Coronary calcification as a predictor of cardiovascular mortality in advanced chronic kidney disease: a prospective long-term follow-up study.

BACKGROUND

Patients with advanced chronic kidney disease (CKD) exhibit higher prevalence of coronary artery calcification (CaC) than general population. CaC has been proposed as a risk factor for mortality in end-stage CKD, but most studies in the field are based on short-term follow-up.

METHODS

We conducted a cohort, 10-year prospective longitudinal study of consecutive cases referred to the renal unit. A non-enhanced multislice coronary computed tomography was performed at baseline. CaC was assessed by Agatston method. Patients were stratified according to their CaC score: severe calcification group (CaCs< 400 HU) and mild-moderate calcification group (CaCs≥400 HU). The overall and cardiovascular (CV) mortality, CV events, and factors potentially associated with CaC development were recorded.

RESULTS

137 patients with advanced CKD were enrolled and provided consent. Overall mortality rate was 58%; 40% due to CV events. The rate of overall mortality in the severe calcification group was 75%, and 30% in the low calcification group, whereas the rate of CV mortality was 35% vs. 6%, respectively (p < 0.001). The severe calcification group was older, had higher prevalence of type 2 diabetes mellitus, former cardiologic events, and lower albumin serum levels than the mild-moderate calcification group. In a multivariate Cox model, severe CaC was a significant predictor of CV mortality (HR 5.01; 95%CI 1.28 to 19.6, p = 0.02).

CONCLUSIONS

Among advanced CKD, there was a significantly increase of CV mortality in patients with severe CaCs during a 10-year follow-up period. CaCs could be a useful prognostic tool to predict CV mortality risk in CKD patients.