Abstract 17858: Decline in Peak Oxygen Consumption on Serial Cardiopulmonary Exercise Tests Predicts Death or Transplantation in Adults With a Single Ventricle Fontan Circulation
Introduction: Peak oxygen consumption (pVO2) measured by cardiopulmonary exercise testing (CPET) predicts mortality in adults with a Fontan circulation. We investigated the additive prognostic value of change in pVO2 over time.
Hypothesis: We hypothesized that change in pVO2 between consecutive CPETs would predict time to death or transplantation in adults with a Fontan circulation.
Methods: We analyzed all adult patients with a Fontan circulation at our institution between 2003-2015 with 2 maximal (RER>1.05) CPETs separated by 6-30 months. Freedom from death or cardiac transplant was analyzed using Log Rank tests and Cox regression, with % change in pVO2 (mL/kg/min) between the 2 CPETs as the independent variable (univariate and adjusting for baseline pVO2). Change in pVO2 was also analyzed as a dichotomous variable.
Results: The study included 268 CPET pairs from 124 patients. Age averaged 26.6+/-9.5 years, 41% were female and the most common underlying diagnoses were tricuspid atresia (31.0%), double inlet left ventricle (19.8%) and hypoplastic left heart syndrome (19.0%). Average time between CPETs was 1.3+/-0.5 years. Eleven patients died and 2 underwent transplant. On average, pVO2 declined 9.8+/-14.6% between tests for patients who subsequently died or underwent transplant; in contrast, there was no change for those who did not suffer this outcome (0.0+/-13.0%). Decrease in pVO2 between tests was associated with increased risk of death or transplant in univariate analysis (per 10% decrease in pVO2, HR 1.9, 95%CI 1.2-3.0, p=0.004) (figure shows change in pVO2 as dichotomous variable). Change in pVO2 remained a significant predictor after controlling for baseline pVO2 (HR 2.5, 1.6-4.1, p<0.001).
Conclusions: A decline in pVO2 between consecutive CPETs predicts increased risk for death or transplant in adults with a Fontan circulation independent of initial pVO2. These results support the additive clinical value of serial CPET in this group of patients.
Author Disclosures: J.W. Cunningham: None. J. Rhodes: None. K.M. Shafer: None. A.R. Opotowsky: None.
- © 2016 by American Heart Association, Inc.