Bioelectrical Impedance Vector Analysis Identifies Body Composition Differences by Sex and Functional Class in Individuals With Heart Failure

Heart failure often leads to changes in body composition; however, conventional assessment methods struggle to differentiate body components. Bioelectrical impedance vector analysis (BIVA) offers a straightforward measurement, efficient in distinguishing fluid retention from lean mass loss. We aimed to assess body composition and bioelectrical parameters, including BIVA, among individuals with heart failure categorized by New York Heart Association (NYHA) functional classification, and to analyze sex-related differences in BIVA's detection capacity. This cross-sectional study included individuals with heart failure categorized according to NYHA functional class. We collected clinical data, anthropometry, bioelectrical impedance, incorporating BIVA. Statistical analysis included tests for normality and variance homogeneity, group comparisons using analysis of variance or Kruskal-Wallis with appropriate post hoc tests, Fisher's exact test for categorical data, and Hotelling'sT² test for vector analysis. Significance was set at P < .05. Participants with NYHA III/IV had significantly lower values in phase angle (P = .002) compared with the other groups. BIVA identified statistically significant vector differences between NYHA II and NYHA I groups (P = .002). Comparison between NYHA I and NYHA II versus NYHA III/IV group (P < .001 and P = .015, respectively) revealed greater fluid overload in those with more advanced classification. Males in all groups exhibited more pronounced fluid abnormalities, whereas females-especially those in the NYHA III/IV-exhibited with anasarca or obesity, and either reduced body cell mass or hyperhydration. BIVA effectively identified body composition variations across NYHA functional classes and between sexes. These findings emphasize the need for a multidisciplinary approach to personalized nutritional management for heart failure.