Chelsea Christensen, PA-C, is a cardiology physician assistant at Sentara Virginia Beach General Hospital.

Chelsea Christensen, PA-C

ZOLL Heart Failure Management System Predicts Events Before Hospitalization, With Chelsea Christensen, PA-C

The ZOLL Heart Failure Management System (HFMS) has demonstrated efficacy in the clinic by predicting and warning clinicians and patients of 

 events before they occur, avoiding hospitalizations.

American College of Cardiology (ACC) Scientific Sessions 2026

 editorial team spoke with Chelsea Christensen, PA-C, a cardiology physician assistant at Sentara Virginia Beach General Hospital, to discuss her experience with the ZOLL HFMS device.

“A lot of times, patients are frustrated – they’re back in the hospital for the third, fourth, even fifth time," Christensen told 

 in an exclusive interview. “It’s been really interesting to use the HFMS device and catch this fluid before the patients even know that it’s coming back.”

The ZOLL HFMS system is a wearable patch that utilizes radiofrequency to detect changes in pulmonary fluid levels early. Radar waves propagate through the lungs to measure interstitial edema – changes in the signal path delay or strength indicate changes in fluid presence. Additionally, the waves are highly modulated by tissue hydration, generating a sensitive and robust measurement named the Thoracic Fluid Index (TFI). Proprietary algorithms then determine patient-specific changes in pulmonary fluid before symptoms begin.

The ZOLL HFMS first received clearance from the US Food and Drug Administration (FDA) in 2019. This decision was made following positive data from a multicenter, multinational, prospective, concurrent-control clinical trial composed of 2 arms – Benefit of Microcor in Ambulatory Decompensated Heart Failure (control arm) (BMAD-HF), and Benefit of Microcor in Ambulatory Decompensated Heart Failure (intervention arm) (BMAD-TX). The study was powered for a primary endpoint of the comparison of HF hospitalization by time to first event between the 2 arms.

Patients were eligible for inclusion in BMAD-HF or BMAD-TX if they had been discharged from the hospital for HF in the previous 10 days and had an HF event within the previous 6 months, which was defined as a hospitalization, emergency department visit, or an unplanned clinical visit. Patients with wearable cardiac defibrillators, subcutaneous implantable cardioverter-defibrillators, or those who had a life expectancy of <1 year due to noncardiac diseases, among other criteria, were excluded.

Patients were asked to wear the HFMS continuously for ≤90 days with the option to extend to ≤180 days. They were required to fill out a diary throughout the study, recording any HF symptoms/events or medication changes. Additionally, all patients received standard-of-care management, participating in weekly phone calls and monthly office visits to collect HF symptom and event information.

In the control arm, both patients and investigators were blinded to the device data; in the intervention arm, device data was shared with the investigators, who could then share reviewed data with patients in the study. The impact of HF management with the HFMS was evaluated using Kaplan-Meier analysis of the time to first HF hospitalization for each patient.

A total of 522 patients were enrolled across 93 sites – of these, 245 subjects in BMAD-HF and 249 in BMAD-TX were eligible for intention-to-treat analysis. By the 90-day marker, 108 hospitalizations occurred in 82 patients. Based on these data, investigators determined that patients in the arm managed using HFMS data to direct HF therapy exhibited a 38% lower HF hospitalization rate during the 90 days following an HF hospitalization versus the control arm (HR, 0.62; 

 = .03), with an absolute reduction of 7%.

Christensen also discussed her clinic’s plans to expand the use of the HFMS to a broader patient cohort, as well as larger-scale plans for accessibility.

“I think there are definitely ways to expand it, and that’s where we’re at in my program right now,” Christensen said. “But it’s all about getting bigger, because we’ve seen such great results with it. The name of the game is just making it bigger and trying to make it more accessible to more patients.”

Editors’ Note: Christensen reports no relevant disclosures.

Heart failure management system (HFMS) medical professional overview. ZOLL. Accessed April 10, 2026. 

https://cardiac.zoll.com/medical-professionals/heart-failure-management-system

Boehmer, J, Cremer, S, Abo-Auda, W. et al. Impact of a Novel Wearable Sensor on Heart Failure Rehospitalization: An Open-Label Concurrent-Control Clinical Trial. 

https://doi.org/10.1016/j.jchf.2024.07.022

Videos

Christensen discusses the mechanics and practical applications of the HFMS, emphasizing its success in predicting HF events based on pulmonary fluid levels.

Chelsea Christensen, PA-C

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