Myocardial fibrosis and viability: the role of imaging and biomarkers in patients with chronic total occlusion on coronary angiography.

摘要

In patients with chronic total occlusion on coronary angiography, myocardial viability assessment is an essential tool in guiding treatment decisions, especially revascularization. Current non-invasive tests are often limited by the presence of myocardial fibrosis. This narrative review incorporates evidence from 76 studies and aims to provide an updated overview of non-invasive methods for myocardial viability assessment, with emphasis on the role of myocardial fibrosis. Every imaging modality provides valuable information, even though they differ in sensitivity, specificity, availability, radiation exposure, contraindications and limitations in the presence of fibrosis. Biomarkers that provide insight into different aspects of myocardial fibrosis - including collagen synthesis (procollagen type I carboxy-terminal propeptide and procollagen type III amino-terminal propeptide), as well as inflammation and fibrotic signalling (galectin-3) - may complement imaging by reflecting myocardial remodelling. However, main limitations to this approach are no standardized reference ranges and cut-off values, analytical variability and insufficient validation for clinical outcomes prediction. Despite their potential to guide personalized revascularization decisions, circulating fibrosis biomarkers currently remain experimental tools. Further large-scale prospective clinical studies that incorporate biomarkers with imaging are needed before their implementation into clinical practice.