Acute aortic dissections with pregnancy in women with ACTA2 mutations

Abstract

Mutations in ACTA2 predispose to thoracic aortic aneurysms and dissection as well as coronary artery and cerebrovascular disease. Here we examined the risk of aortic dissections, stroke and myocardial infarct with pregnancy in women with ACTA2 mutations. Of the 53 women who had a total of 137 pregnancies, eight had aortic dissections in the third trimester or the postpartum period (6% of pregnancies). One woman also had a myocardial infarct that occurred during pregnancy that was independent of her aortic dissection. Compared to the population-based frequency of peripartum aortic dissections of 0.6%, the rate of peripartum aortic dissections in women with ACTA2 mutations is much higher (8 out of 39; 20%). Six of these dissections initiated in the ascending aorta (Stanford type A), three were fatal. Three women had ascending aortic dissections at diameters less that 5.0 cm (range 3.8-4.7 cm). Aortic pathology showed mild to moderate medial degeneration of the aorta in three women. Of note, five of the women had hypertension either during or before the pregnancy. In summary, the majority of women with ACTA2 mutations did not have aortic or other vascular complications with pregnancy. However, these findings show that pregnancy is associated with significant risk for aortic dissection in women with ACTA2 mutations. Women with ACTA2 mutations who are planning to get pregnant should be counseled about this risk of aortic dissection, and proper clinical management should be initiated to reduce this risk.

Keywords: ACTA2; aortic dissection; myocardial infarct; pregnancy; stroke.

Figure 1

Contrast-enhanced axial CT images of the chest showing dissection in the ascending aorta measuring 4.2 cm in Patient 2 (A); dissecting aneurysm arising from the aortic root measuring 4.7 cm in Patient 7 (B); and ascending aortic dissection measuring 3.8 cm in Patient 8.

Figure 2

Aortic pathology of women with ACTA2 mutations and peripartum aortic dissections. (A) Compared with the control aorta, H&E and Movat staining of the aortic media from Patients 2, 7 and 8 showed mild medial degeneration characterized by focal proteoglycan accumulation (stained blue by Movat staining) and loss of SMCs and elastic fibers (stained black by Movat staining). (B) Movat staining demonstrated occlusion of vasa vasorum (arrow) in Patient 7 which is absent in the control.