Effect of Renal Transplantation on Coronary Artery Calcification in Hemodialysis Patients

Abstract

Objective. Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive, and progresses more rapidly among subjects with chronic kidney disease (CKD) than in the general population. It is also considered to be a marker of coronary heart disease, the main cause of increased morbidity and mortality among patients either on maintenance hemodialysis or after transplantation. The aim of this study was to evaluate the effect of renal transplantation on the calcium scores of coronary arteries among hemodialysis patients. Patients and Methods. The study included 31 patients (17 males and 14 females) of age range 19 to 56 years (mean, 38.08 +/- 13.49 years) who had been hemodialyzed 3 times a week for 6 to 49 months (mean, 20 +/- 15.72 months) prior to renal transplantation. Homocysteine, intact parathyroid hormone (iPTH), calcium, phosphate, and indices of lipid metabolism such as total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides were measured before and at 6 months after transplantation. To evaluate coronary artery calcification, all patients underwent multidetector coronary computed tomography (MDCT) using the Agatston technique for calcium scoring (CS) and color Doppler ultrasound for IMT before and at 6 months after the procedure. Results. The prevalence of coronary artery calcifications among dialysis patients was 96% with a total CS ranging from 0 to 198. It affected more than 2 vessels in >50% of subjects with higher calcium scores in the left anterior descending artery (LAD). Mean total CS decreased significantly from pre- (39.82 +/- 63.05) to postoperation (24.34 +/- 39.55; P < .001). CS decreased from pre- to postprocedure in the left main artery (7.4 +/- 13.03 to 4.3 +/- 8.54; P < .01) and in LAD (15.76 +/- 23.53 to 10.23 +/- 15.81; P < .01 and in the circumflex (7.8 +/- 14.98 to 5.1 +/- 9.57; P < .001) and in the right coronary artery (9.2 +/- 17.18 to 4.7 +/- 8.18; P < .01). The CS before the procedure correlated significantly with age (r = .39; P < .005), P (r = .33; P < .05), Ca X P product (r = .39; P < .05), iPTH (r = .43; P < .001), and IMT (r = .56; P < .0001). There was a linear, meaningful correlation between CS and iPTH and Ca X P product reduction after renal transplantation. Conclusions. Renal transplantation significantly reduced coronary artery calcification among dialysis patients. It linearly correlated with a decrease in iPTH and Ca X P product at an early period after renal transplantation.