Computing Fractional Flow Reserve From Invasive Coronary Angiography

It is now nearly 25 years since Pijls et al’s1 first description of the experimental basis for fractional flow reserve (FFR). In that article, the purpose of FFR was stated as “assessing functional stenosis severity before and after percutaneous transluminal coronary angioplasty” (PTCA). Since then, and particularly in the past 15 years, a wealth of evidence has accrued demonstrating that FFR guidance improves outcomes in patients being treated for coronary artery disease when compared with conventional angiographic guidance alone. Adoption into the major guideline documents has since followed.2–4 Yet FFR measurement is performed in only a minority of patients. Why is this?See Article by Pellicano et al First, FFR requires time to set up, pass the wire and infuse adenosine, all of which increase the procedure time. Second, short-term cost is increased, even though FFR is cost-effective in the longer term. Third, an experienced interventionist may feel that he/she knows which lesion(s) to treat and which to leave alone. When faced with lesions of intermediate severity, diffuse disease and long segments, such subjective judgment is often inaccurate. Fourth, if noninvasive testing for ischemia has already provided a clear indication of the location of ischemia, FFR may not be necessary. Fifth, the implications of a positive FFR result are that PTCA should be performed, and for this to happen there has to be planning for that procedure, with appropriate antiplatelet agents, counseling, and yet more time scheduled; time which, of course, may not, in the end, be used. Sixth, the weight of evidence supporting FFR is in the context of chronic stable coronary disease, whereas the workload of the interventionist is increasingly made up of acute or unstable disease.So FFR use remains trapped within the world of (largely elective) PTCA guidance, as originally outlined by …