Abstract DP050: Daily Venous Thromboembolism Risk During Acute Ischemic Stroke Admission

Background and Aims: In hospitalized patients with acute ischemic stroke (AIS), the duration of venous thromboembolism (VTE) prophylaxis is often determined by the timing of hospital discharge rather than the interval since stroke onset. Evidence to support prophylaxis beyond 30 days of hospitalization is limited. We evaluated the incidence of VTE during AIS admissions in British Columbia (B.C.), Canada, stratified by length of stay (LOS). Methods: We identified consecutive AIS admissions in B.C. from 2015–2023 using ICD-10 codes from the Discharge Abstract Database. Comorbidities, reperfusion treatments, and new diagnoses of deep vein thrombosis (DVT) or pulmonary embolism (PE) were captured using ICD-10 and procedure codes. Patients were grouped by LOS (<8, 8–14, 15–21, 22–28, and >28 days), and the mean rate of DVT and PE per 10,000 inpatient days was calculated. Results: The overall incidence of DVT or PE was 1.5% (DVT 0.8%; PE 1.0%). Patients with longer LOS were older, had more comorbidities (including cancer), and higher rates of mechanical ventilation and surgical feeding tube placement (Table 1). Despite these elevated risk profiles, average daily VTE rates declined with increasing LOS (DVT: 5.9, 5.4, 6.5, 4.9, 2.6; PE: 9.6, 8.5, 11.5, 3.7, 2.4 per 10,000 inpatient days) (Figure 1). This pattern persisted when restricting analyses to patients discharged alive and after adjusting for patient age, sex, reperfusion therapy and history of cancer (Table 2). Conclusions: The observed decline in daily VTE rates with longer LOS may reflect a combination of front-loaded VTE risk, differences in prophylaxis strategies and depletion of susceptible patients. A large RCT is necessary to therefore define the optimal duration of VTE prophylaxis in this population.