Design of the rivaroxaban for heparin-induced thrombocytopenia study.

Rivaroxaban is an ideal potential candidate for treatment of heparin-induced thrombocytopenia (HIT) because it is administered orally by fixed dosing, requires no laboratory monitoring and is effective in the treatment of venous and arterial thromboembolism in other settings. The Rivaroxaban for HIT study is a prospective, multicentre, single-arm, cohort study evaluating the incidence of new symptomatic venous and arterial thromboembolism in patients with suspected or confirmed HIT who are treated with rivaroxaban. Methodological challenges faced in the design of this study include heterogeneity of the patient population, differences in the baseline risk of thrombosis and bleeding dependent on whether HIT is confirmed or just suspected, and heterogeneity in laboratory confirmation of HIT. The rationale for how these challenges were addressed and the final design of the Rivaroxaban for HIT study is reviewed.