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

Harvey RL, Lovell LL, Belanger N, Roth EJ. The effectiveness of anticoagulant and antiplatelet agents in preventing venous thromboembolism during stroke rehabilitation: a historical cohort study. Arch Phys Med Rehabil 2004;85:1070-5. 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.