Abstract 13530: A Novel Risk Model to Predict Emergency Department Associated Mortality for Patients Supported With a Ventricular Assist Device: The Ed-vad Risk Score

Introduction: The past decade has seen tremendous growth in ambulatory ventricular assist device (VAD) patients. We sought to identify patients that present to the emergency department (ED) who are at the highest risk of death. Methods: We performed a retrospective analysis of ED encounters of VAD patients using data from the Nationwide Emergency Department Sample (NEDS) from 2010-2017. Demographic and clinical variables significantly associated with mortality (p < 0.2) in a univariate analysis were evaluated in a multivariate model. Using a random sampling of patient encounters, 80% were assigned to development and 20% to validation cohorts. A risk model was derived from independent predictors of mortality, which were weighted using integer-normalized beta coefficients. Each patient encounter was assigned to one of three groups based on risk score. Results: A total of 44,042 ED encounters of VAD patients were included in the study. The majority of patients were male (73.6%), <65 years old (60.1%), and 29% presented with bleeding, ischemic/hemorrhagic stroke, or device complication. Independent predictors of mortality during the ED visit or subsequent admission included age ≥65 years (OR 1.8, 95% CI 1.3, 4.6), primary diagnoses [stroke (OR 19.4, 95% CI 13.1, 28.8), device complication (OR 10.1, 95% CI 6.5, 16.7), cardiac (OR 4.0 95% CI 2.7, 6.1), infection (OR 5.8, 95% CI 3.5, 8.9)], and blood transfusion (OR 2.6, 95% CI 1.8, 4.0), while history of hypertension was protective (OR 0.69, 95% CI 0.5, 0.9)]. The risk score predicted mortality with an area under the curve of 0.78 and 0.71 for development and validation, respectively. Encounters in the highest risk score strata tertile had a 16-fold higher mortality compared to lowest risk tertile (15.8% vs 1.0%). Conclusions: We present a novel risk score and its validation for predicting mortality of VAD patients who present to the ED, which can serve as useful tool for clinicians caring for this high-risk, and growing, population.