title: Prognostic value of exercise variables in 335 patients after the Fontan operation: a 23-year single-center experience of cardiopulmonary exercise testing.
abstract: BACKGROUND
  The prognostic value of cardiopulmonary exercise testing (CPX) for mortality risk remains controversial in Fontan patients.
  
  
  OBJECTIVE
  Our goal of the present study was to clarify the prognostic value of major CPX variables and the factors determining exercise capacity in a large cohort of Fontan patients.
  
  
  METHODS
  Since 1990, heart rate (HR), oxygen uptake (VO2 ), and ventilatory equivalent for carbon dioxide production (VE/VCO2 ) at peak exercise were determined in 335 Fontan patients (18 ± 5 years old), and the CPX variables were compared with the clinical profile and events.
  
  
  RESULTS
  When compared with 209 controls, peak HR (148 ± 24 bpm), VO2 (27 ± 7 mL/kg/minute, [61 ± 15%]), and VE/VCO2 (40 ± 8 [117 ± 24%]) were markedly impaired in the Fontan patients (P < .0001). During a follow-up of 3.1 ± 2.7 years, 62 Fontan pathophysiological-associated events requiring unscheduled hospitalization (USH) occurred, and 24 patients died. All the CPX variables predicted the USH and mortality (P < .001-.0001). On multivariate analysis, in addition to use of diuretics (P = .0007) and low cardiac index (P = .0426), peak VO2 independently predicted the USH (hazard ratio: 0.95 per %, 95% confidence interval: 0.91-0.99, P = .014), while for mortality, multivariate analysis revealed that, in addition to heterotaxy syndrome (P = .0128) and year at first Fontan operation (P = .0532), peak VO2 independently predicted mortality (hazard ratio: 0.88 per %, 95% confidence interval: 0.76-0.98, P = .0217).
  
  
  CONCLUSIONS
  Fontan patients exhibit markedly impaired CPX variables, and all the major variables, especially peak VO2 , predicted the risk of both morbidity and mortality.
authors.affiliation: Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Ohuchi
authors.forename: Jun
authors.initials: J
authors.lastname: Negishi
authors.forename: Kanae
authors.initials: K
authors.lastname: Noritake
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Hayama
authors.forename: Heima
authors.initials: H
authors.lastname: Sakaguchi
authors.forename: Aya
authors.initials: A
authors.lastname: Miyazaki
authors.forename: Koji
authors.initials: K
authors.lastname: Kagisaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamada
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005080:Exercise Test; D005260:Female; D018729:Fontan Procedure; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors
keywords: Exercise Testing; Fontan; Heart Failure; Mortality; Peak Oxygen Uptake