title: Estimated glomerular filtration rate calculated using different creatinine and cystatin based formulas in prediction of trough plasma Dabigtran concentration.
abstract: BACKGROUND
  In this paper we evaluated the relationship between trough DAB concentration with eGFR calculated using CRE and CYS based formulas.
  
  
  METHODS
  We considered 100 patients. eGFR was calculated using CKD-EPIcreat, CG, MDRD, CKD-EPIcys and CKD-EPIcombined equations. DAB dosage was selected on the basis of CKD-EPIcreat and relationship between trough DAB concentration and eGFRs was evaluated.
  
  
  RESULTS
  Trough DAB concentration roughly correlates with eGFR calculated using various formulas. CKD-EPIcreat eGFR was higher than CKD-EPIcys. In patients receiving a DAB dosage considered adequate using CKD-EPIcreat eGFR but considered excessive using CKD-EPIcys, we observed higher DAB trough concentration and an increased prevalence of subjects with drug concentration >200ng/mL.
  
  
  CONCLUSIONS
  These results suggest that eGFR alone was unable to fully explain trough DAB plasma concentration. Therefore a drug's prescription schedule based on eGFR only should be inadequate. We observed a better correlation between trough DAB concentration and CKD-EPIcys rather than CKD-EPIcreat eGFR. Thus, in patients chronically treated with DAB for thromboprophylaxis in nonvalvular atrial fibrillation evaluation of eGFR using a cystatin base formula should be considered.
authors.affiliation: Transfusional Dept., Ospedale dell'Angelo, Mestre, Italy. Electronic address: gianluca.gessoni@ulss12.ve.it.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gessoni
authors.affiliation: Clinical Pathology Dept., Ospedale Madonna della Navicella, Chioggia, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Valverde
authors.affiliation: Clinical Pathology Dept., Ospedale Madonna della Navicella, Chioggia, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gessoni
authors.affiliation: Cardiology and Intensive Coronary Unit, Ospedale Madonna della Navicella, Chioggia, Italy.
authors.forename: Letizia
authors.initials: L
authors.lastname: Valle
authors.affiliation: Cardiology and Intensive Coronary Unit, Ospedale Madonna della Navicella, Chioggia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Valle
mesh_terms: D000368:Aged; D003404:Creatinine / Q000097:blood*; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D015891:Cystatins; D003404:Creatinine
keywords: CKD-EPI; Cockcroft-Gault; Creatinine; Cystatin; Dabigatran; MDRD; eGFR