Case: High-risk elderly primary MR — is TEER an option?
A 79-year-old with severe symptomatic primary MR declines open-heart surgery. LVEF 52%, EROA 0.48 cm². Surgical mortality estimate is prohibitive. When and how to consider transcatheter edge-to-edge repair in primary MR.
Clinical scenario
79-year-old woman, NYHA Class III dyspnea, severe primary MR with bileaflet prolapse. EROA 0.48 cm², LVEF 52%, LVESD 46 mm. STS predicted operative mortality 9.2%. Frailty index elevated. She declines open-heart surgery after discussion with the surgical team.
Can TEER be offered? What anatomical and clinical requirements need to be assessed?
When TEER enters the discussion in primary MR
In primary MR, surgical repair is the preferred treatment when feasible. TEER — transcatheter edge-to-edge repair using devices such as MitraClip — is a reasonable option when the patient has symptomatic severe primary MR and the surgical risk is high or prohibitive. The ACC/AHA VHD 2020 guideline acknowledges TEER as reasonable (Class IIb) in this setting when anatomy is suitable. The goal shifts from cure to palliation — reducing regurgitation enough to improve symptoms and quality of life.
Why anatomy determines TEER feasibility
TEER works by clipping the anterior and posterior leaflets together at the point of maximal regurgitation, creating a double-orifice mitral valve. In degenerative primary MR, the leaflets often have significant mobility and coaptation loss — which creates the anatomical challenge. Key requirements for TEER in primary MR include: flail gap ≤ 10 mm, flail width ≤ 15 mm, posterior leaflet length ≥ 10 mm, adequate mitral valve area to avoid iatrogenic stenosis after clip placement (MVA > 4.0 cm² target), and absence of severe calcification at the grasping zone. Bileaflet prolapse — as in this patient — adds complexity because both leaflets are involved.
The EVEREST II data — what it shows
The EVEREST II trial randomized primary MR patients to TEER versus surgery. TEER reduced MR less effectively — 21% of TEER patients had residual MR ≥3+ versus 1% after surgery. Reoperation rates were higher at 1 year. However, TEER had lower 30-day procedural risk. Importantly, the trial enrolled primarily low-to-intermediate risk patients; the high-risk population — like this patient — was not well represented, and observational data in high-risk primary MR suggests clinically meaningful symptom improvement even with incomplete MR reduction.
Anatomy must be assessed by TEE before referral for TEER
TEER feasibility in primary MR cannot be determined from TTE alone. Detailed anatomical assessment — flail dimensions, leaflet morphology, calcification, and MVA — requires TEE, ideally 3D. Even with suitable echo anatomy, the structural heart team makes the final feasibility determination based on CT and hemodynamic data.
Setting realistic expectations
The goal of TEER in high-risk primary MR is not the same as surgical repair — it is palliation. Residual MR of 1–2+ after TEER in primary MR is common and may provide meaningful symptom relief even when elimination of MR is not achieved. Conversely, if anatomy is unfavorable — particularly flail segment dimensions outside the device range — proceeding with TEER risks an unsuccessful procedure without the benefit of surgical backup.
The role of the structural heart team
In this patient, the next step is not TEER — it is referral to a center with both surgical and structural heart team expertise to reassess whether surgical risk is truly prohibitive, confirm TEE anatomy for TEER eligibility, and discuss goals of care. The patient's preference is an essential input, but it should be informed by a complete anatomical assessment.
Perioperative perspective
In a frail patient with symptomatic severe MR and elevated pulmonary pressure, the perioperative question is not only anesthetic technique. The team should ask whether valve treatment, medical optimization, or postponement of elective surgery should be discussed first. Frailty combined with severe MR and pulmonary hypertension significantly amplifies hemodynamic instability risk in the perioperative period.
What is the correct approach?
- 1.Refer to a center with structural heart team for TEE anatomy assessment and TEER evaluation✓ Recommended
Correct. High-risk symptomatic severe primary MR with patient refusal of surgery — the next step is detailed anatomy assessment at a center capable of TEER.
- 2.Proceed with TEER immediately based on TTE and STS score⚠ Not recommended
Not appropriate. TEER feasibility in primary MR requires detailed TEE anatomy assessment. STS score alone does not confirm TEER eligibility.
- 3.Offer medical therapy only — no intervention given high surgical risk△ Consider
Consider. Medical therapy may be reasonable if TEER anatomy is unfavorable, but the workup for TEER eligibility should be completed first.
Teaching points
- TEER in primary MR is considered when surgical risk is high or prohibitive and anatomy is suitable — not as a first-line alternative to repair in operable patients.
- Anatomical suitability for TEER requires dedicated TEE assessment: flail gap and width, posterior leaflet length, mitral valve area, and calcification pattern.
- The goal of TEER in high-risk primary MR is symptom palliation, not cure — residual MR 1–2+ is expected and may still provide meaningful benefit.
- Referral to a center with structural heart team capability is required — TEER feasibility cannot be determined from TTE or STS score alone.
- Patient preference is a legitimate factor in the decision, but should follow — not replace — a complete anatomical assessment.
Apply this in practice
Use the Primary MR Intervention Navigator to evaluate the indication class and TEER pathway for high-risk patients.
Primary MR Intervention Navigator