Optical coherence tomography assessment of a PLGA-polymer with electro-grafting base layer versus a PLA-polymer sirolimus-eluting stent at three-month follow-up: the BuMA-OCT randomised trial

Abstract

Aims: To compare stent strut coverage using optical coherence tomography (OCT) at three-month follow-up between a PLGA-polymer with electro-grafting base layer sirolimus-eluting stent (SES) (BuMA) and a PLA-polymer SES (EXCEL).

Methods and results: This prospective, single-centre, non-inferiority randomised BuMA-OCT trial enrolled patients with de novo coronary artery lesions, treated with either the BuMA or the EXCEL stent. The study primary endpoint was OCT-evaluated stent strut coverage at three months. Secondary endpoints were neointimal thickness of stent struts, and incomplete stent apposition evaluated with OCT. A total of 80 patients were randomly assigned to receive the BuMA (n=40) or the EXCEL (n=40) stent. In OCT follow-up (achieved in 86.3% of cases: BuMA, n=33; EXCEL, n=36), the percentage of stent strut coverage was significantly higher in the BuMA vs. the EXCEL group (strut level: 94.2% vs. 90.0%, p<0.01; p(non-inferiority)<0.0001; p(superiority) <0.0001), while the proportion of malapposed struts (strut level: 1.28% vs. 1.80%, p=0.51) and the mean neointimal thickness (strut level: 0.07±0.03 mm vs. 0.06±0.02 mm, p=0.31) were similar. Rates of myocardial infarction (periprocedural non-Q-wave, 7.5% vs. 7.5%, p=1.00) and target lesion failure (7.5% vs. 7.5%, p=1.00) were similar between groups, with no cardiac death or stent thrombosis.

Conclusions: In the BuMA-OCT randomised trial, the novel BuMA PLGA-polymer with electro-grafting base layer SES was superior to the EXCEL PLA-polymer SES in the primary endpoint of stent strut coverage at three-month follow-up.