Extended-Duration Betrixaban Reduces the Risk of Stroke Versus Standard-Dose Enoxaparin Among Hospitalized Medically Ill Patients: An APEX Trial Substudy (Acute Medically Ill Venous Thromboembolism Prevention With Extended Duration Betrixaban)

Background: Stroke is a morbid and potentially mortal complication among patients hospitalized with acute medical illness. The potential of extended-duration thromboprophylaxis with the factor Xa inhibitor betrixaban to reduce the risk of stroke compared with standard-dose enoxaparin in this population was assessed in this retrospective APEX trial substudy (Acute Medically Ill Venous Thromboembolism Prevention With Extended Duration Betrixaban).

Methods: Hospitalized acutely medically ill subjects (n=7513) were randomized in a double-dummy double-blind fashion to either extended-duration oral betrixaban (80 mg once daily for 35-42 days) or standard-dose subcutaneous enoxaparin (40 mg once daily for 10±4 days) for venous thromboprophylaxis. Stroke events were adjudicated by an independent, blinded event adjudication committee.

Results: The mean age of study participants was 76 years; 45% were male; 13% had had a stroke; and 45% had congestive heart failure. There were fewer all-cause strokes (0.54% versus 0.97%; relative risk [RR]=0.56; 95% confidence interval, 0.32-0.96; P=0.032; adjusted RR=0.43%; number needed to treat=233) and ischemic strokes (0.48% versus 0.91%; RR=0.53; 95% confidence interval, 0.30-0.94; P=0.026; adjusted RR=0.43%; number needed to treat=233) among patients treated with betrixaban versus enoxaparin through 77 days of follow-up. Among high-risk subjects, those with congestive heart failure or ischemic stroke as their index event, betrixaban reduced the risk of all-cause stroke (0.72% versus 1.48%; RR=0.49; 95% confidence interval, 0.26-0.90; P=0.019; adjusted RR=0.76%; number needed to treat=132) and ischemic stroke (0.63% versus 1.38%; RR=0.45; 95% confidence interval, 0.24-0.87; P=0.014; adjusted RR=0.75%; number needed to treat=134) compared with enoxaparin.

Conclusions: Among hospitalized medically ill patients, extended-duration betrixaban significantly reduced all-cause stroke and ischemic stroke through 77 days of follow-up CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01583218.