Abstract
Background and Aims
Vascular calcification is a risk factor for cardiovascular disease and mortality in dialysis and transplant patients. Previous studies have shown that coronary artery calcification correlates with cardiovascular mortality. However, it is not known whether vascular calcification of the abdominal aorta and common iliac artery (CIA) may impact clinical outcomes after kidney transplantation. The aim of this study was to identify the risk factors of vascular calcification after kidney transplantation.
Method
In this retrospective study, we assessed 100 patients who underwent kidney transplantation between 2008 and 2017. Of these, 62 patients received a computed tomography (CT) scan of the abdomen twice with an interval of at least 6 months. We examined the characteristics of vascular calcification of the abdominal aorta and iliac artery and divided the patients into three groups based on dialysis modality before transplantation: hemodialysis (HD group), peritoneal dialysis (PD group) and preemptive kidney transplantation (PEKT group). Then, we identified the risk factors for the progression of calcification. Abdominal aortic calcification was assessed based on the aortic calcification index (ACI), and calcification of CIA was assessed based on the maximal thickness of calcification.
Results
At baseline, abdominal aortic calcification was present in 66% of patients, and the median ACI was 10 [0-30]. Calcification of the CIA was present in 62% of patients, and maximal thickness of the CIA was 2.4 mm [0-4.6]. The mean duration of follow-up was 68 ± 29 months, and the mean interval of CT was 40 ± 29 months. After kidney transplantation, the progression rate of ACI and maximal thickness of CIA were 1.6 ± 2.5 per year and 0.17 ± 0.41 mm per year, respectively. The maximal thickness of CIA calcification was significantly higher, and ACI tended to be higher in the HD group than in the PEKT group. Age, male gender, diabetes mellitus and dialysis vintage were the independent variables related to both ACI and maximal thickness of CIA calcification. The progression rates of ACI and maximal thickness of CIA were comparable among the three groups in terms of dialysis modality. Age and rejection within the first 6 months were independent risk factors for ACI progression, and diabetes mellitus was an independent risk factor for progression of maximal thickness of CIA. No significant association was found between the progression of vascular calcification and dialysis-related parameters, including dialysis modality and vintage.
Conclusion
This study suggests that dialysis vintage was the independent variable related to calcification of the abdominal aorta and common iliac artery, whereas dialysis modality was not a significant predictor of vascular calcification and its progression in these blood vessels.
Noninvasive imaging in cardiovascular therapy: the promise of coronary arterial18F-sodium fluoride uptake as a marker of plaque biology