Abstract 17542: Diagnostic Efficacy of Instantaneous Wave-free Ratio (iFR), Resting Distal Coronary Artery Pressure / Aortic Pressure, and iFR During Adenosine Administration Among Intermediate Coronary Lesions
Background: Fractional flow reserve (FFR) is an index of the severity of coronary stenosis that has been clinically validated in previous randomized trials. Instantaneous wave-free ratio (iFR) and resting distal coronary artery pressure / aortic pressure (Pd/Pa) are nonhyperemic pressure-derived indices of the severity of stenosis with discordant reports regarding their accuracy compared with FFR. This study sought to examine the correlation between FFR and other parameters including iFR, Pd/Pa and iFR during adenosine administration (iFRa).
Methods: iFR, Pd/Pa, iFRa, and FFR were performed in 49 intermediate lesions in 43 patients. iFR and Pd/Pa were measured without hyperemia. iFRa and FFR were measured during maximal hyperemia using intravenous adenosine. We examined the correlation between FFR and each of iFR, Pd/Pa, and iFRa. Using the cut off value of 0.80 by FFR as a gold standard of ischemic threshold, the specific thresholds of iFR, Pd/Pa and iFRa were assessed.
Results: Of 49 submitted lesions, 2 (4%) were excluded because of inadequate acquisition of pressure values, leaving 47 for final analysis. The correlation between FFR and iFR, Pd/Pa, and iFRa demonstrated an r of 0.71 (p<0.001), 0.76 (p<0.001), 0.95 (p<0.001), respectively. The optimal iFR cut point to predict FFR≤0.80 was 0.91 (area under the curve (AUC): 0.86, overall accuracy: 81%), for Pd/Pa was 0.92 (AUC: 0.83, overall accuracy: 77%), and for iFRa was 0.69 (AUC: 0.95, overall accuracy: 89%).
Conclusions: iFR and Pd/Pa had less accuracy to predict myocardial ischemia as compared with iFRa, indicating that these pressure derived index without vasodilatation might be insufficient to assess coronary stenosis severity.
Author Disclosures: K. Matsushita: None. K. Hibi: None. E. Akiyama: None. K. Takano: None. N. Maejima: None. N. Iwahashi: None. K. Tsukahara: None. M. Kosuge: None. T. Ebina: None. S. Sumida: None. S. Umemura: Research Grant; Modest; Torii. Research Grant; Significant; Pfizer, Dainippon-Sumitomo, Astellas, Shionogi, Daiichi-Sankyo, MSD, Astrazeneca, Novartis, Nihon-Boehringer-Ingelheim. Honoraria; Modest; Shionogi, MSD, Kyowa-Hakko-Kirin. K. Kimura: Research Grant; Significant; Toa Eiyo Ltd, Bayer, MSD, Astellas, Astrazeneca, Sanofi, Eli Lilly Japan, Research Institute for Production Development, Novartis, Bayer, Pfizer, Shionogi, Kowa-souyaku, Daiichi-Sankyo, Mitsubishi Tanabe, Nihon-Boehringer -Ingelheim, Takeda, Otsuka, Ono. Honoraria; Modest; Astrazeneca. Honoraria; Significant; MSD.
- © 2014 by American Heart Association, Inc.