Clinical Research Myocardial Fractional Flow Reserve Measurement Using Contrast Media as a First-Line Assessment of Coronary Lesions in Current Practice

Background: Fractional flow reserve (FFR) measurement requires adenosine injection. However, adenosine can induce conductive and rhythmic complications, or be contraindicated in some patients. Contrast-induced hyperemia could provide a simple first-line method (contrast-enhanced FFR; cFFR) to assess coronary lesions. In this study we evaluated the accuracy of cFFR to predict lesion significance. Methods: This prospective study included 104 patients with 138 coronary lesions. Each stenosis was evaluated using resting distal coronary pressure to aortic pressure ratio (Pd/Pa) measurements using intracoronary iodixanol (cFFR) and adenosine (FFR) injection. An FFR value � 0.8 defined a significant lesion. Results: Dose-ranging analysis (n ¼ 12 lesions) showed that 10 mL iodixanol was required to obtain the lowest cFFR value. Intermeasurement reproducibility of cFFR (n ¼ 18 lesions) showed limited variability and small mean estimated bias (0.001 � 0.014). Values of cFFR and FFR were highly correlated in a first series of n ¼ 36 lesions (r ¼ 0.9; P < 0.001). Receiver-operating characteristic curve analysis