Aorto-Iliac Artery Calcification and Graft Outcomes in Kidney Transplant Recipients

Abstract

While the association of vascular calcification with inferior patient outcomes in kidney transplant recipients is well-established, the association with graft outcomes has received less attention. With this dual-centre cohort study, we aimed to determine the clinical impact of recipient pre-transplant aorto-iliac calcification, measured on non-contrast enhanced computed tomography (CT)-imaging within three years prior to transplantation (2005–2018). We included 547 patients (61.4% male, age 60 (interquartile range 51–68) years), with a median follow-up of 3.1 (1.4–5.2) years after transplantation. The aorto-iliac calcification score (CaScore) was inversely associated with one-year estimated-glomerular filtration rate (eGFR) in univariate linear regression analysis (standard β −3.3 (95% CI −5.1 to −1.5, p < 0.0001), but not after adjustment for potential confounders, including donor and recipient age (p = 0.077). In multivariable Cox regression analyses, a high CaScore was associated with overall graft failure (p = 0.004) and death with a functioning graft (p = 0.002), but not with death-censored graft failure and graft function decline. This study demonstrated that pre-transplant aorto-iliac calcification is associated with one-year eGFR in univariate, but not in multivariable linear regression analyses. Moreover, this study underlines that transplantation in patients with a high CaScore does not result in earlier transplant function decline or worse death censored graft survival, although ongoing efforts for the prevention of death with a functioning graft remain essential.

Ipsilateral Aorto-Iliac Calcification is Not Directly Associated With eGFR After Kidney Transplantation: A Prospective Cohort Study Analyzed Using a Linear Mixed Model

“…This prospective cohort study found no direct association between AIC and eGFR after transplant. The results from this study are in line with earlier studies who did not find an association between AIC and post-transplant graft function (11)(12)(13)(14)16). However, we found a significant interaction between time and ipsilateral calcification score, indicating that patients with a higher calcification score had a lower eGFR trajectory during the follow-up time.…”

“…Current studies that investigated the relationship between AIC and graft function have several limitations, from which the most important ones are a retrospective design, a subjective quantification method of aorto-iliac vascular disease which limits generalizability and the use of statistical methods that do not account for drop-out (10)(11)(12)(13)(14)(15)(16). To address these issues, we performed a prospective cohort study in which all patients underwent non-contrast-enhanced CT-scan for objective, quantitative assessment of AIC using an adaptation of the Agatston score.…”

Association of Abdominal Arterial Calcification Score with Patients’ Survival and Kidney Allograft Function after Kidney Transplant

“…Most of these studies did not have a unified reporting of the abdominal calcification and were based on different assessment modalities. Benjamens et al showed similar results with overall decrease survival among kidney transplant recipients when they have significant arterial calcifications [7,30]. In our study, we were able to correlate the AAC value, in addition to survival, with the abnormal pulse pressure and the decreased iothalamate clearance as clinical and laboratory markers for overall survival.…”

Association of the Calcification Score of the Abdominal Aorta, Common Iliac, and Renal Arteries with Outcomes in Living Kidney Donors

“…Ichii et al arrived at the statistically independent association between lower eGFR and the quantitative degree of aortic calcification in non-dialysis patients [17]. Moreover, in 2021, Benjamens et al demonstrated that pre-transplant aorto-iliac calcification is associated with 1-year eGFR in univariate linear regression analyses [23]. Tatami et al identified trends between abdominal aortic calcifications and cardiovascular events in asymptomatic non-dialysis patients (median eGFR, 43.2 + 17.7 mL/min/1.73 m 2 ) [24].…”