10-Year Outcomes From a Randomized Trial of Polymer-Free Versus Durable Polymer Drug-Eluting Coronary Stents

Abstract

Background: Outcome data after extended long-term follow-up of patients with coronary artery disease treated with drug-eluting stents (DES) in randomized clinical trials are scant.

Objectives: Performance differences among devices may be expected to emerge over time depending on whether stenting is done with polymer-free or durable polymer DES. This study assessed the 10-year outcomes of patients enrolled in the ISAR-TEST-5 (Test Efficacy of Sirolimus- and Probucol-Eluting Versus Zotarolimus-Eluting Stents) trial.

Methods: A total of 3,002 patients were randomized to treatment with either polymer-free sirolimus- and probucol-eluting stents (n = 2,002) or durable polymer zotarolimus-eluting stents (n = 1,000). The primary endpoint was the composite of cardiac death, target vessel-related myocardial infarction, or target lesion revascularization (a device-oriented composite endpoint [DOCE]). Additional endpoints of interest were the patient-oriented composite endpoint (POCE), including all-cause death, any myocardial infarction, or any revascularization; individual components of the composite endpoints; and definite or probable stent thrombosis.

Results: The median age of the patients at randomization was 67.8 years. At 10 years, 63.9% of patients were alive. The rates of DOCE and POCE were high in both groups with no difference in the incidence between polymer-free sirolimus- and probucol-eluting stents and durable polymer zotarolimus-eluting stents (DOCE: 43.8% vs. 43.0%, respectively; hazard ratio: 1.01; 95% confidence interval [CI]: 0.89 to 1.14; p = 0.90; POCE: 66.2% vs. 67.7%, respectively; hazard ratio: 0.94; 95% CI: 0.86 to 1.04; p = 0.22). The rates of the individual components of the composite endpoints were comparable in both groups. The incidence of definite/probable stent thrombosis over 10 years was low and comparable in both groups (1.6% vs. 1.9%; hazard ratio: 0.85; 95% CI: 0.46 to 1.54; p = 0.58).

Conclusions: At 10 years, there were no measurable differences in outcomes between patients treated with polymer-free versus durable polymer DES. The incidence of stent thrombosis was low and comparable in both groups. High overall adverse clinical event rates were observed during extended follow-up. (Test Efficacy of Sirolimus- and Probucol-Eluting Versus Zotarolimus-Eluting Stents [ISAR-TEST-5]; NCT00598533).

Keywords: drug-eluting stent; durable polymer; long-term follow-up; polymer free; probucol; randomized controlled trial; sirolimus; zotarolimus.