title: Prevalence of lactic acidaemia in patients with advanced heart failure and depressed cardiac output.
abstract: Heart failure (HF) has been defined classically as a condition in which the heart is unable to deliver sufficient oxygen to match the needs of the metabolizing tissues. Surprisingly, this definition has never been validated. The goal of this study was to determine the prevalence of elevated lactate levels in a cohort of patients with advanced heart failure.
  
  
  
  We retrospectively analysed the arterio-venous oxygen difference (A-V O2), haemodynamics, and plasma lactate levels in stage D heart failure patients who were being evaluated for a left ventricular assist device (LVAD). We identified 359 patients with a right heart catheterization (RHC) performed prior to LVAD implantation. Plasma lactate was available for 96 patients. RHC showed that 93% of the patients had an A-V O2above the upper limit of normal (>5 mL/100 mL). Among patients with measured lactate levels, the prevalence of elevated lactate (>2.1 mmol/L) was 25% (95% confidence interval 16.7-34.9). The A-V O2was widened in all patients with elevated lactate, but plasma lactate did not correlate with A-V O2(r = 0.02) and only 27% of patients with increased A-V O2had elevated plasma lactate.
  
  
  
  Lactate levels were normal in ∼75% of the patients with advanced heart failure and a widened A-V O2, suggesting that the cardiac output was sufficient to meet the metabolic needs of the peripheral metabolizing tissues. Given that ∼4% of heart failure patients are in NYHA class IV, these findings suggest that the classic definition of heart failure pertains to ∼1% of patients with HF.
authors.affiliation: Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Luigi
authors.initials: L
authors.lastname: Adamo
authors.affiliation: Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Nassif
authors.affiliation: Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Erik
authors.initials: E
authors.lastname: Novak
authors.affiliation: Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Shane J
authors.initials: SJ
authors.lastname: LaRue
authors.affiliation: Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Mann
mesh_terms: D015415:Biomarkers / Q000097:blood; D002302:Cardiac Output / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000150:complications* / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology*; D006353:Heart-Assist Devices; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008659:Metabolic Diseases / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D015995:Prevalence; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology; D016278:Ventricular Function, Right / Q000502:physiology
chemical_list: D015415:Biomarkers; D019344:Lactic Acid; D010100:Oxygen
keywords: Cardiac output; Heart failure with reduced ejection fraction; Lactic acid; Left ventricular assist device