Arterial stiffness and renal transplantation

Progression of pulse pressure in kidney recipients durably exposed to CsA is a risk factor for epithelial phenotypic changes: an ancillary study of the CONCEPT trial

In this ancillary study of the CONCEPT trial, we studied the role of CsA withdrawal at 3 months (3M) post-transplant on the intensity of epithelial phenotypic changes (EPC, an early marker for kidney fibrogenesis) on the 12 M surveillance biopsy. Although conversion from CsA to sirolimus (SRL) at 3M was reported to have improved mean graft function at 12 M, it did not reduce the score of EPC (1.73 ± 1.15 in the SRL group vs. 1.87 ± 1 in the CsA group, P = 0.61). Acute rejection, which had occurred twice more frequently in SRL-converted patients included here, was associated with 12 M EPC. Interestingly, we observed that the patients durably exposed to CsA and who developed 12 M EPC had a significant progression of blood pulse pressure (pp) from 1 to 6M post-transplantation (Δpp = +12.3 mmHg, P = 0.0035). Pulse pressure at 4, 6, and 9 M and pp progression from 1 to 6M were significantly associated with the development of EPC at 12 M in renal grafts. Logistic regression analysis revealed that a high 6M pp (≥ 60 mmHg) was an independent risk factor for 12 M EPC with an odds ratio of 2.25 per additional 10 mmHg pp (95%CI: 1.14-4.4, P = 0.02) after adjustment with recipient's and donor's age, acute rejection incidence and immunosuppressive regimen. A post hoc analysis of the data collected in the whole population CONCEPT study revealed that pp was significantly higher at 6 months in patients maintained on CsA and that at this time point pp correlated negatively with GFR at 1 year.

Cardiovascular and renal outcome in recipients of kidney grafts from living donors: role of aortic stiffness

BACKGROUND

Cardiovascular (CV) risk remains high in renal transplant patients despite a clear improvement conferred by transplantation. This risk is attributed mostly to recipient-related risk factors. Donor vascular characteristics, such as arterial stiffness, have been poorly investigated in this regard.

METHODS

Recipients of living-related (n = 75) and living-unrelated (n = 20) kidney grafts were recruited at a mean time of 107 ± 41 months after transplantation for baseline evaluation and follow-up for the occurrence of the following composite outcome: myocardial infarction, stroke, CV death, doubling of serum creatinine or development of end-stage renal disease (ESRD). At inclusion, recipients and their corresponding donors underwent complete history, physical examination, laboratory tests and non-invasive measurement of aortic pulse wave velocity (PWV).

RESULTS

During a mean follow-up of 56 ± 18 months, 20 recipients doubled their serum creatinine, of whom 16 reached ESRD, and 9 suffered of a new CV event (5 of which were fatal). Cox proportional hazards regression analysis showed that, in addition to recipient-related parameters, such as the presence of CV event and the estimated glomerular filtration rate at inclusion, donor aortic PWV was a strong and independent predictor of the composite recipient outcome.

CONCLUSIONS

Donor large artery stiffness may predict recipient CV and graft outcome. This finding demonstrates the tight link that exists between the vascular system and the kidneys and suggests that donor contribution to recipient outcome goes beyond simple parameters like age, gender and even familial or non-familial donor type.

Asymmetrical dimethylarginine is associated with renal and cardiovascular outcomes and all-cause mortality in renal transplant recipients

Increased plasma levels of asymmetric dimethylarginine (ADMA) are associated with endothelial dysfunction and predict the progression to dialysis and death in patients with chronic kidney disease. The effects of these increased ADMA levels in renal transplant recipients, however, are unknown. We used the data from ALERT, a randomized, double-blind, placebo-controlled study of the effect of fluvastatin on cardiovascular and renal outcomes in 2102 renal transplant recipients with stable graft function on enrollment. Patients who were initially randomized to fluvastatin or placebo in the 5- to 6-year trial were offered open-label fluvastatin in a 2-year extension of the original study. After adjustment for baseline values for established factors in this post hoc analysis, ADMA was found to be a significant risk factor for graft failure or doubling of serum creatinine (hazard ratio 2.78), major cardiac events (hazard ratio 2.61), cerebrovascular events (hazard ratio 6.63), and all-cause mortality (hazard ratio 4.87). In this trial extension, the number of end points increased with increasing quartiles of plasma ADMA levels. All end points were significantly increased in the fourth compared to the first quartile. Our study shows that elevated plasma levels of ADMA are associated with increased morbidity, mortality, and the deterioration of graft function in renal transplant recipients.