PMID- 30621972 OWN - NLM STAT- MEDLINE DCOM- 20191218 LR - 20191218 IS - 1876-7605 (Electronic) IS - 1936-8798 (Linking) VI - 12 IP - 1 DP - 2019 Jan 14 TI - Impact of On-Clopidogrel Platelet Reactivity on Incidence of Hypoattenuated Leaflet Thickening After Transcatheter Aortic Valve Replacement. PG - 12-18 LID - S1936-8798(18)31766-7 [pii] LID - 10.1016/j.jcin.2018.08.008 [doi] AB - OBJECTIVES: To assess the impact of on-clopidogrel platelet reactivity (PR) on HALT, the authors prospectively tested whether patients with below-median on-clopidogrel PR have a lower incidence of HALT compared with those with above-median on-clopidogrel PR. BACKGROUND: It is unclear whether the apparent ineffectiveness of clopidogrel in preventing hypoattenuated leaflet thickening (HALT) after transcatheter aortic valve replacement (TAVR) questions the concept of P2Y(12) inhibition after TAVR or is a consequence of an inadequate response to clopidogrel in elderly patients with severe aortic stenosis. METHODS: Patients were either on long-term dual antiplatelet therapy with clopidogrel and acetylsalicylic acid or were given bolus doses of both drugs the day before TAVR. Adenosine diphosphate (ADP)-induced multielectrode impedance aggregometry was performed before TAVR. After TAVR, clopidogrel was continued in all patients. Computed tomographic angiography was performed to detect HALT. RESULTS: Of 331 patients enrolled, computed tomographic angiography was performed in 200 at 5 days (interquartile range: 4 to 6 days). Among patients with below-median ADP-induced PR (<180 AU . min), 16 were diagnosed with HALT, whereas 20 patients with above-median PR were diagnosed with HALT (p = 0.58). Among patients with high on-clopidogrel PR (>468 AU . min; n = 29), 7 (24%) displayed HALT, compared with 19 (17%) with ADP-induced PR