A wearable patch with the ability to track cardiac activity can assess patients’ heart failure status, researchers reported in Circulation: Heart Failure this week.

The custom patch was created for and tested on both compensated and decompensated heart failure (HF) patients, co-lead study author Omer T. Inan, PhD, and colleagues wrote, and has the basic abilities of an echocardiogram and seismocardiogram.

Consistently tracking heart failure patients’ health status after discharge isn’t routine practice, but despite efforts to reduce heart failure hospitalizations and deaths across the U.S., almost a quarter of  HF patients are re-hospitalized within a month of their first event. Those hospitalizations impact mortality rates and, generally, lead to longer hospital stays and more severe risk of death.

“There are millions of patients with HF worldwide who still lack an effective solution for adequate, remote proactive care,” Inan et al. wrote. “Although treatment during hospitalization reduces signs and symptoms of congestion, even at discharge, nearly half of patients with HF still show such signs and, in fact, this subset of patients has been demonstrated to be at a significantly higher risk of readmission and long-term mortality.”

Of course, the authors wrote, they weren’t the first to attempt an effective strategy for monitoring outpatient heart activity. In the past, clinicians have tried daily weight measurements, telemonitoring of patient-reported symptoms and vitals, natriuretic peptides, noninvasive bioimpedance monitors and implantable hemodynamic sensors. None have successfully improved patient outcomes barring the implantable sensors, which are able to directly measure intracardiac filling pressures but also cost upwards of $20,000 each.

“A noninvasive and inexpensive alternative capable of measuring relevant hemodynamic parameters associated with HF worsening could significantly advance home HF management,” Inan and co-authors said.

Inan’s team worked to create a wearable patch that could monitor cardiovascular hemodynamics in any given patient. Before and after a noninvasive six-minute walk test, the researchers measured the device’s seismocardiogram signal, which represents the vibrations of the chest wall in response to the movement of blood through the arterial tree. The signal’s waveforms and timings change dramatically when a healthy person exercises.

The patch worked in both compensated and decompensated patients, the authors reported—their devised graph similarity score was able to assess the state of HF in 45 patients whose scores correlated to clinical improvement. Of those individuals, 32 were compensated.

“Wearable technologies recording cardiac function and machine learning algorithms can assess compensated and decompensated HF states by analyzing cardiac response to submaximal exercise,” Inan and colleagues wrote. “These techniques can be tested in the future to track the clinical status of outpatients with HF and their response to pharmacological interventions.”