Transcatheter Annuloplasty for Mitral Regurgitation with an Adjustable Semi-Rigid Complete Ring: Initial Experience with the Millipede IRIS Device

ABSTRACT

Background: Complete, semi-rigid annuloplasty rings result in more durable reduction of mitral regurgitation (MR) over time than partial or flexible bands. We herein report the initial experience with the IRIS transcatheter adjustable semi-rigid complete annuloplasty ring.

Methods: Seven patients were treated with the IRIS ring. Inclusion criteria included: 3–4+ functional MR, symptomatic New York Heart Association (NYHA) II–IV, and left ventricle (LV) end systolic dimension ≤ 65 mm. Exclusion criteria included: left ventricular ejection fraction (LVEF) < 20%, aortic valve disease, right-sided heart failure, and pulmonary artery systolic pressure (PASP) > 70 mmHg. Baseline and 30-day transthoracic echocardiography and computed tomography (CT) imaging was performed.

Results: In Phase 1, four patients had surgical IRIS mitral ring implantation, and two had rings placed for associated functional tricuspid regurgitation (TR). In Phase 2, three patients had transfemoral, transseptal delivery of the IRIS mitral ring. There was no procedural death, stroke, or myocardial infarction (MI). One patient from Phase 1 expired 2 days post-procedure from chronic renal failure complications. The mitral septal-lateral (SL) diameter was reduced from 38.0 ± 4.1 mm to 25.9 ± 4.9 mm at 30 days (31.8% SL reduction, n = 7). MR was reduced from baseline 3–4+ to 0–1+ in all patients at 30 days. There were improvements in NYHA class, and there was a decrease in diastolic LV volumes from 182.4 ± 54.3mL to 115.3 ± 98.8 mL at 30 days (36.8% reduction). In the two patients with tricuspid annuloplasty, TR grade and tricuspid annular diameter reductions were baseline 4+ to 1+ at 30 days (37% annular reduction) and baseline 3+ to 0 at 30 days (36% annular reduction).

Conclusion: This initial experience with the Millipede IRIS adjustable semi-rigid complete ring has demonstrated robust reductions in the mitral SL diameter, MR grade, and LV volumes.

KEYWORDS:

• Mitral regurgitation
• mitral annuloplasty
• transcatheter mitral valve repair

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Acknowledgments

We acknowledge Brian Sheahan, Donna Merithew, Laura Minarsch, Randy Lashinski, Lidia Ellis, and Lesli Rochon for their assistance with the implants and in the preparation of this manuscript.

Disclosure statements

Drs. Bolling, Boyd, Grube, Rogers, and Smith are consultants to Millipede, Inc. Dr. Ebner has no conflicts to report.