Clinical impact of preexisting vascular calcifications on mortality after renal transplantation

Background. Vascular calcifications (VC) are a well-known cardiovascular risk factor (CVRF) in uremic patients. However, their role on mortality after renal transplantation (RT) is unclear. Methods. In 1117 RT recipients, we investigated the association between long-term survival and the presence of VC, evaluated by preoperative posteroanterior plain radiography from aorto-iliac region, at the time of RT. The primary study outcome was all-cause mortality. Other perioperative CVRF were also collected. Results. VC were observed in 273 patients (24.4%) before RT; additionally, 132 (12%) patients died during follow-up, due, mainly, to cardiovascular (39%) or infectious (24%) complications. As expected, patients with VC showed a higher age and a greater number of CVRF than those without VC. Overall mortality rate was also higher in VC group (19 vs. 9.5%; P = 0.0001), as well as cardiovascular mortality (9.5 vs. 3.1; P = 0.048). Multivariate Cox model showed that VC were predictor of overall mortality [relative risk (RR) 1.8; 95 % CI 1.1-2.8; P = 0.015] and cardiovascular mortality (RR 2.6; 95%CI 1.1-6); P = 0.033), independently of other CVRF. An interaction between the presence of VC and diabetes was found. The effect of VC on mortality was evident in nondiabetic patients, that is, those with VC had a significantly higher mortality rate than patients without VC (21 vs. 9%; P = 0.0001). By contrast, these differences were not observed in diabetic patients (16.5 vs. 14.3%; P = 0.656). Conclusion. VC evaluated by a simple and inexpensive plain radiography are an independent predictor of cardiovascular and all-cause mortality following RT. This finding may encourage the implementation of appropriate therapeutic strategies after RT.