Rivaroxaban versus enoxaparin plus clopidogrel therapy for hypertrophic cardiomyopathy-associated thromboembolism in cats.

Background and Aim: Cardiogenic embolism (CE) is a common complication of feline hypertrophic cardiomyopathy (HCM), leading to severe clinical symptoms. This study compared the effects of rivaroxaban and enoxaparin combined with clopidogrel on cats. Materials and Methods: This was a single-center, prospective, randomized controlled trial. In this study, rivaroxaban or enoxaparin plus clopidogrel was prescribed to 23 cats for at least one of the following events: Abnormal movement of the anterior mitral leaflet during systole, enlargement of the left atrium, spontaneous echocardiographic contrast, or presence of arterial thromboembolism. Oral rivaroxaban (2.5 mg, q24 h) was prescribed to six cats. Subcutaneous injections of enoxaparin (1 mg/kg, q24 h) plus oral clopidogrel (3 mg/kg, PO q24 h) for 60 days were administered to 17 cats. Renal insufficiency and bleeding complications were observed. Plasma concentrations of D-dimer, prothrombin time (PT), partial thromboplastin time, and international normalized ratio (INR) were evaluated. We analyzed the relationship between echocardiography parameters and the effects of coagulation. Blood samples were collected from all cats at baseline and at 1 and 2 months post-treatment. Results: Rivaroxaban alone and in combination with enoxaparin and clopidogrel significantly affected PT and INR. In cats treated with 2.5 mg/kg rivaroxaban for 60 days, no bleeding or recurrence of thrombus formation was observed. These data support the use of rivaroxaban for the treatment of HCM-associated thromboembolism in cats. Conclusion: Treatment of HCM-associated thromboembolism with rivaroxaban alone demonstrated clinical effectiveness with no clinical complications in cats.