To Compare the Pharmacodynamic and Short-term Clinical Effects of Standard DAPT, DAPT With Half-dose Ticagrelor, and Aspirin-free Half-dose Ticagrelor Monotherapy From the Day of PCI in Chronic Coronary Syndrome (CCS)

Plain-language summary

Six months of aspirin plus clopidogrel remains the recommended antiplatelet regimen after percutaneous coronary intervention (PCI) for chronic coronary syndrome (CCS), with the more potent P2Y₁₂ inhibitors reserved for the acute coronary syndromes (ACS) that produced their pivotal evidence. Yet the contemporary landscape of post-PCI antithrombotic therapy has shifted considerably since PLATO and TRITON-TIMI 38, and the conventional algorithm sits increasingly uneasily with two well-established realities. The first is the now consistent demonstration that aspirin contributes more to bleeding than to ischemic protection in patients adequately treated with a P2Y₁₂ inhibitor. TWILIGHT, TICO, T-PASS, ULTIMATE-DAPT and GLOBAL LEADERS have, in sequence, established that withdrawing aspirin after a defined period of P2Y₁₂-based DAPT reduces clinically relevant bleeding without an excess of ischemic events. Each of these trials, however, retained ticagrelor at the standard 90 mg twice-daily dose, required a run-in of conventional DAPT before aspirin was stopped, and enrolled populations dominated by ACS. The second is the persistent and now mechanistically grounded observation that East-Asian patients tolerate less antithrombotic intensity than the Caucasian populations on whom dose recommendations were calibrated. Ticagrelor exposure is higher in East-Asian patients, baseline platelet reactivity is lower, and the bleeding-to-ischemia ratio is shifted relative to PLATO-era expectations. Pharmacokinetic and pharmacodynamic work in Chinese and Japanese cohorts has shown that ticagrelor 45 mg twice daily - half the standard maintenance dose - yields platelet inhibition statistically indistinguishable from the 90 mg regimen. No randomised trial has yet tested an aspirin-free, half-dose ticagrelor monotherapy strategy initiated at the index PCI in CCS patients. The closest registered protocol of which we are aware (NCT07080684) uses ticagrelor 60 mg twice daily following a one-month DAPT lead-in, with a two-arm design. We therefore conducted a three-arm randomised pilot trial in East-Asian CCS patients to compare standard DAPT, DAPT with half-dose ticagrelor, and aspirin-free half-dose ticagrelor monotherapy from the day of PCI, using the change in P2Y₁₂ reaction units (PRU) as the primary pharmacodynamic readout and twelve-month clinical events as exploratory endpoints.

Who can participate

What they're measuring

Trial details