Abstract 4372993: Regural Physical Activity is Associated with High Exercise Performance in ACHD Patients

Background: Exercise tolerance is known to be decreased in adults with congenital heart disease (ACHD), and this is associated with prognosis. While regular physical activity is essential in ACHD patients, it is known to be impaired. However, there are few reports on the effects of regular exercise on exercise tolerance in ACHD patients. This study examined the association between regular exercise and exercise tolerance in contemporary ACHD patients. Methods: Among ACHD patients who attended our hospital regularly between April 2019 and March 2025, information on their employment status and exercise habits was obtained from a transition questionnaire. Those who underwent cardiopulmonary exercise stress testing (CPX) were selected for a retrospective study. NT-proBNP, ventricular contractility, maximal oxygen uptake (MVO2) and predicted MVO2 (ppMVO2) data were collected from blood samples, echocardiography, cardiac MRI and CPX. In addition, daily physical activity METs of 4 METs or more were defined as high activity (HA) and less than 4 METs were defined as low activity (LA). The association between each covariate and ppMVO2 was analysed. Results: A total of 30 patients were analyzed: median age at CPX was 27 [IQR 23-39] years, 37% male, BMI was 21.4±3.9, disease complexity was 46%/27%/27% complex/moderate/simple, median NT-proBNP was 90 [53-156] pg/mL, MVO2 21.1±5.1 ml/min/kg (ppMVO2 76.2±14.9%), with the high MVO2 group accounting for 40% of the total and HA for 37% of the total. The percentages of patients with normal/mildly/moderately/severely impaired ventricular contractility were 22/5/2/1 (73%/17%/7%/3%) and 22/5/2/1 (73%/17%/7%/3%), respectively. In univariate analysis, systemic ventricular contractility was not associated with high MVO2, but disease complexity and high activity group were significantly associated (p=0.01, respectively). Logistic regression analysis showed no association between NT-proBNP and high MVO2 (p=0.01 and p=0.005, respectively). Only HA was significantly associated in multivariate analysis with disease complexity and HA as covariates (p=0.002). Conclusions: Regular physical activity of 4 METs or more was associated with higher exercise tolerance. Although a cross-sectional study, the results suggest that regular physical activity in adulthood may improve exercise tolerance in ACHD patients.