As eGFR Goes Down, Coronary Artery Calcium Goes Up

 

Worsening chronic kidney disease (CKD) is linked to increasing coronary artery calcification (CAC) independently of traditional risk factors, reports a study in the American Journal of Kidney Diseases.

The study included a multiethnic sample of CKD patients from the Chronic Renal Insufficiency Cohort Study. All patients underwent coronary calcium scanning with calculation of the Agatston CAC score. The association between estimated GFR (eGFR) and CAC was assessed.

The results showed a strong graded association between decreased kidney function and increased CAC. On unadjusted analysis, the odds ratio for having a higher CAC score increased from 1.68 at an eGFR of 50 to 59 mL/min/1.73 m2 to 2.82 at an eGFR less than 30 mL/min/1.73 m2. The association was somewhat weakened on multivariate analysis but was still significant: odds ratio 1.53 at an eGFR less than 30 mL/min/1.73 m2. The association was independent of traditional risk factors and albuminuria.

Coronary artery calcium is a risk factor for fatal and nonfatal cardiovascular events, but its significance in the CKD population is unclear. This cross-sectional study of CKD patients finds that lower levels of kidney function are independently associated with higher CAC scores.

The results may have important implications for the care of patients with CKD, especially in light of recent guidelines calling for vascular/valvular calcification to be considered in individualized treatment. The ongoing study will collect data on how CAC affects the rates of cardiovascular and renal events in patients with CKD. [Budoff MJ, et al. Relationship of estimated GFR and coronary artery calcification in the CRIC (Chronic Renal Insufficiency Cohort) study. Am J Kidney Dis 2011; 58:519–526.]


December 2011 (Vol. 3, Number 12)