[Mitral annular calcification in dialysis patients].

Degenerative mitral anular calcifications (MAC) are most often found between the posterior mitral anulus and the left ventricular posterior wall. In advanced stages they may encircle the mitral valve and thus involve the insertion of the anterior mitral leaflet and the posterior part of the aortic root. They are usually found only after the age of 70. Among 33 patients on chronic dialysis for renal failure who were investigated by echocardiography (2-D and m-mode) we found an MAC incidence of 55% but no cases among a control population of the same age and sex (p less than 0.001). The diameter of the calcification exceeded 5 mm in 9 cases out of 18. Four of these calcifications extended in a circular fashion around the mitral valve. Additional significantly associated echocardiographic features included dilatation of the left atrium and sclerosis of the aortic root and valve. Furthermore, 12 patients with MAC had dysfunction of the mitral valve (p less than 0.05), viz. 10 isolated mitral valve regurgitations and 2 mitral stenosis, combined with regurgitation. The patients with MAC were older than those without MAC, their mean duration of dialysis was longer and parathormone level higher. The incidence of mitral anular calcifications is much higher among patients on chronic dialysis. The clinical significance of these calcifications lies primarily in the consequent dysfunction of the mitral valve.