Coronary artery calcification progression and long-term cardiovascular outcomes in renal transplant recipients: an analysis by the joint model

Background Compared to the general population, the risk of death is substantially higher in renal transplant recipients than in age and sex matched individuals in the general population. In the general population, coronary artery calcification (CAC) predicts all-cause and cardiovascular mortality. In this study, we aimed to analyze these relationships in renal transplant recipients. Methods We examined 178 renal transplant patients in this prospective observational cohort study. We measured coronary artery calcification with multidetector spiral computed tomography using Agatston score at multiple time points. Overall, 411 scans were performed in 178 patients over an average 12.8 years follow up. The clinical end point was a composite including all cause death and non-fatal cardiovascular events. Data analysis was performed by the joint model. Results During a follow-up of 12.8 ± 2.4 years, coronary calcification progressed over time (P < 0.001) and the clinical endpoint occurred in 54 patients. In the analysis by the joint model both the baseline CAC score and the CAC score progression were strongly associated with the incidence rate of the composite event (HR: 1.261, 95% CI: 1.119-1.420, p = 0.0001) Conclusion Coronary artery calcification at baseline and coronary calcification progression robustly predict the risk of death and cardiovascular events in renal transplant recipients. These findings support the hypothesis that the link between the calcifying arteriopathy of renal transplant patients and clinical end points in these patients is causal in nature.