Edema index established by a segmental multifrequency bioelectrical impedance analysis provides prognostic value in acute heart failure

Abstract

Objectives: A segmental multifrequency bioelectrical impedance analysis (SMBIA) is a noninvasive and reproducible modality for estimating the fluid state. The aim of this study was to test whether the SMBIA-derived edema index provides prognostic value in patients hospitalized due to acute heart failure (AHF).

Methods: To estimate the 6-month prognostic value of the predischarge edema index in patients hospitalized due to AHF, 112 patients were consecutively enrolled. Both predischarge edema index and B-type natriuretic peptide (BNP) were measured. Outcome follow-up focused on heart failure-related and all-cause re-hospitalizations and all events.

Results: On the basis of a cutoff value of edema index of 0.390, patients were separated into two groups: edema index more than 0.390 (n = 44) and edema index of 0.390 or less (n = 68). Compared with patients with edema index 0.390 or less, those with edema index of more than 0.390 were older, had lower blood albumin and hemoglobin levels, and had higher predischarge BNP levels, functional class, incidence of diabetes mellitus, valvular cause, and diuretic use. Although edema indexes were correlated with BNP levels (r = 0.47, P < 0.0001), a mismatch was noted in 33 (29%) patients. Univariate and multivariate analysis showed that an edema index of more than 0.390 predicted a higher incidence of heart failure-related re-hospitalization [odds ratio (OR) = 4.14, confidence interval (CI) = 1.05-15.28, P = 0.04] and all events (OR = 3.97, CI = 1.4-11.25, P = 0.01). The edema index provided a prognostic value superior to that of BNP. Reducing the edema index in high-risk patients resulted in fewer heart failure-related re-hospitalizations (OR = 0.81, CI = 0.77-0.84, P < 0.001) and all events (OR = 0.8, CI = 0.76-0.85, P < 0.001).

Conclusion: Edema index provides 6-month prognostic values in patients hospitalized due to AHF. Reducing the edema index in high-risk patients results in better outcomes.

Trial registration: ClinicalTrials.gov NCT01416285.