Direct comparison of coronary bare metal vs. drug-eluting stents: same platform, different mechanics?

Abstract

BackgroundDrug-eluting stents (DES) compared to bare metal stents (BMS) have shown superior clinical performance, but are considered less suitable in complex cases. Most studies do not distinguish between DES and BMS with respect to their mechanical performance. The objective was to obtain mechanical parameters for direct comparison of BMS and DES.MethodsIn vitro bench tests evaluated crimped stent profiles, crossability in stenosis models, elastic recoil, bending stiffness (crimped and expanded), and scaffolding properties. The study included five pairs of BMS and DES each with the same stent platforms (all n = 5; PRO-Kinetic Energy, Orsiro: BIOTRONIK AG, Bülach, Switzerland; MULTI-LINK 8, XIENCE Xpedition: Abbott Vascular, Temecula, CA; REBEL Monorail, Promus PREMIER, Boston Scientific, Marlborough, MA; Integrity, Resolute Integrity, Medtronic, Minneapolis, MN; Kaname, Ultimaster: Terumo Corporation, Tokyo, Japan). Statistical analysis used pooled variance t tests for pairwise comparison of BMS with DES.ResultsCrimped profiles in BMS groups ranged from 0.97 ± 0.01 mm (PRO-Kinetic Energy) to 1.13 ± 0.01 mm (Kaname) and in DES groups from 1.02 ± 0.01 mm (Orsiro) to 1.13 ± 0.01 mm (Ultimaster). Crossability was best for low profile stent systems. Elastic recoil ranged from 4.07 ± 0.22% (Orsiro) to 5.87 ± 0.54% (REBEL Monorail) including both BMS and DES. The bending stiffness of crimped and expanded stents showed no systematic differences between BMS and DES neither did the scaffolding.ConclusionsBased on in vitro measurements BMS appear superior to DES in some aspects of mechanical performance, yet the differences are small and not class uniform. The data provide assistance in selecting the optimal system for treatment and assessment of new generations of bioresorbable scaffolds.Trial registration: not applicable

Influence of Drug Incorporation on the Physico-Chemical Properties of Poly(l-Lactide) Implant Coating Matrices—A Systematic Study

“…Drug-eluting stents (DES), in particular those of newer generations, are superior to bare metal stents in the treatment of coronary artery stenosis [ 1 , 2 , 3 , 4 , 5 ]. Among others, frequently used drugs are from the Limus family, especially sirolimus (SIR) [ 6 , 7 , 8 , 9 ], but also paclitaxel (PTX) [ 10 ], dexamethasone (DEX) [ 11 , 12 ], and cyclosporine A (CYCLO) [ 13 , 14 ].…”

“…As DES coatings usually possess a thickness in a range of only 10 µm for hemodynamic reasons, they are prone for fracturing or peeling off due to mechanical stress during implantation which is caused by stent insertion and dilatation [ 4 , 38 ]. Therefore, a drug containing coating does not only have to show appropriate release and biocompatibility, but furthermore a suitable mechanical performance paired with resilience against delamination and particle detachment, which is required e.g., in DIN EN ISO 25539-2 [ 39 ].…”

Incidence of cardiac death and recurrent stent thrombosis after treatment for angiographically confirmed stent thrombosis

“…The baseline and angiographic profiles of our 210 patients with DES ST and 33 patients with BMS ST did not significantly differ, except for a larger proportion of elderly patients in the BMS ST group (data not shown). Among the reported advantages of BMS versus DES are their better mechanical properties, including a low profile as well as better trackability and crossability [17]. Many clinical circumstances and angiographic profiles not registered in the current study might have impacted BMS selection.…”

Development of a biodegradable microstent for minimally invasive treatment of Fallopian tube occlusions

“…The Microstent prototypes show low values for bending stiffness, comparable with commercially available biodegadable stents for vascular application such as BIOTRONIK Magmaris 3.0/20 (EI = 0.89 Nmm 2 ), Abbott Absorb GT1 3.0/18 (EI = 4.20 Nmm 2 ) or Elixir DESolve 3.0/18 (EI = 1.50 Nmm 2 ) [5]. Commercially available drugeluting stents for vascular application such as BIOTRONIK Orsiro 3.0/15 (EI = 8.8 Nmm²) are commonly by one order of magnitude stiffer [6].…”