production and partly due to enhanced metabolism. Among heart failure patients, a decrease in BMI—particularly a reduction in body fat mass, even without a marked decline in skeletal muscle mass—is associated with increased mortality. In addition to optimal guideline-directed medical therapy, it is essential to place greater emphasis on preserving physical activity and maintaining adequate nutritional status in patients with heart failure.