title: Explanation of the variance in quality of life and activity capacity of patients with heart failure by laboratory data.
abstract: BACKGROUND
  This study was conducted to explain the variance in quality of life (QoL) and activity capacity of patients with congestive heart failure from pathophysiological changes as estimated by laboratory data.
  
  
  METHODS
  Peak oxygen consumption (peak VO2) and ventilation (VE)/carbon dioxide output (VCO2) slope derived from cardiopulmonary exercise testing, plasma N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and echocardiographic markers [left atrium (LA), left ventricular ejection fraction (LVEF)] were measured in 62 patients with congestive heart failure, who also completed the Minnesota Living with Heart Failure Questionnaire and the Specific Activity Questionnaire. All regression models were adjusted for age and sex.
  
  
  RESULTS
  On linear regression analysis, peak VO2 with P value less than 0.001, VE/VCO2 slope with P value less than 0.01, LVEF with P value less than 0.001, LA with P=0.001, and logNT-proBNP with P value less than 0.01 were found to be associated with QoL. On stepwise multiple linear regression, peak VO2 and LVEF continued to be predictive, accounting for 40% of the variability in Minnesota Living with Heart Failure Questionnaire score. On linear regression analysis, peak VO2 with P value less than 0.001, VE/VCO2 slope with P value less than 0.001, LVEF with P value less than 0.05, LA with P value less than 0.001, and logNT-proBNP with P value less than 0.001 were found to be associated with activity capacity. On stepwise multiple linear regression, peak VO2 and LA continued to be predictive, accounting for 53% of the variability in Specific Activity Questionnaire score.
  
  
  CONCLUSIONS
  Peak VO2 is independently associated both with QoL and activity capacity. In addition to peak VO2, LVEF is independently associated with QoL, and LA with activity capacity.
authors: First Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece. athanleon@hotmail.com
authors: Leonidas V
authors: LV
authors: Athanasopoulos
authors: Athanasios
authors: A
authors: Dritsas
authors: Helen A
authors: HA
authors: Doll
authors: Dennis V
authors: DV
authors: Cokkinos
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006115:Greece; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010101:Oxygen Consumption; D010446:Peptide Fragments / Q000097:blood; D011237:Predictive Value of Tests; D012123:Pulmonary Ventilation; D011788:Quality of Life; D012720:Severity of Illness Index; D013318:Stroke Volume; D011795:Surveys and Questionnaires; D016277:Ventricular Function, Left
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain