New echo guidance aims to standardize transcatheter mitral repair procedures

Clinical Takeaway: Use a standardized, multiparametric TEE workflow—centered on real-time 3D imaging—to guide device positioning, confirm leaflet grasp, and balance MR reduction with transmitral gradients (<5 mm Hg).

The American Society of Echocardiography (ASE) has released its first comprehensive guideline on intraprocedural imaging for transcatheter mitral valve repair, providing a structured, step-by-step approach to improve consistency and outcomes across centers. Expert transesophageal echocardiography (TEE)—particularly 3D and multiplanar reconstruction (MPR)—is emphasized as essential to procedural success.

“Expert imaging is paramount for the success of these procedures,” the authors note, underscoring the need for standardized communication between imaging and interventional teams.

The document outlines a full procedural imaging pathway, beginning with baseline TEE to confirm MR mechanism, severity, and anatomic suitability. Key thresholds include adequate leaflet length (≥6–9 mm device-dependent), mitral valve area ≥4.0 cm² (preferred), and exclusion of left atrial thrombus.

Optimal transseptal puncture—critical for device maneuverability—is recommended at ~4.5–5.0 cm above the leaflet coaptation plane, guided by biplane and 3D imaging.

During device deployment, 3D en face imaging is used to align the device perpendicular to the coaptation line and confirm adequate leaflet capture, including creation of a stable “tissue bridge.” Residual MR should be assessed using a multiparametric approach combining 2D/3D color Doppler, pulmonary vein flow, and hemodynamics, since conventional measures may be unreliable after repair.

Before release, operators must balance MR reduction against mitral stenosis risk. Ideal targets include residual mean gradient <5 mm Hg and mitral valve area ≥2.0 cm². Decisions about additional clips should aim for mild-or-less MR with acceptable gradients.

Postdeployment reassessment is essential, and routine closure of iatrogenic atrial septal defects is not recommended unless clinically significant shunting occurs.

Key points

• First unified ASE guidance standardizing intraprocedural imaging for transcatheter mitral repair
• Strong emphasis on real-time 3D TEE and MPR imaging for guidance
• Defined procedural targets (gradient <5 mm Hg; MVA ≥2.0 cm² post-repair)
• Formal criteria for adequate leaflet grasp and “tissue bridge” confirmation
• Multiparametric approach to residual MR assessment
• Tailored guidance on transseptal puncture height and positioning
• Recommendation against routine closure of iatrogenic atrial septal defects

Overall, the guideline positions standardized imaging as central to safer, more reproducible mitral repair procedures.

Source: Little SH, et al. (2026, June). J Am Soc Echocardiogr. Guidelines for the Intraprocedural Imaging for Mitral Valve Transcatheter Edge-to-Edge Repair (M-TEER): Recommendations from the American Society of Echocardiography