Randomized, non-inferiority trial of three limus agent-eluting stents with different polymer coatings: the Intracoronary Stenting and Angiographic Results: Test Efficacy of 3 Limus-Eluting Stents (ISAR-TEST-4) Trial

Abstract

Aims: Although biodegradable polymer drug-eluting stent (DES) platforms have potential to enhance long-term clinical outcomes, data concerning their efficacy are limited to date. We previously demonstrated angiographic antirestenotic efficacy with a microporous, biodegradable polymer DES. In the current study, we hypothesized that at 12 months, its clinical safety and efficacy would be non-inferior to that of permanent polymer DES.

Methods and results: This prospective, randomized, open-label, active-controlled trial was conducted at two tertiary referral cardiology centres in Munich, Germany. Patients presenting with stable coronary disease or acute coronary syndromes undergoing DES implantation in de novo native-vessel coronary lesions were randomly assigned to treatment with biodegradable polymer DES (rapamycin-eluting; n = 1299) or permanent polymer DES (n = 1304: rapamycin-eluting, Cypher, n = 652; or everolimus-eluting, Xience, n = 652) and underwent clinical follow-up to 1 year. The primary endpoint was a composite of cardiac death, myocardial infarction (MI) related to the target vessel, or revascularization related to the target lesion (TLR). Biodegradable polymer DES was non-inferior to permanent polymer DES concerning the primary endpoint [13.8 vs. 14.4%, respectively, P(non-inferiority) 0.005; relative risk = 0.96 (95% confidence interval, 0.78-1.17), P(superiority) = 0.66]. Biodegradable polymer DES in comparison with permanent polymer DES showed similar rates of cardiac death or MI related to the target vessel (6.3 vs. 6.2%, P = 0.94), TLR (8.8 vs. 9.4%, P = 0.58), and stent thrombosis (definite/probable: 1.0 vs. 1.5%, P = 0.29). Subgroup analysis of the biodegradable polymer DES vs. individual Cypher and Xience stent arms revealed no signal of performance difference.

Conclusion: A biodegradable polymer rapamycin-eluting stent is non-inferior to permanent polymer-based DES in terms of clinical efficacy over 1 year. These results provide a framework for testing the potential clinical advantage of biodegradable polymer DES over the medium to long term. The trial was registered at ClinicalTrials.gov (identifier: NCT00598676).