Transcatheter Mitral Valve Interventions

OVERVIEW 

In this meeting, Dr Faeez Mohamad Ali presented the clinical evidence base for MTEER, tracing its development from the Alfieri surgical technique through landmark trials including EVEREST II, COAPT, MITRA-FR, RESHAPE-HF2, and MATTERHORN . He also covered patient selection, current and eveloving guidelines, and shared the experience of the Waikato programme - one of New Zealand's most established TEER services, with approximately 170 patients treated since 2014.

Dr Pranesh Jogia provided an expert deep-dive into the role of TOE in guiding these procedures - from the systematic pre-assessment protocol to real-time 3D multiplanar reconstruction during clip deployment. 

We also discissed the cost-effectiveness of TEER vs recurrent heart failure hospitalisation in NZ context.

Part 1: Transcatheter Edge-to-Edge Repair (TEER) for Mitral Regurgitation

• 1992: Alfieri edge-to-edge surgical technique (suturing A2 to P2) - the biological basis for TEER

• 2003: First human percutaneous TEER (Feldman et al.) - catheter-based clip delivered via transseptal puncture

• 2014: First TEER performed in New Zealand (Waikato Hospital)

• Two devices currently used: MitraClip (Abbott) and PASCAL (Edwards Lifesciences) - both transcatheter clip systems

• As of 2025 approx. 170 patients treated at Waikato

•  EVEREST II: RCT comparing TEER vs surgical repair for primary MR. TEER non-inferior for safety; slightly less MR reduction but acceptable outcomes in high-risk patients

• COAPT: TEER + optimal medical therapy (OMT) vs OMT alone for secondary MR. Significant reduction in heart failure hospitalisation and all-cause mortality; NNT ~3 at 2 years; benefit sustained at 5-year follow-up

• MITRA-FR: No benefit in secondary MR. Key difference was patient selection (disproportionate MR)

• RESHAPE-HF2: Positive results for secondary MR in heart failure patients on OMT

• MATTERHORN: TEER vs surgical repair in primary MR. Comparable outcomes

• REPAIR-MR: Ongoing trial expected to support Class I guideline upgrade for secondary MR

• ACC/AHA 2020: Class IIa recommendation for high-risk primary MR surgical candidates AND symptomatic secondary MR patients on guideline-directed OMT

• Secondary MR patients average ~2–2.5 heart failure admissions per year at ~$50,000 per admission → ~$100,000/year in hospital costs. Clip device cost ~$30,000; procedure prevents recurrent hospitalisation and reduces mortality

• COAPT: One third of patients on transplant waiting list were removed after successful TEER

• Cost-effectiveness analysis conducted at Waikato (Faeez et al.) - under review for publication

Part 2: TOE Guidance in Percutaneous Mitral Interventions

• TEER is fundamentally an imaging-driven procedure. Interventional imager = primary procedure leader

• TOE provides real-time guidance for every step: pre-assessment, septal puncture, device navigation, leaflet capture, and outcome assessment

• Pre-assessment TOE takes 45–50 minutes and produces a detailed anatomical worksheet

• SCAI structural imaging resource (scai.org) recommended for training

• Key imaging views:

  • Bicommissural view (~60°): Shows A1–A2–A3 / P1–P2–P3 across the full valve; apex centred; papillary muscles visible - confirms orientation

  • Long axis/LVOT view (~120–130°): Orthogonal to bicom; aortic valve visible opening/closing; confirms on-axis imaging for A2–P2\

  • 3D en face view: Left atrial perspective looking down onto the valve; identifies commissures, clefts, and prolapse segments

  • On-axis imaging is critical: in bicom view clip arms should be invisible (no rotation); in long axis view arms must be at full length

• Pre-assessment protocol:

  • Patient positioned supine (not left lateral) to emulate procedural conditions and avoid heart-shift errors

  • X-Plane sweep from bicom view: colour off → colour on at each sector (lateral → A1/P1, central → A2/P2, medial → A3/P3) to map flow convergence

  • Key measurements: posterior leaflet length (adequate for gripper capture), mitral valve area (>4 cm² allows multiple clips), septal puncture height (≥4 cm from annulus)

  • Dual-orifice / 3D colour: identifies multiple jets and precise location of maximum co-aptation defect

  • 3D MPR: uses volume data set with multi-view/crosshair alignment to walk through valve from lateral to medial, confirming maximum MR location

• Procedural Echo Guidance:

  • Septal puncture: mid-fossa, slightly posterior; height confirmed with bicom and long axis views

  • Guide catheter and device introduction into left atrium: guided by 3D to avoid hitting atrial walls

  • Left atrial steering: track device trajectory toward mitral valve

  • Clip positioning: bicom confirms no arm rotation; long axis confirms full arm length = on-axis

  • Leaflet grasping: TGC manipulation to visualise arms below valve; grippers checked with X-Plane; slow controlled capture to avoid leaflet trauma

  • Post-clip assessment: residual MR (location and grade), tissue bridge quality, mean mitral gradient (target <6 mmHg), mean LA pressure trend

  • 3D MPR used intra-procedurally when anatomy is complex (medial/commissural prolapse requiring off-axis clip angle)

• Communication:

  • Standardised communication language: anterior/posterior (relative to aortic valve) and medial/lateral (relative to interatrial septum/LAA) — no left/right, no clock positions during procedure

  • Team meeting pre-procedure and morning-of to align on strategy and contingencies

• Learning Curve:

  • 25 cases recommended before operating independently (ACC/ESC guidance). Results plateau at approximately 100 cases

  • Waikato overall (since 2014, including private): ~170 patients

  • Tricuspid work beginning: first percutaneous tricuspid valve replacement in NZ performed; TriClip not yet started