IMPEDANCE‑HFPEF: Early Noninvasive Detection of Lung Fluid Reduces Death, Hospitalization

A novel noninvasive lung‑impedance monitoring device significantly reduced heart failure (HF) hospitalizations and mortality in patients with heart failure with preserved ejection fraction (HFpEF), according to the IMPEDANCE‑HFPEF trial presented at ACC.26. 

The study evaluated the CardioSet Edema Guard Monitor, which isolates lung‑specific electrical‑impedance signals to detect early pulmonary fluid accumulation before symptoms appear, allowing clinicians to adjust therapy earlier than with standard clinical assessment alone.

Conducted at a single center in Israel, the single‑blind trial enrolled 150 HFpEF patients (median age ~75, 62% women, LVEF ~60%). Half were randomized to lung‑impedance‑guided care, where clinicians used impedance trends to guide medication changes, and half received standard care; both groups had the same number of clinic visits.

 Over a median follow‑up of 38.4 months, the impedance‑guided group had an 81% reduction in recurrent HF hospitalizations, with a median time to first HF hospitalization of 602 days versus 83 days in the standard‑care arm. 

The impedance group also saw a 65% lower rate of all‑cause death and an 81% lower rate of HF‑related death, with no device‑related adverse events.

The investigators attribute much of the benefit to earlier, more frequent medication adjustments once subclinical lung congestion was detected. They emphasize that the device enables intervention at the “preclinical” stage of congestion, when the response to diuretics and other HF therapies appears most powerful. 

For cardiology practice, IMPEDANCE‑HFPEF suggests that routine lung‑fluid monitoring could become a key tool for proactive, personalized HFpEF management, though multi‑center trials and broader implementation data will be needed before widespread adoption.