Clinical Study of Coronary Extension Catheter

Inclusion Criteria: * Age ≥18 years, regardless of gender; * Patients suitable for percutaneous coronary intervention (PCI) and for whom the use of an extension catheter is planned to assist the intervention; * Ability to understand the purpose of the study, willingness to voluntarily participate, and ability to provide written informed consent. Exclusion Criteria: * Reference vessel diameter \< 2 mm; * Presence of thrombus in the target vessel; * Unprotected left main coronary artery disease; * Acute myocardial infarction occurring within 7 days prior to enrollment; * Known intolerance to anticoagulant or antiplatelet therapy, or known allergy to contrast media; * Concurrent severe hepatic or renal disease, or other severe systemic conditions that render the patient unsuitable for PCI; * Pregnant or lactating women; * Currently participating in another clinical trial of a drug or medical device without having reached the primary endpoint or completed the trial; * Any other condition that, in the investigator's opinion, makes the patient ineligible for participation in this study.