Treatment of Chronic Mitral Regurgitation

1
Treatment of Chronic Mitral Regurgitation

• Howard A. Cooper, M.D.
• Georgetown University Medical Center
• Washington, D.C.

2
Prevalence

• True prevalence unknown
• CARDIA Study 10.9 of young adults
• Cardiovascular Health Study (Agegt65)
• 30.1 of participants had MR
• 26.6 of MR cases had moderate-to-severe
• In 1995 , 26,000 mitral valve surgeries in U.S.
  medicare patients

3
Etiology

• In U.S., etiology changed over last 40 years
• 1965 primarily rheumatic (40)
• 1985 primarily degenerative (42-62) and
  ischemic (12-30)

4
Natural History

• Morbidity
• Congestive Heart Failure
• Atrial fibrillation
• Pulmonary hypertension
• Embolization
• Mortality
• 5-year mortality of 31-54 for severe MR

5
Assessment of Severity

• Physical exam (murmur, S3, diastolic rumble)
• Electrocardiogram (LAE, LVH, Afib)
• Chest Xray (cardiomegaly, LAE)
• Cardiac catheterization (V-wave, ventriculogram)

6
Assessment of Severity (Cont.)

• Echocardiogram
• Qualitative assessment of regurgitant jet
• Volumetric flow analysis
• Proximal convergence analysis (PISA)
• Vena contracta

7
Medical Therapy

• Not appropriate for symptomatic patients (unless
  surgery contraindicated)
• Hemodynamic improvement
• Nitroprusside
• Hydralazine
• Captopril
• Nifedipine
• Long-term benefits unproved

8
Surgical Therapy - Timing

• Surgery reduces morbidity and mortality from
  severe MR but exposes patient to risk of surgery
  and prosthetic valve
• Surgery should be performed before onset of
  severe symptoms or development of LV contractile
  dysfunction

9
Symptoms

• Class III or IV symptoms (even if transient)
  always indicate need for surgery
• Class II symptoms indicate need for surgery in
  patients with repairable valves
• ETT may reveal concealed symptoms

10
Ejection Fraction

• Strongest predictor of outcome following surgery
• Should be assessed quantitatively
• Surgery indicated if LV EF is below normal (60)
• If EF normal, follow every 6 to 12 months
• If EF lt30, medical management (valve repair
  experimental in this setting)

11
Load-Independent Measures of LV Function

• Complex measurements
• LV dP/dT
• End-systolic stress-strain
• Myocardial Elastance
• Peak systolic pressure/end-systolic volume
• End-systolic diameter
• LVIDs gt45 predicts poor outcome
• End-systolic volume index
• ESVI gt50cc/m2 predicts poor outcome

12
Other Indications

• Flail mitral leaflet
• Left atrial dimension gt45mm
• Paroxysmal atrial fibrillation

13
Surgical Technique

• Valve replacement
• Mortality 2-7
• Anticoagulation
• Decreased LV EF
• Valve repair
• Mortality 2-3
• No anticoagulation
• Preservation of LV EF
• Valve repair always preferable
• Feasible in 70-90 of patients

14
Indications for Surgery Severe, Isolated,
Chronic MR

• Definite (major criteria)
• NYHA Class III or IV heart failure (any duration)
• EF lt60
• EF gt60 but decreasing on serial measurements
• LVIDs gt45mm
• ESVI gt50cc/m2

15
Indications for Surgery Severe, Isolated,
Chronic MR

• Emerging (minor criteria)
• Any symptoms of heart failureor
  suboptimalexercise tolerance test
• Flail mitral leaflet
• Left atrial diameter gt45mm
• Paroxysmal atrial fibrillation
• Abnormal exercise end-systolic volume index or
  ejection fraction