Association of renal function, estimated by four equations, with coronary artery disease

Individuals with impaired renal function are at increased risk of coronary artery disease (CAD). CAD is also associated with an increased likelihood of having chronic kidney disease (CKD). In the present study, we sought to determine the association between impaired renal function with CAD presence and CAD severity based on four different estimated glomerular filtration rate (eGFR) equations.

We estimated GFR values using four equations: modification of diet in renal disease (MDRD), Cockcroft-Gault (C-G), chronic kidney disease epidemiology (CKD-Epi), and Mayo Quadratic. Three hundred and fifty-six CAD patients were classified by the number of stenotic coronary arteries occluded >50%, while the CAD severity was categorized based on the number of involved coronary arteries determined to be healthy, single- and multi-vessel disease.

The mean values of eGFR calculated by CKD-Epi, MDRD, Mayo, and C-G equations were 77.44, 71.34, 96.33, and 89.49 mL/min/1.73 m(2) respectively. Based on these equations, the prevalence of eGFR <60 mL/min/1.73 m(2) among the patients with significant CAD was 41.5, 45.2, 50, and 42.9%, respectively. eGFR values calculated by four formulas were significantly higher in healthy subjects than those with single-vessel disease (p < 0.001, p = 0.004, p = 0.003, and p = 0.028, respectively). Prediction of CAD severity was statistically significant for men but not women. After controlling for the confounding effects of other covariates, three of the equations were independently related to significant CAD: CKD-Epi (p = 0.004, β = 0.969), MDRD (p = 0.003, β = 0.965), and C-G (p = 0.021, β = 0.978).

The present study established that accurate eGFR equations commonly used still accurate to determine the association of the impaired renal function with CAD presence and extent.