How should I decide between mitral valve repair and mitral valve replacement for a patient?

Mitral Valve Repair vs. Replacement Decision Algorithm

Mitral valve repair should be strongly preferred over replacement in virtually all cases of primary mitral regurgitation where a successful and durable repair is technically feasible, as repair reduces operative mortality by approximately 50%, better preserves left ventricular function, and avoids prosthetic valve complications. 1

Primary Decision Framework: Type of Mitral Regurgitation

Primary (Organic) Mitral Regurgitation

For primary MR, repair is the standard of care and should be attempted whenever technically possible. 1

Posterior Leaflet Disease Only

• Repair is mandatory when disease is limited to the posterior leaflet (up to half the leaflet can be excised, plicated, or resuspended). 1
• Operative mortality <1%, with 95% freedom from reoperation and >80% freedom from recurrent moderate-severe MR at 15-20 years. 1
• Any surgeon performing mitral valve procedures should achieve ≥90% success rate for posterior leaflet repair. 1
• Replacement should NOT be performed for isolated posterior leaflet disease unless repair has been attempted and failed. 1

Anterior Leaflet or Bileaflet Disease

• Repair remains strongly preferred when a successful and durable repair can be accomplished. 1
• More complex repair with less certain durability: approximately 80% freedom from reoperation and 60% freedom from recurrent moderate-severe MR at 15-20 years. 1
• These outcomes still superior to replacement, even in elderly patients. 1
• Requires referral to experienced mitral valve surgeons at high-volume centers (>140 mitral operations/year have 77% repair rates vs. 48% at low-volume centers). 1

When to Choose Replacement Over Repair

• When in doubt, replacement is preferable to a poor repair. 1
• Rheumatic lesions, extensive valve prolapse, leaflet calcification, or extensive annular calcification have less predictable repair outcomes. 1
• Very complex repairs in younger patients may be matched by durable mechanical valve replacement with careful anticoagulation management. 1

Secondary (Functional) Mitral Regurgitation

The decision-making for secondary MR differs fundamentally from primary MR. 2

• Medical optimization is mandatory first: ACE inhibitors/ARBs, beta-blockers, aldosterone antagonists, and cardiac resynchronization therapy if indicated. 2
• For severe secondary MR in patients undergoing CABG with LVEF >30%, concomitant mitral surgery is indicated. 2
• Isolated mitral surgery for secondary MR has no proven survival benefit and should only be considered for severely symptomatic patients who remain symptomatic despite optimal medical therapy. 2
• No clear survival advantage between repair vs. replacement for secondary MR. 2, 3

Age Considerations

Age alone should NOT determine the choice between repair and replacement. 1

• Mitral valve repair is indicated over replacement even in patients >65 years of age. 1
• In patients ≥75 years old, repair has significantly lower mortality (7.1% vs. 23.4%), lower stroke rates (0% vs. 12.8%), and better long-term survival compared to replacement. 4
• Across all age groups, repair achieves better survival than replacement; tissue valves never achieve equivalent survival to either repair or mechanical valves at any age. 5

Surgical Expertise and Volume Requirements

The likelihood of successful repair correlates directly with surgeon and hospital volume. 1

• Hospitals performing >140 mitral operations/year achieve 77% repair rates with 50% lower mortality compared to low-volume centers. 1
• Patients with predictable complex repairs (anterior or bileaflet involvement) should be referred to experienced repair centers with high repair rates and low operative mortality. 1
• For asymptomatic patients with preserved LV function, repair is reasonable only when likelihood of successful durable repair is >95% with expected mortality <1% at a Heart Valve Center of Excellence. 1

Specific Clinical Scenarios

Rheumatic Mitral Valve Disease

• Repair may be considered when surgical treatment is indicated if durable repair is likely OR if reliability of long-term anticoagulation management is questionable. 1
• Rheumatic lesions have less consistent repair outcomes even in experienced hands. 1

Concomitant Cardiac Surgery

• Concomitant mitral valve repair is reasonable for chronic moderate primary MR when undergoing cardiac surgery for other indications. 1
• Concomitant repair or replacement is indicated for chronic severe primary MR during other cardiac surgery. 1

Severe LV Dysfunction (LVEF ≤30%)

• Mitral valve surgery may be considered in symptomatic patients with chronic severe primary MR and LVEF ≤30%, though effect on survival is largely unknown. 1
• Decision depends on response to medical therapy, comorbidity, and likelihood of successful repair. 1

Critical Pitfalls to Avoid

• Do not delay surgery in symptomatic severe primary MR waiting for further LV deterioration—this causes irreversible ventricular damage. 2
• Do not perform replacement for isolated posterior leaflet disease without attempting repair first. 1
• Do not apply primary MR surgical indications to secondary MR—the pathophysiology and treatment approach are fundamentally different. 2
• Do not assume tissue valves are equivalent to repair in elderly patients—repair remains superior across all age groups. 4, 5

Mortality and Morbidity Outcomes

Repair offers superior outcomes across multiple domains: 1

• Operative mortality approximately half that of replacement (data from STS database and multiple clinical reports). 1
• Better preservation of LV function by maintaining mitral apparatus integrity. 1
• Avoids prosthetic valve complications: thromboembolism, anticoagulation-related hemorrhage (mechanical valves), and structural valve deterioration (bioprosthetic valves). 1
• Long-term survival equivalent to age-matched general population for posterior leaflet repair. 1