Aortic Dissection in BAV Patients: The IRAD Experience and Beyond

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1 Aortic Dissection in BAV Patients: The IRAD Experience and Beyond Eduardo Bossone, MD, Ph.D, FESC, FACC Cardiology Division - Heart Dept. University of Salerno, Italy

2 I have no financial relationships to disclose.

3 Background BAV is the most common congenital cardiac defect, with a prevalence at birth of 1 2%. Males are more often affected than females, with the ratio ranging from 2:1 to 4:1. Cumulative incidence of 6% of Type A AD in untreated patients with BAV and aortic dilation over a mean follow-up of 65 months has been reported. However in the current era of early preventive surgery this is difficult to assess. There are no reliable historical data. The prevalence of BAV ranges from 2 9% in Type A AD and 3% in Type B AD, both only slightly higher than the prevalence of BAV in the general population (1 2%). Erbel R. ESC Guidelines on the Diagnosis and Treatment of Aortic Diseases. EHJ Michelena et al.jama.2011; 306: Michelena H et al. Circulation.2014;129: Davies RR et al.ann Thorac Surg 2007;83: Ando M et al.cardiovasc Surg 1998;6:

4 Mackram F Eleid et al. Heart 2013;99:

5 Michelena H et al. Circulation.2014;129:

6 Risk of Aortic Surgery After Definite Bicuspid Aortic Valve Diagnosis Michelena et al.jama.2011; 306: Kaplan-Meier risk of AVR and aorta surgery (all causes) 25 years after definitive diagnosis of BAV. After 25 years of follow-up, the risk of undergoing AVR doubles that of aortic surgery.

7 International Registry of Acute Aortic Dissections IRAD represents an investigational collaboration that has collected information on unselected consecutive cases of AAD from 30 aortic referral centers in 10 countries since January 1, Patients with AAD were identified either prospectively at presentation or retrospectively by searching hospital discharge diagnosis records and/or surgery, pathology, and imaging databases. Diagnosis was based on imaging, surgical visualization, or on autopsy. Patients data were collected using standardized forms entered into an online database maintained at the University of Michigan and reviewed for face validity and completeness.

8 Aortic Diameter 5.5 cm Is Not a Good Predictor of Type A Aortic Dissection

9 Distribution of aortic size at time of presentation with acute type A aortic dissection (cm) Shaded bars indicate 59% of patients with diameters< 5.5 cm. Pape L A et al. Circulation. 2007;116:

10 Patients with Marfan Syndrome were excluded from the analysis. The prevalence of Type A and Type B AAD differed between groups (p<0.001)

11 Chi-Squares analysis or Fischer s Exact Test where appropriate was used to compare categorical variables. Continuous variables were analyzed by students t-test or non-parametric test of medians for variables with skewed distributions.

12 Aortic Diameters: BAV vs TAV

13 The dissected aorta in BAV and TAV patients BAV TAV

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15 Limitations and strengths Although our findings were significant, reasonable, and consistent with other studies, the total number of BAV patients in our study was small. As a consequence we were not able to further characterize interesting subgroups of BAV patients such as those with age <40 years or type B dissection. Aortic diameters were not available prior to dissection for either group. Thus, conclusions and implications related to the larger aortic dimension of BAV vs. TAV patients should be taken with caution: a larger aortic diameter after dissection does not necessarily imply a larger aortic diameter prior to dissection and it cannot be excluded that altered biomechanical properties of the BAV vessel may have resulted in a greater acute increase in aortic diameter at the time of aortic wall laceration. Nevertheless, other investigators in smaller study populations have already reported the observation of a larger aorta in the BAV dissected patients, and our registry data appear to confirm this observation On behalf of IRAD Investigators

16 Conclusions BAV individuals with AAD presented with distinct morphological and clinical characteristics: they were on average 10 years younger than TAV subjects, had less hypertension and diabetes but more known aortic aneurysm and previous aortic valve replacement surgery. The dissected aorta of BAV patients was larger than that of TAV patients at the aortic root, and was more often associated with aortic valve insufficiency, pericardial effusion and arch vessel involvement. Despite its characteristic as a disease of the proximal aorta, 20 patients with BAV presented with type B dissection. BAV patients with type A AAD underwent more root replacement operations. Despite their younger age, BAV patients did not enjoy better hospital outcomes. Additional research into risk factors for acute dissection in BAV patients, including aortic wall stress, genetic markers, and novel imaging is warranted to optimize timing of prophylactic aortic resection in this population.

17 Coarctation of the aorta, systemic hypertension, family history of dissection, or increase in aortic diameter.>.3 mm/year (on repeated measurements using the same imaging technique, measured at the same aortic level, with side-by-side (comparison and confirmed by another technique).