1. Objective Objective: > The purpose of this study is to evaluate whether a short-term (1-month) dual antiplatelet therapy (DAPT) followed by single antiplatelet therapy (SAPT) is non-inferior to the standard 6-month DAPT in patients undergoing Drug-Coated Balloon (DCB) angioplasty for de novo small coronary artery disease.

   Methods: > This is an open-label, randomized, non-inferiority trial. Patients will be assigned to either 1 month or 6 months of DAPT after successful DCB treatment. The study will compare the incidence of Net Adverse Clinical Events (NACE)-a composite of cardiovascular death, myocardial infarction, target vessel revascularization, and major bleeding-between the two groups from 1 to 12 months post-procedure.

2. Background Following percutaneous coronary intervention (PCI), dual antiplatelet therapy (DAPT) is essential to prevent stent thrombosis and ischemic events. While short-duration DAPT (e.g., 4 weeks) has shown benefits in patients at high bleeding risk, evidence regarding the optimal DAPT duration specifically after Drug-Coated Balloon (DCB) angioplasty for small vessel disease remains insufficient. This study aims to fill this clinical gap by comparing 1-month versus 6-month DAPT strategies.

Primary Objective To demonstrate the non-inferiority of 1-month DAPT (followed by SAPT up to 12 months) compared to 6-month DAPT in terms of Net Adverse Clinical Events (NACE) occurring between 1 and 12 months post-randomization.

Secondary Objectives To evaluate ischemic safety (CV death, MI, TLR). To assess bleeding safety (BARC type 2, 3, or 5). To analyze individual components of the primary composite endpoint, including all-cause death and stent thrombosis.

Inclusion Criteria:

• 1)Adults aged 19 years or older 2)Subjects who have undergone drug-coated balloon (DCB) angioplasty 3) Subjects with stable angina, asymptomatic ischemia, and angiographically confirmed coronary lesions 4)Patients who have not undergone coronary intervention and whose coronary angiography demonstrates a reference vessel diameter between 2.0 mm and 3.0 mm, meeting all of the following conditions: No severe dissection corresponding to National Heart, Lung, and Blood Institute (NHLBI) grade C to F No reduction in coronary blood flow defined as TIMI flow grade < 2 No residual stenosis ≥ 30% 5)Patients newly diagnosed with small-vessel coronary artery disease among those maintained on single antiplatelet therapy (SAPT) for at least 6 months after undergoing: de novo percutaneous coronary intervention (de novo PCI),in-stent restenosis PCI (ISR PCI), or percutaneous transluminal coronary angioplasty (PTCA) 6)Subjects who voluntarily agree to participate in this clinical study and provide written informed consent

Exclusion Criteria:

• 1) Patients diagnosed with Acute Coronary Syndrome (ACS), including STEMI, NSTEMI, or Unstable Angina.

  2) Patients undergoing concomitant Percutaneous Coronary Intervention (PCI) during the Drug-Coated Balloon (DCB) procedure.

  3) Patients undergoing PCI for In-Stent Restenosis (ISR). 4) Patients with a diagnosis of active bleeding or coagulation disorder within 2 months prior to obtaining informed consent.

  5) Patients who underwent surgery with moderate-to-high risk within 6 weeks prior to obtaining informed consent.

  6) Patients with a history of intracerebral hemorrhage (ICH). 7) Patients with Hemoglobin < 10 g/dL or Platelet count < 100 x 10³/mm³. 8) Patients unable to discontinue oral anticoagulation therapy (OAC). 9) Patients on long-term treatment with NSAIDs or COX-2 inhibitors (excluding aspirin).

  10) Patients with a life expectancy of less than 1 year due to malignancy or other comorbidities.

  11) Patients with moderate-to-severe hepatic impairment. 12) Patients at risk of symptomatic bradycardia (e.g., 2nd-degree Mobitz Type II block or 3rd-degree AV block).

  13) Patients with dyspnea, such as those with Chronic Obstructive Pulmonary Disease (COPD).

  14) Patients with intolerance or hypersensitivity to the investigational medicinal products.

  15) Patients who participated in other clinical trials within 3 months prior to informed consent (excluding non-interventional observational studies).

  16) Women who are pregnant or breastfeeding. 17) Patients with End-Stage Renal Disease (ESRD) on hemodialysis or peritoneal dialysis, or those who have undergone a kidney transplant.

  18) Patients with rare hereditary metabolic disorders, such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption.

  19) Any patient deemed unsuitable for participation in the clinical trial at the investigator's discretion.

Individual participant data (IPD) will not be shared to protect the privacy of study participants and to comply with the hospital's Institutional Review Board (IRB) policies and local data protection regulations

This study is an open-label trial as the duration of DAPT (1 month vs. 6 months) cannot be masked from participants and investigators. However, to ensure objectivity, an independent endpoint adjudication committee, whose members are blinded to the treatment assignment, will adjudicate all clinical endpoints. Additionally, data analysts will remain blinded to the treatment groups until the final database lock.