Ultrathin Bioresorbable Polymer Sirolimus-Eluting Stents Versus Thin Durable Polymer Everolimus-Eluting Stents

Coronary drug-eluting stent development has introduced new metal alloys, changes in stent architecture, and bioresorbable polymers. Whether these advancements improve long-term clinical safety and efficacy has been inconsistent in prior studies.

The authors sought to compare late-term clinical outcomes among patients treated with an ultrathin strut (60 μm) bioresorbable polymer sirolimus-eluting stent (BP SES) and a thin strut (81 μm) durable polymer everolimus-eluting stent (DP EES) in a large randomized trial.

BIOFLOW V (Biotronik Prospective Randomized Multicenter Study to Assess the Safety and Effectiveness of the Orsiro Sirolimus Eluting Coronary Stent System in the Treatment of Subjects with Up to Three De Novo or Restenotic Coronary Artery Lesions V) was an international randomized trial comparing coronary revascularization with BP SES and DP EES regarding the primary endpoint of 12-month target lesion failure (TLF). Analysis of pre-specified 2-year clinical outcomes was performed.

Among 1,334 patients randomized to treatment with BP SES (n = 884) or DP EES (n = 450), the 2-year TLF rate was 7.5% for BP SES and 11.9% for DP EES (-4.33% treatment difference; 95% confidence interval: -8.16% to -0.91%; p = 0.015), driven by differences in target vessel myocardial infarction (MI) (5.3% vs. 9.5%; p = 0.01) and ischemia-driven target lesion revascularization (2.6% vs. 4.9%; p = 0.04). Rates of cardiac death or MI were 7.0% versus 10.4% for BP SES and DP EES, respectively (p = 0.047). Late/very late definite stent thrombosis was statistically lower for BP SES compared with DP EES (0.1% vs. 1.0%; p = 0.045).

In a large randomized trial, significant differences in both TLF and target vessel-related MI persisted through 2 years, favoring treatment with BP SES over DP EES. Significantly lower cumulative target lesion revascularization and late/very late stent thrombosis were also observed with BP SES. (Safety and Effectiveness of the Orsiro Sirolimus Eluting Coronary Stent System in Subjects With Coronary Artery Lesions [BIOFLOW-V]; NCT02389946).