Abstract 3064: Assessment of Coronary Intervention by Optical Coherence Tomography in Acute Coronary Syndrome: Comparison with Stable and Unstable Angina
[Background] The outcome after percutaneous coronary intervention (PCI) in acute coronary syndrome is worse than that in stable angina pectoris. Conventional contrast angiography and intravascular ultrasound provide a limited identification of vessel microstructure, and it might be difficult to evaluate incomplete stent apposition and tissue protrusion between stent struts accurately using these conventional diagnostic tools. Optical Coherence Tomography (OCT) is a high resolution coronary artery imaging modality and it has the potential to address important diagnostic and management problems in coronary heart disease. This study was performed to compare the results of PCI between stable and unstable plaques by OCT.
[Methods and Results] Thirty five coronary lesions (stable angina: n=15, unstable angina: n=20) were examined in this study. OCT catheters were successfully passed in all lesions, and images were obtained before initial balloon dilatation and following stent deployment. Before PCI, the incidences of ruptured fibrous cap (65% vs. 13%, p<0.001) and intraluminal thrombus (94% vs. 13%, p<0.001) in unstable angina were higher than those in stable angina, and the fibrous cap thickness was thinner in unstable angina (55 +/− 28 vs.310 +/− 221 micrometer, p<0.001). After stent deployment, the incidences of PCI induced dissection, incomplete stent apposition and irregular strut distribution were not different between both groups, but intraluminal thrombus (85% vs. 33%, p<0.001), tissue protrusion between stent struts (70% vs. 26%, p<0.001) were observed more often in unstable angina compared with those in stable angina.
[Conclusion] Intravascular OCT was feasible for monitoring vessel and stent structures during PCI in not only stable angina but also unstable angina. The frequent intramural thrombus and tissue protrusion between stent struts were demonstrated by OCT in unstable angina, and they might affect on the prognosis after PCI.