Cardiovascular Risk Prediction with the Kidney Failure Risk Equation in the Chronic Renal Insufficiency Study.

BACKGROUND: The Kidney Failure Risk Equation (KFRE) is an established tool to predict the risk of kidney failure among patients with CKD. Patients with CKD more often die from cardiovascular (CV) causes than renal causes, and more often experience a non-fatal CV event than progress to kidney failure. The CV predictive ability of the KFRE in CKD is unclear. METHODS: We investigated the association of the 8-variable 5-year KFRE with CV disease (composite of heart failure hospitalization, myocardial infarction, or stroke) and death among 3,203 patients with eGFR 15-60 mL/min/1.73m2 in the Chronic Renal Insufficiency Cohort (CRIC). KFRE was modeled continuously and by quartiles. We evaluated KFRE's predictive performance in a subgroup of 2,124 patients without prior CV disease. Discrimination was assessed using Harrell's C-statistic, and compared to the American Heart Association PREVENT equations. RESULTS: Mean eGFR was 38±11 mL/min/1.73 m2; median UACR was 71 [11, 523] mg/g; median KFRE score was 0.69 [0.19, 3.0] %. Over a median follow-up time of 8.6 years, 1128/3184 (35%) CV events occurred. KFRE score (per log-unit) was associated with a 27% higher risk of CV disease (HR 1.27; 95%CI 1.22-1.31), and an 18% higher risk of death (HR 1.18; 95%CI 1.15-1.22). In quartile analyses, KFRE was associated with a 3.34-fold higher risk of CV disease (HRQ4:Q1 3.34; 95%CI 2.77-4.03), and a 2.38-fold higher risk of death (HRQ4:Q1 2.38; 95%CI 2.04-2.78). Among those without prior CV disease (548 events over a median 10.6 years), KFRE showed modest discrimination (C-statistic 0.642), while the 10-year UACR-enhanced AHA PREVENT equation achieved 0.698 (p<0.001). CONCLUSIONS: A higher KFRE was associated with a higher risk of CV disease and death. Although lower than PREVENT, KFRE showed moderate discrimination for CV disease prediction, offering dual kidney and CV risk stratification with a single simple tool.