Randomized Trial of Polymer-Free Sirolimus- and Probucol-Eluting Stents Versus Durable Polymer Zotarolimus-Eluting Stents: 5-Year Results of the ISAR-TEST-5 Trial

Abstract

Objectives: The aim of this study was to evaluate the late clinical performance of a polymer-free sirolimus- and probucol-eluting stent compared with a new-generation durable polymer-based zotarolimus-eluting stent.

Background: It was previously shown that polymer-free sirolimus- and probucol-eluting stents were noninferior to zotarolimus-eluting stents at 12 months. However, long-term follow-up of these devices is critical to evaluate late comparative efficacy.

Methods: In a clinical trial with minimal exclusion criteria, 3,002 patients were randomly assigned to treatment with polymer-free sirolimus- and probucol-eluting stents versus zotarolimus-eluting stents. The primary endpoint was the combined incidence of cardiac death, target vessel-related myocardial infarction, or target lesion revascularization.

Results: At 5 years, there was no difference in the incidence of the primary endpoint between sirolimus- and probucol-eluting stents and zotarolimus-eluting stents (23.8% vs. 24.2%, respectively; hazard ratio: 0.98; 95% confidence interval: 0.84 to 1.15; p = 0.80). The rates of the individual components of the primary endpoint were also comparable in both groups. The incidence of definite or probable stent thrombosis was low in both groups (1.3% vs. 1.6%, respectively; hazard ratio: 0.86; 95% confidence interval: 0.46 to 1.62; p = 0.64). The rates of any death, myocardial infarction, and revascularization were similar in both groups. Results were consistent across pre-specified subgroups of age, sex, diabetes, and vessel size.

Conclusions: Long-term outcomes of patients treated with polymer-free sirolimus- and probucol-eluting stents compared with a new-generation durable polymer-based zotarolimus-eluting stent were similar. Rates of stent thrombosis were low and comparable in both treatment groups, with few events beyond 12 months. (Efficacy Study of Rapamycin- vs. Zotarolimus-Eluting Stents to Reduce Coronary Restenosis [ISAR-TEST-5]; NCT00598533).

Keywords: drug-eluting stent(s); long-term follow-up; probucol; randomized controlled trial; sirolimus; zotarolimus.