Vol 27, No 5 (2020)
Original articles — Interventional cardiology
Published online: 2018-10-19

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Elliptical stretch as a cause of side branch ostial compromise after main vessel stenting in coronary bifurcations: New insights from numerical analysis

Dobrin Iotkov Vassilev1, Ghassan S. Kassab2, Carlos Collet3, Juan Luis Gutiérrez-Chico4, Gianluca Rigatelli5, Robert J. Gil6, Patrick W. Serruys7
Pubmed: 30394509
Cardiol J 2020;27(5):507-517.


Background: The side branch (SB) compromise after main vessel (MV) stenting remains a significant problem in coronary bifurcation treatment. Currently the two major hypotheses for the mechanism of SB compromise are carina shift from MV into the SB and plaque shift into the ostium of side vessel. It is proposed herein, SB ostial deformation leading to reshaping of the ostium from circle to ellipse is a third possible mechanism. In the current study, the theoretical effects and correlation of ostial deformation with fractional flow reserve (FFR) is explored.

Based on angiographic measurements and theoretical analysis formulas, three different SB ostial areas using circular ostial shape assumption and elliptical ostial shape assumption were calculated. Three different types of ostial areas with FFR values after MV stenting in 49 patients from the FIESTA registry were compared and analyzed.

It was found that there is significant overestimation of stenosis severity when estimated by the circle formula, than with the ellipse formula — ASc vs. ASds with 25% ± 13%, p < 0.001, ASc vs. ASmld with 9% ± 10%, p < 0.001. The elliptical shape assumptions provide more accurate ostial area stenosis, which correlates better with FFR. This finding is more significant in less severe stenosis (< 70% area stenosis) than in a more severe one.

A third possible mechanism of SB compromise after MV stenting of coronary bifurcation stenosis is elliptical ostial deformation at the ostium of SBs. The ostial area, calculated based on elliptical assumption correlates better with FFR, than area stenosis calculated with the traditional circular formula.

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  1. Lassen JF, Holm NR, Banning A, et al. Percutaneous coronary intervention for coronary bifurcation disease: 11th consensus document from the European Bifurcation Club. EuroIntervention. 2016; 12(1): 38–46.
  2. Vassilev D, Gil RJ. Relative dependence of diameters of branches in coronary bifurcations after stent implantation in main vessel--importance of carina position. Kardiol Pol. 2008; 66(4): 371–379.
  3. Vassilev D, Gil RJ. Changes in coronary bifurcations after stent placement in the main vessel and balloon opening of stent cells: theory and practical verification on a bench-test model. J Geriatr Cardiol. 2008; 5: 43–49.
  4. Vassilev D, Gil R. Clinical verification of a theory for predicting side branch stenosis after main vessel stenting in coronary bifurcation lesions. J Interv Cardiol. 2008; 21(6): 493–503.
  5. Cho S, Kim JS, Ha J, et al. Three-Dimensional optical coherence tomographic analysis of eccentric morphology of the jailed side-branch ostium in coronary bifurcation lesions. Can J Cardiol. 2016; 32(2): 234–239.
  6. Yang PS, Ha J, Kim JS, et al. Eccentric morphology of jailed side-branch ostium after stent crossover in coronary bifurcation lesions: a three-dimensional optical coherence tomographic analysis. J Cardiol. 2015; 65(4): 305–310.
  7. Kolh P, Windecker S, Alfonso F, et al. European Society of Cardiology Committee for Practice Guidelines, EACTS Clinical Guidelines Committee, Task Force on Myocardial Revascularization of the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery, European Association of Percutaneous Cardiovascular Interventions, Authors/Task Force members. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J. 2014; 35(37): 2541–2619.
  8. Sýkora S. Approximations of Ellipse Perimeters and of the Complete Elliptic Integral E(x). Review of known formulae DOI:10.3247/SL1Math05.004. http://www.ebyte.it/library/docs/math05a/EllipsePerimeterApprox05.html.
  9. Sýkora S. Advances in Approximations of Ellipse Perimeters and of the Complete Elliptic Integral. DOI: 10.3247/SL2Math07.001. http://www.ebyte.it/library/docs/math07/EllipsePerimeterApprox07.html.
  10. Almkvist G, Berndt B. Gauss, Landen, Ramanujan, the Arithmetic-Geometric Mean, Ellipses, π, and the Ladies Diary. The American Mathematical Monthly. 2018; 95(7): 585–608.
  11. Hudson RG, Lipka J, A manual of mathematics, 1st Edition 1917.
  12. Lockwood EH. Length of ellipse. The Mathematical Gazette. 1932; 16(220): 269–270.
  13. Gérard P. Michon Perimeter of an Ellipse. http://www.numericana.com/answer/ellipse.htm.
  14. Latka F., Collection of Mathematical Formulae, Hungarian Edition, Budapest 1985.
  15. Barnard R, Pearce K, Schovanec L. Inequalities for the Perimeter of an Ellipse. Journal of Mathematical Analysis and Applications. 2001; 260(2): 295–306.
  16. Gould KL, Johnson NP. Physiologic stenosis severity, binary thinking, revascularization, and "hidden reality". Circ Cardiovasc Imaging. 2015; 8(1).
  17. Gould KL, Johnson NP, Bateman TM, et al. Anatomic versus physiologic assessment of coronary artery disease. Role of coronary flow reserve, fractional flow reserve, and positron emission tomography imaging in revascularization decision-making. J Am Coll Cardiol. 2013; 62(18): 1639–1653.
  18. Vassilev D, Dosev L, Collet C, et al. Intracoronary electrocardiogram to guide percutaneous interventions in coronary bifurcations – a proof of concept: the FIESTA (Ffr vs. IcEcgSTA) study. EuroIntervention. 2018; 14(5): e530–e537.
  19. Ha J, Kim JS, Mintz GS, et al. 3D OCT versus FFR for jailed side-branch ostial stenoses. JACC Cardiovasc Imaging. 2014; 7(2): 204–205.
  20. Kang SJ, Kim WJ, Lee JY, et al. Hemodynamic impact of changes in bifurcation geometry after single-stent cross-over technique assessed by intravascular ultrasound and fractional flow reserve. Catheter Cardiovasc Interv. 2013; 82(7): 1075–1082.
  21. Johnson PM, Madamanchi C, Sharalaya ZM, et al. Angiographic severity does not correlate with fractional flow reserve in heavily calcified coronary arteries. Catheter Cardiovasc Interv. 2017; 89(2): 226–232.