The primary endpoint was adequate platelet antiaggregation, defined as absence of HTPR (less than 208 PRU), which was greater in the ticagrelor-treated group than the clopidogrel-treated group at 6 hours (91% vs. 4%), 5 days (100% vs. 10%), and 3 months (100% vs. 21%). In the patients without HTPR, the proportion with adequate platelet antiaggregation at these three time points were 73%, 64%, and 78%, respectively.
“The net difference in the randomized arms over the course of the study was 79%,” reported Dr. Jimenez Diaz, emphasizing that the study verified the hypothesis that ticagrelor would provide a more consistent antiplatelet effect than clopidogrel.
Although in-hospital bleeding complications were numerically higher in the clopidogrel-treated group (25% vs. 4%), this difference did not reach significance, and there were no significant differences in bleeding complications at any other time points or overall. There were two deaths in the clopidogrel-treated group, two deaths in the group without baseline HTPR, but no deaths in the ticagrelor-treated group.
While acknowledging that this study was small and not powered to show a difference in clinical events, Dr. Jimenez Diaz said it is important to emphasize that two-thirds of patients had HTPR at baseline. The high rate of HTPR among TAVI patients on clopidogrel and aspirin at baseline was identified as an important message from this study. However, a study is now needed to determine whether a ticagrelor strategy improves clinical outcomes when compared with a clopidogrel strategy.