Impact of Coronary Stent Architecture on Clinical Outcomes: Do Minor Changes in Stent Architecture Really Matter?

INTRODUCTION The objective of this study was to compare the accumulated clinical outcomes of two Malaysian all-comers populations, each treated with different polymer-free sirolimus-eluting stents (PF-SES) of similar stent design. METHODS The Malaysian subpopulation of two all-comers observational studies based on the same protocol (ClinicalTrials.gov Identifiers: NCT02629575 and NCT02905214) were combined and compared to a Malaysian-only cohort which was treated with a later-generation PF-SES. The PF-SES's used differed only in their bare-metal backbone architecture, with otherwise identical sirolimus coating. The primary endpoint was the accumulated target lesion revascularization (TLR) rate at 12 months. The rates of major adverse cardiac events (MACE), stent thrombosis (ST) and myocardial infarction (MI) were part of the secondary endpoints. RESULTS A total of 643 patients were treated with either the first-generation PF-SES (413 patients) or second-generation PF-SES (230 patients). Patient demographics were similar in terms of age (p = 0.744), male gender (0.987), diabetes mellitus (p = 0.293), hypertension (p = 0.905) and acute coronary syndrome (ACS, 44.8% vs. 46.1%, p = 0.752) between groups. There were no differences between treatment groups in terms of lesion length (20.8 ± 7.3 mm vs. 22.9 ± 7.9, p = 0.111) or vessel diameter (2.87 ± 0.39 vs. 2.93 ± 0.40, p = 0.052) despite numerically smaller diameters in the first-generation PF-SES group. The second-generation PF-SES tended to have more complex lesions as characterized by calcification (10.3% vs. 16.2%, p = 0.022), severe tortuosity (3.5% vs. 6.9%, p = 0.041) and B2/C lesions (49.2% vs. 62.8%, p < 0.001). The accumulated TLR rates did not differ significantly between the first- and second-generation PF-SES (0.8% vs. 0.9%, p = 0.891). The accumulated MACE rates were not significantly different (p = 0.561), at 1.5% (6/413) and 2.2% (5/230), respectively. CONCLUSIONS Modifications in coronary stent architecture which enhance the radial strength and radiopacity without gross changes in strut thickness and design do not seem to impact clinical outcomes. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov Identifiers: NCT02629575 and NCT02905214.