Fractional Flow Reserve–Guided Percutaneous Coronary Intervention Is Not a Valid ConceptResponse to Arbab-Zadeh
The concept of fractional flow reserve (FFR)–guided percutaneous coronary intervention (PCI) has gained worldwide acceptance in the cardiology community.1 Hemodynamic assessment with FFR in the cardiac catheterization laboratory is now routinely being performed in intermediate-range coronary arterial stenoses to inform the decision to proceed with PCI.2 The paradigm of the FFR concept holds that clinical benefit of PCI is confined to coronary artery stenoses that restrict blood flow as documented by an abnormal FFR value (<0.75 or 0.80 typically).1 Correct measurement of FFR requires advancing a small wire distal to the stenosis that compares the intracoronary pressure with a proximal reference site under hyperemic conditions, for example, after application of adenosine.3,4 The procedure is invasive and adds cost, procedural time, radiation, contrast, and risk of vascular injury to standard angiography.5,6 To overcome the limitation of an invasive procedure, enormous efforts are being undertaken to assess FFR noninvasively.7 Several clinical studies reported modest to good accuracy of obtaining FFR estimates by computed tomography imaging, whereas other efforts have aimed at combining coronary anatomic information with myocardial perfusion information to simulate the same, seemingly desirable, outcome.8,9 Given the widespread use and large impact on the practice of cardiology, it appears prudent to critically review the evidence for the concept of FFR-guided revascularization.
Response by Fearon p 1878
The FFR Rationale
The FFR concept as outlined in the Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study is based on the premise that performing PCI on coronary arterial stenoses causing myocardial ischemia leads to reduced adverse cardiac events, while it is not beneficial to revascularize lesions that do not cause ischemia.10 This premise, however, does not adequately consider the complicated relationship among coronary artherosclerotic disease, coronary arterial blood flow, myocardial ischemia, …