Continuum of Vasodilator Stress From Rest to Contrast Medium to Adenosine Hyperemia for Fractional Flow Reserve Assessment

Abstract

cFFR provides diagnostic performance superior to that of Pd/Pa or iFR for predicting FFR. For clinical scenarios or health care systems in which adenosine is contraindicated or prohibitively expensive, cFFR offers a universal technique to simplify invasive coronary physiological assessments. Yet FFR remains the reference standard for diagnostic certainty as even cFFR reached only ∼85% agreement.

Instant Wave-Free Ratio or Fractional Flow Reserve for Hemodynamic Coronary Lesion Assessment?

“…Initial sentiment suggested that iFR discordance naturally implied inferiority of that index to FFR which has been backed by a large body of literature and clinical experience and some proposed the concept of a pyramid of accuracy in which FFR is placed on top and above all resting indices. 8 More recent evidence, including the present study, indicates that the diagnostic accuracy of iFR and FFR is very similar and statistically not different when compared with an independent ischemia test such as positron emission tomography. This may be partially related to the difficulty of defining true myocardial ischemia with any diagnostic test but also to the fact that many discordant iFR/FFR pairs are not really discordant.…”

Simplifying the assessment of coronary artery stenosis by enhancing instantaneous wave free ratio

“…Contrast media, on the other hand has already been evaluated as a hyperemic agent in FFR (14)(15)(16)(17). In one multicenter study, adjudicated by a central core laboratory, contrast mediated FFR compared favorably to adenosine mediated FFR and was superior to iFR for predicting CAS severity (15). This study differs from our study in that all coronary lesions were included for analysis regardless if values were in the intermediate (inconclusive) zone.…”

“…In order to facilitate FFR adoption, two different approaches have been proposed: intra coronary adenosine administration (13), and more recently introduction of contrast medium as an alternative hyperemic agent. Contrast medium induced FFR, studies have shown a good correlation between contrast induced Pd/Pa and adenosine mediated FFR (14)(15)(16)(17).…”

“…Saline solution decreases coronary resistances and increases vasodilatation (11,12). Contrast media, on the other hand has already been evaluated as a hyperemic agent in FFR (14)(15)(16)(17). In one multicenter study, adjudicated by a central core laboratory, contrast mediated FFR compared favorably to adenosine mediated FFR and was superior to iFR for predicting CAS severity (15).…”

Fractional Flow Reserve and Coronary Computed Tomographic Angiography

“…Unfortunately, multiple large, multicenter studies have shown that these indices are only ≈80% accurate when compared with FFR. 17,18 The FAME 2 trial highlighted an important concept that the greater the burden of ischemia-producing CAD, the higher the event rate with medical therapy alone. Other studies have also found a relationship between the FFR value across the lesion and the risk of adverse events with medical therapy alone, which is attenuated by revascularization, 19 even when focusing only on the gray zone of FFR values.…”