Transcatheter Mitral Valve Implantation with TIARA: Transapical Results and Transseptal Design

Objectives: The TIARA mitral valve system is a catheter-based self-expanding mitral bioprosthesis implanted via transapical access in clinical use and transseptal in preclinical stage. Its D-shaped frame, which also captures and tethers the anterior leaflet, aids in avoiding LVOT obstruction.

Methods: Seventy-nine patients have been treated with the transapical Tiara system in 3 clinical studies: first-in-human (n = 22); TIARA-I early feasibility study (n = 25); and TIARA-II clinical study (n = 32).

Result: Overall, the treated cohort (73.4% males, mean age: 74.1 ± 9.3) is characterized with dilated LV (average LD diastolic diameter: 63.1 ± 7.9 mm), severe mitral regurgitation (84.8%), low LVEF (mean: 36.5 ± 9.2), and high rate of cardiac and extracardiac comorbidities (STS mean 7.9 ± 6.7%). Renal dysfunction was present in 74.7%, previous aortic valve replacement in 20.3%, and previous MV repair in 6.3%. There was no procedural mortality, and 92.4% procedural success rate. At 30 days and 12 months, 97.3% and 100% of patients in TIARA-I and TIARA-II had MR ≤ mild. Symptomatic relief was observed with 88.9% of patients in NYHA classes I/II at 1 year.

The transseptal device version is currently in a quality structured development process targeting a first-in-human (FIH) implant for late in 2020. Bench and animal studies (n = 5) have demonstrated: successful access of the venous vasculature, crossing the septum, tracking into the mitral annulus, orienting the asymmetric implant, alignment, anchoring and accurate deployment with minimal to no tissue trauma. The preclinical assessments have demonstrated feasibility for the transseptal device technology.

Conclusion: As of October 2019, a total of 79 patients with severe MR, at high risk for conventional open-heart surgery, were treated with this device worldwide. Results demonstrate excellent procedural safety, 0% procedural mortality, high rate (92.4%) of procedural success, resolution of MR to ≤ mild in all patients at 1 year follow-up, and symptom improvement in most patients. The transseptal extension of this device will enter first clinical evaluation shortly.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
19 February 2021