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• Bicuspid aortopathy: searching for the answer in "non- progressors"
  Evaldas Girdauskas
  Published on: 23 November 2015

• Published on: 23 November 2015

  Bicuspid aortopathy: searching for the answer in "non- progressors"

  • Evaldas Girdauskas, Assistant Director/ Department of Cardiac Surgery
  • Other Contributors:
    • Michael A. Borger

  Evaldas Girdauskas1, Michael A. Borger2

  1- Department of Cardiac Surgery, Central Hospital Bad Berka, Germany 2- Department of Cardiac Surgery, Heart Center Leipzig, University Leipzig, Germany

  Keywords: bicuspid aortic valve, aortic aneurysm, aortopathy

  Corresponding author: Evaldas Girdauskas, MD, PhD (Address: Department of Cardiac Surgery, Central Hospital Bad Berka, Robert-Koch- Allee 9,...

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  Evaldas Girdauskas1, Michael A. Borger2

  1- Department of Cardiac Surgery, Central Hospital Bad Berka, Germany 2- Department of Cardiac Surgery, Heart Center Leipzig, University Leipzig, Germany

  Keywords: bicuspid aortic valve, aortic aneurysm, aortopathy

  Corresponding author: Evaldas Girdauskas, MD, PhD (Address: Department of Cardiac Surgery, Central Hospital Bad Berka, Robert-Koch- Allee 9, 99437 Bad Berka, Germany. Tel.: +49 3645851101; Fax: +49 3645853510 E-mail address: egirdauskas@web.de)

  We read with a great interest the manuscript by Detaint and co- authors published in the last issue of Heart [1]. The authors should be congratulated for their efforts to shine some light on the controversial issue of bicuspid aortic valve (BAV)-associated aorthopathy in their current longitudinal echocardiographic study. Indeed, there are some novel and intriguing findings in this manuscript which may deserve a more extensive commentary.

  The authors were able to demonstrate the fastest aortic dilatation rate at the ascending aortic level and smaller baseline aortic diameter being predictor of rapid aortic progression. Importantly, no correlation was found between aortic dilatation rate and BAV morphology as well as basic aortic phenotype. Typical morphology of BAV (i.e., L-R BAV fusion pattern) was independently associated with the baseline dilatation of the entire aortic root, which may reflect specific patterns of transvalvular flow in this BAV subtype [2].

  The BAV population analyzed in this study is quite distinct from the "typical" surgical BAV population and these differences should be highlighted. First of all, 113/353 (32%) BAV patients without raphe were identified in the current study. In our experience, it is rather rare to find a BAV without raphe during aortic valve replacement (AVR) surgery. Similarly, BAV without raphe was identified in only 7% patients in the surgical series by Sievers and co-authors [3]. Another major difference is the low proportion of patients with a BAV stenosis in the study (i.e., 14% of the study population). Calcific stenosis is the most common fate of congenital BAV (i.e., accounts for up 85% of surgically treated patients [4]) which is clearly underrepresented in the current series. As opposed to this, the authors revealed significant (i.e., at least moderate) BAV insufficiency in 123/353 (35%) study patients. Therefore, BAV cohort analyzed in this manuscript may represent a specific referral pattern of the tertiary care center. How many patients underwent AVR surgery during study period? Were these patients excluded from further echocardiographic follow-up? Is there any role of the variable "AVR surgery" in the progression of aortic diameters?

  Was there a subgroup of BAV patients with the maximal progression of aortic diameters at the level of the sinuses of Valsalva? There is some evidence in the literature that patients with so-called "root phenotype" (i.e., Valsalva sinuses > ascending aorta) may represent a predominantly congenital form of BAV disease which is associated with a higher risk of adverse aortic events [5]. What was the proportion of BAV patients in the subgroup of "sinuses phenotype" which showed stable aortic diameters at follow-up echocardiography?

  However, the most intriguing question from this manuscript - why did aortic diameters remain stable in nearly half of the BAV patients? Is this only a function of limited echocardiographic follow-up interval (i.e., aortopathy would progress over longer follow-up periods) or a real phenotypic difference in BAV patients? Provided that it is a real phenotypic difference- what are the predictors of non-progressive aortopathy in BAV disease? Obviously, this issue was not the main focus of the current manuscript and no specific analysis has been performed. However, based on the presented data, risk stratification for aortic events based on BAV morphology and baseline aortic diameter would be inadequate. A higher level of complexity in determinants of BAV-associated aortopathy has been proposed by the authors. In our opinion, this question will be impossible to address without knowing the precise haemodynamic profile of transvalvular flow in these BAV patients. Moreover, the presented data underscore still significant gaps in knowledge in the development of BAV aortopathy.

  References

  1. Detaint D, Michelena HI, Nkomo VT, Vahanian A, Jondeau G, Sarano ME. Aortic dilatation patterns and rates in adults with bicuspid aortic valves: a comparative study with Marfan syndrome and degenerative aortopathy. Heart. 2014;100:126-34.

  2. Mahadevia R, Barker AJ, Schnell S, Entezari P, Kansal P, Fedak PW, Malaisrie SC, McCarthy P, Collins J, Carr J, Markl M. Bicuspid Aortic Cusp Fusion Morphology Alters Aortic 3D Outflow Patterns, Wall Shear Stress and Expression of Aortopathy. Circulation. 2013 Dec 17.

  3. Sievers HH, Schmidtke C. A classification system for the bicuspid aortic valve from 304 surgical specimens. J Thorac Cardiovasc Surg. 2007;133:1226-33.

  4. Sabet HY, Edwards WD, Tazelaar HD, Daly RC. Congenitally bicuspid aortic valves: a surgical pathology study of 542 cases (1991 through 1996) and a literature review of 2,715 additional cases. Mayo Clin Proc. 1999;74:14-26.

  5. Girdauskas E, Disha K, Secknus M, Borger M, Kuntze T. Increased risk of late aortic events after isolated aortic valve replacement in patients with bicuspid aortic valve insufficiency versus stenosis. J Cardiovasc Surg (Torino). 2013;54:653-9.

  Conflict of Interest:

  None declared

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  Conflict of Interest:
  None declared.

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