Myocardial remodelling in aortic regurgitation: time to think beyond volumes and function?

Current guideline criteria for surgical intervention in chronic aortic regurgitation (AR) rely on fixed thresholds of left ventricular size and ejection fraction, but these metrics may overlook early myocardial injury and under-appreciate patient heterogeneity, particularly in women and older adults. Cardiovascular magnetic resonance (CMR) offers robust quantification of regurgitant volume, three-dimensional ventricular volumes, and both focal (late gadolinium enhancement) and diffuse (T1-mapping-derived extracellular volume) fibrosis. Observational studies have linked CMR-detected fibrosis to worse clinical outcomes and less favourable reverse remodelling after valve intervention, suggesting that fibrosis may mark the transition from compensated overload to irreversible myocardial damage. In this narrative review, we appraise the limitations of current guidelines, compare echocardiographic and CMR approaches to AR assessment, and summarize the evidence supporting myocardial fibrosis as a potential imaging biomarker for risk stratification. We discuss how integrating CMR-derived fibrosis metrics with volumetric and functional data could personalize timing of aortic valve intervention. While prospective studies are needed to validate fibrosis-guided decision-making, this evolving paradigm holds promise for earlier identification of patients at risk for irreversible myocardial injury, with the ultimate goal of preserving ventricular function and improving long-term outcomes.