Abstract TP119: Recurrent Thromboembolic Events After Ischemic Stroke in Patients with Cancer

Abstract

Background: Cancer often causes hypercoagulability, leading to venous and arterial thromboembolic events such as stroke. The rate and type of recurrent thromboembolic events (RTE) in cancer patients after stroke is unknown. Methods: We retrospectively identified consecutive patients with active cancer diagnosed with acute ischemic stroke by MRI at Memorial Sloan-Kettering Hospital from 2008 to 2010. Study neurologists collected demographic and clinical data using a standardized abstraction tool, and reviewed all electronic records after patients’ index stroke for the primary composite outcome of RTE, defined as any recurrent ischemic stroke, TIA, MI, systemic artery thrombosis, DVT, or PE. Kaplan-Meier statistics were used to calculate the cumulative rate of RTE and recurrent ischemic stroke; follow-up was censored when patients experienced an outcome or died. In an exploratory analysis, bivariate Cox proportional hazard analysis was used to compare rates of RTE on anticoagulation compared with antiplatelet agents. Results: Acute ischemic stroke was diagnosed in 119 patients with active cancer (mean age 66 [SD 13]; 49% women) during the study period. Patients’ underlying cancer was usually a carcinoma (83%) and was advanced (systemic metastases in 74%). Using TOAST criteria, stroke mechanisms were classified as 16% large artery atherosclerosis, 21% cardioembolism, 6% small vessel, 4% of other determined cause, and 53% of undetermined etiology. Despite a very short median survival in these patients (85 days [IQR 24-495 days]), RTE were diagnosed in 37 (31%), consisting of 16 DVTs, 12 recurrent ischemic strokes, 3 PEs, 2 MIs, and 2 systemic artery thromboses. Kaplan-Meier cumulative rates of RTE were 20% at 1 month, 29% at 3 months, and 31% at 6 months, while cumulative rates of recurrent ischemic stroke were 7% at 1 month, 15% at 3 months, and 15% at 6 months. There was no significant difference in event rates on anticoagulation compared with antiplatelet agents (HR=1.2, 95% CI 0.5-2.8). Conclusions: The short-term risk of RTE and recurrent ischemic stroke in patients with active cancer and ischemic stroke is substantial.