Cold-Region Exposure and Cardiac Remodeling After PCI

Inclusion Criteria: * Age 18 to 75 years. Angiographically confirmed coronary artery disease treated with successful percutaneous coronary intervention, defined as residual stenosis \<30% with final TIMI grade 3 flow. Clinically stable after PCI. Expected survival of at least 12 months. Able and willing to undergo baseline cardiovascular magnetic resonance imaging and baseline and 6-month transthoracic echocardiography. Able to provide residential, occupational, training/deployment, and other relevant exposure histories for the 3 years preceding PCI. Written informed consent provided. Exclusion Criteria: * Severe valvular heart disease, cardiomyopathy, congenital heart disease, or other major structural heart disease. Previous coronary artery bypass grafting or heart transplantation. End-stage heart failure or New York Heart Association class IV heart failure. Severe renal dysfunction, defined as estimated glomerular filtration rate \<30 mL/min/1.73 m². Known contraindication to cardiovascular magnetic resonance imaging or gadolinium-based contrast agents. Inability to complete transthoracic echocardiographic assessment. Inability to reliably recall or verify major residential or occupational exposure history during the 3 years preceding PCI. More than five major changes in primary residence during the 3 years preceding PCI that preclude reliable estimation of cumulative cold-region exposure.