Myocardial Contractile Mechanics in Ischemic Mitral Regurgitation: Multicenter Data Using Stress Perfusion Cardiovascular Magnetic Resonance.

BACKGROUND

Left ventricular (LV) ischemia has been variably associated with functional mitral regurgitation (FMR). Determinants of FMR in patients with ischemia are poorly understood.

OBJECTIVES

This study sought to test whether contractile mechanics in ischemic myocardium underlying the mitral valve have an impact on likelihood of FMR.

METHODS

Vasodilator stress perfusion cardiac magnetic resonance was performed in patients with coronary artery disease (CAD) at multiple centers. FMR severity was confirmed quantitatively via core lab analysis. To test relationship of contractile mechanics with ischemic FMR, regional wall motion and strain were assessed in patients with inducible ischemia and minimal (≤5% LV myocardium, nontransmural) infarction.

RESULTS

A total of 2,647 patients with CAD were studied; 34% had FMR (7% moderate or greater). FMR severity increased with presence (P < 0.001) and extent (P = 0.01) of subpapillary ischemia: patients with moderate or greater FMR had more subpapillary ischemia (odds ratio [OR]: 1.13 per 10% LV; 95% CI: 1.05-1.21; P = 0.001) independent of ischemia in remote regions (P = NS); moderate or greater FMR prevalence increased stepwise with extent of ischemia and infarction in subpapillary myocardium (P < 0.001); stronger associations between FMR and infarction paralleled greater wall motion scores in infarct-affected territories. Among patients with inducible ischemia and minimal infarction (n = 532), wall motion and radial strain analysis showed impaired subpapillary contractile mechanics to associate with moderate or greater FMR (P < 0.05) independent of remote regions (P = NS). Conversely, subpapillary ischemia without contractile dysfunction did not augment FMR likelihood. Mitral and interpapillary dimensions increased with subpapillary radial strain impairment; each remodeling parameter associated with impaired subpapillary strain (P < 0.05) independent of remote strain (P = NS). Subpapillary radial strain (OR: 1.13 per 5% [95% CI: 1.02-1.25]; P = 0.02) and mitral tenting area (OR: 1.05 per 10 mm

CONCLUSIONS

Among patients with CAD and ischemia, FMR severity and adverse mitral apparatus remodeling increase in proportion to contractile dysfunction underlying the mitral valve.

Informations de copyright

Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Déclaration de conflit d'intérêts

Funding Support and Author Disclosures Supported by National Institutes of Health grants R01 HL128278 (to Drs Weinsaft, Levine, and J. Kim), R01 HL128099 and R01 HL141917 (to Dr Levine), K23 HL140092 (to Dr J. Kim), K23 HL132011 (to Dr Shenoy), and T32 HL7854-23 (to Dr Kochav), as well as by the Glorney-Raisbeck Fellowship/New York Academy of Medicine (to Dr Kochav). Dr Judd has an equity interest in and has been a consultant for Heart Imaging Technologies. Dr Klem has been a consultant and speaker for Bayer; and has received funding from Medtronic. Dr Leon has received funding from Abbott Vascular, Boston Scientific, and Medtronic. Dr R. Kim has served on the Board of Directors of Heart Imaging Technologies. Dr Weinsaft has received a speaker honorarium from General Electric Healthcare; and has been a consultant for Lexeo Therapeutics. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.