Clinical or Symptomatic Leaflet Thrombosis Following Transcatheter Aortic Valve Replacement: Insights from the U.S. FDA MAUDE Database

Background: Data on clinical or symptomatic leaflet thrombosis after transcatheter aortic valve replacement (TAVR) are limited. Whether clinical leaflet thrombosis has significance beyond peri-TAVR stroke or transient ischemic attacks (TIA) is yet to be elucidated. Methods: Between January 2012 and October 2015, we searched the MAUDE database for all entries with the identifier code, "NPT," designated by the U.S. FDA to identify TAVR-related adverse events (AEs). Selected entries were searched further for the terms "leaflet," "central aortic regurgitation," and "aortic stenosis" to capture all events related to leaflet thrombosis causing structural valve dysfunction (SVD). Presentation of leaflet thrombosis (aortic stenosis or regurgitation or mixed valve lesion), mode of diagnosis (echocardiography, computed tomography, surgical explantation, or autopsy), and timing of presentation after TAVR were recorded. For all AEs of SVD due to leaflet thrombosis, the following outcomes were recorded: stroke or TIA, cardiogenic shock, and death from any cause. Results: A total of 5691 TAVR-related AEs were reported in the MAUDE database. SVD due to leaflet thrombosis was reported in 30 cases. Most cases (n = 18/30, 60.0%, 95% CI 0.41-0.77) occurred in the first year following TAVR. SVD manifested as either aortic stenosis (n = 16/30, 53.3%, 95% CI 0.34-0.72), or regurgitation (n = 7/30, 23.3%, 95% CI 0.10-0.42), or both (n = 4/30, 13.3%, 95% CI 0.04-0.31). Interventions to address leaflet thrombosis included either escalation of antiplatelet or anticoagulant therapy (n = 9/30, 30.0%, 95% CI 0.15-0.49), valve-in-valve TAVR (n = 5/30, 16.7%, 95% CI 0.06-0.35), or surgery (n = 14/30, 46.7%, 95% CI 0.28-0.66), or their combination. Outcome following leaflet thrombosis included stroke/TIA (n = 3/30, 10.0%, 95% CI 0.02-0.27), cardiogenic shock (n = 2/30, 6.7%, 95% CI 0.01-0.22), and death (n = 9/30, 30.0%, 95% CI 0.15-0.49). Conclusion: Clinically manifest leaflet thrombosis was associated with serious manifestations that included stroke, cardiogenic shock, and death.