The role of platelet reactivity assessment in dual antiplatelet prophylaxis after transcatheter aortic valve implantation

Abstract

Background: Dual antiplatelet therapy (DAPT) is recommended prophylaxis after transcatheter aortic valve implantation (TAVI). The usefulness of platelet reactivity (PLTR) tests in predicting the safety of periprocedural DAPT in the TAVI population is unknown.

Aim: To analyze the value of aspirin/clopidogrel PLTR testing in predicting the risk of in-hospital TAVI-related bleeding.

Methods: PLTR, expressed as P2Y₁₂/aspirin reaction units (PRU/ARU), was performed using optical aggregometry with the VerifyNow^® device, in the 24h before and on the sixth day after TAVI. Follow-up was by telephone. Bleeding was defined according to VARC-2, and comprised in-hospital, major and life-threatening events.

Results: Overall, 100 patients undergoing TAVI were included; 30 (30%) had bleeding. Clopidogrel PLTR before TAVI (area under the curve [AUC] 0.686, 95% confidence interval [CI] 0.542-0.808; P=0.02) and after TAVI (AUC 0.970, 95% CI 0.904-0.995; P<0.001) correlated with bleeding, with PRU cut-off values of ≤204 and ≤124 as bleeding predictors, respectively. A significant periprocedural decrease in clopidogrel PLTR was noted, with a PRU drop of >78 as bleeding predictor (AUC 0.851, 95% CI 0.725-0.935; P<0.001). Only postprocedural aspirin PLTR was associated with bleeding (AUC 0.697, 95% CI 0.585-0.794; P=0.008). Follow-up (359±73 days after TAVI) included 85 patients (85%) (after exclusion for in-hospital death [n=4] and lack of contact [n=11]). Major bleeding was noted in four patients (4.7%), all on combined prophylaxis.

Conclusions: TAVI-related bleeding occurs mainly during the procedure or in the early postprocedural period. Testing of periprocedural clopidogrel PLTR, but not aspirin PLTR, seems useful because of its predictive value for TAVI-related bleeding. PLTR testing suggests that premedication with clopidogrel, enhanced response to clopidogrel early after TAVI and significant periprocedural drop in clopidogrel PLTR might increase the risk of TAVI-related bleeding.

Keywords: Bleeding complications; Complications hémorragiques; Implantation de valve aortique transcathéter; Platelet reactivity assessment; Transcatheter aortic valve implantation; Évaluation de la réactivité plaquettaire.