Primary Results of the HABIT Trial (Heart Failure Assessment With BNP in the Home)

Study Questions:

How do daily B-type natriuretic peptide (BNP) concentrations in at-risk heart failure (HF) patients correlate with HF events?

Methods:

This was a multicenter double-blinded study of daily BNP measurements in patients with a recent HF decompensation. Patients were enrolled regardless of ejection fraction, but were required to have had a hospitalization for HF with a BNP >400 pg/ml during admission, or were noted to have signs or symptoms of HF in an outpatient clinic or urgent care. A daily fingerstick was performed in the outpatient setting for BNP measurement, and BNP values along with patient weight and a symptom review were transmitted electronically for 60 days. Practitioners and patients were blinded to all results. The primary endpoint was a composite of cardiovascular death, HF admission, or clinical HF decompensation without admission warranting medication change.

Results:

There were 6,934 BNP values recorded from 163 patients (median 43 BNP measurements per patient) over the 60-day study. Median patient age was 63 years, 30% had a left ventricular ejection fraction >40%, and the median initial BNP was 431 pg/ml. There were 56 events in 40 patients (22 HF hospitalizations, 1 death, and 33 HF decompensations not requiring admission). For each unit increase in BNP, the hazard ratio (HR) for an event was 1.8 [1.4-2.4]. On a day of weight gain >5 pounds, the HR for an event was 3.6 [1.8-7.2] per unit rise in BNP. An upward trend of BNP was associated with a higher risk of an event (60% increase) than an upward trend of weight (26% increase).

Conclusions:

The authors concluded that home BNP measurement may be a means of identifying patients at increased risk for HF events.

Perspective:

In this pilot study, daily BNP measurement appeared to predict adverse events in patients with HF. BNP values were not used to guide therapy or admissions. Rather, it was observed that patients with HF decompensations requiring intervention (medication change and/or hospitalization) had increases in BNP over time, and the increase was associated with a greater risk of events than the present standard of weight monitoring and symptom review. However, before wide adoption of a likely costly and time-intensive system, more information is needed. It appears that an acute rise in BNP was not predictive of an event (HR, 1.01) and BNP did demonstrate day-to-day variability. Thus, the threshold for ‘intervention’ for HF patients will not be readily clear until intrapatient trends are established. Further, it remains to be studied if interventions based on BNP trends actually improve HF outcomes beyond standard medical management, or just lead to more changes in diuretic dosing.

Clinical Topics: Heart Failure and Cardiomyopathies, Acute Heart Failure, Heart Failure and Cardiac Biomarkers

Keywords: Biological Markers, Heart Failure, Natriuretic Peptide, Brain


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