In heart failure with mid-range ejection fraction (HFmrEF) and preserved ejection fraction (HFpEF), feasible surrogate end points are needed for phase II trials. The aim was to assess whether a reduction in N-terminal pro–B-type natriuretic peptide (NT-proBNP) is associated with improved mortality/morbidity in an unselected population of HFmrEF and HFpEF patients.Methods and Results—
In the Swedish Heart Failure Registry, HFmrEF (EF=40%–49%) and HFpEF (EF≥50%) patients reporting at least 2 consecutive outpatient NT-proBNP assessments were prospectively studied. Associations between reduction in NT-proBNP and overall mortality, HF hospitalization, and their composite were assessed by multivariable Cox regressions, with NT-proBNP changes modeled as binary (decrease/increase) or quantitative predictor by restricted cubic splines. In 650 patients, at a median of 7 months between the 2 measurements of NT-proBNP and over a median follow-up of 1.65 years, 361 patients (55%) showed a reduction and 289 patients (45%) an increase in NT-proBNP. Change in NT-proBNP was associated with risk of outcomes. Fifty-seven patients (16%) who decreased their NT-proBNP versus 78 patients (27%) who increased it died from any cause (adjusted hazard ratio=0.53; 95% confidence interval=0.36–0.77), 61 (17%) versus 86 (30%) were hospitalized for HF (hazard ratio=0.41; 95% confidence interval=0.29–0.60), and 96 (27%) versus 125 (43%) reported the composite outcome (hazard ratio=0.46; 95% confidence interval=0.34–0.62). These findings were replicated in HFmrEF and HFpEF separately.Conclusions—
In HFmrEF and HFpEF during routine care, decreases in NT-proBNP were associated with improved mortality and morbidity. Studies to determine whether NT-proBNP changes in response to therapy predict drug efficacy are needed.