034: Identification of mechanisms underlying very late stent thrombosis by optical coherence tomography imaging

BackgroundVery late stent thrombosis (VLST) is a rare but severe complication of percutaneous coronary intervention. We sought to analyze the mechanisms involved in the pathophysiology of using optical coherence tomography (OCT) imaging techniques.MethodsPatients with an acute coronary syndrome related to VLST from two catheterization facilities were included in this multicenter registry and underwent a standard coronary angiography and intra coronary OCT. Uncovered strut was defined as a strut of measured neointimal thickness equal to 0μm. Intra stent neo atherosclerosis (ISNA) was defined as the combination of neointimal diffuse proliferation, lipid-laden intima with plaque organization and fibrous cap with no evidence of uncovered strut.ResultsA total of 1539 patients with acute coronary syndromes (ACS) were admitted in both centers between October 2010 and March 2012. Sixteen of these subjects (1.03%) presented a definite VLST (drug eluting stents: 38% of the cases), including n=8 subjects with OCT evidences of ISNA lesions and n=8 patients with lack of struts neointimal coverage.We observed that the delay between the initial PCI and the thrombotic event was longer in ISNA subjects compared to the others (10.1±1.8 vs. 3.9±0.5 y, p=0.01). Moreover, a history of dyslipidemia was more frequent in the ISNA group (100% vs. 50%, p=0.04) and the mean baseline LDL-cholesterol value tended to be higher compared to the other group (1.36±0.16 vs. 0.95±0.14g/l, p=0.07).All lesions were treated by initial thrombectomy that was completed by redo stenting in n=7 ISNA patients (DES in 86% of the cases). No adverse cardiovascular event (cardiovascular death, reinfarction, urgent PCI or stroke) was observed during the first 30 days following VLST.ConclusionOur data show that ISNA is common in patients with VLST. These results suggest that OCT imaging is useful to identify the mechanisms underlying VLST and to help the clinical decision-making process