Fibromuscular dysplasia appears frequently in acute type A aortic dissection, especially in women
Fibromuscular dysplasia, a non-inflammatory and non-atherosclerotic arterial disease marked by the classic string-of-beads pattern, surfaced with surprising frequency in a cohort of patients presenting with acute type A aortic dissection. In this retrospective single-center study from Erasmus University Medical Center, the phenotype was identified in 18 of 200 included patients, equal to 9% of the cohort. None of those patients carried a prior diagnosis of fibromuscular dysplasia.
The signal was stronger in women. Among 62 women with acute type A aortic dissection, 12 had confirmed fibromuscular dysplasia, a proportion of 19%. Among 138 men, 6 had the diagnosis, or 4%. The difference reached statistical significance, and it points toward a vascular substrate that may be present before the dissection is recognized at the bedside.
A vascular phenotype hiding in plain sight
This matters because fibromuscular dysplasia is not a rare curiosity in the renal or carotid circulation alone. It is a systemic arteriopathy, and the study places it in direct proximity to one of the most catastrophic cardiovascular emergencies. The observed enrichment in women fits the broader epidemiology of fibromuscular dysplasia, which predominantly affects female patients and often goes undetected until imaging is performed for another reason.
The cohort was restricted to patients younger than 70 years with acute type A aortic dissection and ECG-triggered aortic CT angiography. From 214 screened patients, 200 were included, with the imaging review concentrated on the highest-quality CT angiogram available for each case. An experienced cardiovascular radiologist performed the first review, and all suspected cases underwent independent confirmation by a second radiologist before consensus diagnosis. That workflow strengthens internal consistency, especially for a morphology-based diagnosis in which subtle arterial beading can be overlooked or misclassified.
Renal involvement dominated, but carotid disease was also present
The anatomic pattern followed what vascular specialists would expect from fibromuscular dysplasia. Renal arteries were the main territory involved. Among the 18 patients with fibromuscular dysplasia, additional carotid CT angiography was available in 7, and 3 of those 7 showed carotid involvement. Carotid imaging was available in only 49 of the 200 patients overall, so the true frequency of cervical artery involvement in this cohort almost certainly remains incompletely measured.
A single sentence captures the clinical implication: the dissection was the presenting catastrophe, but the arterial disease was likely there first.
In practical terms, that sequence raises the possibility that some patients who present with acute type A aortic dissection may have a broader vasculopathy rather than an isolated aortic event. Fibromuscular dysplasia can weaken arterial architecture through abnormal medial and fibrous proliferation, predisposing to stenosis, aneurysm formation, tortuosity, and dissection in susceptible vessels. The aorta is not the classic location, yet systemic vascular fragility may still shape the risk profile in a subset of patients, particularly women with otherwise unexplained arterial events.
What the numbers can and cannot support
The sample size remains modest, and the design was retrospective and single-center. Those features limit how far the estimates can travel, especially beyond a tertiary referral setting with expert vascular imaging review. Even so, the confidence intervals were not trivial: fibromuscular dysplasia was confirmed in 9% of all included patients, with a 95% confidence interval of 6% to 14%, and in 19% of women, with a 95% confidence interval of 11% to 31%.
The paper does not establish causality, and it does not prove that fibromuscular dysplasia triggered the dissection. It does show that the phenotype was common enough to merit attention rather than dismissal as an incidental imaging curiosity. The absence of prior fibromuscular dysplasia diagnoses in all 18 affected patients is especially striking. It suggests a meaningful degree of underrecognition in routine care, not merely a failure of classification at the research level.
Imaging review may need to look beyond the aorta
This study also presses radiology and vascular medicine toward a broader reading of the CTA obtained during acute aortic syndromes. When the scan is already in hand, the opportunity exists to inspect other arterial beds for beading, stenosis, and aneurysmal change. The renal arteries deserve particular attention in this setting because they were the most frequently involved territory here, and renal fibromuscular dysplasia can coexist with hypertension, vascular dissection, and other manifestations that alter long-term management.
In women with acute type A aortic dissection, the finding may have even more relevance. Female patients already carry a well-described burden of underdiagnosed vascular disease, and a phenotype such as fibromuscular dysplasia can be missed when the emergency focus is narrowed to the ascending aorta and surgical repair. A more systematic review of extracardiac vessels could reveal a broader arteriopathy that influences follow-up imaging, blood pressure surveillance, and screening of other vascular territories.
A preprint that expands the differential in acute aortic syndromes
Because this is a preprint, the results have not yet undergone peer review. The study should not be used to direct immediate clinical practice, and the data still need external validation in larger, multicenter cohorts. Even so, the clinical message is hard to ignore: fibromuscular dysplasia was identified in a substantial fraction of patients with acute type A aortic dissection, with a clear sex skew toward women and a dominant renal artery pattern.
For clinicians evaluating a woman with acute aortic dissection, the finding expands the differential diagnosis from the index emergency to the underlying vascular phenotype. For imaging teams, it argues for deliberate inspection of extra-aortic arteries when CTA quality allows it. For researchers, it raises a precise question about whether fibromuscular dysplasia marks a subgroup with distinct biology, vascular risk, or long-term outcomes after repair of the acute event.