Bio-width index: a novel biomarker for prognostication of long term outcomes in patients with anaemia and heart failure

Background: The utility of biomarkers for prognostication of long term outcomes in patients with anaemia and heart failure(HF) is not well defined. The objective of this study was to assess the ability of a novel biomarker, bio-width index (BWI),to improve risk stratification in patients with anaemia and acutely decompensated heart failure(ADHF), in comparison to conventional markers, B-type natriuretic peptide(BNP) and red- cell distribution width(RDW). Methods: Data from 1569 consecutive patients with ADHF treated at a multidisciplinary HF unit was analysed in this study. The bio-width index (BWI) was calculated by multiplying BNP to RDW and dividing the product by 10 (BWI = BNP x RDW/10). The primary outcome was one year all-cause mortality. Results: During follow up (median 422 days), subjects with anaemia had significantly higher one year mortality (49.6 vs. 30.5%, p <.001). Cox regression analysis revealed that, BWI(HR 2.13, 95%CI 2.02–2.24, p =.018) as well as BNP(HR 1.86, 95%CI 1.78–1.94, p =.024), and RDW (HR 1.98, 95%CI 1.91–2.05, p =.033) were all independent predictors of one year mortality after adjusting for conventional risk factors. BWI had a higher discriminative ability compared to BNP(AUC 0.90 vs. 0.75, p <.001) and RDW(AUC 0.90 vs. 0.81, p =.012). The patients with higher BWI (>1024.9) had a higher one year mortality(85.1 vs. 29.2%, p <.001). In addition, BWI significantly improved the net reclassification compared to both BNP(p =.002) and RDW(p =.018). Conclusions: In patients with anaemia and ADHF, bio-width index is superior to the established biomarkers such as BNP and RDW in prognostication of long term mortality.