Variation in post-TAVR antiplatelet therapy utilization and associated outcomes: Insights from the STS/ACC TVT Registry

Background: Dual antiplatelet therapy (DAPT) is recommended following transcatheter aortic valve replacement (TAVR); however, the optimal antiplatelet strategy is undefined, and little is known about practice patterns. We aimed to describe contemporary practice patterns of antiplatelet therapy and their relationship to outcomes post-TAVR. Methods: The population was derived from the National Cardiovascular Data Registry, Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry with Center for Medical Services linkage for 1-year outcomes from October 1, 2011 to June 30,2016. The primary outcome measured was DAPT use in patients without anticoagulation. Secondary outcomes included death, major bleeding, myocardial infarction (MI), and stroke at 1 year. Results: Overall, 16,694 patients underwent transfemoral TAVR at 444 hospitals and were discharged without anticoagulation. Among these, 13,546 (81.1%) patients were discharged on DAPT, whereas 3,148 patients (18.9%) were discharged on monotherapy. Patients discharged on DAPT versus monotherapy were similar in age, sex, and most comorbid illnesses but had higher rates of coronary artery disease (64.6% vs 52.3%; P <.01) and peripheral artery disease (25.2% vs 22.3%; P <.01). Hospital prescribing patterns varied significantly (median frequency of DAPT 85.7%, interquartile range 94.1%-74.2%). DAPT (vs monotherapy) patients had a similar mortality risk at 1 year (adjusted hazard ratio 0.92, 95% CI 0.81-1.05), significantly higher risk for major bleeding (1.48, 1.10-1.99), and similar hazard for stroke (1.04, 0.83-1.31) and MI (1.00, 0.72-1.39). Conclusions: In the United States, most patients were discharged on DAPT following TAVR. Practice patterns varied significantly among hospitals. Patients discharged with DAPT had a similar adjusted risk of mortality, stroke, and MI compared to antiplatelet monotherapy, although risk for bleeding was significantly higher. Future investigation is needed to define the optimal antiplatelet therapy for patients undergoing TAVR.