Bicuspid Aortic Valve


Article Author:
Ateeq Mubarik


Article Editor:
Mark Law


Editors In Chief:
Michael Firstenberg
Lawrence Greiten


Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Frank Smeeks
Kristina Soman-Faulkner
Radia Jamil
Patrick Le
Sobhan Daneshfar
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Pritesh Sheth
Hassam Zulfiqar
Navid Mahabadi
Steve Bhimji
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Nazia Sadiq
Hajira Basit
Phillip Hynes
Tehmina Warsi


Updated:
3/14/2019 4:41:08 PM

Introduction

A bicuspid aortic valve is the most common congenital heart defect, occurring in approximately 1% of the general population (male:female 2:1). The bicuspid aortic valve leads to degenerative changes of the aortic valve and associated with dilation of the ascending aorta.  

Etiology

Bicuspid aortic valve can be sporadic or familial. Evidence supports that mode of inheritance for familial bicuspid aortic valve is variable but it could be an autosomal dominant.[1] Almost 20% to 30% of other family members have a bicuspid aortic valve.  

The exact mechanism of bicuspid aortic valve is still unknown. There are different theories regarding its pathogenesis. One theory suggest that abnormal blood flow across the valve during a development phase results in incomplete separation of the valve. [2] Kappetein AP and et al. also investigated one another theory according to which abnormal neural crest migration resulting in fusion of valve cushions. [3] Some suggest absence of endothelial nitric oxide synthetase causes bicuspid aortic valve.[4] 

Epidemiology

Bicuspid aortic valve occurs in 1-2% of the general population. Its prevalence has been increased after the advent echocardiography. 50%-75% patients with coarctation of aorta have a bicuspid aortic valve.[5] It's also prevalent in other syndromes like Turner syndrome (30% of cases).[6] Similarly, 30% of cases of William's syndrome and Ventricular septal defect is also associated with it. It is also prevalent in some rare syndrome like Shone's syndrome. [7]

Pathophysiology

The normal aortic valve consists up of three leaflet cusps. 

  1. Right coronary cusp
  2. Left coronary cusp
  3. Non-coronary cusp

It named like this as they overlie on the sinuses from where coronary artery arises with the same name. [8]

Bicuspid aortic valve comprises two cusps and a majority of time its unequal, rarely they are symmetrical which is a pure bicuspid with no raphe. Mostly, it's due to fusion of right and left coronary cusp and this anomaly associated with coarctation of aorta. It could be due to fusion of non-coronary cusp and right coronary cusp which associated with valvular abnormality like aortic stenosis and aortic regurgitation. [9] Valvular abnormality mainly depends on the presence or absence of redundant tissue. Bicuspid valves in which there is predominantly no redundant tissue develop stenosis; in contrast, in the presence of redundant tissue, the predominant gained pathology is valvular incompetence.[10]

History and Physical

The presentation of bicuspid valve is variable and varies depending on the degree of stenosis and/or insufficiency of the valve.  The most benign pediatric presentation is without symptoms or features of valve dysfunction.  In this case, the physical examination may show a low pitched systolic ejection murmur and ejection click.  In the young population often have an early ejection sound followed by a systolic ejection murmur. The ejection sound depends on the mobility of the valve so as the valve cusps become more immobile the ejection sounds diminish. The examination also depends on the severity of the valvular insufficiency. In mild to moderate aortic regurgitation ejection sound is definitely there but in severe aortic regurgitation the ejection sound usually absent. 

Evaluation

The evaluation of a bicuspid valve routinely includes and electrocardiogram and echocardiogram.  If there is severe stenosis, the electrocardiogram can show left ventricular hypertrophy with increased voltages in the lateral precordial lead and potentially T-wave inversion, consistent with a strain pattern.  The echocardiogram is the most common way to understand the features and function of a bicuspid aortic valve. 2D echocardiography will demonstrate where the fusion of the valve leaflets occur, systolic doming (can not visualize when extensive calcification present), an eccentric valve closure in the parasternal long-axis views, the demonstration of a single commissural line in diastole with the characteristic two cusps and two commissures, leaflet redundancy, presence of a raphe, eccentric valve closure in the parasternal short-axis views and can fairly reliable measurements of the ascending aorta.[11],[12]  Doppler echocardiography can provide information on the degree of stenosis with a peak and mean gradient with the mean gradient correlating with invasive catheter measurements.  Furthermore, Doppler measurements can be made to demonstrate the degree of insufficiency of the valve.  Rarely invasive cardiac catheter measurements are made for diagnostic purposes only, but are usually reserved when an intervention is planned.  CT scan and MRI imaging can be obtained to help make a more accurate measurement of the ascending aorta.  

2D echocardiography has a sensitivity of 78%, a specificity of 96%, and a predictive accuracy of 93%. [13]

Treatment / Management

The well functioning bicuspid aortic valve requires periodic outpatient follow up.  Families should be advised that the bicuspid aortic valve predictably will degenerate during one's lifetime.  So far there is no medical intervention which can slow the progression of the bicuspid aortic valve into aortic stenosis or aortic regurgitation. 

All first-degree relatives of bicuspid aortic valve patient with aortopathy should be screened. Otherwise, there are no such recommendations to screen all family members.[14] One time transthoracic echocardiography required in a patient known bicuspid aortic valve to evaluate its morphology, severity of aortic stenosis or aortic regurgitation if they are present, and the size of aortic sinuses and ascending aorta.[15]

Bicuspid aortic valve with ascending aorta diameter of 4 cm needs periodic surveillance through echocardiography (if not visualized by it then Aortic magnetic resonance angiography or CT angiography). If size is over 4.5 cm, then annually echocardiography recommended by American Heart Association. 

Surgical intervention indications in a pediatric population;

  • Peak-to-peak gradients over 50 mm Hg with EKG changes (ST- or T-wave changes) at rest or with exercise or who are interested in taking part in athletics
  • Asymptomatic children with peak-to-peak gradients greater than 60 mm Hg

Gold standard surgical intervention in the pediatric population is valvuloplasty. 

In the bicuspid aortic valve population age greater than 18 years the indications of aortic valve replacement is same as tricuspid aortic valve but the bicuspid aortic valve population receiving aortic valve replacement is much younger so the decision of mechanical or bioprosthetic is a little challenging. 30% of bicuspid aortic valve patient needs aortic sinuses or ascending aorta surgery along with aortic valve replacement.[16] Current AHA guidelines recommend that if for any reason surgeon performing aortic valve replacement and size of root of the aorta is greater than 4.5 cm than replace aortic root as well in the same surgery.[17]

Complications

Bicuspid aortic valve can lead to significant valvular dysfunction which could be an aortic stenosis or aortic regurgitation. The risk of infective endocarditis is high among population have bicuspid valve. 

Bicuspid aortic valve is also associated with:

  • Coarctation of aorta
  • Ascending aortic dilatation 40%-60%
  • Aortic aneurysm 

Enhancing Healthcare Team Outcomes

Bicuspid aortic valve is commonly encountered in clinical practice by the primary care provider, internist and nurse practitioner. The key is to refer the patient to the cardiologist to determine the severity of the valve disorder, the presence of symptoms and age of the patient. The treatment options in children include balloon valvoplasty or observation. In adults, the only treatment for symptomatic patients is valve replacement. The prognosis for most patients after valve replacement is good. After valvoplasty, recurrence of symptoms is common.[18]


Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Bicuspid Aortic Valve - Questions

Take a quiz of the questions on this article.

Take Quiz
In an 18-year-old born with a congenital bicuspid aortic valve, what is the most common abnormal heart sound?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Fusion of which cusps is involved a bicuspid aortic valve?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
Which of the following is not true of the bicuspid aortic valve?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A patient presented to the emergency department complaining of dyspnea and chest pain. While being worked up for a myocardial infarction, he arrested and expired. An autopsy is performed and the pathologist states that his death was most likely associated with valvular heart disease seen in the image below. With such a valve, the fusion of the cusps is most common between which of the following?

(Move Mouse on Image to Enlarge)
  • Image 5949 Not availableImage 5949 Not available
    image donated by sbhimji
Attributed To: image donated by sbhimji



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up
A 55-year-old male with a history of bicuspid aortic valve presents for follow up after 2D echocardiography. It showed a bicuspid aortic valve with trivial aortic regurgitation and an aortic root diameter of 4.6 cm. The patient denied any symptoms. What will be the next step in the management of this patient?



Click Your Answer Below


Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.


Sign Up

Bicuspid Aortic Valve - References

References

Panayotova R,Macnab A,Waterworth PD, A pilot project of familial screening in patients with bicuspid aortic valve disease. The Journal of heart valve disease. 2013 Mar     [PubMed]
Sans-Coma V,Fernández B,Durán AC,Thiene G,Arqué JM,Muñoz-Chápuli R,Cardo M, Fusion of valve cushions as a key factor in the formation of congenital bicuspid aortic valves in Syrian hamsters. The Anatomical record. 1996 Apr     [PubMed]
Kappetein AP,Gittenberger-de Groot AC,Zwinderman AH,Rohmer J,Poelmann RE,Huysmans HA, The neural crest as a possible pathogenetic factor in coarctation of the aorta and bicuspid aortic valve. The Journal of thoracic and cardiovascular surgery. 1991 Dec     [PubMed]
Lee TC,Zhao YD,Courtman DW,Stewart DJ, Abnormal aortic valve development in mice lacking endothelial nitric oxide synthase. Circulation. 2000 May 23     [PubMed]
Roos-Hesselink JW,Schölzel BE,Heijdra RJ,Spitaels SE,Meijboom FJ,Boersma E,Bogers AJ,Simoons ML, Aortic valve and aortic arch pathology after coarctation repair. Heart (British Cardiac Society). 2003 Sep     [PubMed]
Sybert VP, Cardiovascular malformations and complications in Turner syndrome. Pediatrics. 1998 Jan     [PubMed]
Bolling SF,Iannettoni MD,Dick M 2nd,Rosenthal A,Bove EL, Shone's anomaly: operative results and late outcome. The Annals of thoracic surgery. 1990 Jun     [PubMed]
Harris C,Croce B,Munkholm-Larsen S, Bicuspid aortic valve. Annals of cardiothoracic surgery. 2017 Nov     [PubMed]
Siu SC,Silversides CK, Bicuspid aortic valve disease. Journal of the American College of Cardiology. 2010 Jun 22     [PubMed]
Pomerance A, Pathogenesis of aortic stenosis and its relation to age. British heart journal. 1972 Jun     [PubMed]
Fowles RE,Martin RP,Abrams JM,Schapira JN,French JW,Popp RL, Two-dimensional echocardiographic features of bicuspid aortic valve. Chest. 1979 Apr     [PubMed]
Nanda NC,Gramiak R,Manning J,Mahoney EB,Lipchik EO,DeWeese JA, Echocardiographic recognition of the congenital bicuspid aortic valve. Circulation. 1974 May     [PubMed]
Brandenburg RO Jr,Tajik AJ,Edwards WD,Reeder GS,Shub C,Seward JB, Accuracy of 2-dimensional echocardiographic diagnosis of congenitally bicuspid aortic valve: echocardiographic-anatomic correlation in 115 patients. The American journal of cardiology. 1983 May 15     [PubMed]
Kang JW,Song HG,Yang DH,Baek S,Kim DH,Song JM,Kang DH,Lim TH,Song JK, Association between bicuspid aortic valve phenotype and patterns of valvular dysfunction and bicuspid aortopathy: comprehensive evaluation using MDCT and echocardiography. JACC. Cardiovascular imaging. 2013 Feb     [PubMed]
Pachulski RT,Weinberg AL,Chan KL, Aortic aneurysm in patients with functionally normal or minimally stenotic bicuspid aortic valve. The American journal of cardiology. 1991 Apr 1     [PubMed]
Tzemos N,Therrien J,Yip J,Thanassoulis G,Tremblay S,Jamorski MT,Webb GD,Siu SC, Outcomes in adults with bicuspid aortic valves. JAMA. 2008 Sep 17     [PubMed]
Davies RR,Kaple RK,Mandapati D,Gallo A,Botta DM Jr,Elefteriades JA,Coady MA, Natural history of ascending aortic aneurysms in the setting of an unreplaced bicuspid aortic valve. The Annals of thoracic surgery. 2007 Apr     [PubMed]
Tripathi A,Wang Y,Jerrell JM, Population-based treated prevalence, risk factors, and outcomes of bicuspid aortic valve in a pediatric Medicaid cohort. Annals of pediatric cardiology. 2018 May-Aug;     [PubMed]

Disclaimer

The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of Surgery-Cardiac. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for Surgery-Cardiac, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in Surgery-Cardiac, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of Surgery-Cardiac. When it is time for the Surgery-Cardiac board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study Surgery-Cardiac.