Abstract 11: Persistent Risk Of Venous Thromboembolism After Discharge Among Stroke Survivors - A Seven-Years Longitudinal Study
Background and Purpose: Risk of venous thromboembolism (VTE) in stroke patients persists after discharge from hospital due to residual deficits. Quantification of VTE risk at various post-discharge intervals may have implications for surveillance and/or prophylactic strategies for high-risk individuals. We therefore, studied incidence rates and risk factors of deep venous thrombosis (DVT) and pulmonary embolism (PE) among stroke survivors after discharge from the hospital. Methods: Adults with principle diagnosis of ischemic stroke discharged alive from acute care hospitals in California State between January 2005 and December 2010 were followed up until December 2011 using state inpatient and emergency department databases for development of DVT and/or PE. Case ascertainment was done using International Classification of Diseases -9 codes. We calculated incidence rates of DVT and PE during first 30 days, 31-90 days, 91-365 days and >1-year after the discharge. We calculated independent risk factors for VTE within 90 days after discharge by using logistic regression controlling for baseline demographics, comorbidities, inpatient complications and procedures. Results: A total of 168,194 stroke survivors were followed up for a mean duration of 3.6+/-1.9 (SD) years after discharge. Among these, 6,179 (3.7%) developed DVT and 2,487 (1.5%) developed PE resulting in incidence rate of 1.02 and 0.41 per 100 person year for DVT and PE respectively. The incidence rates of DVT during first 30 days, 31-90 days, 91-365 days and >1-year post-discharge were 6.53, 2.91, 1.24 and 0.66 per 100 person year respectively. Similarly, the incidence of PE was 3.04, 1.13, 0.46 and 0.26 during first 30 days, 31-90 days, 91-365 days and >1-year after discharge respectively. Factors independently associated with VTE within 90 days were age>65 years, African-American race, higher Charlson comorbidity index, metastatic cancer, anemia, obesity, acute myocardial infarction, pneumonia, sepsis, hemodialysis, gastrostomy and mechanical ventilation during index admission. Conclusions: VTE risk remains high among stroke survivors even after discharge from the hospital. The risk is highest during first 30 days and remains high as long as 1 year after discharge.