The effectiveness of anticoagulant and antiplatelet agents in preventing venous thromboembolism during stroke rehabilitation: a historical cohort study

OBJECTIVE: To determine the effectiveness of anticoagulant and antiplatelet agents in preventing venous thromboembolism (VTE) during stroke rehabilitation. DESIGN: Historical cohort study. SETTING: Acute inpatient rehabilitation hospital. PARTICIPANTS: Consecutive patients (N=1506) with ischemic and hemorrhagic stroke admitted for rehabilitation. INTERVENTIONS: Documented use of anticoagulants (warfarin or anticoagulant doses of heparin), heparin in prophylactic doses, and antiplatelet agents. MAIN OUTCOME MEASURE: Occurrence of deep vein thrombosis detected by ultrasound or venography or pulmonary embolism detected by ventilation perfusion scan, spiral computed tomography, or pulmonary angiography. RESULTS: Fifty-eight VTE events occurred (3.9% incidence or 1.36 events per 1000 patient days), with higher risk in patients with severe stroke. Only therapeutic anticoagulation had a statistically significant protective effect for VTE risk in univariate analysis (odds ratio OR]=.44; 95% confidence interval CI],.20-.98). After adjusting for multiple medication use and other factors, including age, stroke onset to admission interval, length of rehabilitation stay, cause of stroke, and admission National Institutes of Health Stroke Scale score, therapeutic anticoagulation gave strong protection against VTE (OR=.37; 95% CI,.15-.88), followed by heparin (OR=.48; 95% CI,.23-.98) but not by antiplatelet agents (OR=.79; 95% CI,.40-1.57). No medications were associated with significant bleeding complications. CONCLUSIONS: Use of therapeutic anticoagulants or prophylactic heparin prevented VTE in stroke patients during inpatient rehabilitation.