The bicuspid aortic valve and its relation to aortic dilation

Abstract

BACKGROUNDA bicuspid aortic valve (BAV) is a common congenital heart disease, which affects 1–2% of the population. However, the relationship between BAVs and aortic dilation has not been sufficiently elucidated.METHODSA total of 241 BAV patients who were referred to this hospital for cardiac surgey over a 4.75-year period were included in this study. In addition to the clinical characteristics of the included patients, the morphological features of the aortic valve and aorta, the length of the left main coronary artery, and the laboratory findings (the coagulation and hematological parameters as well as the total cholesterol concentration) were determined and compared with those of the tricuspid aortic valve (TAV) patients.RESULTSThe BAV patients were younger than the TAV patients for a valve surgery in the last 3 months of the study period. The BAV patients were predominantly male. Most of the BAVs that were surgically treated were stenotic, regurgitant, or combined, and only 19 (7.88%) were normally functioning valves. According to echocardiography or operative records, 148 (78.31%) were type A, 31 (16.40%) were type B, and 10 (5.29%) were type C. The left main coronary artery was much shorter in the BAV patients than it was in the TAV patients. There was no significant difference between BAV and TAV patients in the total cholesterol concentrations; whereas differences were noted between patients receiving lipid-lowering therapy and those not receiving lipid-lowering therapy. The dimensions of the aortic root, sinotubular junction, and ascending aorta were beyond normal limits, while they were significantly smaller in the BAV patients than in the TAV patients. They were also much smaller in patients receiving statin therapy than those not receiving statin therapy in both groups. Moreover, the aortic dilation in the BAV group was found to be significantly associated with patient age.CONCLUSIONSThe BAV patients developed aortic wall and aortic valve disorders at a younger age than the TAV patients and were predominantly male. Aortic dilation was observed in the aortic root, sinotubular junction, and ascending aortic segments in both the BAV and TAV patients undergoing surgical aortic valve replacement, although the BAV patients had a smaller degree of dilation than the TAV patients, and dilation was also significantly age-related in this group. The shorter left main coronary artery that the BAV patients possess may contribute to the progressive course of aortic dilation that these patients experience. Statin therapy did not affect the aortic annulus in either group, but did decrease the dimensions of the aortic root, sinotubular junction and ascending aorta. In general, statin therapy had a better effect on the aortas of the TAV patients than it did on those of the BAV patients.

Statin Use and Aneurysm Risk in Patients With Bicuspid Aortic Valve Disease

“…17 Similarly, our observations are concordant with a report showing that statin therapy is associated with smaller aortic size among BAV patients with severe AS. 12 By contrast, a small study of BAV patients with aortic roots ≤4.5 cm found that statin therapy did not significantly affect aortic root diameter over a mean followup of 6.2 ± 2 years after AVR.…”

“…14 -16 Recent studies have suggested that statin therapy might also be associated with reduced ascending aortic dilatation in BAV disease. 12,17 In this study, we characterized the association between preoperative statin use and aortic dilatation in a surgical cohort of BAV patients. Current practice at our institution is to perform preoperative magnetic resonance (MR) or computed tomography (CT) imaging for patients with suspected BAV.…”

Clinical and Genetic Aspects of Bicuspid Aortic Valve: A Proposed Model for Family Screening Based on a Review of Literature

“…16 Dilatation of the thoracic aorta, most commonly located in the ascending aorta, has been reported in 35-80% of adult BAV patients and has rarely been observed as early as childhood. [11][12][13][14][20][21][22][23][24][25] In adults TAA is defined as an aortic diameter with a z-score of ≥2, corresponding to an observed value >1.96 standard deviations above the predicted value for age, gender, and body surface area (BSA). 26 An aortic root >4.0 cm in adults is considered to be dilated irrespective of age, gender or BSA.…”

“…[27][28][29] Aortic dilatation in BAV may be restricted to the ascending aorta, but can also include the aortic root. 25,30 In a retrospective study among 241 BAV patients referred for cardiac surgery, mean age 56 (range 16-85) years, aortic dilatation was seen in 97 patients (40%). The aortic root was involved in 9 (9.3%), the ascending aorta in 68 (70.1%), both the root and the ascending aorta in 14 (14.4%), the ascending aorta and the aortic arch in 5 (5.2%) and the root, ascending and aortic arch in 1 of the patients (1%).…”

“…The aortic root was involved in 9 (9.3%), the ascending aorta in 68 (70.1%), both the root and the ascending aorta in 14 (14.4%), the ascending aorta and the aortic arch in 5 (5.2%) and the root, ascending and aortic arch in 1 of the patients (1%). 25 The relatively rare dilatation restricted to the aortic root is most commonly observed in men below the age of 40 and is reported to be associated with an increased risk of aortic dissection. This root phenotype has been proposed to be the form of bicuspid aortopathy most likely to be associated with a genetic cause.…”