Objective: To investigate the difference in neointimal hyperplasia (NIH) between ST-segment elevation myocardial infarction (STEMI), stable angina pectoris (SAP), and unstable angina pectoris (UAP).
Patients and methods: From formal core laboratory intravascular ultrasound substudies, we compared NIH after paclitaxel-eluting stents (PES) or bare metal stents (BMS) in STEMI lesions from HORIZONS-AMI trial with SAP and UAP lesions from TAXUS IV, V, and ATLAS studies.
Results: At follow-up, %NIH at the minimum lumen area (MLA) site was less in STEMI (n=212) than in UAP (n=233) and SAP (n=440) lesions treated with PES (19.6 vs. 26.2 vs. 25.0%, P=0.002; all intravascular ultrasound data shown as least-square means in abstract) and less in STEMI (n=66) than in UAP (n=72) and SAP (n=143) lesions treated with BMS (34.0 vs. 26.7 vs. 45.5%, P=0.0003). As a result, MLA at follow-up was larger in STEMI than in UAP and SAP lesions treated with PES (5.9 vs. 5.2 vs. 5.0 mm2, P<0.0001) or treated with BMS (5.1 vs. 4.3 vs. 4.0 mm2, P=0.002). Net volume obstruction ([NIH/stent volume]×100) at follow-up was significantly less in STEMI than in UAP and SAP lesions treated with PES (7.8 vs. 13.4 vs. 13.4%, P<0.0001) or BMS (20.6 vs. 28.5 vs. 32.1%, P<0.0001). Multivariate linear regression analysis showed that STEMI was correlated independently and inversely with net volume obstruction compared with SAP (regression coefficient −6.99, P<0.0001) or UAP (regression coefficient −6.29, P<0.0001).
Conclusion: Implantation of PES or BMS in STEMI compared with UAP and SAP was associated with less NIH.