Mitral valve repair procedure tested in dogs with severe heart valve

Abstract

OBJECTIVE: To determine procedural feasibility, safety, and short-term efficacy in dogs with severe degenerative mitral regurgitation (MR) undergoing transcatheter edge-to-edge repair (TEER) with a canine-specific device. DESIGN: Prospective, single-arm (uncontrolled), single-institution clinical feasibility study. ANIMALS: Fifty client-owned dogs with severe degenerative MR operated over a 28-month period. METHODS: TEER was performed using the canine mitral V-Clamp via a transapical approach using transesophageal echocardiographic and fluoroscopic guidance. Indices of MR severity were determined by echocardiography the day before and 2 to 3&#x202f;days after the procedure. RESULTS: Procedural feasibility was 96% based on delivery of at least one device in 48 of 50 dogs. There were no procedural deaths. Procedural safety was 96% based on survival to hospital discharge in 48 of 50 dogs. Euthanasia in 2 dogs prior to hospital discharge was due to damage of the mitral valve and worsened MR after the procedure. Device-related adverse event rate was 6.3% based on 3 events (single-leaflet device detachment, locking failure, locking failure with device embolization) in 59 implanted devices. All three events were nonfatal and successfully treated with a second device. Median regurgitant volume (mL/kg) decreased (&#x202f;<&#x202f;0.001) from 2.3 [1.9, 3.1] to 1.1 [0.3, 1.8]. Median effective regurgitant orifice area (cm/m) decreased (&#x202f;<&#x202f;0.001) from 0.60 [0.40, 0.80] to 0.25 [0.10, 0.50]. CONCLUSION AND CLINICAL IMPORTANCE: Initial feasibility results support continued development of TEER as a procedurally feasible, relatively low-risk, and low morbidity treatment for degenerative MR in dogs. Operator experience and case selection are likely to be important components of success of this technique. Evidence of short-term efficacy is promising but needs to be verified with longer-term follow up.