Simplifying the Assessment of Coronary Artery Stenosis by Enhancing Instantaneous Wave Free Ratio

Abstract

Background: Instantaneous wave free ratio (iFR) does not require adenosine, but has a relatively wide intermediate range where functional assessment remains inconclusive. In this pilot study, we sought to enhance iFR through with the use of intracoronary (IC) saline (iFRs) and contrast media (iFRc) and determine whether these techniques correlated well with fractional flow reserve (FFR). Conclusions: When iFR is in the intermediate zone, functional assessment of CAS by iFR is enhanced with the use of contrast media but not saline. This pilot study could be hypothesis generating for further study to enhance iFR specificity and sensibility.

Current approach to the diagnosis of atherosclerotic coronary artery disease: more questions than answers

“…These techniques have generally required the use of adenosine (in the same way perfusion imaging is performed, above); however, more recent applications have used the intrinsic characteristics of blood flow alone, 92 or under the influence of saline or contrast injections. 93 Studies utilizing some form of intravascular functional assessment compared to ICA alone have generally shown greater specificity of CAD 'significance', and thus a tendency to reduce likely unnecessary PCI,, 94,95 and the potential to meaningfully change management and revascularization strategy when performed upfront in ICA (CABG versus PCI versus optimal medical therapy). 96,97 In line with the earlier discussion around functional significance, it remains unclear whether an invasive functional assessment significantly impacts hard outcomes beyond urgent revascularization.…”