Posthospitalization VTE Prophylaxis for Some Patients with COVID-19

Therapeutic anticoagulation after hospital discharge does not benefit moderate-risk patients recovering from COVID-19 (NEJM JW Gen Med Aug 1 2021 and Lancet 2021; 397:2253), but whether high-risk patients might benefit is unclear. Brazilian investigators enrolled 320 patients (from 14 hospitals) with COVID-19 and high risk for venous thromboembolism (VTE), based on a high IMPROVE VTE risk score (≥4) or a moderate IMPROVE VTE risk score (2–3) plus an elevated D-dimer level (>500 ng/dL). Patients were randomized to receive either rivaroxaban (10 mg daily) for 35 days after discharge or no intervention; all patients received standard inpatient VTE prophylaxis and lower-extremity ultrasound and contrast-enhanced chest imaging at 35 days following discharge. Patients with creatinine clearance <30 mL/minute, active cancer, gastrointestinal ulcer, or dual antiplatelet requirements were excluded. Half of patients had intensive care stays during hospitalization.

The primary outcome of symptomatic or asymptomatic VTE or arterial embolism or cardiovascular-related death was significantly lower in the rivaroxaban group than in the no-treatment group (3% vs. 9%; number needed to treat, 16). This difference primarily was driven by significantly lower symptomatic or fatal VTE (0.6% vs. 5.0%; NNT, 23). No major bleeding occurred in either group.