BNP-Response to Acute Heart Failure Treatment Identifies High-Risk Population

Background: Using serial measurements of brain natriuretic peptide (BNP) has been proposed as a method to guide therapy for patients treated for acute decompensated heart failure. However, 20–47% of patients do not achieve the target BNP thresholds despite treatment. We hypothesised that “BNP unresponsive” patients represent a distinct group at high risk for poor outcomes and sought to examine the characteristics and outcomes of this group. Methods: In a retrospective study using electronic health record (EHR) data, we examined the outcomes of patients admitted with acute decompensated heart failure. Patients were divided into two groups based on their pro-BNP response to treatment: (1) pro-BNP responsive to treatment (decrease by at least 30%) and (2) pro-BNP unresponsive to treatment (decrease by less than 30%). The primary outcomes of interest were 180-day mortality and 180-day readmission. Univariate and multivariate Cox proportional hazard models were used to assess the independent association between pro-BNP response to treatment and 180-day mortality and readmission. Adjustment variables included age, gender, Charlson co-morbidity score, admission creatinine, admission haematocrit, ejection fraction, preserved ejection fraction, and LV end-diastolic dimension. Results: The total study population included 819 patients with 455 (55.6%) in the pro-BNP responsive group and 364 (44.4%) in the pro-BNP unresponsive group. Admissions whose BNP was unresponsive to treatment had significantly increased risk for 180-day mortality, compared with BNP-responsive admissions (26.4% vs. 13.2%, p < 0.001). Brain natriuretic peptide unresponsiveness remained significantly associated with increased 180-day mortality after adjustment for demographic and clinical characteristics (HR_adj = 2.19, 95% CI: 1.52–3.14). BNP-unresponsiveness was not associated with significantly increased 180-day readmission rates (HR_adj = 1.07, 95% CI: 0.92–1.25). Conclusions: Patients whose pro-BNP did not improve by >30% were at increased risk for 180-day mortality, but not 180-day readmission. Thus, BNP-unresponsiveness provides meaningful prognostic information, and it may define a patient population that would benefit from specific therapies to reduce the risk.