Hunting for the Long-Term EffeCts of P2Y12 Inhibitor monotHerapy and Coagulation Monitoring After PCI: an Open-label, Randomized Study.
Hunting for the Long-Term EffeCts of P2Y12 Inhibitor monotHerapy and Coagulation Monitoring After PCI: an Open-label, Randomized Study.
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.
HI-TECH 2 is a prospective, investigator-initiated, single-center, open-label clinical trial designed to optimize P2Y12 inhibitor monotherapy following percutaneous coronary intervention (PCI), with a focus on achieving a predefined therapeutic window of platelet reactivity and characterizing coagulation system activation over time.
Despite widespread use of P2Y12 inhibitor monotherapy after completion of dual antiplatelet therapy (DAPT), substantial interindividual variability in pharmacodynamic response persists. Both high platelet reactivity (HPR) and low platelet reactivity (LPR) have been associated with adverse clinical outcomes, including thrombotic and bleeding events, respectively. A therapeutic window of platelet reactivity has been proposed to balance these competing risks. However, the optimal drug selection and dosing strategy to consistently achieve this window in contemporary PCI patients remain uncertain.
The study is structured in two sequential phases.
Phase 1 (dose-finding phase):
This phase aims to identify reduced-dose regimens of ticagrelor and prasugrel that achieve platelet reactivity within the predefined therapeutic range. Patients eligible for P2Y12 inhibitor monotherapy after PCI undergo serial platelet function testing using two validated assays (VerifyNow and Multiplate) at steady state. Ticagrelor and prasugrel are administered with stepwise dose reductions at predefined intervals, allowing within-subject pharmacodynamic assessment across multiple dosing regimens. The relationship between drug dose and platelet reactivity is characterized to determine the dose associated with the highest proportion of measurements within the target therapeutic window.
Phase 2 (randomized phase):
Following identification of the optimal dosing regimens in Phase 1, patients are randomized in a 1:1:1 ratio to receive clopidogrel at standard dose or ticagrelor or prasugrel at the optimized regimens. Randomization is stratified according to key clinical variables, including clinical presentation and diabetic status. Platelet function testing is performed under standardized conditions to assess pharmacodynamic response at steady state. This phase is designed to compare the proportion of patients achieving platelet reactivity within the therapeutic window across treatment groups.
In addition to platelet function assessment, a comprehensive panel of circulating biomarkers is evaluated in a predefined subset of patients to investigate the activation and persistence of coagulation pathways following PCI. These biomarkers include markers of thrombin generation, fibrinolysis, endothelial function, and platelet activation, providing mechanistic insight into the interplay between platelet inhibition and coagulation system activity in the chronic phase after PCI.
Pharmacogenetic analyses are also incorporated to explore the influence of CYP2C19 genotype and a composite ABCD-gene score on treatment response and the likelihood of achieving the therapeutic window. This component aims to assess the potential role of genotype-guided strategies in tailoring P2Y12 inhibitor therapy.
All analyses in the randomized phase are primarily conducted according to the intention-to-treat principle, with complementary per-protocol analyses to evaluate the robustness of findings. The study is powered to detect clinically relevant differences in pharmacodynamic response between treatment strategies, with adjustment for multiple comparisons.
Overall, HI-TECH 2 integrates dose optimization, randomized comparison, biomarker profiling, and pharmacogenetics to provide a comprehensive evaluation of long-term P2Y12 inhibitor monotherapy after PCI. The results are expected to inform individualized antiplatelet strategies aimed at improving the balance between thrombotic and bleeding risk in this population.
Inclusion Criteria:
Exclusion Criteria:
marco.valgimigli@eoc.ch+41 (0) 91 811 51 11
enrico.frigoli@eoc.ch+41 (0)91 811 53 04