Total NT-proBNP in heart failure with preserved vs reduced ejection fraction

Commercially available NT-proBNP assays can underestimate concentration as the detecting antibody binds to NT-proBNP glycosylated epitopes, thereby underestimating the total NT-proBNP, impairing diagnostic and prognostic performance in heart failure (HF) patients.

To explore glycosylatated and unglycosylatated, total NT-proBNP (tNT-proBNP) research-assay and associations with clinical characteristics and outcomes compared to NT-proBNP in HF with preserved (HFpEF) and reduced (HFrEF) ejection fraction.

In HFpEF (LVEF≥45%, NT-proBNP≥300 pg/ml) and HFrEF (LVEF<40%) patients tNT-proBNP and NT-proBNP were measured, associations with clinical characteristics and composite outcomes assessed and prognostic accuracy compared.

Patients with HFpEF (n = 83) vs. patients with HFrEF (n = 82), were older (73 vs. 63 years) and more often female (51% vs. 18%). tNT-proBNP and NT-proBNP were lower in HFpEF 3830(1990;6482) and 1055(466;2344)pg/ml vs. HFrEF 10,468(4667;21,007) and 3196(1423;6967)pg/ml, all p < 0.001. There was a strong association between tNT-proBNP and NT-proBNP (HFpEF;β = 0.762;p < 0.001, HFrEF β = 0.819;p < 0.001). NT-proBNP/tNT-proBNP was lower in HFpEF vs. HFrEF (0.27 vs. 0.32;p = 0.019). Higher tNT-proBNP was independently associated with outcome in both HFpEF (HR 1.77 [95% CI 1.08-2.88];p = 0.022) and HFrEF (HR 1.94 [95% CI 1.36-2.76];p < 0.001). In the overall cohort AUROC was higher for tNT-proBNP (0.710) vs. NT-proBNP (0.682;p = 0.068) with similar trends in HFpEF and HFrEF.

This first report of tNT-proBNP by LVEF categories displays similar associations with clinical characteristics and outcomes in HFpEF and HFrEF. Proportion of glycosylated NT-proBNP was higher in HFpEF vs HFrEF. tNT-proBNP trended to have superior prognostic ability regardless of LVEF and may be a superior risk marker especially in HF populations with high prevalence of glucose perturbations.

ClinicalTrials.govNCT00774709https://clinicaltrials.gov.