From the Guidelines
Mitral regurgitation is most commonly caused by primary valvular abnormalities such as mitral valve prolapse, and secondary causes including coronary artery disease and dilated cardiomyopathy, as supported by the most recent evidence 1. The risk factors for mitral regurgitation can be categorized into primary and secondary causes. Primary causes involve direct damage to the mitral valve, including:
- Mitral valve prolapse
- Rheumatic heart disease
- Infective endocarditis
- Congenital heart defects
- Connective tissue disorders like Marfan syndrome Secondary causes result from left ventricular dysfunction that affects the valve apparatus, including:
- Coronary artery disease
- Myocardial infarction
- Cardiomyopathy
- Long-standing hypertension Age is also a significant risk factor as valve degeneration naturally occurs over time 1. Other contributing factors include radiation therapy to the chest, certain medications like ergotamine derivatives and some diet drugs, and chest trauma. Mitral regurgitation develops when these factors compromise the normal function of the valve leaflets, chordae tendineae, papillary muscles, or the left ventricular wall, preventing proper closure of the valve during systole and allowing blood to flow backward from the left ventricle into the left atrium, as described in 1. This regurgitation increases pressure in the left atrium and can eventually lead to left atrial enlargement, pulmonary hypertension, and heart failure if left untreated, highlighting the importance of early identification and management of mitral regurgitation risk factors, as emphasized in the most recent study 1.
From the Research
Risk Factors for Mitral Regurgitation (MR)
The risk factors for Mitral Regurgitation (MR) can be classified into several categories, including:
- Degenerative causes, such as valve prolapse 2
- Ischaemic causes, resulting from coronary disease 2
- Rheumatic causes, particularly in developing countries 2, 3, 4, 5, 6 Other risk factors include:
- Age, with older patients being more likely to experience MR progression 3
- Left atrial volume, with increased volume being associated with MR progression 3
- Atrial fibrillation, which can contribute to MR progression 3
- Prior rheumatic fever, which may lead to mitral valve prolapse and subsequent MR 5
Rheumatic Mitral Regurgitation
Rheumatic mitral regurgitation is a significant cause of MR, particularly in developing countries 2, 3, 4, 5, 6. The progression of MR in patients with rheumatic heart disease is influenced by factors such as age and left atrial volume 3. Mitral valve repair is a viable treatment option for rheumatic mitral regurgitation, with satisfactory survival rates and a significant reduction in the need for reoperation 6.
Mitral Valve Prolapse
Mitral valve prolapse is a common cause of MR, particularly in patients with a history of rheumatic fever 5. The presence of mitral valve prolapse can be detected using echocardiography, and it is often associated with isolated mitral regurgitation 5. The relationship between mitral valve prolapse and rheumatic heart disease suggests that postinflammatory changes in valvular tissue resulting from rheumatic fever may be the etiology of mitral valve prolapse in these patients 5.