Aspirin Versus Clopidogrel as Single Antithrombotic Therapy After Transcatheter Aortic Valve Replacement: Insight From the OCEAN-TAVI Registry

Background: Current guidelines recommend dual antiplatelet therapy for the first 1 to 6 months after transcatheter aortic valve replacement (TAVR); however, recent studies have reported better outcomes with single antiplatelet therapy than with dual antiplatelet therapy in the occurrence of bleeding events, while not increasing thrombotic events. However, no data exist about optimal single antiplatelet therapy following TAVR. Methods: Patients who underwent TAVR between October 2013 and May 2017 were enrolled from the OCEAN-TAVI Japanese multicenter registry (Optimized Transcatheter Valvular Intervention). After excluding 1759 patients, 829 who received aspirin (100 mg/d) or clopidogrel (75 mg/d) after TAVR were identified and stratified according to the presence or absence of anticoagulation. Propensity score matching was performed to adjust the baseline characteristics between the aspirin and clopidogrel groups. Outcomes of interest were all-cause and cardiovascular deaths, stroke, and life-threatening or major bleeding within 2 years following TAVR. Results: After propensity score matching, 98 and 157 pairs of patients without and with anticoagulation, respectively, were identified. Falsification end points of pneumonia, urinary tract infection, and hip fracture were evaluated, and their rates were not different between groups. All-cause deaths were not statistically different between the groups in patients with (aspirin, 17.5%; clopidogrel, 11.1%; log-rank P =0.07) and without (aspirin, 29.6%; clopidogrel, 20.1%; log-rank P =0.15) anticoagulation at 2 years post-TAVR, whereas clopidogrel was associated with a lower cardiovascular mortality at 2 years in patients with (aspirin, 8.5%; clopidogrel, 2.7%; log-rank P =0.03) and without (aspirin, 18.0%; clopidogrel, 5.2%; log-rank P =0.02) anticoagulation. Conclusions: We demonstrated that clopidogrel monotherapy was associated with a lower incidence of cardiovascular death compared with aspirin monotherapy during the 2-year follow-up after TAVR regardless of anticoagulation use. Registration: URL: https://upload.umin.ac.jp ; Unique identifier: UMIN000020423.