Mitral annulus calcification is a degenerative process involving the mitral valve ring, that sometimes extends to the whole valvular apparatus. It has the same risk factors as atherosclerosis and is more often found in chronic kidney disease, radiation therapy, and elderly patients. This condition sometimes causes mitral stenosis and more often mitral regurgitation and is associated with atrial fibrillation, atrioventricular block, stroke and cardiovascular mortality, being a good indicator of global atherosclerotic burden.
Mitral annulus calcification is usually asymptomatic unless it is severe enough to impair forward blood flow or cause severe mitral regurgitation, leading to left atrial enlargement and atrial fibrillation  or is associated with significant degenerative disease of the aortic valve . Severe calcification may cause mitral stenosis  and is associated with multiple coronary artery disease with an unstable plaque and high myocardial infarction risk and increased likelihood of stroke . However, it is unclear whether the mitral calcification causes stroke by embolization or the cerebral disease is due to cerebrovascular atherosclerosis because patients with this mitral abnormality also have significant aortic and carotid plaque. Also, affected individuals develop endocarditis more often . Heart rhythm can also be impaired by mitral annulus calcification, that is associated with atrial fibrillation and conduction abnormalities: atrioventricular block and bundle branch block . Aortic valve calcification and stenosis may also be present, sometimes causing symptoms .
Blood workup has no specific findings in mitral annulus calcification, but it may reveal high cholesterol and glycemia levels, high inflammation markers, as well as indicators of impaired renal function: increased creatinine, potassium, and low glomerular filtration rate.
The diagnosis is made using various imaging methods. The plain thoracic radiography is sometimes able to describe it if calcification is important. Calcium deposits take the shape of the mitral annulus, being observed as "J", "C" or "O" letters. Echocardiography is a much more reliable diagnostic method, describing calcification as a hyperechoic mass or band attached to the anterior or posterior mitral leaflets . More importantly, echocardiography evaluates the degree to which calcification impairs leaflet mobility and causes stenosis or regurgitation, by measuring gradients and determining mitral valve area. Also, this method evaluates the presence of aortic calcification, chamber dilatation, left ventricular hypertrophy and wall kinetics, diastolic mitral flow reversal, this being especially important in individuals that have atrial fibrillation or angina patients. The degree of severity is evaluated in parasternal short axis view: mild (focal), moderate (involving one-third to one-half of the annulus) or severe (more than one-half of the ring is implicated). The mitral valve per se may be difficult to evaluate if calcification is severe because calcium is echo-dense and prevents posterior structures visualization.
When echocardiography raises suspicion of endocarditis, thrombosis or cardiac tumors, cardiac magnetic resonance imaging and computed tomography scanning are useful in establishing the correct diagnosis . Still, these methods are bound by motion artifacts. Multislice (spiral) and electron-beam computed tomography are more effective diagnostic techniques that also apply to the aortic valve. Another visualization method is fluoroscopy performed during coronarography, but this is only used if coronary artery disease is suspected.