P825Evaluation of intracoronary thrombus by optical coherence tomography: characterization, quantification, prognostic impact in patients with non-ST-elevation acute coronary syndrome. A DOCTORS substudy

Abstract

Background: We aimed to evaluate the impact of thrombus burden as measured by Optical Coherence Tomography on the occurrence of peri-procedural myocardial infarction (type IVa MI) among patients undergoing percutaneous coronary intervention (PCI) in non ST elevation acute coronary syndrome (NSTE-ACS). Method(s): Prospective multicenter study including patients treated for NSTE-ACS (<72 h) undergoing PCI of the infarct related artery (IRA). OCT was performed before and after PCI. Thrombus burden was measured quantitatively by planimetry, and semi quantitatively by the OCT thrombus score. The primary endpoint was the rate of type IVa MI. Secondary endpoints evaluated the rate of type IVa MI according to the quantification of the thrombus on OCT, the relationship between the OCT characteristics of the IRA and volume of thrombus, and the correlation between the thrombus volume measured pre PCI and the functional outcome of the angioplasty evaluated by fractional flow reserve (FFR) at the end of the procedure. Result(s): 120 patients aged 60.8+/-11 years were included in the study. Thrombus was more frequently present on OCT (83 (69%)) than on angiography (54 (45%), p<0.0001). There was no significant difference in antithrombotic treatments between groups. Type IVa MI occurred in 48 patients (40%). The occurrence of type IVa MI was not related to presence of thrombus on OCT (33 (40%) with vs 15 without (41%) p=0.93). Thrombus volume evaluated by planimetry or semiquantitavely was not predictive of type IVa MI. There was a strong association between presence of thrombus pre PCI and presence of tissue prolapse post PCI. The volume of thrombus was significantly correlated with the volume of tissue prolapse (p=0.03 and p=0.01). The presence of thrombus and volume of thrombus as measured pre PCI did not affect post PCI FFR (0.94+/-0.04 vs 0.93+/-0.04, for presence vs absence of thrombus, p=0.51). Conclusion(s): OCT allows better visualization of thrombus than angiography in NSTE-ACS. In patients receiving antithrombotic therapy, neither the presence nor the volume of thrombus impacts the occurrence of a periprocedural myocardial infarction. Thrombus burden does not influence the functional outcome of angioplasty as measured by FFR.