Increased Exposure to X-Rays During Coronary Angiography and Percutaneous Coronary Interventions Associated with Fractional Flow Reserve Measurement and Endocoronary Imaging Techniques.

Growing use of fractional flow reserve (FFR) and intracoronary imaging techniques by optical coherence tomography or intravascular ultrasound has raised concerns about additional exposure during coronary angiography and percutaneous coronary interventions (PCIs). Using data from the prospective CRAC-France PCI Prospective Multicentre registry, we sought to evaluate the effect of these new techniques on the radiation dose to patients undergoing coronary procedures. Data on Kerma Area Product (PKA), total air kerma (KAr) and fluoroscopy time from 42 182 coronary procedures were retrospectively compared, using multivariable linear regression, according to whether they included FFR and intracoronary imaging. In coronary angiography, FFR was associated with longer fluoroscopy time and higher PKA (21.0 vs. 18.9 Gy.cm2) and KAr (372 vs. 299 mGy) (all p < 0.001). Intracoronary imaging was associated with longer fluoroscopy time, higher contrast volume (both p < 0.001), lower PKA (18.3 vs. 19.0 Gy.cm2, p = 0.02) and similar KAr. In PCI, FFR was associated with a moderate increase in KAr (682 vs. 626 mGy, p < 0.01) but not PKA (35.9 vs. 33.7 Gy.cm2, p = 0.34). For intracoronary imaging, there were no differences between groups, except for contrast volume. Increased patient exposure associated with FFR and intracoronary imaging is moderate in diagnostic coronary angiography and minimal or none in PCI, provided optimization techniques are used. It should not be a limitation on the use of these techniques given the important additional information they provide.