How to Interpret Predictors of Dilation in Bicuspid Aortic Valve and Aortic Disease

Abstract

We read with interest the article by Avadhani et al1Avadhani S.A. Martin-Doyle W. Shaikh A.Y. Pape L.A. Predictors of ascending aortic dilation in bicuspid aortic valve disease: a five-year prospective study.Am J Med. 2015; 128: 647-652Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar about the progression of aortic dilation in bicuspid aortic valve individuals. The authors prospectively evaluate an asymptomatic cohort of bicuspid aortic valve individuals and assess the rate of aortic growth with time. They find a mean annual rate of growth of 0.47 mm/year in ascending aorta diameter, with 30% of individuals who do not show any progression at all and 15.6% who dilate >1 mm/year. Interestingly, the only independent predictor of aortic growth over time is the family history of aortic valve disease. This association is interesting from a practical and bilateral point of view:a)Bicuspid aortic valve has a significant familial clustering2Kerstjens-Frederikse W.S. Du Marchie Sarvaas G.J. Ruiter J.S. et al.Left ventricular outflow tract obstruction: should cardiac screening be offered to first-degree relatives?.Heart. 2011; 97: 1228-1232Crossref Scopus (44) Google Scholar and meets the established criteria for disease screening in adult first-degree relatives. This is supported strongly as outlined in the American College of Cardiology/American Heart Association 2008 guidelines for the management of adults with congenital heart disease.3Warnes C.A. Williams R.G. Bashore T.M. et al.ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults With Congenital Heart Disease). Developed in collaboration with the American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons.J Am Coll Cardiol. 2008; 52: e143-e263Abstract Full Text Full Text PDF PubMed Scopus (538) Google Scholar Therefore, once a case of bicuspid aortic valve (proband) is diagnosed, an echocardiographic screening should be offered to all the first-degree relatives. Ideally, this screening would consider not only aortic valve, but also ascending aorta diameter.b)Given the findings of Avadhani et al,1Avadhani S.A. Martin-Doyle W. Shaikh A.Y. Pape L.A. Predictors of ascending aortic dilation in bicuspid aortic valve disease: a five-year prospective study.Am J Med. 2015; 128: 647-652Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar aortic growth rate is higher in the familial form of bicuspid aortic valve. Therefore, a closer ascending aorta diameter follow-up should be considered in individuals with bicuspid aortic valve with a family history of aortic valve disease. However, there are some findings that could be discussed. Firstly, the asymptomatic nature of the cohort studied limits the possible association of valve dysfunction and ascending aorta diameter. If valve dysfunction was not severe enough to develop symptoms, the hemodynamic stress also could be insufficient to translate into measurable changes to ascending aorta diameter. Secondly, the authors do not mention the prevalence or association with other cardiovascular malformations. Well known are the influence of aortic coarctation on aortic dimensions, its higher risk of aortic dissection, and the frequent coexistence of these 2 abnormalities.4Warnes C.A. Bicuspid aortic valve and coarctation: two villains part of a diffuse problem.Heart. 2003; 89: 965-966Crossref PubMed Scopus (101) Google Scholar Finally, aortic evaluation has been limited to aortic root and ascending aorta, while bicuspid aortopathy is a diffuse disease that extends up to the aortic arch. Therefore, the assessment of other aortic segments could have raised different results, either in the progression of aortic growth or in its association with cusp morphology or valve function.