Figure 5.

Proposed Integration of Myocardial Fibrosis Into the Classical Description of the Natural History of Aortic Stenosis

Adaption of the outcome curve originally proposed by Braunwald in 1968 (76). Prior to the onset of symptoms, there is a long latent period in aortic stenosis where subclinical myocardial changes take place, including the development of reversible diffuse fibrosis followed by irreversible replacement fibrosis. These changes may be assessed with the imaging modalities denoted in the figure. Exploratory data suggest that diffuse fibrosis is associated with an adverse long-term outcome in aortic stenosis. The prognostic data related to the noninfarct pattern of late gadolinium enhancement (LGE) as a marker of replacement fibrosis is comparatively robust, establishing LGE as a powerful independent predictor of long-term clinical outcomes. According to current guidelines and routine clinical practice, AVR is performed after the onset of symptoms. Future and ongoing trials, including the EVOLVED trial, are required to determine whether targeted early intervention utilizing cardiac magnetic resonance (CMR) to detect fibrosis will lead to improved clinical outcomes. Abbreviations as in Figures 2 and 4.