Platelet and Monocyte Activation After Transcatheter Aortic Valve Replacement (POTENT-TAVR): A Mechanistic Randomized Trial of Ticagrelor Versus Clopidogrel.

Background: Inflammation and thrombosis are often linked mechanistically and are associated with adverse events after transcatheter aortic valve replacement (TAVR). High residual platelet reactivity (HRPR) is especially common when clopidogrel is used in this setting, but its relevance to immune activation is unknown. We sought to determine whether residual activity at the purinergic receptor P2Y12 (P2Y12) promotes prothrombotic immune activation in the setting of TAVR.
Methods: This was a randomized trial of 60 patients (enrolled July 2015 through December 2018) assigned to clopidogrel (300mg load, 75mg daily) or ticagrelor (180mg load, 90 mg twice daily) before and for 30 days following TAVR. Co-primary endpoints were P2Y12-dependent platelet activity (Platelet Reactivity Units; VerifyNow) and the proportion of inflammatory (cluster of differentiation [CD] 14+/CD16+) monocytes 1 day after TAVR.
Results: Compared to clopidogrel, those randomized to ticagrelor had greater platelet inhibition (median Platelet Reactivity Unit [interquartile range]: (234 [170.0-282.3] vs. 128.5 [86.5-156.5], p < 0.001), but similar inflammatory monocyte proportions (22.2% [18.0%-30.2%] vs. 25.1% [22.1%-31.0%], p = 0.201) 1 day after TAVR. Circulating monocyte-platelet aggregates, soluble CD14 levels, interleukin 6 and 8 levels, and D-dimers were also similar across treatment groups. HRPR was observed in 63% of the clopidogrel arm and was associated with higher inflammatory monocyte proportions. Major bleeding events, pacemaker placement, and mortality did not differ by treatment assignment.
Conclusions: Residual P2Y12 activity after TAVR is common in those treated with clopidogrel but ticagrelor does not significantly alter biomarkers of prothrombotic immune activation. HRPR appears to be an indicator (not a cause) of innate immune activation in this setting.
Competing Interests: David A. Zidar reports research grant support from AstraZeneca, honoraria from GSK/Pfizer and Medtronic. Steven Filby is a consultant for Boston Scientific. Nicholas T. Funderburg is a consultant for Gilead. Mehdi Shishebhor is a consultant for Abbott Vascular, Medtronic, Terumo, Philips, and Boston Scientific. Sahil A. Parikh serves on the advisory Board of Abbott, Boston Scientific, Medtronic, Philips, Janssen, Cordis, Efemoral, and Advanced Nanotechnologies; receives research support from Abbott, Boston Scientific, surmodics, shockwave, and trireme; and is a consultant for Inari, Penumbra, Abiomed, and Terumo. Guilherme Attizzani is a consultant and advisory board member of Medtronic and Abbott Vascular. Daniel I. Simon reports honoraria from Medtronic.