title: Exercise testing identifies patients at increased risk for morbidity and mortality following Fontan surgery.
abstract: OBJECTIVE
  The objective of this study was to examine the relationship between exercise test data and mortality in patients who have had the Fontan procedure.
  
  
  METHODS
  The study was designed as a retrospective cohort study.
  
  
  METHODS
  The study was set in a tertiary care center.
  
  
  METHODS
  All study participants were Fontan patients ≥16 years old who had cardiopulmonary exercise tests at our institution between November 2002 and March 2010. The first exercise test with adequate effort during the study period was retained for analysis. We enrolled 146 patients at a median age of 21.5 years (16.0-51.6); 15.8 years (1.2-29.9) after Fontan surgery.
  
  
  METHODS
  The outcome measures were exercise test data (peak oxygen consumption, peak heart rate, etc.); mortality.
  
  
  RESULTS
  Peak oxygen consumption averaged 21.2 ± 6.2 mL/kg/min, 57.1 ± 14.1% predicted. Follow-up data were collected 4.0 ± 2.0 years (range 0.3-7.7) after the exercise test. Sixteen patients (11%) died during follow-up; their peak oxygen consumption (16.3 ± 4.0 mL/kg/min) was significantly less than the survivors' (21.8 ± 6.2 mL/kg/min; P < .0001). Recursive partitioning and Cox proportional hazards modeling revealed that the hazard for death for patients with a peak oxygen consumption of <16.6 mL/kg/min was 7.5 (95% confidence interval: 2.6, 21.6; P < .0002) times that of patients with a higher peak oxygen consumption. Similarly, the hazard ratio for patients with peak-exercise heart rates of <122.5 bpm was 10.6 (3.0, 37.1; 0 < 0.0002). Data from exercise tests could also identify patients at increased risk for a combined morbidity/mortality end point.
  
  
  CONCLUSIONS
  In adults with Fontan surgery, exercise test data can identify patients at increased risk of midterm morbidity and mortality.
authors.affiliation: Department of Cardiology, Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Fernandes
authors.forename: Mark E
authors.initials: ME
authors.lastname: Alexander
authors.forename: Dionne A
authors.initials: DA
authors.lastname: Graham
authors.forename: Paul
authors.initials: P
authors.lastname: Khairy
authors.forename: Mathieu
authors.initials: M
authors.lastname: Clair
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Rodriguez
authors.forename: Dorothy D
authors.initials: DD
authors.lastname: Pearson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Landzberg
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rhodes
mesh_terms: D000293:Adolescent; D000328:Adult; D001900:Boston; D016009:Chi-Square Distribution; D005080:Exercise Test; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects* / Q000401:mortality; D005541:Forced Expiratory Volume; D006339:Heart Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013147:Spirometry; D013997:Time Factors; D016896:Treatment Outcome; D014797:Vital Capacity; D055815:Young Adult