What is the best approach for managing mitral regurgitation (MR) in patients with chronic kidney disease (CKD)?

Management of Mitral Regurgitation in Chronic Kidney Disease

For patients with mitral regurgitation (MR) and chronic kidney disease (CKD), transcatheter mitral valve repair (TMVR) is the preferred intervention over surgical mitral valve repair (SMVR) due to significantly lower in-patient morbidity and mortality in this high-risk population. 1

Assessment and Classification

Initial Evaluation

• Determine MR etiology (primary vs. secondary) and severity
• Assess CKD stage and renal function (eGFR)
• Evaluate symptoms (dyspnea, fatigue, palpitations)
• Perform echocardiography to quantify:
  • Effective regurgitant orifice area (EROA)
  • Regurgitant volume (RVol)
  • Left ventricular (LV) function
  • Left atrial (LA) size

Staging Considerations

• Primary MR: Direct valve abnormality
• Secondary MR: Functional due to LV dysfunction
• CKD staging impacts treatment approach:
  • CKD stages 1-2 (eGFR ≥60 mL/min/1.73m²): Lower risk
  • CKD stage 3 (eGFR 30-59 mL/min/1.73m²): Moderate risk
  • CKD stages 4-5 (eGFR <30 mL/min/1.73m²): High risk

Treatment Algorithm

Medical Management (First-Line for All Patients)

• Optimize guideline-directed medical therapy (GDMT) for heart failure 2
  • ACE inhibitors/ARBs (monitor renal function and potassium)
  • Beta-blockers
  • Mineralocorticoid receptor antagonists (with caution in advanced CKD)
  • Diuretics for volume control
• Monitor for hyperkalemia and worsening renal function with RAAS inhibitors 3
• Consider cardiac resynchronization therapy (CRT) when indicated 2

Intervention Decision-Making

1. Symptomatic severe MR:

   • TMVR preferred over SMVR in CKD patients 1, 4
   • Consider TMVR especially when:
     • CKD stage 3 or worse
     • High surgical risk
     • Favorable valve anatomy for repair

2. Asymptomatic severe MR:

   • Close monitoring with serial echocardiography every 6-12 months 2, 5
   • Consider intervention if:
     • LV dysfunction develops (LVEF <60%)
     • LV dilation (LVESD ≥40mm)
     • Pulmonary hypertension
     • New-onset atrial fibrillation

3. Moderate MR with CKD:

   • Medical therapy optimization
   • More frequent monitoring (every 6 months)
   • Consider intervention if undergoing other cardiac surgery

Special Considerations in CKD

Benefits of TMVR in CKD

• Lower in-hospital mortality (13.8% vs 1.3% compared to SMVR) 1
• Shorter hospital stay (12.6 vs 22.8 days) 1
• Lower costs ($52,646 vs $98,165) 1
• Potential improvement in renal function:
  • CKD stage 4-5 patients showed mean eGFR improvement of +4.8 mL/min/1.73m² at 1 year 6
  • 50% of CKD stage 4-5 patients showed improved kidney function at readmission 4

Risks and Caveats

• Despite potential renal function improvement, baseline CKD still predicts worse long-term outcomes 6, 4, 7
• Higher readmission rates in ESRD patients (41.2% at 90 days vs 21% in non-CKD) 4
• Increased risk of acute kidney injury post-procedure in CKD patients 4
• CKD stage 4-5 patients have highest mortality risk regardless of intervention type 6, 7

Monitoring After Intervention

• Renal function assessment at baseline, discharge, 30 days, 6 months, and 1 year
• Serial echocardiography to assess MR reduction and cardiac remodeling
• Heart failure symptom evaluation
• Medication adjustment based on renal function changes

Multidisciplinary Approach

• Heart team discussion involving:
  • Cardiologist
  • Cardiac surgeon
  • Nephrologist
  • Interventional cardiologist
  • Heart failure specialist

The evidence strongly suggests that while CKD patients have worse outcomes overall after mitral valve interventions, TMVR offers significant advantages over surgery in this population, with potential for renal function improvement in those with advanced CKD. The decision-making process should carefully weigh the risks and benefits, with TMVR emerging as the preferred option for most CKD patients with severe symptomatic MR.