Sex-Based Differences in the Distribution of Ascending Aortic Diameters at the Time of Type A Dissection

P0301 

Abstract Submission 

Christina Waldron (1), Mohammad Zafar (2), Zachary Perez (2), John Elefteriades (2)

(1) Yale School of Medicine, New Haven, CT, (2) Yale New Haven Hospital, New Haven, CT

Christina Waldron    -  Contact Me
Yale School of Medicine

Mohammad Zafar    -  Contact Me
Yale New Haven Hospital

Zachary Perez    -  Contact Me
Yale New Haven Hospital

*John Elefteriades    -  Contact Me
Yale New Haven Hospital

Christina Waldron    -  Contact Me
Yale School of Medicine

Objectives: Acute type A aortic dissection (TAAD) is a catastrophic disorder associated with high mortality rates. Current guidelines recommend a threshold diameter of 5.0-5.5 cm for surgery, irrespective of sex. Although men are more affected than women, the distribution of aortic diameters at the time of TAAD stratified by sex remains unknown.

Methods: Maximal ascending aortic size at the time of naturally occurring acute flap-type TAAD was measured in 258 patients with still-available radiographic images of sufficient quality to permit size measurement presenting between 1990-2023. Demographic and comorbidity data were extracted from electronic medical records. Aortic size was re-measured from CT or MRI images in a standardized method. We compared the ascending aortic diameter at time of dissection between men and women. Aortic diameters were indexed to height, and histograms were constructed to display the raw and indexed aortic size at time of dissection.

Results: Among 258 patients with measurable TAAD (median age 63 years [IQR 53, 73]; 33% (N=86) female), the average maximal ascending aortic diameter was 5.05 cm [4.6, 5.6]. Men were taller (178 cm vs 163 cm, p<0.001), had a higher BMI (28 kg/m2 vs. 26 kg/m2, p=0.005), and had lower rates of COPD than women (9.9% (N=15/172) vs. 20% (N=15/86), 0.04). Other comorbidities were comparable. Women had a smaller ascending aortic diameter (4.95 vs. 5.10 cm, p=0.014) and presented at an older age than men (69 vs. 60, p<0.001). Among women, a larger proportion of aortic diameters were below 5.5 cm (77% (N=66/86) vs. 66% (N=114/172), p=0.084) and 5.0 cm (51% (N=44/86) vs. 37% (N=63/172), p=0.025) compared to men. After normalizing the ascending aortic diameter to the patient's height, the difference in ascending aortic diameter between women and men diminished (3.03 cm/m vs. 2.87 cm/m, p=0.079, respectively).

Conclusions: Although overall aortic diameter at the time of TAAD is consistent with updated guideline recommendations for prophylactic surgery, more than half of female patients dissected below 5.0 cm. An earlier intervention criterion below 5.0 cm may prove to be appropriate for women. Indexing aortic diameter to patient height reduces the size disparity and risk for women, endorsing the use of aortic diameter indexing when determining patient risk for TAAD. Female patients were almost a decade older at presentation; the pathophysiologic reasons for this age difference remain to be clarified.

Dissection