Chapter 48: Degenerative Mitral Valve Disease
A 45-year-old woman with a prior history of diet-controlled type 2 diabetes and chronic obstructive pulmonary disease (COPD) was referred by her GP to the cardiology clinic because of a heart murmur. She was very active and without any cardiovascular symptoms. Physical examination revealed a soft late-systolic murmur best heard at the apex and radiating to the axilla. An echocardiogram was obtained demonstrating mild prolapse and leaflet thickening with normal coaptation. Left ventricular function and dimensions are normal (ejection fraction 65%). Which of the following is the best next step in the management of this patient?
C. Elective mitral valve repair
D. Elective mitral valve replacement
E. Observe with echocardiographic annual follow-up
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 48) Currently there is no indication to intervene (options C and D) in less than severe primary mitral regurgitation, except in symptomatic patients where there is a high suspicion that MR grade may be underestimated. The use of beta-blockers (option B) or vasodilators (option A) to treat mitral valve prolapse in normotensive subjects is not recommended. The correct answer is therefore to observe with echocardiographic annual follow-up (option E).
Mortality after mitral valve repair in patients with degenerative disease correlates with age, with an average risk of 1% for patients below 65 years, 2% for those aged 65 to 80 years, and 4% for octogenarians. Which of the following is not an independent predictor of postoperative survival?
A. Severe symptoms (NYHA class III or IV)
C. A regurgitant orifice area ≥ 40 mm2
D. A large color Doppler jet appearance
E. The presence of long-standing atrial fibrillation
The answer is D. (Hurst’s The Heart, 14th Edition, Chap. 48) Some of the identified independent predictors of postoperative survival include severe symptoms (NYHA class III or IV—option A is thus true and therefore incorrect), LV dysfunction (EF < 60% or LVESD > 40 mm—option B is thus incorrect), a regurgitant orifice area ≥ 40 mm2 (option C is thus incorrect), left atrial dimensions (left atrial index ≥ 60 mL/m2 or LA > 55 mm), or the presence of pulmonary hypertension or long-standing atrial fibrillation (option E is thus incorrect). The size of the color Doppler jet is subject to many technical parameters, and it is not reliably predictive of outcomes after repair. The correct answer is therefore D.