New study expands antithrombotic options after feline ATE

CURRENT BRIEF VERSION: A new multicenter prospective study suggests that rivaroxaban performs about as well as clopidogrel for preventing recurrent arterial thromboembolism in cats that survived a cardiogenic thromboembolic event, adding fresh evidence to a treatment area that has long relied on clopidogrel-first practice and smaller retrospective datasets. In the SUPERCAT study, published in the Journal of the American Veterinary Medical Association in December 2024, 45 cats were randomized to receive either clopidogrel or rivaroxaban for up to two years after the initial event. Investigators reported equivalent impacts on thromboembolism recurrence and survival between the two monotherapy groups. That follows earlier UC Davis work showing dual therapy with clopidogrel plus rivaroxaban was generally tolerated in high-risk cats and associated with a relatively low recurrence rate in a retrospective series. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, the new study helps move rivaroxaban from promising alternative to evidence-backed option in post-ATE management. Current consensus and review literature have favored clopidogrel, especially after the FAT CAT trial, while reserving factor Xa inhibitors or combination therapy for very high-risk patients, including cats with prior ATE, intracardiac thrombi, spontaneous echocardiographic contrast, marked left atrial enlargement, or other features tied to Virchow’s triad of stasis, endothelial injury, and hypercoagulability. SUPERCAT doesn't show superiority for rivaroxaban, but it does support it as a reasonable monotherapy choice when clopidogrel response, administration, tolerability, or adherence are concerns for the pet parent. Mechanistic work from UC Davis also suggests the clopidogrel-rivaroxaban combination may have synergistic antithrombotic effects, which helps explain why cardiologists have explored dual therapy in select cats despite limited prospective outcomes data. (pmc.ncbi.nlm.nih.gov)

What to watch: Whether this evidence changes cardiology prescribing patterns, consensus guidance, or sparks a prospective trial of dual therapy in cats most at risk for recurrence will be worth watching. It will also be worth watching how clinicians position these data alongside the separate RAPACAT/rapamycin conversation in feline cardiomyopathy, which reflects the same broader push toward more rigorous cat-specific cardiovascular evidence rather than a direct antithrombotic link. (pubmed.ncbi.nlm.nih.gov)