[Comparison of the cardiovascular predictive value of MDRD and CKD-EPI in estimating chronic kidney disease]

Abstract

Objective: To assess predictive value of the cardiovascular prognosis by comparing the two most used formulas for the estimation of glomerular filtration rate in hypertensive patients.

Material and methods: A retrospective cohort study was designed that included 405 patients diagnosed with essential hypertension. The patients were referred from Primary Care to the Hypertension and Vascular Risk Unit between January 1, 1998 and August 31, 1999. Blood pressure measurements, blood and urine analysis, and echocardiography were simultaneously performed. They were followed up for 12.5 years (mean [± IQR]: 10.61 [± 3.11] years) and 174 events were recorded.

Results: The study included 405 patients (53.8% women), with a mean age of 55.5 years. The estimated glomerular filtration rate according to the MDRD and CKD-EPI equations was 73.9±2.6 mL/min/1.73m(2) and 76.9±2.2 mL/min/1.73m(2), respectively. The prevalence of chronic kidney disease was 31.6% and 23.9%, respectively. Using the CKD-EPI equation led to the re-classification of 22.9% of patients. The incidence rate ratio (IRR [95%CI] for chronic kidney disease identified by the MDRD equation was 2.4 [1.8-3.3], and for the CKD-EPI calculation it was 2.5 [1.8 to 3.3]).

Conclusions: Both equations estimate similar magnitudes of renal function, although the CKD-EPI equation has less false positives, and both have similar prognostic values in patients at high cardiovascular risk as well those at low risk.

Keywords: CKD-EPI; Cardiovascular prognosis; Chronic kidney disease; Enfermedad renal crónica; MDRD; Pronóstico cardiovascular.