Roy Davenport, Mercer University College of Pharmacy
Cerebral venous thrombosis (CVT) is associated with embolic complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE) – collectively known as venous thromboembolism (VTE). In contrast to VTE, CVT has been stated to occur three times more often in women than men.  Patients are diagnosed with magnetic resonance imaging, computerized tomography venography, or catheter angiography. A diagnosis of CVT has been shown to increase the risk of VTE or the recurrence of CVT. The quantifiable risk of a VTE after CVT has not been evaluated to indicate whether recurrence of a VTE in CVT patients is similar to that of DVT. 
|Risk of Pulmonary Embolism After Cerebral Venous Thrombosis |
|Design||Retrospective cohort; N= 246,030|
|Objective||To determine if the risk of PE after CVT is similar to the risk after DVT|
|Study Groups||DVT (n= 241,276); CVT (n= 4,754)|
|Methods||Patients were identified with either CVT or DVT. To assess incident cases of PE, patients with diagnoses of PE before the index visit for CVT or DVT were excluded. To minimize misclassification error, patients with both CVT and DVT during the same index hospitalization were excluded. Patients were censored at the time of death or at the end of the follow-up period. Patients with CVT or DVT were censored if they had a subsequent encounter before the primary outcome of interest. Kaplan–Meier survival statistics and Cox proportional hazards models were used to compare the risk of PE after CVT versus PE after DVT. The Elixhauser comorbidity index was used to account for disease severity in patients with comorbidities.|
|Duration||Mean follow-up ± SD: 3.4 ± 2.4 years|
|Primary Outcome Measure||PE occurrence at hospitalization, follow-up, and 5 years|
— CVT patients had a lower hazard of PE than patients with DVT (HR: 0.26; 95% CI: 0.22–0.31)
|Adverse Events||Common Adverse Events: N/A|
|Serious Adverse Events: N/A|
|Percentage that Discontinued due to Adverse Events: N/A|
|Study Author Conclusions||The risk of PE after CVT was lower than after DVT. Among patients with CVT, the greatest risk for PE was during the index hospitalization.|
Only cases of CVT diagnosed at an emergency department (ED) visit or hospitalization were considered, but patients were not differentiated into asymptomatic or symptomatic groups, as in other studies. More severe disease presentations were included, which may have increased the risk of PE, and patients brought to the ED are more than likely at a higher risk for an embolic events. The rate at which PE occurred was higher in DVT, but the higher rate of general thromboembolic event production between disease states went unmeasured. Although the study accounted for multiple thromboembolic risk factors, mass index, immobility, oral contraception use, and relevant laboratory data were not included.
 Hiltunen S, Putaala J, Haapaniemi E, Tatlisumak T. Long-term outcome after cerebral venous thrombosis: analysis of functional and vocational outcome, residual symptoms, and adverse events in 161 patients. J Neurol. 2016;263(3):477-84.
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 Liberman AL, Merkler AE, Gialdini G, et al. Risk of Pulmonary Embolism After Cerebral Venous Thrombosis. Stroke. 2017;48(3):563-567.