Abstract 19875: IMPROVEDD Score: Addition of D-Dimer to the IMPROVE Score Improves Venous Thromboembolism Risk Stratification. An APEX Trial Substudy

Introduction: The IMPROVE score is used to stratify medical patients by their risk of venous thromboembolism (VTE). We explored whether the addition of D-dimer (DD) to create the IMPROVEDD Score would further improve risk stratification. Methods: The association of the IMPROVE score and central DD ≥ 2x the upper limit of normal (ULN) with the 35 day risk of symptomatic deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE), and VTE-related death was assessed in 7,513 hospitalized medically ill subjects randomized in the APEX Trial. Events were adjudicated by an independent committee. Based upon the results of the logistic regression, the IMPROVE score was modified by adding +2 points if DD + was ≥ 2x ULN and -2 points if DD - was < 2x ULN. Results: In a multivariate model, DD was associated with the outcome (p<0.001) independent of the IMPROVE Score. Stratification of the IMPROVE score by DD + or - identified patients with high IMPROVE scores who were actually at much lower risk and patients with l...