Outcomes Associated with Mitral Regurgitation Reduction and Myocardial Work After Mitral Valve Transcatheter Edge-to-Edge Repair in Dogs

Transcatheter edge-to-edge repair (TEER) is a recent minimally invasive method of managing mitral regurgitation (MR) in dogs with myxomatous mitral valve disease (MMVD). The goal of interventions is to minimize MR severity. The objective of this study was to determine the association between reduced MR and changes in myocardial work indices after TEER in dogs. Client-owned dogs with moderate-to-severe MR were enrolled in the study. TEER performance was completed with multimodal imaging guidance in all 10 dogs. Before and after the procedure, myocardial work was analyzed. MR severity, transmitral pressure gradients, left atrial and ventricular measurements, and index of myocardial work (GWI, GCW, GWW, and GWE) were calculated. TEER significantly reduced MR severity in the majority of dogs. MR decrease was associated with a greater efficiency of myocardial work, more constructive work, and less wasted energy. No significant negative associations of moderate post-procedure gradients with short-term clinical outcomes emerged. TEER-mediated reduction of MR improves myocardial function in dogs. However, long-term studies are also needed to examine the effects of residual MR and transmitral gradients on cardiac function and clinical outcome.