Drug-coated balloon angioplasty for catastrophic left main STEMI in a 24-year-old with antiphospholipid syndrome: a case report.

Antiphospholipid syndrome (APS), characterized by antiphospholipid antibody (aPL)-driven thrombosis, is increasingly recognized as a critical etiology of catastrophic coronary events in young adults lacking traditional cardiovascular risk factors. This report delineates a 24-year-old male with left main coronary artery (LMCA) ST-segment elevation myocardial infarction (STEMI), managed through a novel strategy combining drug-coated balloon (DCB) angioplasty and APS-targeted pharmacotherapy (anticoagulation and immunomodulation). The case underscores the necessity of etiological exploration in young STEMI populations and challenges the conventional stent-based revascularization paradigm in hypercoagulable states. One-year follow-up demonstrated sustained patency without recurrent thrombosis, validating the efficacy of pathophysiology-guided interventions.