What is the recommended management for a patient with anterior mitral valve prolapse causing severe mitral regurgitation?

Management of Anterior Mitral Valve Prolapse with Severe Mitral Regurgitation

For anterior mitral valve prolapse causing severe mitral regurgitation, mitral valve repair using artificial polytetrafluoroethylene (PTFE) neochordae reconstruction with annuloplasty ring is the definitive treatment, and should be performed at an experienced center where near 100% repair rates are achievable. 1, 2

Surgical Approach: Repair Over Replacement

The 2020 ACC/AHA guidelines explicitly state that patients should not undergo valve replacement unless repair has been attempted and was unsuccessful 1. This is critical because:

• Repair provides superior long-term survival compared to replacement for anterior leaflet prolapse (42% vs 31% at 14 years, adjusted risk ratio 0.67, p=0.028) 3
• Modern reference centers achieve 99.9% repair rates even for complex anterior leaflet pathology 4
• While anterior leaflet prolapse historically had higher reoperation rates than posterior leaflet (28% vs 11% at 15 years), recent improvements have reduced this to 10% at 10 years 3

Specific Repair Techniques for Anterior Leaflet Prolapse

The 2020 ACC focused update provides clear technical guidance 1:

Primary Technique: PTFE Neochordae Reconstruction

• Nonresection technique using PTFE neochord reconstruction with annuloplasty ring is the preferred approach
• May be used for isolated anterior leaflet prolapse
• Can address focal leaflet flail or bileaflet prolapse
• This technique has become standard over the past decade, particularly for minimally invasive approaches 5

Alternative: Focal Triangular Resection

• Rarely used for focal anterior leaflet defects 1
• Recent data (2026) shows this can be effective for extensive myxomatous anterior leaflet prolapse with proper surgical marking techniques 6
• However, this remains a secondary option given the success of neochordae techniques

Critical Preoperative Considerations

Timing of Surgery

Based on the 2021 ACC/AHA staging system 2, surgery is indicated when:

• Stage D (Symptomatic severe MR): Decreased exercise tolerance or exertional dyspnea present
• Stage C (Asymptomatic severe MR) with:
  • LVEF declining toward 60% (remember: "normal" LVEF in MR is ~70% due to favorable loading conditions)
  • LV end-systolic dimension ≥40 mm
  • New onset atrial fibrillation or pulmonary hypertension

Severity Criteria for "Severe" MR 2:

• Vena contracta ≥0.7 cm
• Regurgitant volume ≥60 mL
• Regurgitant fraction ≥50%
• Effective regurgitant orifice (ERO) ≥0.40 cm²
• Central jet >40% left atrium or holosystolic eccentric jet

Important Caveats and Pitfalls

Beware of "Pseudoprolapse"

Not all apparent anterior leaflet prolapse requires leaflet repair 7. Pseudoprolapse (anterior leaflet appearing prolapsed but not dropping beyond the annular line into the left atrium) may respond to simple annuloplasty alone. These cases are characterized by:

• Lower ejection fraction
• Lower regurgitation volume
• A2 segment involvement
• Often represents atrial functional MR or focal posterior leaflet tethering

Arrhythmic Risk Assessment

Even with only mild-moderate MR, 83% of MVP patients show myocardial inflammation on PET imaging, and 75% have concurrent scar on MRI 8. Evaluate for:

• Complex ventricular ectopy
• T-wave abnormalities in inferior leads
• Consider ICD evaluation if high-risk features present, even before severe MR develops 9

Surgical Center Selection

Refer to experienced mitral valve repair centers where surgeons routinely handle complex anterior leaflet pathology 1. Factors requiring advanced mitral surgical expertise include:

• Bileaflet involvement
• Barlow's disease (diffuse myxomatous degeneration)
• Annular or commissural calcification (present in 27% of cases) 4
• Basal septal hypertrophy with risk of systolic anterior motion

Expected Outcomes at Reference Centers 4:

• In-hospital mortality: 0.8%
• Major stroke: 0.5%
• 7-year freedom from reoperation: 97.1%
• 7-year freedom from ≥2+ MR: 91%

The key message: anterior leaflet prolapse is repairable in virtually all cases when performed by experienced surgeons, and repair must be attempted before considering replacement given the significant survival advantage.