From the Guidelines
Mitral valve calcifications are primarily classified based on their location, including annular calcification, leaflet calcification, and commissural calcification, with severity graded as mild, moderate, or severe. The classification of mitral valve calcifications is crucial for determining the appropriate treatment approach, as it affects valve function and patient outcomes. According to the 2021 ACC/AHA guideline for the management of patients with valvular heart disease 1, the location and extent of calcification play a significant role in treatment decisions.
Classification and Severity
- Annular calcification occurs at the fibrous ring surrounding the valve
- Leaflet calcification affects the valve cusps themselves
- Commissural calcification involves the areas where the leaflets meet The severity of calcification is typically graded based on the thickness and extent of calcium deposits, which can be assessed using echocardiography or CT scans.
Diagnostic Tools
- Echocardiography is the primary diagnostic tool for classification
- CT scans provide more detailed calcium quantification when needed
Treatment Decisions
The classification system helps guide treatment decisions, ranging from monitoring for mild cases to surgical intervention for severe calcifications causing significant valve dysfunction. As noted in the 2014 AHA/ACC guideline for the management of patients with valvular heart disease 1, intervention should be delayed until symptoms are severely limiting and cannot be managed with diuresis and heart rate control. The most recent guideline from 2021 1 emphasizes the importance of considering the high procedural risk and individual patient preferences and values when deciding on valve intervention for severely symptomatic patients with extensive mitral annular calcification.
From the Research
Classification of Mitral Valve Calcifications
- Mitral annular calcification (MAC) refers to calcium deposition in the fibrous skeleton of the mitral valve 2
- There is no universally accepted definition or classification system of MAC severity, but a novel classification system based on qualitative and quantitative measurements derived from echocardiography and cardiac CT has been proposed 2
- MAC can be graded semiquantitatively using two-dimensional and three-dimensional echocardiography, and its extent and distribution can be assessed 3
- A proposed grading and staging system using both anatomical and clinical features has been developed by an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists 4
Factors Influencing Classification
- The severity of MAC is associated with mean mitral valve gradient and the presence and severity of mitral stenosis and mitral regurgitation (MR) 3
- The distribution of annular calcium can be uneven, with the middle and lateral anterior segments being less often calcified than the anterior-medial or posterior segments 3
- Calcification in any annular segment is highly associated with restricted motion of the attached leaflet segment 3