ABSTRACT
BACKGROUND: Heart failure is a common cause of hospitalization and can be divided into types with preserved and reduced ejection fraction (HFpEF and HFrEF, respectively). In this subanalysis of the HABIT (Heart Failure Assessment With BNP in the Home) trial, we examined the differences between home B-type natriuretic peptide (BNP) testing and weight monitoring in patients with HFpEF and with HFrEF before decompensation. METHODS AND RESULTS: This was a retrospective review of patients with HFpEF and HFrEF from the HABIT trial. The HFpEF patients compared with HFrEF patients were older and more obese and had lower baseline BNP values. Intra-individual BNP dispersion (spread of distribution over time) was greater in HFpEF than in HFrEF owing to rapid fluctuations (within 3 days). Slowly varying changes in BNP (estimated by a moving average) were equally predictive of ADHF risk in both HFpEF and HFrEF. However, in HFpEF, a rapid rise in BNP >200 pg/mL within 3 days was associated with an increased risk of acute decompensated heart failure (ADHF; hazard ratio 4.0), whereas a similar association was not observed in HFrEF. Weight gain ≥5 lb in 3 days had a high specificity but low sensitivity for ADHF in both HFpEF and HFrEF, whereas a lower threshold of ≥2 lb weight gain over 3 days in patients with HFpEF (but not HFrEF) was a moderately sensitive cutoff associated with decompensation (60% sensitivity). CONCLUSIONS: Patients with HFpEF and HFrEF have variations in their BNP and weight before decompensation. The rapid time scale behaves differently between the groups. In those with HFpEF, a 3-day period characterized by ≥2 lb weight gain and/or >200 pg/mL BNP rise was significantly associated with decompensation. Future prospective studies investigating different weight and BNP cutoffs for home monitoring of HFpEF and HFrEF patients should be performed to fully learn the value of BNP changes before clinical deompensation.
Subject(s)
Heart Failure/blood , Heart Failure/diagnosis , Home Care Services , Natriuretic Peptide, Brain/blood , Stroke Volume/physiology , Weight Gain/physiology , Aged , Biomarkers/blood , Body Weight/physiology , Double-Blind Method , Female , Humans , Male , Middle Aged , Obesity/blood , Obesity/diagnosis , Prospective Studies , Retrospective StudiesABSTRACT
OBJECTIVES: This study was a multicenter, single-arm, double-blinded observational prospective clinical trial designed to monitor daily concentrations of B-type natriuretic peptide (BNP) and to determine how these concentrations correlate with acute clinical heart failure decompensation (ADHF) and related adverse clinical outcomes in at-risk HF patients. BACKGROUND: Although BNP at discharge is predictive of 30-day outcomes, outpatient serial testing may improve the risk of detecting early decompensation. METHODS: A total of 163 patients with HF signs and symptoms of ADHF discharged from the hospital or in an outpatient setting measured their weight and BNP levels daily for 60 days with a finger-stick test. Patients and physicians were blinded to BNP levels. The composite outcome was ADHF events: cardiovascular death, admission for decompensated HF, or clinical HF decompensation requiring either parenteral HF therapy or changes in oral HF medications. RESULTS: A total of 6,934 daily BNP values were recorded, with a median of 46 measures per patient over a monitoring period of 65 days. Forty patients had 56 events. Correlations between BNP measures weakened over time, and the dispersion between BNP measures grew. During 10,035 patient-days, there were 494 (4.9%) days of weight gain (≥5 lbs). The hazard ratio per unit increase of ln BNP was 1.84, and the hazard ratio on a day of weight gain was 3.63. These effects retained significance when controlling for symptoms. When the monitoring period for each subject was broken into intervals based on ADHF events, there were 39 (18.4%) intervals of upward trending BNP corresponding to a risk increase of 59.8% and 64 (30.2%) downward trending intervals corresponding to a risk decrease of 39.0%. There were 94 (44.3%) intervals with 1 or more days of weight gain corresponding to a risk increase of 26.1%. CONCLUSIONS: This pilot study demonstrates that home BNP testing is feasible and that trials using home monitoring for guiding therapy are justifiable in high-risk patients. Daily weight monitoring is complementary to BNP, but BNP changes correspond to larger changes in risk, both upward and downward. (Heart Failure [HF] Assessment with B-type Natriuretic Peptide [BNP] In the Home [HABIT]; NCT00946231).