The ADAPT-CKD trial is an investigator-initiated, multicenter, open-label, prospective, randomized, superiority trial conducted in South Korea. The ADAPT-CKD trial aims to determine the optimal duration of DAPT in patients with advanced CKD undergoing PCI with contemporary DES implantation by comparing abbreviated DAPT strategy with standard DAPT strategy. The study flowchart is presented in Figure 1 . Enrollment began in March 2021 and is expected to be completed by mid-2026. The trial is registered at ClinicalTrials.gov (NCT04708587). Data is reviewed by an independent data and safety monitoring board at regular intervals. The trial is conducted in accordance with the Declaration of Helsinki, and all participants provided written informed consent before randomization. The protocol was approved by the institutional review board of each participating center.

The study flowchart. Patients with advanced CKD undergoing PCI with contemporary DES implantation are randomized in a 1:1 ratio to an abbreviated DAPT strategy (<3 months) or a standard DAPT strategy (≥6 months), each followed by P2Y ₁₂ inhibitor monotherapy with either clopidogrel or prasugrel. The primary endpoint is NACE at 1 year after randomization, defined as a composite of all-cause death, myocardial infarction, stent thrombosis, stroke, or major bleeding. Major bleeding is defined as type 3 or 5 bleeding according to the BARC definition. BARC , Bleeding Academic Research Consortium; CKD , chronic kidney disease; DAPT , dual antiplatelet therapy; DES , drug-eluting stent; MI , myocardial infarction; NACE , net adverse clinical events; PCI , percutaneous coronary intervention.

Patients will be eligible for inclusion if they meet all of the following criteria: (1) age >18 years; (2) advanced CKD defined as an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m ² calculated using the Chronic Kidney Disease Epidemiology Collaboration equation or dialysis dependence ; and (3) undergoing PCI with contemporary DES implantation. Patients undergoing PCI for any clinical presentation, including chronic coronary syndrome and acute coronary syndromes (unstable angina, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction), will be considered eligible provided the above criteria are satisfied. The key exclusion criteria are as follows: (1) age >85 years; (2) conditions conferring unacceptable hemorrhagic risk; or (3) a requirement for oral anticoagulant agents. Detailed inclusion and exclusion criteria are summarized in Table 1 .

Eligible patients are randomly assigned to either the abbreviated DAPT group or the standard DAPT group in a 1:1 ratio using a web-based permuted-block randomization system with block sizes of four or six. Assignment is performed immediately after successful completion of the index PCI. In patients undergoing planned staged PCI, the index PCI is defined as the final installment of the planned staged intervention. Randomization is performed at each participating center. Randomization is stratified by CKD grade (stage IIIb [eGFR ≥ 30 mL/min/1.73 m ²] vs stage IV or V [eGFR < 30 mL/min/1.73 m ² or dialysis-dependent]), clinical presentation (chronic coronary syndrome vs acute coronary syndrome), and DES type (polymer-free vs durable-polymer).

Patients who did not previously receive antiplatelet therapy before PCI receive loading doses of aspirin (300 mg) with either clopidogrel (300 mg) or prasugrel (60 mg) at the time of PCI. After PCI, DAPT consisting of aspirin 100 mg daily with either clopidogrel 75 mg or prasugrel 10 mg daily is prescribed. For the standard DAPT group, DAPT is continued for at least 6 months after PCI in accordance with the contemporary guideline recommendation. ^,,, This duration was selected as a predefined, guideline-based strategy rather than an individualized bleeding risk-guided approach. For the abbreviated DAPT group, DAPT is administered for less than 3 months after PCI; specifically, 1 month of DAPT is recommended for patients presenting with chronic coronary syndrome, and 3 months of DAPT for patients presenting with acute coronary syndrome. The exact duration of DAPT within each assigned strategy is determined at the treating physicians’ discretion in both groups. After DAPT discontinuation, P2Y ₁₂ inhibitor monotherapy with clopidogrel or prasugrel is continued after DAPT in both groups. Prasugrel is preferred (but, left to the physicians’ discretion) over clopidogrel in patients with acute coronary syndrome unless contraindicated. Prasugrel dose reduction to 5 mg daily is permitted at the physicians’ discretion to mitigate bleeding risk. ^, Switching between P2Y ₁₂ inhibitor or use of other P2Y ₁₂ inhibitor (e.g., ticagrelor) is permitted based on a justified decision by the treating physician. Accordingly, switching between P2Y ₁₂ inhibitors will not be considered a protocol violation, provided that the duration of DAPT remains consistent with the assigned randomization. The trial exclusively uses polymer-free biolimus-coated stents (Biofreedom, Biosensors Europe SA, Morges, Switzerland), sirolimus-coated stents (Cre8 EVO, CID S.p.A., Saluggia, Italy), or durable-polymer novolimus-eluting stents (DESyne X2, Elixir Medical Corporation, Milpitas, CA) according to the operators’ preference.

The primary endpoint is net adverse clinical events (NACE), defined as a composite of all-cause death, myocardial infarction, stent thrombosis, stroke, or major bleeding. Major bleeding is defined as the Bleeding Academic Research Consortium type 3 or 5 bleeding. Given the competing ischemic and bleeding risks characteristic of advanced CKD, NACE was selected to provide a comprehensive assessment of balancing the trade-off between ischemic and bleeding events. The secondary endpoints including the separate ischemic and bleeding events are listed in Table 2 . Detailed definitions of the study endpoints are provided in Supplementary Material.

Given the open-label design of the trial, all study endpoints will be independently evaluated by a clinical event adjudication committee. The committee consists of experienced clinicians who are not participating in the trial and are blinded to treatment assignments. The committee will review all investigator-reported endpoints and perform independent confirmation and classification of clinical endpoints according to prespecified definitions based on original source documentation.

Patients will be followed up as scheduled according to the study protocol, with visits at baseline, 1, 3, 6, and 12 months after randomization. At each follow-up visit, general health status, medication use, and the occurrence of study endpoints or adverse events will be assessed. Study drug adherence will be assessed at each follow-up visit based on site-reported medication use, with adherence ≥80% considered adequate. Additional laboratory and imaging studies will be obtained according to usual care, and coronary angiography will not be routinely performed unless myocardial ischemia is suspected. All follow-up procedures and clinical assessments are conducted according to a standardized protocol in both randomized groups.