title: Reduced Cardiac Index Is Not the Dominant Driver of Renal Dysfunction in Heart Failure.
abstract: BACKGROUND
  It is widely believed that a reduced cardiac index (CI) is a significant contributor to renal dysfunction in patients with heart failure (HF). However, recent data have challenged this paradigm.
  
  
  OBJECTIVE
  This study sought to determine the relationship between CI and renal function in a multicenter population of HF patients undergoing pulmonary artery catheterization (PAC).
  
  
  METHODS
  Patients undergoing PAC in either the randomized or registry portions of the ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) trial were included (n = 575). We evaluated associations between CI and renal function across multiple subgroups and assessed for nonlinear, threshold, and longitudinal relationships.
  
  
  RESULTS
  There was a weak but significant inverse correlation between CI and estimated glomerular filtration rate (eGFR), such that higher CI was paradoxically associated with worse eGFR (r = -0.12; p = 0.02). CI was not associated with blood urea nitrogen (BUN) or the BUN to creatinine ratio. Similarly, no associations were observed between CI and better renal function across multiple subgroups defined by indications for PAC or hemodynamic, laboratory, or demographic parameters. A nonlinear or threshold effect could not be identified. In patients with serial assessments of renal function and CI, we were unable to find within-subject associations between change in CI and eGFR using linear mixed modeling. Neither CI nor change in CI was lower in patients developing worsening renal function (p ≥ 0.28).
  
  
  CONCLUSIONS
  These results reinforce evidence that reduced CI is not the primary driver for renal dysfunction in patients hospitalized for HF, irrespective of the degree of CI impairment or patient subgroup analyzed.
authors.affiliation: Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Hanberg
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Krishna
authors.initials: K
authors.lastname: Sury
authors.affiliation: Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut; Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut; Veterans Affairs Medical Center, West Haven, Connecticut.
authors.forename: F Perry
authors.initials: FP
authors.lastname: Wilson
authors.affiliation: Department of Medicine, Cardiology Division, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Brisco
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Tariq
authors.initials: T
authors.lastname: Ahmad
authors.affiliation: University Medical Center, University of Groningen, Groningen, the Netherlands.
authors.forename: Jozine M
authors.initials: JM
authors.lastname: Ter Maaten
authors.affiliation: Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: J Samuel
authors.initials: JS
authors.lastname: Broughton
authors.affiliation: Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Mahlet
authors.initials: M
authors.lastname: Assefa
authors.affiliation: Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: W H Wilson
authors.initials: WHW
authors.lastname: Tang
authors.affiliation: Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut; Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut; Veterans Affairs Medical Center, West Haven, Connecticut.
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Parikh
authors.affiliation: Program of Applied Translational Research, Yale University School of Medicine, New Haven, Connecticut; Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut. Electronic address: jeffrey.testani@yale.edu.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Testani
mesh_terms: D062185:Atrial Pressure / Q000502:physiology; D001806:Blood Urea Nitrogen; D002303:Cardiac Output, Low / Q000503:physiopathology; D002407:Catheterization, Swan-Ganz; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries; D051437:Renal Insufficiency / Q000503:physiopathology*
chemical_list: D003404:Creatinine
keywords: blood urea nitrogen; cardiorenal; creatinine; pulmonary artery catheterization; renal function