ACC: Monitoring Lung Congestion Tied to Better HF Outcomes

CHICAGO -- A novel non-invasive device for monitoring lung impedance as an early sign of heart failure decompensation appeared to help reduce hospital admissions and other adverse outcomes compared with typical clinical care, a trial showed.

Acute heart failure hospitalizations were reduced substantially both at 1 year and for the entire 8-year study period (HR 0.51 and 0.63, both P<0.001), Michael Shochat, MD, PhD, of Hillel Yaffe Medical Center in Hadera, Israel, and colleagues found.

Overall and heart failure-related mortality also favored lung impedance monitoring (HR 0.52, P=0.002, and HR 0.30, P<0.001, respectively), they reported here at the American College of Cardiology meeting and online in the Journal of Cardiac Failure.

"This is intriguing because we don't really have any established noninvasive technology to assess volume status and predict exacerbation so this would be a big advance," David Lanfear, MD, of Henry Ford Hospital in Detroit, commented in an interview with MedPage Today. "However, extraordinary findings have to be viewed with some caution because the study is small and [done in] only two centers."

The blinded, randomized IMPEDANCE-HF study included 256 patients at two medical centers who had New York Heart Association class II-IV heart failure with reduced left ventricular ejection fraction (≤35%) and were admitted for an acute episode within 12 months prior to study entry.

The intervention involved a vest-style external device with electrodes in various spots to measure impedance of electromagnetic energy passed through the chest while subtracting out the influence of the chest wall with a proprietary algorithm. Shochat told MedPage Today that the next generation is hoped to be substantially smaller and automatically transmit measurements to the medical team.

The trial suggested an impact on outcomes perhaps related to more frequent medical therapy changes in the monitoring group (P<0.001).

John Jarcho, MD, of Brigham and Women's Hospital in Boston and a deputy editor for the New England Journal of Medicine, called the results exciting, but reemphasized the need for replication. Another question to be answered is how it compares to other modalities, such as invasive monitoring of lung congestion, he added.

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