Comparison of vascular remodeling in patients treated with sirolimus-versus zotarolimus-eluting stent following acute myocardial infarction

Background: The differences in the vascular response to stent implantation or in the incidence of late acquired stent malapposition among different types of drug-eluting stents are not well known in patients with acute myocardial infarction (MI). Hypothesis: The pattern of vascular remodeling and degree of neointimal proliferation were different depending on the different types of drug-eluting stents. Methods: This study used intravascular ultrasound (IVUS) to investigate vascular remodeling in patients treated with implantation of sirolimus-eluting stents (SESs) vs zotarolimus-eluting stents (ZESs) following acute MI. The study population consisted of 100 patients with acute MI who were treated either with SES (n = 41) or ZES (n = 59) and underwent both poststenting and 9-month follow-up IVUS examination. Serial vascular changes surrounding stented segments were compared between SES- and ZES-treated lesions. Results: Percentage of neointimal volume obstruction at follow-up was significantly smaller in SES-treated compared to ZES-treated lesions (2.8 ± 7.1% vs 18.1 ± 15.7%, respectively; P < 0.001). However, positive vascular remodeling, which was defined as greater than 10% increase in external elastic membrane volume index (31.7% vs 10.2%, respectively, P = 0.007), and late acquired stent malapposition (12.0% vs 0%, respectively, P = 0.006) occurred more frequently in SES-treated than in ZES-treated lesions. Conclusions: The pattern of vascular remodeling, including positive remodeling, late acquired stent malapposition, and degree of neointimal proliferation might be different depending on the different types of drug-eluting stents in patients with acute MI.