A novel model of cardiovascular risk based on kidney function

Area of Science:

• Nephrology
• Cardiology
• Epidemiology

Background:

• Estimated glomerular filtration rate (eGFR) based on serum creatinine is linked to cardiovascular events, but optimal thresholds for risk prediction are not well-defined.
• Current guidelines often use a threshold of 60 ml/min/1.73 m(2) to indicate moderate kidney abnormality.

Purpose of the Study:

• To identify serum creatinine and eGFR thresholds that maximize sensitivity and specificity for predicting a composite outcome of coronary heart disease, stroke, and death.
• To compare the predictive utility of different eGFR equations and serum creatinine levels.

Main Methods:

• Classification tree methodology was employed to determine the hierarchical importance of serum creatinine, eGFR, and cardiovascular risk factors in adults aged 45-64.
• Data from the Atherosclerosis Risk in Communities Study (n=15,582) with a 13.1-year follow-up were analyzed.
• Three eGFR equations were used: CKD-EPI, MDRD Study, and Cockcroft-Gault corrected for body surface area (CG/BSA).

Main Results:

• The optimal threshold for serum creatinine to predict the composite outcome was 0.73 mg/dl (sensitivity 0.66, specificity 0.48).
• Optimal eGFR thresholds varied by equation, with CKD-EPI at 95 ml/min/1.73 m(2) (0.52/0.59), CG/BSA at 90 ml/min/1.73 m(2) (0.44/0.67), and MDRD at 75 ml/min/1.73 m(2) (0.16/0.91).
• These thresholds are substantially higher than the commonly used 60 ml/min/1.73 m(2). High-density lipoprotein cholesterol was a stronger predictor than renal function thresholds.

Conclusions:

• Optimal eGFR thresholds for community-based cardiovascular risk stratification are significantly higher than the 60 ml/min/1.73 m(2) threshold.
• The predictive value of creatinine-based risk assessment appears modest in older adult populations.
• Modifiable cardiovascular risk factors, such as HDL cholesterol, may offer superior risk stratification compared to renal function thresholds.