Aortic Diameter Predicts Acute Type A Aortic Dissection in Patients With Marfan Syndrome but Not in Patients Without Marfan Syndrome
Does aortic size identify patients at risk of type A acute aortic dissection (AAD) in patients with and without Marfan syndrome (MFS)?
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.
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).
Type A AAD frequently occurred at sizes smaller than previously reported, and those without MFS had smaller ascending aortas than those with MFS.
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.
Keywords: Odds Ratio, Body Mass Index, Marfan Syndrome
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