Mechanisms of Stent Thrombosis Analysed by Optical Coherence Tomography: Insights from the National PESTO French Registry

Aims: Angiography has limited value for identifying mechanisms triggering stent thrombosis (ST). We studied a large cohort of patients by optical coherence tomography (OCT) to explore ST characteristics and mechanisms.
Methods and Results: A prospective multicentre registry was screened for patients with confirmed ST. OCT was performed after culprit lesion deocclusion (in 69% of cases in a deferred procedure). ST was classified as acute (AST), sub-acute (SAST), late (LST) and very late (VLST). OCT records were analysed in a central core lab. The analysis included 120 subjects aged 61.6 ±1.1 years; 89% male. VLST was the clinical presentation in 75%, LST in 6% and SAST+AST in 19% of patients. Bare metal stents (BMS) were used in 39%, drug-eluting stents (DES) in 59% and bioresorbable vascular scaffolds in 2% of the cases. OCT identified an underlying morphological abnormality in 97% of cases, including significant struts malapposition (34%), neoatherosclerotic lesions (22%), major stent underexpansion (11%), coronary evagination (8%), isolated uncovered struts (8%), edge-related disease progression (8%) and neointimal hyperplasia (4%). Ruptured neoatherosclerotic lesions were more frequent with BMS than with DES (36 vs. 14%, p<0.01), whereas coronary evaginations were more frequent with DES than with BMS (12% vs. 2%, p<0.05). LST+VLST were mainly related to malapposition (31%) and neoatherosclerosis (28%), while prominent mechanisms for AST+SAST were malapposition (48%) and underexpansion (26%).
Conclusions: In patients with confirmed ST, OCT imaging identified an underlying morphological abnormality in 97% of cases and influenced the clinical management in 55% of cases.