FFR / Koo

Anatomic and Functional Evaluation of Bifurcation Lesions Undergoing Percutaneous Coronary Intervention.

Koo BK, Waseda K, Kang HJ, Kim HS, Nam CW, Hur SH, Kim JS, Choi D, Jang Y, Hahn JY, Gwon HC, Yoon MH, Tahk SJ, Chung WY, Cho YS, Choi DJ, Hasegawa T, Kataoka T, Oh SJ, Honda Y, Fitzgerald PJ, Fearon WF.

Circ Cardiovasc Interv. 2010 Apr;3(2):113-9.

OBJECTIVES:

The aim was to investigate the mechanism of geometric changes after main branch (MB) stent implantation and to identify the predictors of functionally significant "jailed" side branch (SB) lesions.

METHODS:

• 77 patients
• 8 U.S., Korean and Japa-nese centers
• Bifurcation lesions only
• MB intravascular ultrasound was performed before and after MB stent implantation, and fractional flow reserve was measured in the jailed SB

SUMMARY:

• The vessel volume index of both the proximal and distal MB was increased after stent implantation.
• The plaque volume index decreased in the proximal MB (9.1 ± 3.0 to 8.4 ± 2.4 mm³/mm, P = 0.001), implicating plaque shift, but not in the distal MB (5.4 ± 1.8 to 5.3 ± 1.7 mm³/mm, P = 0.227), implicating carina shifting to account for the change in vessel size (N = 56).
• The mean SB fractional flow reserve was 0.71 ± 0.20 (N = 68) and 43 % of the lesions were functionally significant.
• Binary logistic-regression analysis revealed that preintervention % diameter stenosis of the SB (odds ratio = 1.05; 95 % CI, 1.01 to 1.09) and the MB minimum lumen diameter located distal to the SB ostium (odds ratio = 3.86; 95 % CI, 1.03 to 14.43) were independent predictors of functionally significant SB jailing.
• In patients with ≥ 75 % stenosis and Thrombolysis In Myocardial Infarction grade 3 flow in the SB, no difference in poststent angiographic and intravascular ultrasound parameters was found between SB lesions with and without functional significance.

CONCLUSIONS:

Both plaque shift from the MB and carina shift contribute to the creation/aggravation of an SB ostial lesion after MB stent implantation. Anatomic evaluation does not reliably predict the functional significance of a jailed SB stenosis.

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