Acute Effects of Aerobic Exercise on Aortic Wall Stress in Thoracic Aortic Disease

Aims: Patients with thoracic aortic disease (TAD; aneurysm and dissection) with well-controlled blood pressure are recommended to perform regular aerobic exercise of light-to-moderate intensity; however, the biomechanical impact on the aortic wall remains unknown. The aim of this study was to quantify aortic wall stress (AWS) and aortic mechanical efficiency (AME; AWS normalized to cardiac output (Qc)), during aerobic exercise in individuals with thoracic aortic disease (TAD). Methods: Fourteen participants with stable TAD (3 females, age 69±9 years; 8 with unrepaired aneurysms) and eleven age-matched controls (CON, 4 females, age 68±7 years) underwent comprehensive cardiac and aortic evaluation using magnetic resonance imaging (MRI). Assessments included Qc and aortic structural parameters (diameter and wall thickness), measured both at rest and during light-to-moderate intensity stepping exercise. Results: Ascending AWS increased in response to light-to-moderate intensity exercise across both groups (p<0.01), with no significant group-by-exercise interaction effect (p=0.793). A similar pattern was observed in the descending aorta. Importantly, all AWS values measured during exercise remained below the established threshold for aneurysmal rupture (850-1200Kpa), with the maximum recorded value being 323kPa. Patients with TAD tended to exhibit lower AME (higher AWS/Qc slopes) in the ascending aorta (16.8 ± 12.8 vs 9.2 ± 4.0 kPa/L/min; p=0.062), but not in the descending aorta (p=0.119). Conclusion: Our study provides new evidence to support the physical activity guidelines for people with aortic disease participating in moderate intensity aerobic exercise. By integrating individual risk profiles with biomechanical data, we can continue to advance clinical understanding of safe and effective exercise in this population.