Long-term safety and durability of percutaneous septal sinus shortening (The PS(3) System) in an ovine model.

Objectives: Chronic implants of the PS(3) system were conducted in an ovine model to assess durability and safety at up to 1 year follow-up.

Background: The long-term durability and safety of emerging percutaneous devices for functional mitral regurgitation remain largely unknown.

Methods: The PS(3) system (consisting of interatrial septal and great cardiac vein devices connected by an adjustable suture bridge) was placed in eight healthy adult sheep. The mitral annular septal-lateral dimension in systole (SLS) was acutely reduced by 15-20%. Animals were sacrificed at up to 12 months postimplant and characterized by intracardiac echocardiography, cardiac computed tomography (CT), and histopathology. In vivo forces exerted on the PS(3) bridge were measured by means of a novel load cell catheter.

Results: At 3, 6, and 12 months after implantation, intracardiac echocardiographic and CT showed the PS(3) systems to be intact without erosion and with overall sustained reductions in the SLS. Histopathologic assessment revealed each component correctly deployed in its respective target site without evidence of erosion, thrombus, or device fracture. The SLS was 26.5 +/- 1.7 mm preimplant, 22.0 +/- 1.4 mm post-PS(3) (17.0% reduction), and 22.0 +/- 2.1 mm at latest follow-up. Mean forces exerted on the bridge in vivo ranged from 1.16 N to 1.87 N.

Conclusions: The PS(3) System demonstrated excellent biocompatibility without evidence of erosion, thrombosis, or perforation at up to one-year follow-up in this chronic healthy ovine model. Forces exerted in the PS(3) system were relatively modest and should contribute to the durability of the device.