Case: Flail posterior leaflet — severe primary MR
A 58-year-old with new-onset exertional dyspnea and a systolic murmur. TTE shows a flail P2 segment with EROA 0.52 cm² and pulmonary vein systolic reversal. What does this mean and what comes next?
Clinical scenario
58-year-old man, previously well. 6 weeks of progressive dyspnea on moderate exertion. Loud holosystolic murmur at the apex radiating to the axilla. TTE: flail P2 posterior leaflet segment, EROA 0.52 cm², regurgitant volume 72 mL/beat, LVEF 58%, LVESD 42 mm, pulmonary vein systolic reversal present.
What is the severity grade, the ACC/AHA stage, and what should happen next?
Interpreting the findings
This presentation has multiple concordant severe-range signals: EROA 0.52 cm² (≥0.40 cm²), regurgitant volume 72 mL/beat (≥60 mL/beat), and pulmonary vein systolic reversal. The structural finding — flail P2 — is consistent with ruptured or elongated chordae to the posterior leaflet. This is the most common cause of severe degenerative primary MR and the lesion most amenable to durable surgical repair.
Stage classification
LVEF is 58% — which, in severe primary MR, crosses the threshold for LV dysfunction (LVEF ≤ 60%). LVESD is 42 mm (≥ 40 mm threshold). The patient also reports dyspnea (symptoms present). This combination puts the patient in Stage D (symptomatic severe MR) by ACC/AHA classification. Even without symptoms, the LV parameters alone would have established Stage C2.
What comes next
Stage D severe primary MR with acceptable surgical risk is a Class I indication for surgical intervention. Dyspnea attributable to MR — with preserved LVEF (even at the lower boundary) and a repairable lesion — calls for Heart Valve Team evaluation. The question is not whether to intervene; it is how to plan the repair. Flail P2 prolapse has some of the highest repair rates at experienced centers, with long-term durability data exceeding 85% freedom from reoperation at 15 years.
The LVEF 58% detail
In a normal heart, LVEF 58% is preserved. In severe chronic primary MR, LVEF ≤ 60% meets the threshold for LV dysfunction — Stage C2 or D in the ACC/AHA staging framework. This patient's LVEF of 58% is therefore not reassuring; it is a signal that myocardial function is beginning to be compromised by the volume overload.
Operative timing
Delaying repair in this patient risks further LV remodeling and decline in myocardial function. Once LVEF falls below 50% or symptoms become severe, post-repair LV recovery is less predictable. The goal of timely intervention is to restore normal loading conditions before irreversible myocardial changes occur.
Perioperative perspective
For elective noncardiac surgery, a flail leaflet with severe symptomatic MR is not just a background murmur. The perioperative team should clarify symptom burden, pulmonary pressure, LV function, and surgical urgency. If surgery can be deferred, valve-center evaluation before proceeding is worth discussing. If surgery cannot be deferred, plan for afterload reduction, volume restraint, and close hemodynamic monitoring.
What is your next step?
- 1.Refer to Heart Valve Team for surgical repair evaluation✓ Recommended
Correct. Stage D severe primary MR with a repairable lesion and acceptable risk — Class I indication for intervention.
- 2.Repeat echo in 6 months and monitor⚠ Not recommended
Incorrect. Symptoms plus LV changes (LVEF 58%, LVESD 42 mm) place this patient in Stage D/C2 — surveillance is not appropriate.
- 3.Refer for TEER (MitraClip) given high EROA⚠ Not recommended
Not indicated here. TEER in primary MR is reserved for patients who are high or prohibitive surgical risk. This patient should first be evaluated for surgical repair.
Teaching points
- Flail P2 is the most common and most repairable cause of severe primary MR.
- LVEF ≤ 60% in severe primary MR meets the threshold for LV dysfunction — the cutoff is not the standard heart failure threshold of 50%.
- Symptoms (Stage D) or LV dysfunction/enlargement (Stage C2) in severe primary MR with acceptable surgical risk represent Class I indications for intervention.
- TEER is not first-line for primary MR in operable patients — repair is the preferred approach when feasible.
- Operative timing should aim to intervene before irreversible LV dysfunction develops.
Apply this in practice
Use the Primary MR Intervention Navigator to work through this patient's indication class and recommended next steps.
Primary MR Intervention Navigator