Long-term clinical outcome after fractional flow reserve– versus angio-guided percutaneous coronary intervention in patients with intermediate stenosis of coronary artery bypass grafts

Selected in American Heart Journal by R. El Mahmoud

References

Authors

Luigi Di Serafino, Bernard De Bruyne, Fabio Mangiacapra, Jozef Bartunek, Pierfrancesco Agostoni, Marc Vanderheyden, Gabriella Scognamiglio, Guy R. Heyndrickx, William Wijns, Emanuele Barbato

Reference

Am Heart J 2013;0:1-9.

Published

May 2013

Link

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My Comment

Background

  • We know that Fractional flow reserve (FFR)guided percutaneous coronary intervention (PCI) of intermediate stenosis in native coronary artery is associated with better clinical outcomes as compared with angiography-guided PCI
  • It is unknown if this applies to coronary artery bypass grafts (CABGs)

Major findings

  • All patients referred to coronary angiography for stable or unstable angina (most had stable angina) from 2000 to 2011 with at least 1 intermediate stenosis of an arterial or a venous bypass graft measured with FFR were included (65 patients)
  • Contemporary patients with previous CABG undergoing coronary angiography with intermediate stenosis of an arterial or a venous bypass graft were used as a reference group (158 patients)
  • 1angio-guided group, where PCI was performed or deferred based on the angiographic appearance of the lesion and 1 FFR-guided group where PCI was performed in case of FFR 0.80 and deferred to optimal medical therapy in case of FFR >0.80.
  • More PCI were performed in angio-guided group vs FFR-guided group (57% vs 35% , p<0.01)
  • In the FFR-guided group, overall FFR value was 0.84 ± 0.13 and the stenosis was more frequently located on arterial grafts
  • An FFR value 0.80 was found in 23 patients (35%) who underwent PCI (FFR 0.68 ± 0.09), whereas 42 (65%) patients (FFR 0.92 ± 0.05) were deferred to medical therapy
  • In the angio-guided group, 90 (57%) patients (QCA: 56.8 ± 13) underwent PCI, whereas 68 (43%) patients (QCA 41.7 ± 9) were deferred to medical treatment.
  • Inhospital outcome was comparable between the 2 groups, excepted a higher rate of periprocedural myocardial infarction (PMI) in the angio-guided group (11% vs 1% in the FFR-guided group, P <0.01) mostly in saphenous vein grafts (SVGs)
  • FFR-guided PCI was associated with a significantly lower MACCE (composite end point of all-cause death, nonfatal MI, target vessel failure and cerebrovascular accidents) rate at 4-year follow-up.
  • Rate of MACCE was lower in the FFR-guided group for patients with arterial graft stenosis, but no significant differences were observed for SVGs stenosis.

My comments

  • FFR-guided PCI of intermediate stenosis in CABGs is safe and results in a better clinical outcome as compared with an angio-guided PCI which was already demonstrated in native coronary artery in FAME study.
  • The clinical benefit is more pronounced in arterial grafts were PCI was more often performed in FFR-guided group which seems logical because arterial grafts are usually supplying larger myocardial territories while in venous bypass grafts, the benefit was limited to a reduction of PMI
  • Embolic protection devices were only used in few cases which might have been responsible for the higher PMI rate in the angio-guided group but we know that using these devices is not always easy in venous bypass grafts
  • An important technical aspect when performing FFR in bypass grafts is that pressure wire should be advanced 2 to 3 mm beyond the anastomosis in case the native vessel upstream the anastomosis is not completely occluded. If the native vessel is occluded, the pressure wire is positioned at least 10 mm beyond the stenosis
  • This study is a retrospective registry and it will be suitable to have a randomized trial which is not so easy because patients with CBAGs who need PCI became scarce.
  • Among the deferred patients, freedom from chest pain was significantly more frequent in the FFR-guided group which indicated that FFR can better identified the lesions which need PCI to avoid recurrence of pectoris angina

 

2 comments

  • Rajeev Gupta 20 Jul 2013

    The rate of MACCE was lower ( with FFR guided group) in Arterial graft stenosis and not in SVGs stenosis.This statement in the major findings has serious limitation as the total number of pts is very much limited ( 65 pts.only) and statistically it is hard to appreciate the difference for venous grafts.A larger study is needed.

  • RAMI EL MAHMOUD 23 Jul 2013

    You're right. A larger study and randomized is needed to conclude but the limited number of patients included in 11 years in this study shows that it is difficult to find patienst with CABG who need PCI.