Adjunctive Antithrombotic Therapy for Patients with Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Importance: Transcatheter aortic valve replacement (TAVR) is an established alternative to surgery for patients with severe symptomatic aortic stenosis. Adjunctive antithrombotic therapy used to mitigate thrombotic risks in patients undergoing TAVR must be balanced against bleeding complications, since both are associated with increased mortality. Observation: Stroke risk associated with TAVR is lower than that associated with surgical aortic valve replacement in recent trials including patients at intermediate or low risk, but it is constant beginning at the time of implant and accrues over time based on patient risk factors. Patients with aortic stenosis undergoing TAVR also have a sizable risk of life-Threatening or major bleeding. Although dual antiplatelet therapy for 3 to 6 months after TAVR is the guideline-recommended regimen, this practice is not well supported by current evidence. In patients with no indication for oral anticoagulation, current registry-based evidence suggests that single antiplatelet therapy may be safer than dual antiplatelet therapy. Similarly, oral anticoagulation monotherapy appears superior to anticoagulation plus antiplatelet therapy in those where oral anticoagulant use is indicated. To date, no risk prediction models have been established to guide antithrombotic therapy. Conclusions and Relevance: Despite the growing volume of TAVR procedures to treat patients with severe aortic stenosis, evidence for adjunctive antithrombotic therapy remains rather scarce. Ongoing clinical trials will provide better understanding to guide antithrombotic therapy.