Central Illustration. Myocardial Contractile Mechanics in Ischemic Mitral Regurgitation.
Multicenter stress CMR data from the SCMR registry demonstrated LV ischemia with contractile dysfunction in mitral valve adjacent (sub-papillary) territories to associate with FMR: Sub-papillary ischemia was associated with ≥moderate FMR independent of ischemia in remote regions. Associations between sub-papillary ischemia and FMR were weaker than for sub-papillary infarction, paralleled by greater dysfunction in infarcted segments – for both ischemia and infarction, only affected segments with contractile dysfunction conferred increased likelihood of FMR. Strain analysis in patients with and without ≥moderate FMR matched on ischemia distribution/extent demonstrated sub-papillary radial strain impairment to be associated with ≥moderate FMR and mitral apparatus remodeling independent of impaired strain in remote LV regions. Findings support a key role for ischemia-mediated contractile dysfunction in LV myocardium underlying the mitral valve in FMR.