title: Chronic kidney disease and prognosis in elderly patients with cardiovascular disease: Comparison between CKD-EPI and Berlin Initiative Study-1 formulas.
abstract: Chronic kidney disease (CKD) is frequent in patients with cardiovascular (CV) disease and impacts prognosis in these subjects. While current guidelines recommend the CKD-EPI equation for the estimated glomerular filtration rate (eGFR) and recognizing CKD, a new creatinine-based equation - the Berlin Initiative Study-1 (BIS-1) - was generated for elders with a high prevalence of CV disease. We assessed whether BIS-1 provided more accurate risk stratification than the CKD-EPI equation in unselected aged patients with CV disease.
  
  
  
  Patients aged ≥70 years who were seen consecutively at the Cardiovascular Centre of Trieste (Italy) between November 2009 and October 2013 were recruited into this study. The correlation and agreement between the BIS-1 and CKD-EPI formulas were evaluated and intra-class correlation coefficients (ICCs) were computed in order to estimate the correlation between the two formulas. Patients were followed for all-cause death, composite outcomes of all-cause death/all-cause hospitalization and all-cause death/CV hospitalization.
  
  
  
  A total of 7845 subjects met the inclusion criteria for this study. GFR as estimated with the BIS-1 and the CKD-EPI equation was highly correlated (ICC: 0.81; 95% confidence interval [CI]: 0.79-0.82; p < 0.0001). When allocating patients in Kidney Disease Improving Global Outcomes classes of eGFR, compared to CKD-EPI, the BIS-1 formula reclassified 2720 (34.7%) patients: 53 (1.9%) were placed in a better class and 2667 (98.1%) were placed in a worse class. Multivariable Cox models showed that BIS-1 compared to CKD-EPI had a significantly better accuracy for predicting death (NRI: 0.12; 95% CI: 0.03-0.19; p = 0.001), death/CV hospitalization (net reclassification improvement [NRI]: 0.34; 95% CI: 0.27-0.38; p < 0.001) and death/all-cause hospitalization (NRI: 0.14; 95% CI: 0.06-0.21; p = 0.001).
  
  
  
  The BIS-1 formula is better than the CKD-EPI formula for risk stratification of CKD in elderly people with CV disease.
authors.affiliation: UOC Cardiologia, Azienda ULSS Numero 1, Belluno, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Tarantini
authors.affiliation: Division of General Internal Medicine, University of Alberta, Edmonton, AB, Canada.
authors.forename: Finlay Aleck
authors.initials: FA
authors.lastname: McAlister
authors.affiliation: Cardiovascular Center, ASS 1 Trieste, Trieste, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Barbati
authors.affiliation: Division of General Internal Medicine, University of Alberta, Edmonton, AB, Canada Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada.
authors.forename: Justin Adrian
authors.initials: JA
authors.lastname: Ezekowitz
authors.affiliation: Department of Cardiology, Villa Bianca Hospital, Trento, Italy gcioffi@villabiancatrento.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cioffi
authors.affiliation: Department of Cardiology, Spedali Civili, Brescia, Italy.
authors.forename: Pompilio
authors.initials: P
authors.lastname: Faggiano
authors.affiliation: Department of Cardiology, S. Camillo Hospital, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pulignano
authors.affiliation: Cardiovascular Center, ASS 1 Trieste, Trieste, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Cherubini
authors.affiliation: UOC Cardiologia, Azienda ULSS Numero 1, Belluno, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Grisolia Franceschini
authors.affiliation: Cardiovascular Center, ASS 1 Trieste, Trieste, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Lenarda
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000150:complications* / Q000401:mortality; D002423:Cause of Death / Q000639:trends; D003404:Creatinine / Q000097:blood; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate / Q000639:trends
chemical_list: D003404:Creatinine
keywords: BIS-1 formula; CKD-EPI formula; Cardiovascular disease; chronic kidney disease; glomerular filtration rate; prognosis