Study of the Long-term Effects of P2Y12 Inhibitor Monotherapy and Coagulation Markers After Percutaneous Coronary Angioplasty.

Patients who undergo percutaneous coronary intervention (PCI) are commonly treated with antiplatelet therapy to prevent stent thrombosis and recurrence of events. After an initial period of dual antiplatelet therapy, long-term treatment with a single P2Y12 inhibitor (such as clopidogrel, ticagrelor, or prasugrel) is often prescribed. However, the optimal drug and dose for long-term monotherapy remain uncertain, as patients may experience either insufficient platelet inhibition (leading to ischemic events) or excessive inhibition (increasing bleeding risk). The HI-TECH 2 study aims to identify the most appropriate type and dose of P2Y12 inhibitor monotherapy to achieve a balanced level of platelet inhibition within a predefined therapeutic range. The study also seeks to better understand how blood coagulation activity evolves over time after PCI. This is a prospective, investigator-initiated, single-center, open-label study conducted in two phases. In Phase 1, patients receive stepwise reduced doses of ticagrelor or prasugrel to determine the optimal dose that most consistently achieves the desired level of platelet inhibition. In Phase 2, patients are randomly assigned to receive clopidogrel or the optimal doses of ticagrelor or prasugrel identified in Phase 1. The main question of the study is whether optimized ticagrelor or prasugrel regimens are more effective than standard-dose clopidogrel in achieving platelet inhibition within the target therapeutic window, as measured by validated platelet function tests. Additional objectives include evaluating the role of genetic factors in treatment response and assessing markers of coagulation activation over time. The results of this study may help personalize long-term antiplatelet therapy after PCI, improving the balance between reducing thrombotic risk and minimizing bleeding complications.