National early warning score predicts 90 days all-cause mortality among patients with acute heart failure

Abstract Background Acute heart failure (AHF) is defined as new-onset or worsening of symptoms and signs of heart failure including symptoms or signs related to congestion and volume overload. Patients presenting with AHF are a heterogeneous group as AHF is not a specific disease but a shared clinical presentation of different cardiac abnormalities. Due to the heterogeneity of the patient population, a prognostic tool is needed to identify AHF patients with a high risk of death. The National Early Warning Score (NEWS) is a system for scoring the vital signs that are measured at the patient's bedside and is developed to predict acute mortality within 24 hours. The NEWS has previously been used to evaluate all cost mortality for patients admitted to the Emergency Department (ED). There is limited data regarding the role of the NEWS in predicting adverse outcomes in patients with acute heart failure. Purpose To evaluate NEWS measured at the ED and clinical outcomes in patients with AHF. Methods This prospective, observational cohort study included consecutive patients with AHF admitted through the emergency department (ED) at a large public hospital from 10 March 2020 to 31 March 2022 and had a follow-up period of 365 days. Trained cardiologists assessed all patients for the presence of AHF. According to the cut-off value for the NEWS, high-risk groups are defined by a NEWS score > 7. The patients were categorized into two groups, high-risk and low-risk, depending on the scores they received from the NEWS assessment. The primary outcome was all-cause mortality at 90 days. We used multivariable Cox regression (hazard ratios [HRs]) to compare survival, adjusting for age, sex, smoking, known heart failure (HF), and lactate levels at admission. Results In the study period from March 10, 2020, to March 31, 2022, 408 patients were identified with AHF. Upon arrival to the ED, the median first NEWS was 4 (IQR 2-6). 323 patients were categorized in the low-risk group and 69 patients in the high-risk group. 16 patients had missing values upon arrival at the ED. The high-risk group exhibited significantly faster heart rate, lower saturation, and higher oxygen demand compared. A Kaplan-Meier plot revealed a statistically significant difference in all-cause mortality over 90 days between low-risk and high-risk groups among AHF patients (log rank, p-value < 0.001). After multivariable adjustment, NEWS>7 (HR, 1.69; CI, 1.18 to 2.45) (p-value= 0.004) and higher age (HR, 1.04; CI 1.03 to 1.07) were statistically associated with higher all-cause mortality (p <0.001). Conclusion In this prospective, observational cohort study of AHF patients presenting at the ED an initial NEWS >7 was associated with a significant all-cause mortality after 90 days.GRAPHIC ABSTRACT