Dilatation of the ascending aorta in paediatric patients with bicuspid aortic valve: frequency, rate of progression and risk factors

Abstract

Objectives: To describe the incidence and rate of dilatation of the ascending aorta in children with bicuspid aortic valve (BAV) and to determine factors that predict rapid aortic dilatation. Design: Retrospective cohort study. Setting: Regional tertiary care children's hospital. Patients: All children aged 0-18 years seen at the authors' institution between 1990 and 2003 with an ''isolated'' BAV. All patients had had more than one technically adequate echocardiogram, at least six months apart, with concomitant height and weight data. Interventions: Offline echocardiographic measurements of multiple levels of the aortic root were completed for each participant at each serial echocardiogram. These measurements were then compared with expected measurements derived from a normal local control population. Main outcome measures: Rate of change of the ascending aorta size over time, where aortic size is expressed as the number of standard deviations above or below the mean size expected for a given body surface area (z score). Results: 279 echocardiograms spanning a period of from 9 months to 13.3 years were analysed for 88 patients with BAV. The ascending aorta in the BAV group was larger than expected for body surface area at diagnosis and continued to increase in relative size at each of the four subsequent follow-up echocardiograms. Ascending aortic z score increased at an average rate of 0.4/year. A faster rate of increase in z score was predicted by both larger initial aortic valve gradient and non-use of b blockers. Conclusions: Children with BAV are at risk of having a dilated ascending aorta. This risk increases with longer follow up.

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

“…54,[65][66][67][68] This is around population risk since 2.3% of the general population, by definition, is expected to have z scores >2. 28,70,71 In the large study by RobledoCarmona et al only mild aortic dilatation (<4 cm) at older age (>50 years), was observed among nine out of 270 first degree relatives with a TAV, comparable to the observations in the control cohort. 68 They concluded that if their findings are confirmed by other studies, echocardiographic follow up of the aortic dimensions of TAV first-degree relatives might not be necessary.…”

Aortic dilation, genetic testing, and associated diagnoses

“…Using the body surface area determined using the method described by Haycock et al, 12 z scores for the aortic sinus of Valsalva and ascending aorta measurements available for each subject then were calculated using the regression equations by Warren et al 13 For the purposes of this study, AoD was described as mild for z scores ≥2 but <4, moderate for z scores ≥4 but <6, and severe for z scores ≥6.…”

Surgical Treatment of Bicuspid Aortic Valve Disease

“…Studies on children (Beroukhim et al, 2006;Warren et al, 2006;Holmes et al, 2007) and adults (Yasuda et al, 2003;Davies et al, 2007;Tadros et al, 2009) have reported significantly faster aortic dilatation in the significantly younger with BAV versus trileaflet aortic valve (Figure). BAV is associated with ascending aortic dilatation and enlargement of the aortic root annulus in as many as half of all individuals (Nkomo et al, 2003;Park et al, 2011).…”

“…Typically, mutation in the NOTCH1 gene leads to signaling abnormalities, which may be responsible for abnormal development of the aortic valve, and later to accelerated valvular calcium deposition (Garg et al, 2005;Mohamed et al, 2006). In patients with BAV, the presence of BAV is an important risk factor for progressive dilatation of the aortic root and ascending aorta, even in BAV patients with normal valvular function (Nkomo et al, 2003;Gurvitz et al, 2004;Warren et al, 2006). Thus, because of its situation, patients with hypoplastic annuli and functional bicuspid valves may be primarily considered for surgery in order to prevent the risk of aortic regurgtation and the need for valve replacement (Reich et al, 2004).…”