The prognosis of kidney transplant recipients with aorto‐iliac calcification: a systematic review and meta‐analysis

The prognosis of kidney transplant recipients (KTR) with vascular calcification (VC) in the aorto-iliac arteries is unclear. We performed a systematic review and meta-analysis to investigate their survival outcomes. Studies from January 1st, 2000 until March 5th, 2019 were included. Outcomes for meta-analysis were patient survival, (death-censored) graft survival and delayed graft function (DGF). Twenty-one studies were identified, eight provided data for meta-analysis. KTR with VC had a significantly increased mortality risk [1-year: risk ratio (RR) 2.19 (1.39-3.44), 5-year: RR 2.28 (1.86-2.79)]. The risk of 1-year graft loss was three times higher in recipients with VC [RR 3.15 (1.30-7.64)]. The risk of graft loss censored for death [1-year: RR 2.26 (0.58-2.73), 3-year: RR 2.19 (0.49-9.82)] and the risk of DGF (RR 1.24, 95% CI 0.98-1.58) were not statistically different. The quality of the evidence was rated as very low. To conclude, the presence of VC was associated with an increased mortality risk and risk of graft loss. In this small sample size, no statistical significant association between VC and DGF or risk of death-censored graft loss could be demonstrated. For interpretation of the outcomes, the quality and sample size of the evidence should be taken into consideration.