Clopidogrel and rivaroxaban equally prevent blood clots in cats

Abstract

OBJECTIVE: To assess the impact of clopidogrel or rivaroxaban administration on recurrence of arterial thromboembolism (ATE) in cats that have recovered from cardiogenic ATE. METHODS: This multicenter prospective double-masked protocol enrolled 45 cats that had recovered from cardiogenic ATE and were randomized to receive either clopidogrel (18.75 mg/cat, PO; n = 19) or rivaroxaban (2.5 mg/cat, PO; 26) as sole anticoagulant therapy for up to 2 years after the initial ATE. Primary outcome measures included recurrent ATE or death from any cause. In addition to bimonthly internet-based surveys of animal quality of life, echocardiograms were performed by veterinary cardiologists at 2, 6, 12, and 18 months after initial ATE. RESULTS: 17 cats experienced ATE recurrence: 7 of 19 (37%) in the clopidogrel group and 10 of 26 (39%) in the rivaroxaban group. Three cats in each group survived for the entire 2-year study without recurrence. In the clopidogrel group, median (95% CI) time to ATE recurrence was 663 days (150 to not calculable) and in the rivaroxaban group, 513 days (242 to not calculable). Median time from enrollment to death from cardiac or noncardiac causes was also not different between treatment groups. CONCLUSIONS: Single-agent antithrombotic therapy with rivaroxaban in cats recovered from cardiogenic embolism delayed recurrence of ATE for a similar time period as single-agent therapy with clopidogrel. CLINICAL RELEVANCE: In cats that have recovered from cardiogenic ATE, either rivaroxaban or clopidogrel may be used for single-agent thromboprophylaxis to delay ATE recurrence.