Prognostic role of phase angle in hospitalized patients with acute decompensated heart failure.

Background & Aims: Patients with acute decompensated heart failure (ADHF) have exacerbation of symptoms and fluid retention, and high risk of re-hospitalizations and mortality. The aim of this study was to evaluate the role of phase angle at hospital admission as a prognostic marker of mortality in patients with ADHF.

Methods: Patients hospitalized for ADHF, with left ventricular ejection fraction (LVEF) <45% and BOSTON criteria ≥8 points were included. The patients were evaluated at hospital admission (first 36 h) and then followed up for assessment of outcomes. Phase angle was measured with tetra polar bioelectrical impedance device. Mortality data was obtained from an average of 24 months after discharge, from the medical records of the hospital and outpatient or telephone contact with patients or family members. The best-discriminatory level of phase angle was selected based on the ROC curve for mortality.

Results: Seventy-one patients were included and the majority was male (63%), with a mean age of 61 ± 12 years, ischemic etiology being the most prevalent (48%) and LVEF average of 26 ± 8%. Mortality was 49% at an average of 24 months after hospital discharge. The average phase angle at hospital admission was 5.6 ± 2°, and lower values were associated with higher mortality. Survivors were compared to died patients in the risk factor variables for mortality. In multivariate analysis adjusting for age, LVEF and urea, phase angle <4.8° was independently associated with increased mortality (HR 2.67; p = 0.015).

Conclusions: Phase angle seems to be a prognostic marker in patients with ADHF independently of other known risk factors.