Coronary stent edge segments as determinant of clinical outcomes: An OCTOBER Trial Substudy

Abstract Background Small lumen dimensions and high plaque burden in stent edge segments are known risk factors for subsequent clinical events after percutaneous coronary intervention (PCI). The evidence using intravascular optical coherence tomography is scarce. Purpose This study aimed to characterize edge segments after PCI and the relation to clinical outcomes in the randomized OCTOBER trial on bifurcation PCI optimized using optical coherence tomography. Methods This is a predefined substudy of the OCTOBER Trial. Edge segments were analysed in detail for degree of stenosis and plaque composition using a dedicated software. Data was planned to be analysed using multi-level cox regression analysis, but descriptive statistics was applied due to very low event rates after OCT-guided PCI. Main endpoints were OCT-detected edge residual stenosis, lipid plaque, calcification, and dissections. Post PCI coronary angiography was analysed for diameter stenosis, edge segment length and minimal lumen diameter. Patients with cardiac events were diagnosed with angiography duringt the two-year follow-up period. Results A total of 597 patients were treated with OCT-guided PCI. Analysable final OCT scans with no additional treatment was available for 505 patients in the main vessel and for the side branch in 289 cases. At deadline for abstract submission 242 scans with 474 edges were analysed and included in preliminary results.Lesions with ≥30% diameter stenosis was found in 20% of proximal edges, 24% of distal edges and 37% of side branch (SB) edges. A plaque burdenOCT ≥180° was found in 74% of proximal edges, 48% of distal edges, and 52% of SB edges. A lipid plaque wafound in 35%, 11% and 14%, dissections in 15%, 6% and 12%, and ≥180° calcium was found in 7%, 4% and 4% of edges respectively. Six patients (1%) of the total OCT-guided population had an edge-related event during the median two-year follow-up. Only two of these 6 patients had post-procedural OCT-scans of the event-related edge, thus 4 of the cases were effectively angiographic guided. Conclusion Only a small fraction of edge segments in the OCTOBER Trial were left with residual edge disease exceeding protocol thresholds. This resulted in historically very low rate of edge related events. No evaluation of a stent edge by OCT in otherwise OCT guided patients appeared to be the main predictor of edge related events. Final results are presented at ESC 2024.