Comparison of neoatherosclerosis and clinical outcomes between bioabsorbable versus durable polymer drug-eluting stent: Verification by optical coherence tomography analysis

Background: Neoatherosclerosis after drug-eluting stent (DES) implantation is known to be related with increased risk of late restenosis and stent thrombosis. Neoatherosclerosis and relevant clinical outcomes between bioabsorbable polymer DES (BP-DES) and second-generation durable polymer DES (DP-DES) were evaluated by optical coherence tomography (OCT) analysis.Methods: A total of 311 patients (319 lesions) undergoing OCT analysis after DES implantation were enrolled and divided into two groups according to stent type (BP-DES [150 patients, 153 lesions] and DP--DES[161 patients, 166 lesions]). Follow-up OCT analysis was performed at least 9 months after index stent implantation. Neoatherosclerosis was defined as presence of thin-cap fibroatheroma, calcified plaque, and lipid plaque. Primary endpoint was the incidence of neoatherosclerosis, and the secondary endpoints were the occurrence of major adverse cardiac events (MACE), defined as a composite of death, myocardial infarction, target lesion revascularization, or stent thrombosis and to find independent predictors of neoatherosclerosis.Results: The incidence of neoatherosclerosis was lower in the BP-DES group than the DP-DES group (5.2% vs. 14.5%, p = 0.008), which was driven by lipid plaque. However, the incidence of MACE did not show statistical difference between the two groups in median 4-year follow-up (3.3% vs. 7.8%, hazard ratio 1.964, 95% confidence interval 0.688-5.611, p = 0.207). Less use of angiotensin converting en- zyme inhibitors/angiotensin II receptor blockade and higher degree of neointimal hyperplasia remained independent predictors of neoatherosclerosis on Cox regression analysis.Conclusions: Patients undergoing BP-DES implantation had lower incidence of neoatherosclerosis than DP-DES, which did not reach statistically better clinical outcomes. (Cardiol J)