Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

Background: Optical coherence tomography (OCT) requires intracoronary injection of contrast media to remove blood from the field of view during image acquisition. Contrast injection may cause a temporal increase in intracoronary pressure. The aim of this study was to compare the intracoronary pressure during contrast injection between OCT and coronary angiography. Methods: We measured intracoronary pressure by using a pressure guidewire during contrast injection for OCT and angiography in 30 coronary arteries (mean fractional flow reserve = 0.90 +/- 0.03). Contrast media was injected into coronary artery through the guiding catheter by using a mechanical injector pump. Results: Intracoronary pressure before contrast injection was similar between OCT and angiography (systolic pressure: 123 +/- 18 mmHg vs. 122 +/- 19mmHg, p = 0.863). Intracoronary pressure was increased due to contrast injection in both OCT (systolic pressure: 123 +/- 18mmHg to 132 +/- 18mmHg, p< 0.001) and angiography (systolic pressure: 122 +/- 19mmHg to 128 +/- 19mmHg, p< 0.001). The increase in intracoronary pressure was slightly greater in OCT compared with angiography (absolute increase of systolic pressure: 9 +/- 2mmHg vs. 6 +/- 1 mmHg, p< 0.001; and relative increase of systolic pressure: 8 +/- 2% vs. 5 +/- 1%, p< 0.001). Intracoronary pressure during contrast injection was not significantly different between OCT and angiography (systolic pressure: 132 +/- 18 mm Hg vs. 128 +/- 19mmHg, p = 0.831). Conclusions: Contrast injection for OCT induced significant but small increase in intracoronary pressure compared with that for angiography. (C) 2019 Published by Elsevier Ltd on behalf of Japanese College of Cardiology.