Ultrathin, Biodegradable-Polymer Sirolimus-Eluting Stent vs Thin, Durable-Polymer Everolimus-Eluting Stent

Background Previous trials suggested the superiority of ultrathin- over thin-strut drug-eluting stents (DES) concerning target lesion failure (TLF) at 1 year after index percutaneous coronary intervention. Objectives The aim of this randomized comparison study of ultrathin-strut and thin-strut DES (CASTLE [Randomized Comparison All-Comer Study of Ultrathin Strut and Thin Strut Drug-Eluting Stent]; jRCTs032180084) was to examine the impact of differences in strut thickness of DES on clinical outcomes when implanted with angiography and intravascular ultrasound or optical coherence tomographic guidance. Methods CASTLE was a multicenter, prospective, noninferiority study conducted at 65 institutions in Japan. Percutaneous coronary intervention patients were assigned (1:1) to an ultrathin, biodegradable-polymer sirolimus-eluting stent (BP-SES) or a thin, durable-polymer everolimus-eluting stent (DP-EES). The primary endpoint was TLF, defined as a composite of cardiac death, target vessel–related myocardial infarction, and clinically driven target lesion revascularization at 1-year follow-up. Results Between May 2019 and March 2020, 1,440 patients were randomly assigned to BP-SES (n = 722) or DP-EES (n = 718). TLF occurred in 6.0% and 5.7% of patients, respectively. Noninferiority (P = 0.040) was met because the upper limit (2.67%) of the 1-sided 95% CI between the groups was lower than the prespecified noninferiority margin (3.3%). No significant interactions were observed in the relative rates of TLF between prespecified subgroups. Conclusions The BP-SES was noninferior to the DP-EES regarding 1-year TLF. This demonstrates that strut thickness differences among DES have little impact on clinical outcomes when implanted with intravascular imaging guidance.