The three year follow-up of the randomised “all-comers” trial of a biodegradable polymer biolimus-eluting stent versus permanent polymer sirolimus-eluting stent (LEADERS)

Reviewer: Dr. Melehat Hicran Aksu

Congress: EUROPCR 2023

Introduction

High bleeding risk patients (HBR), who until recently were excluded from interventional trials, have been treated with bare metal stents (BMS) on the basis that 30 days of dual anti-platelet therapy (DAPT) would minimize bleeding risk and increased mortality. The LEADERS FREE (LF) study focused exclusively on patients with HBR and found that a stainless steel Biolimus-A9 drug-coated stent (SS-DCS) treated with 1 month of DAPT was more effective and safer than a bare metal stent with the same stainless steel platform (SS-BMS). These findings were recently reconfirmed by the LF II study.LF III was designed as a complementary study to LF to investigate the safety and efficacy of a cobalt chromium stent (CoCr-DCS) with thinner strut thickness, which is easier to implant and may lead to less restenosis and lower thrombogenicity. The main improvement of the new CoCr-DCS used in the LF III study compared with the SS-DCS is the reduction of the strut thickness from 114-120 µm to 84-88 µm while keeping all other design elements the same.Objective: To evaluate the safety of the new CoCr-DCS compared to stainless SS-DCS, to compare CoCr-DCS to SS-BMS, and to perform a post-hoc comparison of the effectiveness of CoCr-DCS compared to SS-DCS.

Method

LF III was an international, single-arm, multicenter, prospective study. The study included 401 patients with HBR who were selected with the same inclusion exclusion criteria as LF, treated with the same regimen and studied using the same clinical follow-up and evaluation process. All target lesions were treated with CoCr-DCS. Anti-platelet (aspirin75-250 mg/day) and P2Y12 inhibitor (preferably clopidogrel 75-150 mg/day) were given for 30 days, after which one of the drugs (preferably P2Y12 inhibitor) was stopped and single antiplatelet therapy was continued until the end of the study. Follow-ups were planned at 1 month, 6 months and 1 year by examination and 4 months, 24 months and 36 months by telephone. No planned angiographic follow-up was performed. The primary safety endpoint was the composite of cardiac death myocardial infarction (MI) and definite/possible stent thrombosis. The primary efficacy endpoint was clinically indicated target lesion revascularization at 1-year follow-up. Results from the LF III study were compared with the overall LF study.

Results

The mean stent length was 38.9 ± 27.4 mm for CoCr-DCS in LF III, significantly longer than the LF study values of 34.5 ± 23.1 mm for SS-DCS and 33.4 ± 23.4 mm for SS-BMS. There were no differences between the studies in other procedural variables except for the higher use of radial access in LF III. All other clinical safety endpoints, including all deaths, cardiac death, myocardial infarction and definite/possible stent thrombosis, were numerically lower for CoCr-DCS than SS-DCS, although not statistically significant.Bleeding rates were lower in LF III (5.4%) than in LF (7.2%), although not statistically significant. Procedural device success rate was 97.4% for SS-DCS in LF and 98.9% for CoCr-DCS in LF III. Lesion success was 98.7%, device success was 98.9%, and procedural success was 97.0% in LF III.

Conclusion

This multicenter, non-randomized study had a relatively small sample size and single-arm design. Although the power of the study was insufficient to demonstrate differences in several variables, including stent thrombosis and repeat revascularization, the results confirm non-inferiority in safety compared to its predecessor SS-DCS and superiority in efficacy over SS-BMS. The thin strut demonstrates that the Biolimus A9™-coated Cobalt Chromium coronary stent can be safely used in all patients with HBR and shows good results for patients with HBR treated with Biolimus-A9 drug-eluting stents followed by a 1-month DAPT regimen.