Relationship between quantities of tissue prolapse after percutaneous coronary intervention and neointimal hyperplasia at follow-up on serial optical coherence tomography examination

Background The clinical significance of the extent of tissue prolapse (TP) after percutaneous coronary intervention (PCI) for long-term outcomes remains undetermined. This study investigated the relationship between the quantities of TP immediately after PCI and neointimal hyperplasia (NIH) at follow-up on serial optical coherence tomography (OCT) examination. Methods We evaluated 145 native coronary lesions (89 lesions with stable angina pectoris [SAP] and 56 with acute coronary syndrome [ACS]). OCT was performed to examine pre-PCI plaque morphologies at the narrowest culprit sites, post-PCI TP area in each cross-sectional area (CSA) and TP volume throughout the stented segments, 9-month follow-up NIH area in each CSA and NIH volume throughout the stented segments. We investigated the relationships between the quantities of TP and NIH and their differences according to clinical presentation. Results ACS lesions had a larger TP area at the narrowest culprit sites (0.39 [0.14–0.85] vs. 0.11 [0.00–0.32] mm², P < 0.001) and at the most protruding sites (0.51 [0.24–1.08] vs. 0.21 [0.10–0.52] mm², P < 0.001) compared with SAP lesions. In ACS lesions, TP area was correlated with NIH area at the culprit sites (r = 0.283, P = 0.042) and at the most protruding sites (r = 0.288, P = 0.038). In SAP lesions, TP area was correlated with NIH area at the most protruding sites (r = 0.244, P = 0.030), but not at the culprit sites. Conclusions The extent of TP immediately after PCI was quantitatively related to the degree of NIH at 9-month follow-up on serial OCT examination. The quantities of TP might influence long-term stent outcomes.