Cold-Region Exposure and Cardiac Remodeling After PCI

Overview

This multicenter prospective observational cohort study aims to investigate the association between cumulative cold-region exposure and adverse left ventricular remodeling and cardiovascular outcomes in patients with coronary artery disease undergoing successful percutaneous coronary intervention (PCI). Individual-level chronic cold exposure will be quantified primarily by cumulative months of residence, work, or other relevant exposure in cold regions during the 3 years preceding PCI. Additional exposure measures will include regional cold-wave days derived from meteorological records and winter outdoor occupational exposure. Participants will undergo baseline cardiovascular magnetic resonance (CMR), echocardiography, electrocardiography, and clinical and laboratory assessment after PCI. Echocardiography will be repeated at 6 months to assess left ventricular remodeling. Cardiovascular events will be prospectively collected during follow-up. The study will evaluate whether cumulative cold-region exposure is associated with distinct CMR phenotypes, adverse left ventricular remodeling, and major adverse cardiovascular events (MACE), and whether cold-exposure measures provide incremental prognostic information beyond conventional clinical, imaging, and electrocardiographic risk markers.

Cold exposure has been associated with an increased risk of cardiovascular morbidity and mortality in population-based epidemiological studies. However, limited evidence is available regarding whether chronic cumulative exposure to cold environments is associated with myocardial structural and functional abnormalities or adverse prognosis among patients who have undergone coronary revascularization. The COLD-PCI Study is a multicenter prospective observational cohort study designed to characterize the relationship between chronic cold-region exposure, cardiovascular imaging phenotypes, left ventricular remodeling, and subsequent cardiovascular outcomes after successful percutaneous coronary intervention. The primary environmental exposure will be cumulative cold-region exposure during the 3 years preceding PCI. Exposure histories will be obtained using a standardized Cold Exposure History Questionnaire documenting residential, occupational, training/deployment, and relevant travel histories. Geographic locations will be coded at the county level. Months with at least 15 days of residence or work in a predefined cold region will be counted toward cumulative exposure. Participants will be categorized into three exposure strata: no/minimal exposure (\<6 months), short-term exposure (6 to \<18 months), and long-term exposure (≥18 months). Objective meteorological exposure will additionally be assessed by linking participants' geographic histories to daily meteorological records and calculating the number of regional cold-wave days. Winter outdoor occupational exposure will also be quantified. Baseline CMR will be performed approximately 7-14 days after PCI to characterize ventricular volumes and function, myocardial strain, left ventricular mass, myocardial infarct characteristics, microvascular obstruction, and other available myocardial tissue characteristics. Baseline transthoracic echocardiography will be performed within 3 days of CMR. Twelve-lead electrocardiographic parameters and routine demographic, clinical, angiographic, biochemical, and treatment variables will also be collected. Follow-up echocardiography will be performed at 6 months. The primary outcome is adverse left ventricular remodeling, defined as an increase of at least 20% in left ventricular end-diastolic volume from baseline to the 6-month examination. Participants will additionally undergo longitudinal follow-up for major adverse cardiovascular events. The study will examine associations between cumulative cold-region exposure and CMR phenotypes, evaluate potential imaging mediators of adverse ventricular remodeling, and assess whether cold-exposure variables improve prognostic prediction beyond conventional clinical, CMR, and electrocardiographic markers.