BACKGROUND Antiplatelet treatment is an important component in optimizing the clinical outcomes after percutaneous coronary intervention (PCI) especially in patients with acute coronary syndrome (ACS). Prasugrel, which is a new P2Y12 inhibitor, has been confirmed as efficacious in a large trial in Western countries, and a similar trial is also to be launched in Asian countries. Although a 60-mg loading dose of prasugrel followed by 10 mg per day should be acceptable, there have been no data regarding the optimal dose in Asian patients. Furthermore, serum levels of prasugrel and the rates of platelet inhibition are known to be higher in Asians than Caucasians with the same dose of the drug. Polymer, a key component of drug-eluting stents (DES), has been suggested as the cause of inflammation leading to late complications, and has driven many companies to develop biodegradable-polymer DES. Currently, there are limited data regarding the head-to-head comparison between BP-BES and the biostable polymer CoCr-EES or the newest platinum-chromium everolimus-eluting stent (PtCr-EES). Furthermore, the polymer issue may be more important in ACS where there is ruptured thrombotic plaque where polymer-induced inflammation may affect the local milieu of the stented artery. Therefore, the present study dedicated only to ACS patients, will offer important information on the optimal prasugrel dose in the Asian population by comparing a 10-mg versus a 5-mg maintenance dose beyond 1 month after PCI, as well as giving important insight into the polymer issue by comparing BP-BES versus biostable-polymer PtCr-EES.

METHOD/DESIGN Harmonizing Optimal Strategy for Treatment of coronary artery diseases--comparison of REDUCtion of prasugrEl dose or POLYmer TECHnology in ACS patients (HOST-REDUCE-POLYTECH-ACS) trial is a multicenter, randomized and open-label clinical study with a 2 × 2 factorial design, according to the type of stent (PtCr-EES versus BP-BES) and prasugrel maintenance dose (5 mg versus 10 mg), to demonstrate non-inferiority of PtCr-EES relative to BP-BES or the reduced prasugrel dose relative to conventional dose in an Asian all-comers PCI population presenting with ACS. Approximately 3400 patients will undergo prospective, random assignment separately to either stent or prasugrel arm (1:1 ratio, respectively). When the patients have contraindications to prasugrel, they are categorized into an antiplatelet observation group after stent-randomization. The primary endpoint is the patient-oriented composite outcome, which is a composite of all-cause mortality, any myocardial infarction (MI), any repeat revascularization in the stent arm at 12 months after index PCI. In the prasugrel arm, primary endpoint is any major adverse cardiovascular event, which is a composite of all-cause mortality, any MI, any stent thrombosis (Academic Research Consortium (ARC)-defined), any repeat revascularization, stroke, or bleeding (BARC class ≥ 2).

DISCUSSION The HOST-REDUCE-POLYTECH-ACS RCT is the first study exploring the optimal maintenance dose of prasugrel beyond 1 month after PCI for ACS in Asian all-comers. In addition, this is the largest study dedicated only to ACS patients to evaluate the polymer issue in the situation of ACS by directly comparing biostable-polymer PtCr-EES versus BP-BES.

TRIAL REGISTRATION ClinicalTrials.gov (ID: NCT02193971, 13 July 2014).