The COBRA II (COmplex Bifurcation lesions: RAndomized comparison of a fully bioresorbable modified-T stenting strategy versus bifurcation reconstruction with a dedicated self-expanding stent in combination with bioresorbable scaffolds) study: Final 5-year follow-up.

BACKGROUND

In order to advocate further research in bioresorbable scaffold (BVS) technology we report the final 5-year outcomes of the COBRA II study, the only randomized controlled trial (RCT) performed to investigate the safety, feasibility, and performance of Absorb BVS (Abbott Vascular) in true coronary bifurcations.

METHODS

COBRA II was a prospective single-center RCT. Fifteen patients with true coronary bifurcation lesions were randomized to bifurcation treatment with self-expanding biolimus-eluting Axxess bifurcation device (Biosensors International) combined with additional bioresorbable everolimus-eluting Absorb BVS in the bifurcation branches on (Axxess group) or to 2-stent mod-T stenting technique with Absorb BVS (mod-T group). Optical coherence tomography was performed post-procedure and at 30-months. The primary endpoint was change in minimal luminal area (MLA) on OCT from baseline to 30-months.

RESULTS

Fifteen patients with coronary bifurcation lesions were randomized to the Axxess group (n = 8) or Modified-T group (n = 7). At 30 months, MLAs were significantly smaller than post-procedure in the majority of bifurcation segments treated with BVS due to neointima formation, while MLAs in the proximal Axxess segment remained stable (primary endpoint). Five-year clinical follow-up was available for all patients. Only 1 major adverse cardiac event occurred; a patient underwent target lesion revascularization at 30 months in the Axxess group. There were no cases of cardiac death, spontaneous MI, or stent/scaffold thrombosis.

CONCLUSIONS

In this small RCT bifurcation study, BVS luminal dimensions were significantly smaller at 30 months, with acute strut discontinuities and late Intraluminal dismantling frequently observed, although acceptable clinical outcomes were noted at 5 years.