American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the indication for surgery in patients with chronic severe mitral regurgitation?

1. Only with asymptomatic presentation

2. With mild to moderate LV dysfunction

3. Severe symptoms regardless of LV function

4. Any degree of LV dysfunction

The correct answer is: With mild to moderate LV dysfunction

In the management of chronic severe mitral regurgitation, surgical intervention is generally indicated when there is evidence of left ventricular (LV) dysfunction, even in the absence of symptoms. The rationale for this guideline is based on the understanding that LV function is a critical determinant of long-term outcomes in patients with mitral regurgitation. When LV dysfunction is present, the heart is already experiencing detrimental effects from the hemodynamic overload caused by the regurgitation. If left untreated, this can lead to irreversible changes in cardiac structure and function, significantly increasing the risk of morbidity and mortality. Therefore, surgical repair or replacement is indicated in these patients to prevent progression of heart failure and to improve survival rates. In contrast, treatment in asymptomatic patients without LV dysfunction is generally conservative, as surgical risks can outweigh the potential benefits in this group. Symptomatic patients with severe symptoms typically merit surgery regardless of LV function, as symptoms suggest that the heart is already affected adversely by the regurgitation. However, in cases where there is mild to moderate LV dysfunction, the intervention is important to prevent the progression of the condition.