Acute effects of aerobic exercise on aortic wall stress in thoracic aortic disease

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 TAD. Fourteen participants with stable TAD (3 females, age 69 ± 9 yr; 8 with unrepaired aneurysms) and 11 age-matched controls (CON, 4 females, age 68 ± 7 yr) underwent comprehensive cardiac and aortic evaluation using magnetic resonance imaging. Assessments included Qc and aortic structural parameters (diameter and wall thickness), measured both at rest and during light-to-moderate intensity stepping exercise. Ascending AWS increased in response to light-to-moderate intensity exercise across both groups (<i>P</i> < 0.01), with no significant group-by-exercise interaction effect (<i>P</i> = 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 (850-1,200 kPa), with the maximum recorded value being 323 kPa. 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; <i>P</i> = 0.062) but not in the descending aorta (<i>P</i> = 0.119). 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.<b>NEW & NOTEWORTHY</b> Patients with thoracic aortic disease (<i>n</i> = 14) did not show elevated aortic wall stress compared with age-matched controls (<i>n</i> = 11) during exercise. Aortic mechanical efficiency (increase in aortic wall stress relative to increase in cardiac output during exercise) may be impaired in patients with thoracic aortic disease. All exercise-induced aortic wall stress values remained well below the aneurysmal rupture threshold (800-1,200 kPa).