Peripheral arterial lesions detected by vascular ultrasound and their association with aortic events in heritable thoracic aortic diseases.

Background: Peripheral arterial involvement is increasingly recognized in patients with Marfan syndrome and related heritable thoracic aortic diseases (HTAD), yet its prevalence and clinical relevance remain poorly defined. We aimed to assess the prevalence, anatomical distribution, and association with aortic events of primary peripheral arterial lesions (PPAL) in a genetically characterized HTAD cohort. Methods: We performed a cross-sectional, single-center study including 61 patients with genetically confirmed HTAD who underwent comprehensive pan-arterial vascular ultrasound. PPAL were classified as aneurysm, ectasia, arterial tortuosity, or mega-artery. Associations between PPAL and aortic events (dissection and/or prophylactic surgery) were evaluated. Results: PPAL were identified in 39 patients (63.9%), totaling 126 lesions. Ectasia was most frequent (39%), followed by tortuosity (33%), aneurysms (25%), and mega-arteries (21%). Supra-aortic trunks were the most commonly affected territory. Peripheral aneurysms were significantly associated with aortic dissection (odds ratio [OR] 3.60, 95% confidence interval [CI] 1.03-12.54, p = 0.050). Ectasia was associated with the composite endpoint of dissection and/or surgery (OR 3.19, p = 0.040). A higher lesion burden (≥2 lesion types) was significantly associated with aortic surgery (OR 3.80, p = 0.032). Conclusions: PPAL are highly prevalent in HTAD patients and can be systematically identified using vascular ultrasound. Peripheral aneurysms are associated with aortic dissection, suggesting that comprehensive pan-arterial assessment may improve risk stratification.