Longitudinal Follow-Up of Cardiovascular Comorbidity in Pediatric Renal Transplant Recipients - Results From the 4C-T Study.

Abstract

Children with chronic kidney disease (CKD) carry an increased cardiovascular risk. Cardiovascular death is the second leading cause of death in children after renal transplantation. The 4C-T (Cardiovascular Comorbidity in Children with CKD and Transplantation) study evaluates cardiovascular target organ damage longitudinally in children prior to and after renal transplantation. The multicenter, prospective, observational 4C study enrolled 736 children aged 6 to 17 years with estimated GFR <40 ml/min/1.73 m2 at 55 Pediatric Nephrology centres from 12 European countries. Of these, 161 have started renal replacement therapy (RRT) and entered the 4C-T study. At annual study visits, the morphology and function of the heart and large arteries were monitored by noninvasive methods. 119 of the 161 patients with RRT had a visit 12 months after RRT start and were included in this analysis. 56 patients had started dialysis and 73 received a transplant. Half of the patients (52 %) were transplanted pre-emptively. Overall patients carried a higher cardiovascular risk compared to the age-matched general population as documented by elevated age-adjusted aortic pulse wave velocity (PWV) and carotid intima-media thickness (IMT). After renal transplantation PWV-SDS decreased from 0.31±1.48 to -0.20±1.21 (p=.007, paired t-test), whereas PWV remained unchanged after initiation of dialysis (0.53±1.75 to 0.43±1.24 (p=.66). No differences were seen for IMT and left ventricular mass index. Our preliminary analyses suggest an improvement of the arteriosclerotic profile in patients undergoing transplantation compared to patients starting dialysis. PWV has been the most sensitive measure for those changes. With more and more patients becoming eligible, the 4C-T study will be one of the largest studies investigating the course of cardiovascular comorbidity in pediatric renal transplant recipients.