Abstract 4145104: Can Stress Echocardiography during Cardiopulmonary Exercise Testing Help Predict Clinical Outcomes in Right-Sided Congenital Heart Disease?

Background: The optimal timing for intervention for pulmonary and right ventricular outflow tract stenosis in adult congenital heart disease (ACHD) remains uncertain. While stress echocardiography is an established modality to improve risk stratification in stenotic left-sided lesions, its utility in right-sided valve disease in the ACHD population has not been studied. We assessed if stress echocardiographic assessment of right ventricular (RV) function during cardiopulmonary exercise testing (CPET) can facilitate risk stratification in the ACHD population. Objectives: The purpose of this study was to determine the relationship between RV augmentation on stress echocardiogram during CPET and morbidity in ACHD patients with sub-pulmonary right ventricles and right-sided stenotic lesions. Methods: A retrospective cohort study of ACHD patients with sub-pulmonary right ventricles who underwent CPET with stress echocardiogram was performed. The primary outcome was defined as having at least one of the following: 1) cardiac related hospitalization, 2) new documented arrhythmia, or 3) new or worsening heart failure. RV augmentation on stress echo was verified by concordance with a second observer. Results: The study included 87 patients, 41 (47%) with repaired tetralogy of Fallot, 9 (10.3%) with RV-PA conduits, and 9 (10.3%) with pulmonary stenosis. On baseline transthoracic echocardiogram, median peak pulmonary valve gradient was 38.7 mmHg (Q1 17.9 , Q3 49.0) and 30% of patients had RV dysfunction. On stress imaging, 13 (14.9%) did not demonstrate RV augmentation. Those without RV augmentation had a lower percent predicted peak Vo2 (61.4% vs 75.4%, p=0.007). Eleven (12.6%) met the primary outcome. Lack of RV augmentation was strongly associated with the primary outcome (OR 4.25, CI 1.04 –17.46, p = 0.04). This association remained true in patients with baseline peak PV gradients less than 50mmHg (OR 8.7, CI 1.68 – 46.79, p = 0.009) and was more pronounced in patients with tetralogy of Fallot (OR 33.99, CI 3.29 – 829, p = 0.007). Conclusions: Lack of RV augmentation on stress echo during CPET is associated with increased morbidity in ACHD patients with right-sided stenotic lesions. These results suggest that stress echocardiography at the time of CPET should be considered in this population.