Letter by Nadir Regarding Article, "Optical Coherence Tomography to Optimize Results of Percutaneous Coronary Intervention in Patients With Non-ST-Elevation Acute Coronary Syndrome: Results of the Multicenter, Randomized DOCTORS Study (Does Optical Coherence Tomography Optimize Results of Stenting)".

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HomeCirculationVol. 135, No. 9Letter by Nadir Regarding Article, “Optical Coherence Tomography to Optimize Results of Percutaneous Coronary Intervention in Patients With Non-ST-Elevation Acute Coronary Syndrome: Results of the Multicenter, Randomized DOCTORS Study (Does Optical Coherence Tomography Optimize Results of Stenting)” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Nadir Regarding Article, “Optical Coherence Tomography to Optimize Results of Percutaneous Coronary Intervention in Patients With Non-ST-Elevation Acute Coronary Syndrome: Results of the Multicenter, Randomized DOCTORS Study (Does Optical Coherence Tomography Optimize Results of Stenting)” M. Adnan Nadir, MD, MBBS, MRCP M. Adnan NadirM. Adnan Nadir From University Hospital Birmingham, United Kingdom. Search for more papers by this author Originally published28 Feb 2017https://doi.org/10.1161/CIRCULATIONAHA.116.025486Circulation. 2017;135:e138–e139To the Editor:I read the article by Meneveau et al1 with great interest. The authors concluded that in patients with non-ST-elevation myocardial infarction, optical coherence tomography-guided percutaneous coronary intervention (PCI) is associated with higher postprocedure fractional flow reserve (FFR) than PCI guided by angiography alone without an increase in periprocedural complications.Several concerns surround the use of FFR as a surrogate end point. The utility of FFR is firmly established in stable coronary artery disease but has been widely debated in patients with non-ST-elevation myocardial infarction, particularly in the culprit vessel.2 Valid FFR measurements require maximal coronary hyperemia, which may be less readily achieved in patients with acute coronary disease because of coronary microvascular dysfunction. This in turn may result in a falsely higher FFR value. This outcome is of particular concern when assessing the FFR value after PCI because coronary stenting of a thrombus-laden acute plaque of the culprit lesion in acute coronary syndrome would inevitably carry the risk of some distal embolization, which may further exacerbate the issue. In fact, in this study, 47% to 69% of the patients were noticed to have a discernable thrombus (either angiographically or on optical coherence tomography), and 50% of all participants received GP IIb/IIIa inhibitors. Both of these observations suggest that a legitimate and valid concern existed among the operators regarding the possibility of distal embolization and slow or no-flow phenomenon to account for the unusually high use of GP IIb/IIIa inhibitors. The authors reported that 79% of the patients had tissue protrusion and 43% received overdilatation after stent placement in the optical coherence tomography group. Hence, it is plausible that the higher FFR value seen in the optical coherence tomography group could have been caused by less hyperemia achieved in a distal vascular bed, which is overloaded with microembolization caused by more aggressive overdilatation after stent placement, compared with the angiographic group, which had a much lower rate of overdilataion after stent placement. Last but not least, the normal FFR value is considered to be 0.92 to 1.00, and a recent study investigating the utility of FFR after PCI reported that a FFR value < 0.91 was actually associated with a favorable outcome. Interestingly, in this study, despite the modest difference in absolute value, the mean FFR value after PCI was with in normal limits in both groups, which may further limit the value of FFR after PCI as the primary study outcome measure in this particular study.3M. Adnan Nadir, MD, MBBS, MRCPDisclosuresNone.FootnotesCirculation is available at http://circ.ahajournals.org.