Bioimpedance phase angle is associated with increased heart failure hospitalization risk

Abstract

Background

Outcomes for patients living with heart failure (HF) remain poor with high rates of death and hospitalization due to worsening HF. Noninvasive tools may be useful to identify patients at risk for disease progression before these outcomes occur. For example, loss of cell mass and compromised cell membrane integrity throughout the body are associated with chronic disease, mortality, frailty, and malnutrition. As the cell membrane loses its integrity, its electrical capacitance decreases, lowering bioelectrical phase angle. Data collected during the SCALE-HF 1 study (NCT04882449) was used to evaluate bioelectrical phase angle as a marker for heart failure (HF) hospitalization risk. Phase angle was measured by the FDA-cleared Bodyport Cardiac Scale.

Methods

SCALE-HF 1 was a multicenter, prospective, observational study, investigating HF event prediction. Baseline phase angle was measured during the first week in the study with the patient standing barefoot on the Cardiac Scale at home for approximately 20 seconds. HF hospitalizations were independently adjudicated. The analysis was based on univariable and multivariable Cox regression models adjusted for age, sex, race, body mass index (BMI), left ventricular ejection fraction (LVEF), inpatient status at enrollment, and selected comorbidities and laboratory tests.

Results

329 participants with HF were enrolled across 8 US sites with 238 patient-years of follow-up. 312 (95%) of the participants had a baseline phase angle, and 57 (18%) of those had a HF hospitalization during the follow-up period. Participants with baseline phase angle in the lowest quartile (suggesting worse cell membrane integrity) were at increased risk for HF hospitalization compared to participants with baseline phase angle in the highest quartile (Hazard ratio: 3.44, 95% CI: 1.55 to 7.63, P = .002). When adjusted for risk factors selected from age, sex, race, BMI, LVEF, laboratory tests and comorbidities in the multivariable model, participants with baseline phase angle in the lowest quartile continued to be at increased risk for HF hospitalization compared to participants with baseline phase angle in the highest quartile (Hazard ratio: 3.51, 95% CI: 1.73 to 7.12, P < .001).

Conclusions

Phase angle was found to be independently associated with HF hospitalization risk. The noninvasive measurement, acquired with a familiar scale form factor, may help guide remote care and triage.

Trial Registration

ClinicalTrials.gov NCT04882449. https://clinicaltrials.gov/study/NCT04882449.