Norton score and clinical outcomes following acute decompensated heart failure hospitalization

Abstract

BackgroundNorton scoring system is used to assess frailty of hospitalized patients with various medical conditions. We aimed to evaluate whether admission Norton scoring system predicts adverse outcomes among heart failure patients. MethodsThe study population comprised 4388 acute heart failure patients between the years 2008 and 2017. Patients were allocated to 3 groups according to their admission Norton score [(≤15-low, 16–18-intermediate, and ≥19-high)]. Primary outcome included all-cause mortality at 30, 90 days, and 1 year. Multivariate Cox proportional hazards regression modeling was used to assess the independent association between Norton score and mortality. Net reclassification improvement (NRI) analysis was used to asses Norton's additive predictive ability upon known prognostic factors. ResultsAmong 4388 study patients, 32% (n=1611) had low Norton score, 28% (n=1384) intermediate score, and 40% (n=1900) high score. Kaplan–Meier analysis demonstrated significantly higher 30-day mortality among patients with a low Norton score as compared with those with intermediate or high score (2.6%, 6.3%, and 16.1%; log rank p<0.001). A similar trend was noted at 90 days and 1 year. Multivariate analysis found Norton score to be an independent predictor of mortality with each one-point decrement associated with a significant 15% increased risk for 30-day mortality [HR=1.15 (95%CI, 1.12–1.17) p<0.001]. NRI analysis showed an improvement of 21.5% (95%CI 18.3–25.1%) predicting 1-year mortality. ConclusionOur findings show that the admission Norton score is a powerful marker of short- and long-term mortality. These data suggest that the scale should be added as a risk stratification tool in this high-risk population.