Soft tissue calcification in chronic dialysis patients.

Autopsy protocols and microscopic slides of 56 dialyzed and 18 nondialyzed chronically uremic patients were reviewed to assess the presence, extent, and severity of extraosseous soft tissue calcification. Calcification was identified in 79% of the dialysis patients and 44% of the nondialysis patients (P iss less than .025). Soft tissue calcification most frequently involved the heart, lungs, stomach, and kidneys. Lesions were severe in 36% of the dialysis patients and, when strategically located within the myocardium, were life-threatening. The deaths of 6 dialysis patients were attributed to severe calcification of the cardiac conduction system and/or myocardium. The presence and severity of soft tissue calcification was not related to duration of dialysis, patients' age, degree of parathyroid gland hyperplasia, radiographic evidence of soft tissue calcification, serum calcium and phosphate levels, Ca X P products, or type or severity of metabolic bone disease.