Abstract 15306: Predictors of Aortic Growth After Acute Type B Aortic Dissection
INTRODUCTION A considerable number of patients with acute type B aortic dissection (ABAD) treated with medical management alone will develop aortic enlargement during follow-up (FU), which could potentially lead to aortic rupture. The purpose of this study was to investigate predictors of aortic expansion during FU among ABAD patients enrolled in the International Registry of Acute Aortic Dissection (IRAD).
METHODS We analyzed 191 ABAD patients treated with medical therapy alone enrolled in the IRAD between 1996 and 2010, with available descending aortic diameter measurements at admission, and at 6, 12 and/or 24 months after the acute event. The annual aortic expansion rate was calculated for all patients and multivariate regression analysis was used to investigate factors affecting the expansion rate.
RESULTS Aortic expansion was observed in 59% of patients (mean expansion rate 1.7 ±7.6 mm/year); no ruptures or deaths occurred during the FU period. As the initial aortic diameter increased, the annual expansion rate decreased (figure 1). In multivariate analysis, white race was associated with increased aortic expansion (regression coefficient [RC] 4.9, 95%CI 1.8 to 8.1). Female gender (RC -3.3, 95%CI -5.6 to -0.99), large initial descending aortic diameter (RC -0.29, 95%CI -0.39 to -0.19), intramural hematoma (RC -3.7, 95%CI -6.4 to -1.0), and calcium channel blockers (RC -3.6, 95%CI -6.0 to -1.1) were associated with decreased aortic expansion. The mean expansion rate for patients with calcium channel blockers was 0.5 mm/year compared to 3.9 mm/year for those without (p=0.005).
CONCLUSIONS A small aortic diameter at presentation of ABAD is associated with increased aortic expansion during FU. We observed decreased aortic expansion among patients treated with calcium channel blockers. These data raise the possibility that the use of calcium channel blockers following ABAD may reduce the rate of aortic expansion and therefore further investigation is warranted.
- © 2011 by American Heart Association, Inc.