Impact of Abdominal Aortic Calcification on Long-Term Cardiovascular Outcomes in Patients with Chronic Kidney Disease.

Introduction: Abdominal aortic calcification (AAC) was related to cardiovascular (CV) events in hemodialysis patients. However, little is known about predictive value of the AAC for CV events in chronic kidney disease (CKD) patients. Hypothesis: The purpose of this study was to investigate the prevalence and the predictive value of AAC in asymptomatic CKD patients. Methods: We prospectively evaluated 347 asymptomatic CKD patients (mean estimated glomerular filtration rate: 46.6 ± 22.9 mL/min/1.73 m2). A non-contrast computed tomography scan was used to determine the abdominal aortic calcification index (ACI) as a semi-quantitative measure of aortic calcification. Major adverse cardiovascular events (MACE) were defined as the composite endpoint of cardiovascular death, myocardial infarction, stroke, heart failure, and any coronary revascularization. Results: Among the subjects, AAC was present in 296 patients (86.3%), as defined by ACI > 0, and the median ACI was 11.4% (interquartile ranges; 1.38 - 30.7%). During the median follow-up of 41.5 months, a total of 33 MACEs were observed. Event-free survival rate was significantly associated with ACI tertiles, patients with the high tertile of ACI had the highest risk of MACE compared to the other two groups (high, middle and low tertile; 74.3%, 93.0%, and 96.5%, respectively, p< 0.001). The Cox proportional hazard models adjusted for conventional risk factors showed that the ACI was independently associated with MACE (hazard ratio 1.032, 95% confidence interval, 1.009- 1.055, p= 0.006). Conclusions: Evaluation of the AAC may provide useful information for predicting adverse clinical outcomes among asymptomatic CKD patients.