Changes of coronary calcification after kidney transplantation

Coronary artery calcification (CAC) in patients with end-stage renal disease is driven by uremia and increased serum calcium and phosphate levels. Improvement in calcium-phosphate homeostasis and uremia by kidney transplantation therefore might favorably influence CAC.

We measured the extent of CAC by using multidetector computed tomography in 31 patients immediately after transplantation and at 6 and 12 months' follow-up. Baseline and follow-up measurements were compared, and the effect of atherogenic factors on CAC progression was determined by means of multivariate regression analysis.

Mean total Agatston score increased significantly from baseline to 6 months (716 +/- 980 [SD] versus 916 +/- 1,307; P < 0.001), but remained unchanged at 12 months' follow-up (890 +/- 1,263; P = not significant). Progression of calcification was present only in patients with a baseline total Agatston score higher than 10. In these patients, the score increased from 964 +/- 1,028 to 1,234 +/- 1,385 (P < 0.001) at 6 months and remained stable thereafter (1,199 +/- 1,338; P = not significant). Duration of pretransplantation dialysis treatment and smoking were identified as independent predictors of posttransplantation CAC progression. Conversely, changes in calcium and phosphate levels were not associated with calcification.

This study shows that CAC progresses during the early posttransplantation course, but slows between 6 and 12 months after transplantation. The extent of early calcification is influenced mainly by dialysis treatment duration and smoking.