P3398Cystatin C based eGFR estimation compared to crea-based estimation equation for assessing risk of cardiovascular and total mortality in population-based studies and patients with manifest CVD

Abstract

Abstract Introduction Chronic kidney disease (CKD) represents a global public health problem and affects a large proportion of the adult population worldwide. Early detection, adequate risk stratification and specific treatment can prevent or delay the adverse effects of CKD. Purpose To assess cardiovascular risk and total mortality of subjects with CKD using cystatin C based and Crea-based estimated glomerular filtration rate (eGFR) equations (CKDEpi) in the general population, in diseased cohorts, and in specific subgroups. Methods The present study has been conducted within the BiomarCaRE project, with harmonized data from 21 population-based cohorts from 6 European countries and 3 cardiovascular disease (CVD) cohorts from Germany. Cox proportional hazards models were used to assess hazard ratios (HRs) for the various CKD definitions with adverse outcomes and mortality after adjustment for age, sex, cohort, smoking status, body mass index, history of diabetes, history of hypertension, and total cholesterol. Results 21 population-based cohorts (n=76,954, median age 51 years, 52.2% men, 4.4% diabetic) and 3 diseased cohorts (n=4,982, median age 63 years, 75.6% men, 18.7% diabetic) with an average follow-up between 2.8 and 23.5 years and between 0.5 and 9.4 years, respectively, were included in the analysis. Prevalence of CKD-stage 3–5 by CKD-EPIcrea and CKD-EPIcys eGFR respectively, was 3.4% and 7.3% in the population-based cohorts and 13.9% and 14.4% in the diseased cohorts. In the population-based cohorts the incidence (per 1000 person years) of a non-fatal or fatal CVD event and total mortality respectively, was 10.0 and 11.8, whereas it was 21.2 and 17.8 in the diseased cohorts. In the population-based cohorts the HR for a CVD-event was 1.32 (95% CI 1.21–1.44) for the population with CKD-EPIcrea stage 3–5 and it was 1.47 (95% CI 1.35–1.60) based on CKD-EPIcys after adjustment for covariates. The HR for total mortality for those with CKD-EPIcrea stage 3–5 was 1.31 (1.21–1.41) and for CKD-EPIcys it was 1.86 (95% CI 1.73–2.00). Discrepancies between CKD-EPIcrea and CKD-EPIcys were even more striking across subgroups with and without diabetes or across specific age groups. Conclusion CKD is an important risk factor for subsequent CVD events and total mortality. However, point estimates of CKD-EPIcrea and CKD-EPIcys eGFR differ considerably between specific risk groups. Therefore, the clinical utility of both equations in different risk groups has to be considered and should be evaluated further. Acknowledgement/Funding 7th framework programme collaborative project, grant agreement no. HEALTH-F2-2011-278913