Risk of Venous Thromboembolism in Hospitalized Patients with Acute Ischemic Stroke Versus Other Neurological Conditions

Background: The mechanism of increased risk of venous thromboembolism (VTE) after acute ischemic stroke (AIS) is unclear. In this study, we aimed to evaluate the risk of VTE in hospitalizations due to AIS as compared to those due to non-vascular neurological conditions. We also aimed to assess any potential association between VTE risk and the use of intravenous thrombolysis (rtPA) among hospitalizations with AIS. Materials and methods: In this case-control study, data were obtained from the Nationwide Inpatient Sample 2016-2018. Propensity score matching was used to adjust for the baseline differences between the groups. Logistic regression analy-sis was used to compare the risk of VTE. Results: We identified 1,541,685 hospital-izations due to AIS and 1,453,520 hospitalizations due to non-vascular neurological diagnoses that served as controls. After propensity score matching, 640,560 cases with AIS and corresponding well-matched controls were obtained. Hospitalizations due to AIS had higher odds of VTE as compared to the controls [odds ratio (OR) 1.50, 95% confidence interval (CI) 1.40-1.60, P<0.001]. Among hospitalizations with AIS, 184,065 (11.9%) got rtPA. The odds of VTE were lower among the AIS hospital-izations that received rtPA as compared to those that did not (OR 0.89, 95% CI 0.79-0.99, P0.035). Conclusion: Hospitalizations due to AIS have a higher risk of VTE as compared to the non-vascular neurological controls. Among AIS cases, the risk of VTE is lower among patients treated with rtPA. These epidemiological findings support the hypothesis that the risk of VTE after AIS might be partly mediated by an intrinsic pro-coagulant state.