Factors contributing to oxalate deposits in the myocardia of hemodialysis patients.

Although the deposition of calcium oxalate crystals in the myocardium can be associated with significant morbidity and mortality in hemodialysis patients, the pathogenesis of this deposition is not known. The present study was undertaken in order to clarify the contributing factors in an experimental setting. A simple increase in plasma oxalate levels did not cause deposits in the heart, nor did elevated values of plasma ionized calcium appear to be important in chronic renal failure. Following heterotopic cardiac transplantation, a much larger deposition of crystals was identified in the heart allograft that was histologically damaged by rejection. These findings suggest that the state of the local tissue is a very important factor in the deposition of oxalate crystals.