Feasibility Clinical Study of Transcatheter Edge-to-Edge Repair in Dogs with the Canine Mitral V-Clamp Device

Abstract:
Background: Transcatheter edge-to-edge mitral valve repair (TEER) has been shown in pivotal studies to be an effective treatment for degenerative mitral regurgitation (MR) in humans.

Hypothesis/Objective: Determine feasibility, acute safety, adverse device-related events, early efficacy, and freedom from all-cause and cardiac-related mortality of a canine-specific TEER device (V-Clamp) in dogs with degenerative MR.

Animals: Initial inclusion criteria were dogs with stage C or D degenerative MR. During the study, stage B2 dogs were added if they met guidelines for severe MR.

Methods: Prospective single-arm single-institution FDA feasibility-type study. TEER was performed via a transapical approach under transesophageal echocardiography and fluoroscopic guidance.

Results: Forty dogs were enrolled over a two-year period (12 B2, 26 C, 2 D). Procedural feasibility was 95% based on successful delivery of at least 1 clamp in 38/40 dogs. There were no procedural deaths. Acute procedural safety was 95% based on survival to hospital discharge of 38/40 dogs. Most dogs were discharged by the 2nd day. Adverse device-related event rate was 6.2% based on 3 events (1 single-leaflet detachment, 1 clamp unlock, 1 clamp embolization) in 48 implanted clamps. All 3 events were nonfatal and successfully treated with a second clamp. Regurgitant fraction and volume decreased from 64±12% and 2.4±0.9 mL/kg at baseline to 43±26% (p< 0.0001) and 1.3±1.1 mL/kg (p< 0.0001) at hospital discharge. Freedom from all-cause and cardiac-related mortality at 9 months was 87.4% and 91.1%, respectively.

Conclusions: Initial feasibility results support continued development of TEER as a low-risk and effective treatment for degenerative MR in dogs.