Prognostic role of myocardial fibrosis markers in aortic stenosis: implications for clinical decision-making

Aortic stenosis (AS) causes chronic pressure overload in the left ventricle (LV) that ultimately results in myocardial fibrosis. This fibrosis is associated with advanced symptoms, LV decompensation, and poor prognosis. Cardiovascular magnetic resonance (CMR) offers a non-invasive method to assess myocardial fibrosis, correlating well with histology and predicting adverse events in AS patients. Histologic studies have confirmed the prevalence of myocardial fibrosis in AS and its association with symptoms and LV dysfunction. CMR techniques, including late gadolinium enhancement (LGE) and T1-mapping, effectively demonstrate and quantify fibrosis, with LGE identifying focal replacement fibrosis and T1-mapping assessing diffuse interstitial fibrosis. Both techniques complement each other in capturing the extent of myocardial fibrosis. The reversibility of fibrosis post-aortic valve replacement (AVR) varies, with diffuse fibrosis showing potential for regression while replacement fibrosis remains irreversible. Importantly, recent studies have highlighted the powerful prognostic value of LGE and T1-mapping markers. There are ongoing trials that aim to establish the clinical role of CMR-guided early intervention in improving AS outcomes. Identifying novel indicators for myocardial fibrosis, such as serum biomarkers or strain imaging, could further enhance the prediction of fibrosis and patient selection for CMR. Ultimately, the integration of myocardial fibrosis markers into clinical practice may optimize the timing of intervention and improve prognosis for AS patients. This review summarizes the current evidence from CMR studies investigating myocardial fibrosis in AS, focusing on its prognostic value and potential role in guiding intervention timing.