Abstract 2137: Bicuspid Aortic Valve, Aortic Dissection And Sudden Death In The Young: Just A Matter Of Ascending Aorta Diameters?
Background. Although bicuspid aortic valve (BAV) may remain silent during life, it can announce dramatically with aortic dissection and sudden death. The aim of the study was to determine the aortic diameters and histopathologic background in young people with BAV and aortic dissection.
Design. Among 449 cardiovascular sudden deaths in the young (<35 years), 15 (3.3%), mean age 27±6.6, 14 M/1F, had a mechanical cardiac arrest due to aortic dissection (type I: 7, type II: 6, type III: 2): 6 had isolated BAV, 2 BAV associated with coarctation, 2 Marfan syndrome, 1 coarctation, 1 pregnancy, 1 hypertension and 2 were idiopathic. Ten young BAV patients who died suddenly without aortic dissection and 10 sex and age-matched controls were considered for comparison. Aortic root was measured at 4 levels (A1, annulus; A2, sinuses of Valsalva, A3, supraaortic ridge and A4, proximal ascending aorta). Histopathologic evaluation of the aortic tunica media was performed to assess elastic fragmentation, disarray, medial necrosis, proteoglycans deposits and fibrosis.
Results. Aortic diameter values in dissected BAV vs normal BAV vs controls were: A1, 30.7±2.0 vs 27.4±2.3 (p=0.05) vs 26.3±1.6 (p<0.001); A2, 35.0±5.2 vs 28.9±1.8 (p=0.01) vs 27.3±1.5 (p=0.003); A3, 32.5±5.8 vs 26.7±2.5 (p=0.03) vs 24.5±1.5 (p=0.003); and A4, 38.7±7.0 vs 26.6±3.4 (p=0.002) vs 23.9±1.8 (p<0.001). Aortic diameters were significantly higher in Marfan patients (A1, 34.4±2.7; A2, 44.9±4.0; A3, 45.8±5.4; A4, 46.4±1.9). When comparing BAVs with and without dissection, higher scores of medial necrosis (1.2±0.4 vs 0.2±0.5, p=0.01), elastic fragmentation (2.4±0.5 vs 0.7±0.5, p=0.001) and fibrosis (1.6±0.5 vs 0.2±0.5, p=0.004) were found. Moreover, when comparing dissected BAVs and Marfan patients, similar structural abnormalities were found except lower medial necrosis (1.2±0.4 vs 2±0.0, p=0.002).
Conclusions. Aortic root diameters are lower in dissected BAV than Marfan patients. However, structural abnormalities of the tunica media in terms of elastic fragmentation and fibrosis are similar. Imaging techniques able to assess not only a progressive increase of aortic diameters, but also abnormal aortic elasticity and stiffness are warranted to indentify patients at risk of aortic dissection.