A novel model of cardiovascular risk based on kidney function

Abstract

Background/Aims: Although creatinine-based estimated glomerular filtration rate (eGFR) is associated with cardiovascular events, threshold values for optimum discrimination are unclear. We aimed to identify serum creatinine and eGFR thresholds of maximum sensitivity and specificity (Max Sn+Sp) for a composite outcome of coronary heart disease, stroke, and death. Methods: Classification tree methodology defined the hierarchical rank of serum creatinine, eGFR, and cardiovascular risk factors in adults aged 45-64 years (Atherosclerosis Risk in Communities Study, n = 15,582; follow-up, 13.1 years). The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD) Study, and Cockcroft-Gault corrected for body surface area (CG/BSA) eGFR equations were used. Results: The mean study population age was 54.2 years; 26.4% were African-American. The mean standardized creatinine level was 0.83 mg/dl. The mean eGFR CKD-EPI, eGFR MDRD, and eGFR CG/BSA values were 95.7, 98.6, and 99.7 ml/min/1.73 m 2, respectively. The composite outcome occurred for 22.1% of the population. For all eGFR measures, sensitivity was <0.05 and specificity >0.98 for thresholds of 60 ml/min/1.73 m 2. Max Sn+Sp for serum creatinine occurred at 0.73 mg/dl (sensitivity 0.66/specificity 0.48); corresponding values for eGFR CKD-EPI, eGFR CG/BSA, and eGFR MDRD were 95 (0.52/0.59), 90 (0.44/0.67), and 75 (0.16/0.91) ml/min/1.73 m 2, respectively. Considering optimum thresholds for 10 modifiable risk factors, high-density lipoprotein cholesterol ≤44 mg/dl ranked first; rankings for optimum renal function thresholds varied between sixth and tenth. Conclusions: Optimum eGFR thresholds for community-based risk triage were substantially higher than 60 ml/min/1.73 m 2, which currently defines moderate abnormality. Utility of creatinine-based risk triage in older adults appears modest. Copyright © 2011 S. Karger AG, Basel.