Aortic stiffness in ESRD children before and after renal transplantation

Abstract

Cardiovascular complications are the main cause of death in end-stage renal failure in adult patients, but those complications start in childhood. Renal transplantation (RT) seems to reduce or even reverse certain abnormalities seen in dialyzed patients. Since RT seems to correct metabolic abnormalities that play a role in cardiovascular disease, aortic pulse wave velocity (APWV) was used to evaluate aortic stiffness before and after RT. We included 15 children on chronic hemodialysis (HD), aged 11.1 +/- 4.8 years and dialysis duration was 12.9 +/- 7.4 months. APWV was performed every 6 months before RT and 6 months after. There was no significant difference in APWV (6.1 +/- 1.3 m/s vs 6.5 +/- 1.4 m/s) and augmentation index (AI) on HD and 6 months after RT. APWV pre-transplant was not correlated with time on HD, but increased with age (p = 0.016). No correlation between APWV pre-/post-transplant and other HD parameters or calcineurin inhibitor exposure were found. Only graft function was inversely correlated with APWV post-transplant (p = 0.02). In conclusion, aortic stiffness seems to remain stable before and 6 months after pediatric RT. Graft function was inversely correlated with APWV. Differences in vessel structure among children of the same age group and increase in aortic stiffness with age may jeopardize data interpretation.

Age-related and blood pressure-independent reduction in aortic stiffness after kidney transplantation

“…Our study is also larger and included patients that were relatively older. As the prevalence of aortic stiffness increases with age, previous studies that have included fewer patients, and especially younger patients, might have lacked sufficient power to detect a BP-independent reduction in c-f PWV [26]. In the general population, McEniery et al [12] showed that age-related increase in aortic stiffness was steeper after the fifth decade and, therefore, suggested that aortic PWV is a more sensitive marker of vascular aging after the fifth decade.…”

Arterial Stiffness in Children: Pediatric Measurement and Considerations

“…One study found little improvement before and after the initiation of hemodialysis, suggesting that structural as opposed to functional changes are responsible for increased arterial stiffness in this group [47]. Other pediatric studies have found lower cfPWV and AIx after renal transplantation, suggesting that transplantation can improve the arteriopathy associated with CKD [48,49,50]. While cfPWV tends to improve after renal transplantation, there is disagreement as to whether there is a difference between the cfPWV of patients with a functioning graft versus healthy controls [48,49,51,52].…”

“…Other pediatric studies have found lower cfPWV and AIx after renal transplantation, suggesting that transplantation can improve the arteriopathy associated with CKD [48,49,50]. While cfPWV tends to improve after renal transplantation, there is disagreement as to whether there is a difference between the cfPWV of patients with a functioning graft versus healthy controls [48,49,51,52]. Hypertension is a risk factor for increased AIx in children with glomerulopathies, which was also higher compared to a healthy comparison group [53].…”

Posttransplant Hypertension: Multipathogenic Disease Process

“…In donors and recipients, it was associated with a cluster of cardiovascular risk factors including smoking habits, plasma glucose, and renal factors reflecting nephron mass (eg, time since nephrectomy, age in donors, and rejection in recipients). More recently, pulse wave velocity, in addition to proteinuria and systolic blood pressure, has been reported to be an independent predictor of the rate of decline in renal function in chronic kidney disease patients, 15 and in pediatric 62 and adult kidney transplant recipients. 56,58 While recognizing the likely dual causality between aortic stiffness and renal failure, these observations provide further evidence that atherosclerosis and the resulting arterial stiffness play a pathogenic role in renal function decline.…”

“…[1][2][3] It represents a strong predictor of renal and patient cardiovascular outcomes 1,3,5,6,8,[11][12][13]15,17,35,56,58,[60][61][62][63] ( Figure 2). Therefore, posttransplant hypertension represents a multipathogenic process that amplifies a vicious cycle where allograft and cardiovascular outcomes in kidney transplant recipients are determined by the interaction of 2 distinct donor and recipient genetic make-ups, and the inherited cardiovascular and renal risk factors from earlier phases and new recipient and donor-related environmental and demographic variables that may occur during implantation and posttransplant (Figure 1).…”