From the Guidelines
Mitral valve calcifications are better classified by using a combination of imaging techniques, primarily echocardiography, to assess the location, extent, and severity of calcification. When classifying mitral valve calcifications, it's essential to consider the location and extent of calcification, as this impacts treatment decisions, particularly in patients with severe mitral annular calcification, which can cause problems in securely attaching the prosthetic valve and narrowing of the orifice 1. The most effective approach involves using transthoracic echocardiography (TTE) as the initial imaging modality, followed by transesophageal echocardiography (TEE) for more detailed assessment when necessary. Key considerations in classification include:
- Assessing whether the calcification affects the annulus, leaflets, or both
- Evaluating the degree of associated stenosis or regurgitation using Doppler techniques to determine the hemodynamic significance of the calcification
- Applying the Carpentier classification system to categorize the functional impact of calcification on valve mechanics
- Using cardiac CT scanning to quantify calcium burden using Agatston scores, and cardiac MRI to differentiate between fibrosis and calcification. This comprehensive classification approach is essential for appropriate management decisions, as extensive calcification may complicate repair procedures and favor valve replacement in surgical candidates, particularly in elderly and debilitated patients with multiple comorbidities who are at high risk for surgery 1.
From the Research
Classification of Mitral Valve Calcifications
To better classify mitral valve calcifications, several studies have proposed the use of multimodality imaging evaluation, including echocardiography and cardiac computed tomography (CT) 2, 3, 4.
- Echocardiography is conventionally the first-line imaging modality for anatomic assessment and evaluation of mitral valve function 2, 5.
- Cardiac CT has demonstrated importance in the evaluation and planning of related procedures, as well as in quantitative grading of mitral annular calcification (MAC) 2, 3, 4.
- A novel classification system based on qualitative and quantitative measurements derived from echocardiography and cardiac CT has been proposed 2.
Grading of Mitral Valve Calcifications
The grading of mitral valve calcifications can be performed using different methods, including:
- Semiquantitative analysis of mitral valve calcifications using echocardiography, which can identify areas of calcification as dense conglomerate echoes 6.
- Quantitative calcium extraction using EDTA spectrophotometry, which can provide a measure of the amount of calcium present in the mitral valve 6.
- Grading of mitral annular calcifications as absent, mild, nodular, or diffuse, based on the extent and distribution of calcification 6.
Diagnostic Challenges
Mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges, particularly in patients with comorbid conditions and overlapping symptoms 5.
- Detection of mitral annular calcifications and assessment of related mitral valve disease require comprehensive evaluation using multiple imaging modalities, including two-dimensional echocardiography, multidetector computed tomography, and three-dimensional echocardiography 5.
- Invasive hemodynamic testing with exercise can help identify the cause of symptoms in patients with comorbid conditions 5.