Ticagrelor vs Clopidogrel: the Impact of Platelet Inhibition on Cerebrovascular Microembolic Events during TAVR

Abstract

ObjectivesTo evaluate the effects of ticagrelor versus clopidogrel and of platelet inhibition on the number of cerebrovascular microembolic events, in patients undergoing transcatheter aortic valve replacement (TAVR).BackgroundThe impact of the antiplatelet regimen and the extent of associated platelet inhibition on cerebrovascular microembolic events during TAVR are unknown.MethodsPatients scheduled for TAVR were randomized prior to the procedure to either aspirin and ticagrelor or to aspirin and clopidogrel. Platelet inhibition was expressed in P2Y12 Reaction Units (PRU) and percentage of inhibition. High intensity transient signals (HITS) were assessed with transcranial Doppler (TCD). Safety outcomes were recorded according to the VARC-2 definitions.ResultsAmong 90 patients randomized, six had inadequate TCD signal. The total number of procedural HITS was lower in the ticagrelor group (416.5 [324.8, 484.2]) (42 patients) than in the clopidogrel group (723.5 [471.5, 875.0]) (42 patients), p< 0.001. After adjusting for the duration of the procedure, diabetes, extra-cardiac arteriopathy, BMI, and aortic valve calcium content, patients on ticagrelor had on average 255.9 (95% CI: [-335.4, -176.4]) fewer total procedural HITS, than did patients on clopidogrel. Platelet inhibition was greater in those randomized to ticagrelor 26 [10, 74.5] PRU than in those randomized to clopidogrel 207.5 [120-236.2] PRU, p<0.001 and correlated significantly with procedural HITS (r=0.5, p<0.05). This protective effect was not associated with an increase in complications.ConclusionsTicagrelor resulted in fewer procedural HITS, compared to clopidogrel, in patients undergoing TAVR, while achieving greater platelet inhibition, without increasing the risk for complications.Clinical Trial(ClinicalTrials.gov Identifier: NCT02989558)CONDENSED ABSTRACTWe conducted a two-center, prospective, open label, randomized, controlled clinical trial to compare the efficacy of ticagrelor vs clopidogrel in preventing cerebrovascular embolic events as assessed by transcranial Doppler during TAVR.The total number of procedural HITS was lower in the ticagrelor group (416.5 [324.8, 484.2]) than in the clopidogrel group (723.5 [471.5, 875.0]), p< 0.001. Patients on ticagrelor had on average 255.9 (95% CI: [-335.4, -176.4]) fewer total procedural HITS than those on clopidogrel. This protective effect was not associated with an increase in complications.