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Bicuspid Aortic Valves and Dilated Aortas: A Critical Review of the Critical Review of the ACC/AHA Practice Guidelines Recommendations

2008; Elsevier BV; Volume: 102; Issue: 1 Linguagem: Inglês

10.1016/j.amjcard.2008.01.058

1879-1913

Robert O. Bonow,

Infective Endocarditis Diagnosis and Management

The American College of Cardiology (ACC) and American Heart Association (AHA) practice guidelines have helped define the standard of cardiovascular care in the United States and are widely accepted as the basis for the evidence-based practice of cardiovascular medicine by the providers and the payers of health care and by the developers of clinical performance measures. However, the evidence base for these guidelines is fragmented. Despite the large number of randomized, multicenter cardiovascular clinical trials that are the underpinning for many of the class I guidelines recommendations, most guidelines recommendations are based on consensus of expert opinion rather than solid evidence derived from clinical trials. This is particularly the case in the area of valvular heart disease, in which there is a paucity of prospective clinical trials. However, the ACC/AHA guidelines on valvular heart disease are not unique in this regard. A review of the ACC/AHA guidelines for the management of patients with ST elevation myocardial infarction1Antman E.M. Anbe D.T. Armstrong P.W. Bates E.R. Green L.A. Hand M. Hochman J.S. Krumholz H.M. Kushner F.G. Lamas G.A. et al.ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction: executive summary: a report of the ACC/AHA Task Force on Practice Guidelines (Committee to Revise the 1999 Guidelines on the Management of Patients With Acute Myocardial Infarction).J Am Coll Cardiol. 2004; 44: 671-719Abstract Full Text Full Text PDF PubMed Scopus (1898) Google Scholar and the ACC/AHA guidelines for the diagnosis and management of chronic heart failure,2Hunt S.A. Abraham W.T. Chin M.H. Feldman A.M. Francis G.S. Ganiats T.G. Jessup M. Konstam M.A. Mancini D.M. Michl K. et al.ACC/AHA 2005 guideline update for the diagnosis and management of chronic heart failure in the adult: summary article: a report of the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Update the 2001 Guidelines for the Evaluation and Management of Heart Failure).J Am Coll Cardiol. 2005; 46: 1116-1143Abstract Full Text Full Text PDF Scopus (359) Google Scholar 2 subjects for which there is a wealth of randomized clinical trial data, indicates that only 63 of a total of 311 class I recommendations (20%) are based on level of evidence A (supported by the results on multiple randomized trials), whereas 139 (45%) are considered level of evidence C (based only on expert opinion). Such recommendations are open to legitimate difference of opinion and can often be called into question.In the current issue of The American Journal of Cardiology, guidelines expert opinion is indeed called into question by Dr. Warren Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar on the subject of the management of patients with bicuspid aortic valves (BAVs) and dilatation of the aortic root or ascending aorta. His "critical review" of the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease4Bonow R.O. Carabello B. Chatterjee K. De Leon Jr, A.C. Faxon D.P. Freed M.D. Gaasch W.H. Lytle B.W. Nishimura R.A. O'Gara P.T. et al.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Valvular Heart Disease).J Am Coll Cardiol. 2006; 48: e1-e148Abstract Full Text Full Text PDF PubMed Scopus (1513) Google Scholar is indeed very critical. Several of these criticisms are worthy of comment.Dr. Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar is correct that there are no prospective clinical trials on this subject, and the guidelines recommendations are thus based on observational studies and expert consensus. Dr. Guntheroth is entitled to state his own expert opinion, as he has done. However, he appears to be an "expert" who is out of sync with many other "experts," including but not limited to those on the ACC/AHA guidelines committee. He has ignored the fact that the same threshold for surgery on the aorta (aortic diameter ≥50 mm) recommended in the 2006 ACC/AHA guidelines in patients with BAV was also recommended independently by the writing committee of the 2007 guidelines on the management of valvular heart disease of the European Society of Cardiology.5Vahanian A. Baumgartner H. Bax J. Butchart E. Dion R. Filippatos G. Flachskampf F. Hall R. Iung B. Kasprzak J. et al.Guidelines on the management of valvular heart disease: the Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology.Eur Heart J. 2007; 28: 230-268Crossref PubMed Scopus (1) Google Scholar Aortic dissection may occur at any level of aortic enlargement, but this risk increases exponentially with increases in aortic diameter >50 mm.6Elefteriades J.A. Natural history of thoracic aortic aneurysms: indications for surgery, and surgical versus nonsurgical risks.Ann Thorac Surg. 2002; 74: S1877-S1880Abstract Full Text Full Text PDF PubMed Scopus (583) Google Scholar The guidelines committees on both sides of the Atlantic independently selected this threshold value, recognizing the lack of prospective trial data but cognizant of the risk for dissection with increasing aortic size. This is consistent with the recommendations of the consensus panel of the 1998 New York Aortic Symposium,7Ergin M.A. Spielvogel D. Apaydin A. Lansman S.L. McCullough J.N. Galla J.D. Griepp R.B. Surgical treatment of the dilated ascending aorta: when and how?.Ann Thorac Surg. 1999; 67: 1834-1839Abstract Full Text Full Text PDF PubMed Scopus (181) Google Scholar which recommended surgery for aortic aneurysms measuring ≥50 mm in diameter when associated with BAV and suggested an even lower threshold (≥45 mm) when patients were referred to centers with established expertise in surgical treatment of the ascending aorta.Numerous other experts in the field have raised similar concerns about the risk for dissection in patients with BAVs.8Ward C. Clinical significance of the bicuspid aortic valve.Heart. 2000; 83: 81-85Crossref PubMed Scopus (587) Google Scholar, 9Braverman A.C. Guven H. Beardslee M.A. Makan M. Kates A.M. Moon M.R. The bicuspid aortic valve.Curr Probl Cardiol. 2005; 30: 470-522Abstract Full Text Full Text PDF PubMed Google Scholar, 10Isselbacher E.M. Diseases of the aorta.in: Libby P. Bonow R.O. Mann D.L. Zipes D.P. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Elsevier, Philadelphia, Pennsylvania2007: 1457-1489Google Scholar These and other expert opinions are noted here in relation to specific issues raised by Dr. Guntheroth.3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google ScholarRisk for Aortic DissectionIt is true that the risk for aortic rupture in patients with BAVs varies among many series, as does the frequency of BAV in reported series of aortic rupture. However, the risk is real. According to Isselbacher,10Isselbacher E.M. Diseases of the aorta.in: Libby P. Bonow R.O. Mann D.L. Zipes D.P. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Elsevier, Philadelphia, Pennsylvania2007: 1457-1489Google Scholar "some cases of ascending thoracic aortic aneurysms are associated with an underlying BAV. In fact, the risks of aortic dilatation, aneurysm, and dissection are significantly increased among those with a BAV." It is estimated that aortic dissection occurs 5 to 10 times more frequently in patients with BAVs compared with those with tricuspid aortic valves.8Ward C. Clinical significance of the bicuspid aortic valve.Heart. 2000; 83: 81-85Crossref PubMed Scopus (587) Google Scholar, 9Braverman A.C. Guven H. Beardslee M.A. Makan M. Kates A.M. Moon M.R. The bicuspid aortic valve.Curr Probl Cardiol. 2005; 30: 470-522Abstract Full Text Full Text PDF PubMed Google Scholar, 10Isselbacher E.M. Diseases of the aorta.in: Libby P. Bonow R.O. Mann D.L. Zipes D.P. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Elsevier, Philadelphia, Pennsylvania2007: 1457-1489Google Scholar, 11Roberts C.S. Roberts W.C. Dissection of the aorta associated with congenital malformation of the aortic valve.J Am Coll Cardiol. 1991; 17: 712-716Abstract Full Text PDF PubMed Scopus (228) Google Scholar BAVs are present in 7% to 15% of unselected cases of aortic dissection.8Ward C. Clinical significance of the bicuspid aortic valve.Heart. 2000; 83: 81-85Crossref PubMed Scopus (587) Google Scholar, 11Roberts C.S. Roberts W.C. Dissection of the aorta associated with congenital malformation of the aortic valve.J Am Coll Cardiol. 1991; 17: 712-716Abstract Full Text PDF PubMed Scopus (228) Google Scholar, 12Gore I. Seiwert V.J. Dissecting aneurysm of the aorta.AMA Arch Pathol. 1952; 53: 121-141PubMed Google Scholar, 13Edwards W.D. Leaf D.S. Edwards J.E. Dissecting aortic aneurysm associated with congenital bicuspid aortic valve.Circulation. 1978; 57: 1022-1025Crossref PubMed Scopus (215) Google Scholar, 14Spittell P.C. Spittell J.A. Joyce J.W. Clinical features and differential diagnosis of aortic dissection.Mayo Clin Proc. 1993; 68: 642-651Abstract Full Text Full Text PDF PubMed Scopus (439) Google Scholar Dissection also occurs at a younger age in patients with BAVs.11Roberts C.S. Roberts W.C. Dissection of the aorta associated with congenital malformation of the aortic valve.J Am Coll Cardiol. 1991; 17: 712-716Abstract Full Text PDF PubMed Scopus (228) Google Scholar, 12Gore I. Seiwert V.J. Dissecting aneurysm of the aorta.AMA Arch Pathol. 1952; 53: 121-141PubMed Google Scholar, 15Januzzi J.L. Isselbacher E.M. Fattori R. Cooper J.V. Smith D.E. Fang J. Eagle K.A. Mehta R.H. Nienaber C.A. Pape L.A. Characterizing the young patient with aortic dissection: results from the International Registry of Aortic Dissection (IRAD).J Am Coll Cardiol. 2004; 43: 665-669Abstract Full Text Full Text PDF PubMed Scopus (338) Google Scholar The report of the International Registry of Acute Aortic Dissection concluded, "Compared with older patients with aortic dilatation, young patients have unique risk factors for dissection: Marfan syndrome, bicuspid aortic valves, and larger aortic dimensions."15Januzzi J.L. Isselbacher E.M. Fattori R. Cooper J.V. Smith D.E. Fang J. Eagle K.A. Mehta R.H. Nienaber C.A. Pape L.A. Characterizing the young patient with aortic dissection: results from the International Registry of Aortic Dissection (IRAD).J Am Coll Cardiol. 2004; 43: 665-669Abstract Full Text Full Text PDF PubMed Scopus (338) Google ScholarIn the series reported in 2007 by Davies et al,16Davies R.R. Kaple R.K. Mandapati D. Gallo A. Botta Jr, D.M. Elefteriades J.A. Coady M.A. Natural history of ascending aortic aneurysms in the setting of an unreplaced bicuspid aortic valve.Ann Thorac Surg. 2007; 83: 1338-1344Abstract Full Text Full Text PDF PubMed Scopus (246) Google Scholar 70 of 514 patients (13.6%) with ascending aortic aneurysms had bicuspid valves. Patients with BAVs presented at younger ages and had faster rates of enlargement; similar rates of aortic rupture, dissection, and death; and similar improvement in long-term survival with surgery.Pathophysiology of Aortic EnlargementThe concept of "poststenotic dilatation" implicated by Dr. Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar as the alleged cause of aortic enlargement in BAV is a misconception that was dispelled years ago. Isselbacher10Isselbacher E.M. Diseases of the aorta.in: Libby P. Bonow R.O. Mann D.L. Zipes D.P. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Elsevier, Philadelphia, Pennsylvania2007: 1457-1489Google Scholar noted that "historical teaching attributed such aneurysms to 'poststenotic dilatation' of the ascending aorta, but the data suggest otherwise," pointing out that 52% of young subjects with normally functioning BAVs have echocardiographic evidence of aortic dilatation. Similarly, Braverman et al9Braverman A.C. Guven H. Beardslee M.A. Makan M. Kates A.M. Moon M.R. The bicuspid aortic valve.Curr Probl Cardiol. 2005; 30: 470-522Abstract Full Text Full Text PDF PubMed Google Scholar indicated that "the aortic wall abnormality is entirely independent of any hemodynamically significant valvular disease. In the past, an entity termed 'poststenotic' dilatation was often used for an enlarged aortic root associated with aortic valve disease (especially aortic stenosis). However, recent experience suggests an alternative explanation. It is the very infrequent patient with trileaflet aortic valve disease who has an enlarged aortic root. In contrast, the BAV is much more commonly associated with an enlarged proximal aorta and in the current era must be considered one of the most common etiologies of aortic root enlargement."In invoking and perpetuating poststenotic dilatation as the cause of aortic enlargement, Dr. Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar has ignored 4 important lines of evidence. First, recent studies have demonstrated greater aortic size in patients with BAVs and aortic stenosis compared with those with tricuspid valves and aortic stenosis who are matched for hemodynamic severity.17Keane M.G. Wiegers S.E. Plappert T. Pochettino A. Bavaria J.E. St. John Sutton M.G. Bicuspid aortic valves are associated with aortic dilatation out of proportion to coexistent valvular lesions.Circulation. 2000; 102: III-35-III-39Crossref Google Scholar, 18Novaro G.M. Tiong I.Y. Pearce G.L. Grimm R.A. Smedira N. Griffin B.P. Features and predictors of ascending aortic dilatation in association with a congenital bicuspid aortic valve.Am J Cardiol. 2003; 92: 99-101Abstract Full Text Full Text PDF PubMed Scopus (87) Google Scholar Dr. Guntheroth argues away this evidence by suggesting that the "type of turbulence" caused by a BAV is different from that caused by a tricuspid valve, but he provides no evidence to support this. Second, multiple other studies have reported enlarged aortas in patients (including children) with BAVs but without any aortic stenosis or aortic regurgitation, compared with age-matched normal controls.19Pachulski R.T. Winberg A.L. Chan K.L. Aortic aneurysm in patients with functionally normal or minimally stenotic bicuspid aortic valve.Am J Cardiol. 1991; 67: 781-782Abstract Full Text PDF PubMed Scopus (150) Google Scholar, 20Hahn R.T. Roman M.J. Mogtader A.H. Devereaux R.B. Association of aortic dilation with regurgitant, stenotic and functionally normal bicuspid aortic valves.J Am Coll Cardiol. 1992; 19: 283-288Abstract Full Text PDF PubMed Scopus (331) Google Scholar, 21Nistri S. Sorbo M.D. Marin M. Palisi M. Scognamiglio R. Thiene G. Aortic root dilatation in young men with normally functioning bicuspid aortic valves.Heart. 1999; 82: 19-22PubMed Google Scholar, 22Nkomo V.T. Enrique-Sarano M. Ammash N.M. Melton III, L.J. Bailey K.R. Desjardins V. Horn R.A. Tajik A.J. Bicuspid aortic valve associated with aortic dilatation: a community-based study.Arterioscler Thromb Vasc Biol. 2003; 23: 351-356Crossref PubMed Scopus (155) Google Scholar, 23Gurvitz M. Chang R.K. Drant S. Allada V. Frequency of aortic root dilation in children with a bicuspid aortic valve.Am J Cardiol. 2004; 94: 1337-1340Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar, 24Basso C. Boschello M. Perrone C. Mecenero A. Cera A. Bicego D. Thiene G. De Dominicis E. An echocardiographic survey of primary school children for bicuspid aortic valve.Am J Cardiol. 2004; 93: 661-663Abstract Full Text Full Text PDF PubMed Scopus (228) Google Scholar, 25Cecconi Manfrin M. Moraca A. Zanoli R. Colonna P.L. Bettuzzi M.G. Moretti S. Gabrielli D. Perna G.P. Aortic dimensions in patients with bicuspid aortic valve without significant valve dysfunction.Am J Cardiol. 2005; 95: 292-294Abstract Full Text Full Text PDF PubMed Scopus (105) Google Scholar Third, studies have demonstrated progressive enlargement of the aorta after aortic valve replacement (AVR) in patients with BAVs.26Russo C.F. Mazzetti S. Garatti A. Ribera E. Milazzo A. Bruschi G. Lanfranconi M. Colombo T. Vitali E. Aortic complications after bicuspid aortic valve replacement: long-term results.Ann Thorac Surg. 2002; 74: S1773-S1776Abstract Full Text Full Text PDF PubMed Scopus (161) Google Scholar, 27Yasuda H. Nakatani S. Stugaard M. Tsujita-Kuroda Y. Bando K. Kobayashi J. Yamagishi M. Kitakaze M. Kitamura S. Miyatake K. Failure to prevent progressive dilation of ascending aorta by aortic valve replacement in patients with bicuspid aortic valve: comparison with tricuspid aortic valve.Circulation. 2003; 108: II-291-II-294Google Scholar, 28Borger M.A. Preston M. Ivanov J. Fedak P.W.M. Davierwala P. Armstrong S. David T.E. Should the ascending aorta be replaced more frequently in patients with bicuspid aortic valve disease?.J Thorac Cardiovasc Surg. 2004; 128: 677-683Abstract Full Text Full Text PDF PubMed Scopus (329) Google Scholar Fourth, studies have demonstrated degeneration of the extracellular matrix of the aorta in patients with BAVs, including elastic fiber fragmentation, increased metalloproteinase expression, decreased expression of tissue inhibitors of metalloproteinases, and smooth muscle cell apoptosis.29de Sa M. Moshkovitz Y. Butany J. David T.E. Histologic abnormalities of the ascending aorta and pulmonary trunk in patients with bicuspid aortic valve disease: clinical relevance to the Ross procedure.J Thorac Cardiovasc Surg. 1999; 118: 588-594Abstract Full Text Full Text PDF PubMed Scopus (321) Google Scholar, 30Bauer M. Pasic M. Meyer R. Goetze N. Bauer U. Siniawski H. Hetzer R. Morphometric analysis of aortic media in patients with bicuspid and tricuspid aortic valve.Ann Thorac Surg. 2002; 74: 58-62Abstract Full Text Full Text PDF PubMed Scopus (127) Google Scholar, 31Nataatmadja M. West W. West J. Summers K. Walker P. Nagata M. Watanabe T. Abnormal extracellular matrix protein transport associated with increased apoptosis of vascular smooth muscle cells in Marfan syndrome and bicuspid aortic valve thoracic aortic aneurysm.Circulation. 2003; 108: II-329-II-334Google Scholar, 32Fedak P.W. de Sa M.P. Verma S. Nili N. Kazemian P. Butany J. Strauss B.H. Weisel R.D. David T.E. Vascular matrix remodeling in patients with bicuspid aortic valve malformations: implications for aortic dilatation.J Thorac Cardiovasc Surg. 2003; 126: 797-806Abstract Full Text Full Text PDF PubMed Scopus (358) Google Scholar, 33Cotrufo Della Corte A. De Santo L.S. Quarto C. De Feo M. Romano G. Amarelli C. Scardone M. Di Meglio F. Guerra G. Scarano M. et al.Different patterns of extracellular matrix protein expression in the convexity and the concavity of the dilated aorta with bicuspid aortic valve: preliminary results.J Thorac Cardiovasc Surg. 2005; 130: 504-511PubMed Google Scholar, 34Ikonomidis J.S. Jones J.A. Barbour J.R. Stroud R.E. Clark L.L. Kaplan B.S. Zeeshan A. Bavaria J.E. Gorman III, J.H. Spinale F.G. Gorman R.C. Expression of matrix metalloproteinases and endogenous inhibitors within ascending aortic aneurysms of patients with bicuspid or tricuspid aortic valves.J Thorac Cardiovasc Surg. 2007; 133: 1028-1036Abstract Full Text Full Text PDF PubMed Scopus (177) Google ScholarHistopathologyDr. Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar indicates that the ACC/AHA guidelines "assert that the histology associated with aortic dilatation is cystic medial necrosis." This is not true. In the entire 88,063-word, 124-page guidelines document (excluding references), the terms "cystic" and "cystic medial necrosis" are never mentioned. The guidelines simply state that "there is growing awareness that many patients with BAV have disorders of vascular connective tissue, involving loss of elastic tissue, which may result in dilatation of the aortic root or ascending aorta even in the absence of hemodynamically significant aortic stenosis or aortic regurgitation."4Bonow R.O. Carabello B. Chatterjee K. De Leon Jr, A.C. Faxon D.P. Freed M.D. Gaasch W.H. Lytle B.W. Nishimura R.A. O'Gara P.T. et al.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Valvular Heart Disease).J Am Coll Cardiol. 2006; 48: e1-e148Abstract Full Text Full Text PDF PubMed Scopus (1513) Google Scholar There was no attempt to link aortic dilatation associated with BAV to the histopathology of Marfan syndrome, although, as noted previously, there are some important histopathologic similarities between the 2 conditions.29de Sa M. Moshkovitz Y. Butany J. David T.E. Histologic abnormalities of the ascending aorta and pulmonary trunk in patients with bicuspid aortic valve disease: clinical relevance to the Ross procedure.J Thorac Cardiovasc Surg. 1999; 118: 588-594Abstract Full Text Full Text PDF PubMed Scopus (321) Google Scholar, 30Bauer M. Pasic M. Meyer R. Goetze N. Bauer U. Siniawski H. Hetzer R. Morphometric analysis of aortic media in patients with bicuspid and tricuspid aortic valve.Ann Thorac Surg. 2002; 74: 58-62Abstract Full Text Full Text PDF PubMed Scopus (127) Google Scholar, 31Nataatmadja M. West W. West J. Summers K. Walker P. Nagata M. Watanabe T. Abnormal extracellular matrix protein transport associated with increased apoptosis of vascular smooth muscle cells in Marfan syndrome and bicuspid aortic valve thoracic aortic aneurysm.Circulation. 2003; 108: II-329-II-334Google Scholar, 32Fedak P.W. de Sa M.P. Verma S. Nili N. Kazemian P. Butany J. Strauss B.H. Weisel R.D. David T.E. Vascular matrix remodeling in patients with bicuspid aortic valve malformations: implications for aortic dilatation.J Thorac Cardiovasc Surg. 2003; 126: 797-806Abstract Full Text Full Text PDF PubMed Scopus (358) Google Scholar, 33Cotrufo Della Corte A. De Santo L.S. Quarto C. De Feo M. Romano G. Amarelli C. Scardone M. Di Meglio F. Guerra G. Scarano M. et al.Different patterns of extracellular matrix protein expression in the convexity and the concavity of the dilated aorta with bicuspid aortic valve: preliminary results.J Thorac Cardiovasc Surg. 2005; 130: 504-511PubMed Google Scholar, 34Ikonomidis J.S. Jones J.A. Barbour J.R. Stroud R.E. Clark L.L. Kaplan B.S. Zeeshan A. Bavaria J.E. Gorman III, J.H. Spinale F.G. Gorman R.C. Expression of matrix metalloproteinases and endogenous inhibitors within ascending aortic aneurysms of patients with bicuspid or tricuspid aortic valves.J Thorac Cardiovasc Surg. 2007; 133: 1028-1036Abstract Full Text Full Text PDF PubMed Scopus (177) Google ScholarCounseling PatientsDr. Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar is concerned that the ACC/AHA guidelines recommendations will "threaten" patients all their lives with the risk for sudden death from dissection. The role of physicians is to counsel and advise patients, not to threaten or scare them. Most cardiologists deal with issues such as these on a daily basis in patients with a wide variety of chronic cardiovascular disorders. Of the estimated 2.8 million to 5.6 million with BAVs (Dr. Guntheroth's estimation), roughly half will have no measurable increases in aortic diameter,10Isselbacher E.M. Diseases of the aorta.in: Libby P. Bonow R.O. Mann D.L. Zipes D.P. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Elsevier, Philadelphia, Pennsylvania2007: 1457-1489Google Scholar most with some degree of aortic enlargement will not have severe aortic enlargement, and only a small fraction will achieve the thresholds suggested by the ACC/AHA and European Society of Cardiology guidelines committees for aortic replacement in the absence of symptoms or other indications for AVR. With careful clinical and echocardiographic follow-up by knowledgeable cardiologists, and with more advanced imaging with magnetic resonance or computed tomography when indicated, patients can be managed safely and successfully, and experienced and caring clinicians can do so while maintaining their patients' emotional as well as physical health.Valve-Sparing Aortic Root ReplacementThere is no actual recommendation in the ACC/AHA guidelines for valve-sparing aortic root replacements.4Bonow R.O. Carabello B. Chatterjee K. De Leon Jr, A.C. Faxon D.P. Freed M.D. Gaasch W.H. Lytle B.W. Nishimura R.A. O'Gara P.T. et al.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Valvular Heart Disease).J Am Coll Cardiol. 2006; 48: e1-e148Abstract Full Text Full Text PDF PubMed Scopus (1513) Google Scholar The guidelines do indicate that this may be possible in selected patients at experienced centers when there is no aortic regurgitation or deformed or calcified aortic valves. By the time the ascending aorta reaches the threshold of severe dilatation recommended for surgery, most patients with BAVs have deformities of the valve that preclude valve-sparing procedures, and in addition have some degree of aortic stenosis or regurgitation, and hence most would be candidates for AVR plus replacement of the aorta, not valve-sparing procedures. The guidelines do state that "in general, AVR and aortic root reconstruction are indicated in patients with disease of the aortic root or proximal aorta and aortic regurgitation of any severity when the degree of dilatation of the aorta or aortic root reaches or exceeds 5.0 cm by echocardiography."4Bonow R.O. Carabello B. Chatterjee K. De Leon Jr, A.C. Faxon D.P. Freed M.D. Gaasch W.H. Lytle B.W. Nishimura R.A. O'Gara P.T. et al.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Valvular Heart Disease).J Am Coll Cardiol. 2006; 48: e1-e148Abstract Full Text Full Text PDF PubMed Scopus (1513) Google ScholarRecommendation for Ross ProcedureDr. Guntheroth3Guntheroth W.G. A critical review of the American College of Cardiology/American Heart Association practice guidelines on bicuspid aortic valve with dilated ascending aorta.Am J Cardiol. 2008; (In press)Google Scholar strongly recommends consideration of the Ross procedure in the treatment of patients with BAVs and dilated aortas. The Ross procedure is a topic of debate even among experienced cardiac surgeons. It can be accomplished with excellent results, but only at a very few selected centers in the United States by surgeons highly experienced in this operation. This is a good alternative for children and adolescents who require AVR, as well as young women who wish to become pregnant, but has no proved advantage over standard AVR in other adult patients in terms of hemodynamics or outcome.4Bonow R.O. Carabello B. Chatterjee K. De Leon Jr, A.C. Faxon D.P. Freed M.D. Gaasch W.H. Lytle B.W. Nishimura R.A. O'Gara P.T. et al.ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Valvular Heart Disease).J Am Coll Cardiol. 2006; 48: e1-e148Abstract Full Text Full Text PDF PubMed Scopus (1513) Google Scholar The number of such operations among adult cardiac surgeons has been steadily decreasing for more than a decade. In addition to the increased complexity of the operation itself, with the obligatory longer cardiopulmonary bypass times, this procedure has important limitations in patients with BAVs and aortic aneurysms because of the morphologic similarities between the pulmonary artery and the aorta,29de Sa M. Moshkovitz Y. Butany J. David T.E. Histologic abnormalities of the ascending aorta and pulmonary trunk in patients with bicuspid aortic valve disease: clinical relevance to the Ross procedure.J Thorac Cardiovasc Surg. 1999; 118: 588-594Abstract Full Text Full Text PDF PubMed Scopus (321) Google Scholar such that patients are at risk for the development of aneurysms of the autograft.35Luciani G.B. Casali G. Favaro A. Prioli M.A. Barozzi L. Santini F. Mazzucco A. Fate of the aortic root late after Ross operation.Circulation. 2003; 108: II-61-II-67Google Scholar Some surgeons would consider aortic dilatation in the setting of BAV to be a contraindication to the Ross operation. Dr. Guntheroth proposes the combination of a Ross procedure with some other technique to either externally reinforce the aortic aneurysm or replace the ascending aorta. The advantage of this combined approach compared with a straightforward AVR and replacement