Abstract 19307: Exercise Oscillatory Ventilation in Patients with Fontan Physiology
Background: Exercise oscillatory ventilation (EOV) refers to the presence of regular oscillations in minute ventilation (VE) during exercise. Several studies have shown EOV to correlate with disease severity and prognosis in acquired heart failure. We evaluated the prevalence and predictive value of EOV in patients with Fontan physiology.
Methods: We performed a cross-sectional analysis and prospective survival analysis of patients who had undergone a Fontan procedure and had continuous ramp cycle ergometry cardiopulmonary exercise testing between 2001 and 2013. EOV was defined as regular oscillations continuing for >60% of exercise duration with amplitude>15% of average VE using software developed with MATLAB R2013a (MathWorks, Natick, MA). Clinical data was reviewed for baseline characteristics and mortality or heart transplant. Survival analysis was performed using univariate and multivariable Cox regression to evaluate the predictive value of EOV status.
Results: We analyzed 253 patients with Fontan physiology who had complete follow-up data. EOV was present in 37.5% of tests. Patients with EOV were younger and smaller (Table). There was no difference in peak VO2 (59.7 vs. 61.0%predicted, p=0.51) between those with and without EOV, but patients with EOV had higher mean VE/VCO2 slope (36.8 vs. 33.7, p=0.0002). Over a median 5.5y (IQR 2.5-9.2y) follow-up, 22 patients underwent transplant or died (n=19 died without transplant, n=2 died after transplant, n=1 alive post-transplant). EOV was associated with increased risk of death or transplant (16.8% vs. 3.8%; HR 4.0, 95%CI 1.5-10.1). This association was independent of peak VO2 (multivariable HR 7.1, 95%CI 2.0-24.3), VE/VCO2 (multivariable HR 7.8, 95%CI 2.2-27.3) and NYHA functional class (multivariable HR 3.2, 95%CI 1.3-8.2).
Conclusions: EOV is a strong independent predictor of decreased transplant-free survival after the Fontan procedure.
Author Disclosures: A. Nathan: None. B. Loukas: None. L. Moko: None. F. Wu: None. D. Systrom: None. G. Lewis: None. A. Ubeda Tikkanen: None. J. Rhodes: None. K. Shafer: None. M. Landzberg: Research Grant; Significant; Actelion. A. Opotowsky: Research Grant; Significant; Actelion.
- © 2014 by American Heart Association, Inc.