Frequency and Progression of Lung Disease Patterns in Patients with Fontan and Tetralogy of Fallot

Abnormal spirometry is common in patients with complex congenital heart disease (CHD) and is associated with impaired exercise capacity. This study evaluated longitudinal changes in spirometry and exercise capacity in tetralogy of Fallot (TOF) and Fontan patients through a retrospective chart review of spirometry and cardiopulmonary exercise tests (CPETs). All patients had a CPET with a respiratory exchange ratio (RER) greater than or equal to 1.00. The baseline CPET for patients with a single test was compared to patients with serial testing to evaluate for demographic or clinical differences. For serial testers, the first and last available CPETs were analyzed longitudinally. The study included 207 TOF patients and 147 patients with Fontan physiology. Eighty-seven TOF and 98 patients with Fontan physiology had serial testing over a mean follow-up of 5.5 ± 3.4 and 5.5 ± 3.9 years, respectively. Roughly half of the patients had abnormal spirometry for both TOF and Fontan cohorts, with restrictive lung disease patterns being the most prevalent. Several spirometry markers declined during serial testing; however, the magnitude of the decline was clinically insignificant. Spirometry measures of pulmonary function and markers of exercise capacity appear largely stable during an average 5 year follow up in our cohort of mostly adolescent and young adult TOF and Fontan patients.