Negative impact of ultra-thin strut on neointimal coverage condition within one year after implantation as compared to thin sturt in biogradable-polymer sirorimus eluting stents

BIOSCIENCE randomized trial which compared biodegradable-polymer sirolimus-eluting stents with ultra-thin (60μm) strut (ultra-thin BP-SES) and durable-polymer everolimus-eluting stents with thin (81μm) strut (thin DP-EES) have reported that definite stent thrombosis within 1 year had more frequently occurred in ultra-thin BP-SES (0.9%) than in thin DP-EES group (0.4%) although it was not statistically significant. It suggests that neointimal coverage after stent implantation within 1 year might be different between ultra-thin BP-SES and thin DP-EES. Recently, two types of biogradable-polymer sirorimus eluting stents, thin (80μm) strut type (thin BP-SES) and ultra-thin (60μm) strut type (ultra-thin BP-SES), can be available in clinical settings.

We compared neointimal coverage conditions between ultra-thin BP-SES and thin BP-SES by optical coherence tomography (OCT).

Consecutive Forty-six patients who underwent 21 ultra-thin BP-SESs or 25 thin BP-SESs implantation were enrolled. We compared incidences of acute coronary syndrome, type B2/C lesion, atherectomy device use, stent size, stent length, maximum inflation pressure, and 8-month follow-up OCT parameters including proportions of uncovered struts (%Uncovered), malapposed struts, (%Mallaposed) and mean neointimal hyperplasia thickness (mean NHT) between the two groups.

%Uncovered and %malapposed were significantly higher and mean NHT was significantly lower in ultra-thin BP-SES than in thin BP-SES (Table). The other parameters were similar between the two groups.

Ultra-thin BP-SES showed worse neointimal coverage as compared to thin BP-SES within 1 year after stent implantation, which may increase stent thrombosis.

Type of funding source: None