012 Longitudinal cardiac magnetic resonance assessment of diffuse and replacement myocardial fibrosis in aortic stenosis

Objective To investigate whether cardiac magnetic resonance (CMR) can assess the progression and regression of myocardial fibrosis in patients with aortic stenosis (AS). Methods Sixty-three patients with aortic stenosis were followed up for 2 years with serial CMR and echocardiography: 28 patients (63±13 years, 68% male, 50% asymptomatic severe AS) did not undergo intervention ( natural history cohort ) and 35 patients (67±8 years, 73% male, 83% symptomatic severe AS) underwent aortic valve replacement (AVR) within the first year ( AVR cohort ). Replacement and diffuse myocardial fibrosis were assessed using the late gadolinium enhancement (LGE) and T1 mapping techniques respectively. Annualised change was calculated for all measures. Results In the natural history cohort, left ventricular mass index (LVMi) increased over time (6%±1%, p The AVR cohort displayed a fall in LVMi following surgery (−15%±2%, p Conclusion Changes in diffuse fibrosis can be tracked using iECV and increase with time in patients with AS alongside LV mass and replacement fibrosis. Following AVR there is a fall in LV mass driven predominantly by regression of cellular hypertrophy with more gradual reduction in diffuse fibrosis burden but no change in replacement fibrosis. Mid-wall LGE is present on baseline scan (white arrow) and new areas are seen on 1 year scan (red arrows). Following AVR there is no change in mid-wall LGE (white arrows). Annualised change in imaging measures is presented below in the natural history (black) and AVR (red) groups.