Aortic Diameter Predicts Acute Type A Aortic Dissection in Patients With Marfan Syndrome but Not in Patients Without Marfan Syndrome

Study Questions:

Does aortic size identify patients at risk of type A acute aortic dissection (AAD) in patients with and without Marfan syndrome (MFS)?

Methods:

This retrospective study examined 237 patients with type A AAD enrolled over 25 years at a single site, and compared the maximal ascending aortic diameter between patients with and without MFS.

Results:

Mean age was 58 ± 12 years and 49% (100/206) were male among those without MFS; mean age was 33 ± 10 years and 65% (20/31) were male among the cohort with MFS. In patients presenting with type A AAD, patients with (vs. without) MFS had differences in mean sizes of the aortic root (59 ± 16 vs. 40 ± 6 mm, p < 0.001), and median sizes of the ascending aorta (36 vs. 44 mm, p < 0.001), aortic arch (31 vs. 38 mm, p < 0.001), mid descending aorta (30 vs. 34 mm, p < 0.001), and abdominal aorta (27 vs. 29 mm, p = 0.006). In non-MFS patients with type A AAD, a maximal ascending aorta diameter of <55 mm was present in 87% of patients (170/206). The only independent predictor of aortic dissection in patients without MFS and with a maximal diameter <55 mm was an elevated BMI (odds ratio 1.4, p = 0.001). In MFS patients with type A AAD, a maximal ascending aorta diameter of <45 mm was noted in 25% of patients (8/31).

Conclusions:

Type A AAD frequently occurred at sizes smaller than previously reported, and those without MFS had smaller ascending aortas than those with MFS.

Perspective:

Current guidelines suggest consideration of elective surgery in patients with an ascending aorta that is ≥45 mm in those with MFS, or ≥55 mm in those without MFS. However, the present study observes that type A AAD often occurs in patients with smaller aortas. Importantly, recent literature has reported that AAD results in an acute increase in aortic size as compared to pre-AAD imaging, suggesting that the size after AAD overestimates pre-AAD aortic size. These findings demonstrate the challenges in using aortic diameter to determine which patients are at risk of type A AAD.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Cardiac Surgery and CHD & Pediatrics, Congenital Heart Disease, CHD & Pediatrics and Quality Improvement

Keywords: Odds Ratio, Body Mass Index, Marfan Syndrome


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