Arterial hypertension and aortic root dilatation: an unsolved mystery

Abstract

Introduction: Acute and chronic aortic syndromes are associated with substantial morbidity and mortality. Silent risk factors such as arterial hypertension and aortic root dilatation can increase the likelihood of aortic dissection or rupture. The relationship between arterial hypertension and the dimensions of the aortic root dimension is a topic of active debate. Materials and methods: We reviewed the literature on the physiopathology, diagnosis, natural history, and management of thoracic aortic aneurysms. Results: Biological variables influencing the size of the aorta include age, sex, body surface area, pressure values, and stroke volume. Pathologic enlargement of the thoracic aorta can be caused by genetic, degenerative, inflammatory, traumatic, or toxic factors. Studies investigating the correlation between aortic dimensions and arterial pressures (diastolic, systolic, or pulse) have produced discordant results. Discussion: Classically, emphasis has been placed on the importance of hypertension-related degeneration of the medial layer of the aortic wall, which leads to dilatation of the thoracic aorta, reduced aortic wall compliance, and increased pulse pressures. However, there are no published data that demonstrate unequivocally the existence of a pathogenetic correlation between arterial hypertension and aortic root dilatation. Furthermore, there is no evidence that antihypertensive therapy is effective in the management of nonsyndromic forms of aortic root dilatation. An interesting branch of research focuses on the importance of genetic predisposition in the pathogenesis of thoracic aortic aneurysms. Different genetic backgrounds could explain differences in the behaviour of aortic walls exposed to the same hemodynamic stress. Further study is needed to evaluate these focal physiopathological aspects.

Aortic root dilatation in essential hypertension

“…First of all, it is generally recognized that aortic dimension are strictly related to patients' age [6,17,19,20]. Use of absolute cut offs that do not consider the ageing process may lead to an important under-diagnosis of these pathological features in relatively young adults.…”

“…Moreover, aortic dimensions are generally strictly related to body surface [6,17,19,20]. For this reason, it has been proposed, and recently remarked [3] on the opportunity of an indexation for body surface is a good method for identifying patients with aortic dilatation, considering the high prognostic value of such a diagnosis in the respect of the risk of dissection [21].…”

Relationship between Aortic Root Diameter and Type 2 Diabetes in Hypertensive Patients

“…Traditionally, hypertension causes degeneration of the medial layer of the aortic wall, which results in dilatation of the thoracic aorta, declined aortic wall compliance, and elevated pulse pressures [4,5].…”