title: Cardiac output as a predictor in congenital heart disease: Are we stating the obvious?
abstract: BACKGROUND
  Significant pulmonary regurgitation, declining right-sided ejection fraction, increased right ventricular (RV) volumes as well as left ventricular (LV) dysfunction have all been identified as predictors of poor outcomes in patients with congenital heart disease (CHD). The prognostic value of the cardiac output (CO) in these patients however has never been studied.
  
  
  METHODS
  All consecutive ambulatory adult patients with CHD referred for magnetic resonance imaging (MRI) at the Montreal Children's Hospital between June 2007 and May 2009 were included. Right ventricular (RV) and left ventricular (LV) variables including end diastolic and end systolic volumes (EDV, ESV respectively), ejection fractions (EF) and regurgitant volumes were obtained. Cardiac index (CI) was calculated. Patients were followed for cardiac-related hospitalizations and cardiac interventions.
  
  
  RESULTS
  Ninety-six patients were included. Median follow up was 3.9 ± 1.4 years. Nineteen percent of patients had a systemic CI<2.4 l/min/m(2). LVEDV, LVEF and RVEF were significantly diminished in the low CI group with a significant increase in RVESV and total regurgitant volume. Best predictors of low CI were LVEF (AUC=0.74), RVEF (AUC=0.71), total RV regurgitant volume (AUC=0.64) and RVESV (AUC=0.563). Low systemic CI was the best predictor of cardiac-related hospitalizations (hazard ratio 3.5, 95% confidence interval 1.5-8.5) and cardiac interventions (hazard ratio 2.2, 95% confidence interval 1.3-4.0), superior to LVEF, RVEF, total regurgitant volume and RVESV parameters.
  
  
  CONCLUSIONS
  In patients with congenital heart disease, cardiac index is the best predictor of cardiac hospitalizations and cardiac interventions.
authors.affiliation: Beth Raby Adult Congenital Heart Disease Clinic, Jewish General Hospital, Montréal, Canada.
authors.forename: Ali O
authors.initials: AO
authors.lastname: Abualsaud
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada; Beth Raby Adult Congenital Heart Disease Clinic, Jewish General Hospital, Montréal, Canada.
authors.forename: Boris S
authors.initials: BS
authors.lastname: Lowe
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Guo
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada.
authors.forename: Ariane J
authors.initials: AJ
authors.lastname: Marelli
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Kaouache
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada.
authors.forename: Liming
authors.initials: L
authors.lastname: Guo
authors.affiliation: Montréal Children's Hospital, Montréal, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Jutras
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Martucci
authors.affiliation: McGill Adult Unit for Congenital Heart Disease Excellence (MAUDE Unit), McGill University Health Center, Montréal, Canada; Beth Raby Adult Congenital Heart Disease Clinic, Jewish General Hospital, Montréal, Canada. Electronic address: judith.therrien@mcgill.ca.
authors.forename: Judith
authors.initials: J
authors.lastname: Therrien
mesh_terms: D000293:Adolescent; D000328:Adult; D002302:Cardiac Output / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006760:Hospitalization / Q000639:trends; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D055815:Young Adult
keywords: Cardiac index; Congenital heart disease; Heart failure; Magnetic resonance imaging