Background: Ultrathin-strut biodegradable polymer sirolimus-eluting stents (BP-SES) are superior to thin-strut durable polymer everolimus-eluting stents (DP-EES) with respect to target lesion failure (TLF) at 2 years among patients with ST-segment elevation myocardial infarction (STEMI). We sought to determine the impact of primary percutaneous coronary intervention (pPCI) complexity on long-term clinical outcomes with BP-SES versus DP-EES in STEMI patients.

Methods: We performed a post hoc subgroup analysis from the BIOSTEMI (NCT02579031) randomized trial, which included individual data from 407 STEMI patients enrolled in the BIOSCIENCE trial (NCT01443104). STEMI patients were randomly assigned to treatment with ultrathin-strut BP-SES or thin-strut DP-EES, and further categorized into those undergoing complex versus noncomplex pPCI. Complex pPCI was defined by the presence of ≥1 of the following criteria: 3 vessel treatment, ≥3 stents implanted, ≥3 lesions treated, bifurcation lesion with ≥2 stents implanted, total stent length ≥60 mm, and/or chronic total occlusion treatment. The primary endpoint was TLF, a composite of cardiac death, target-vessel myocardial reinfarction, or clinically indicated target lesion revascularization, within 2 years.

Results: Among a total of 1707 STEMI patients, 421 (24.7%) underwent complex pPCI. Baseline characteristics were similar between groups. At 2 years, TLF occurred in 14 patients (7.1%) treated with BP-SES and 25 patients (11.6%) treated with DP-EES (hazard ratio [HR]: 0.62; 95% confidence interval [CI]: 0.32-1.19; p = 0.15) in the complex pPCI group, and in 28 patients (4.4%) treated with BP-SES and 49 patients (8.2%) treated with DP-EES (HR: 0.54; 95% CI: 0.34-0.86; p = 0.008; p for interaction = 0.74) in the noncomplex pPCI group. Individual TLF components and stent thrombosis rates did not significantly differ between groups.

Conclusion: In a post hoc subgroup analysis from the BIOSTEMI randomized trial, ultrathin-strut BP-SES were superior to thin-strut DP-EES with respect to TLF at 2 years among STEMI patients undergoing both complex and noncomplex pPCI.