Cardiovascular devices: Mechanical characterization of coronary stents

Background: Coronary stents participate to limit cardiovascular death but are associated with some complications. Matching stent biomechanical characteristics with specific coronary lesions could limit these complications.Objectives: Development of a standardized and global bench test protocol and evaluation of most currently used coronary stents to improve stent choice in cathlab.Materials: We evaluated biomechanical characteristics of coronary stents (AbsorbTM-ABBOTT (R), Xience AlpineTM-ABBOTT (R), Resolute IntegrityTM-MEDTRONIC (R), Resolute OnyxTM-MEDTRONIC (R), OrsiroTM-BIOTRONIK (R), SynergyTM-BOSTON SCIENTIFIC (R), OptimaxTM-HEXACATH (R)) in an in vitro study: radial elastic recoil, foreshortening, crimped stent with balloon flexibility and deployed stent flexibility. We also evaluated maximal resistance, elastic strength limit and elastic deformation limit for radial and longitudinal compression. Stentswere deployed in a saline solution at 37+/-0.5 °C. 9 stents were used to evaluate elastic recoil and foreshortening. Then, 3 among them were used to evaluate radial resistance between parallel plates, 3 were used to evaluate longitudinal resistance and 3 others were used to evaluate deployed stent bending stiffness. Before stent inflation 3 stents, among the 9 devices dedicated to biomechanical evaluation, were used to evaluate the uninflated stent with balloon bending stiffness. For a maximum comparability between stent models, we chose the most used stent size in our clinical practice (3.0 mm diameter and the nearest to 20 mm length). For these evaluations, all devices were inflated with them own balloon, at nominal pressure, according to manufacturer's recommendations. Nominal pressure was maintained for 30 seconds. We studied coating with field emission gun scanning electron microscope after POT-SIDE-POT (PSP) simulation to evaluate coating resistance to angioplasty. Bifurcation performances were evaluated by microcomputed tomography imaging of PSP stented silicon bifurcation models. Statistical analyses were performed using XLStats 2017 (Addinsoft).Results: Elastic recoil, deployed stent exibility and crimped stent flexibility were signicantly different between groups (all p < 0.0001); as were radial and longitudinal maximum resistance (p < 0.0001). SynergyTM, OrsiroTM and Xience AlpineTM had the lowest elastic recoil. SynergyTM and Resolute OnyxTM were the most exible. OptimaxTM had the highest radial and longitudinal resistance. Coating lesions after PSP were not signicantly different, excepted for OptimaxTM which had no coating lesion. In bifurcation model, side branch ostium coverage and malapposed strut ratio were signicantly different between groups (respectively, p = 0.01 and p = 0.004). Strut fractures were founded only in AbsorbTM.Conclusion: Currently used stents have very different biomechanical and bifurcation performance proles. Their choice had to be adapted to each coronary lesion particularity to improve coronary interventions results

Standardized bench test evaluation of coronary stents: Biomechanical characteristics

Objectives The purpose of the study was to develop a standardized and global bench test protocol to evaluate the biomechanical characteristics of the most currently used drug-eluting coronary stents. Background The use of coronary stents has contributed to the reduction of cardiovascular mortality but can be associated with specific complications. Improving the biomechanical matching between the stents and the coronary anatomy may reduce these complications. Methods We assessed five commercially available drug-eluting stents: the Absorb, Orsiro, Resolute Onyx, Synergy, and Xience Alpine stents. Following stent deployment at nominal pressure in ambient air, radial elastic recoil and foreshortening were measured. Flexibility (crimped and deployed stents) and longitudinal and radial resistances were evaluated using a mechanical tester. Results Biomechanical characteristics were significantly different for all tested devices (ANOVA, P < 0.01). The Synergy, Orsiro, and Xience Alpine stents presented the lowest elastic recoil. The Synergy and Resolute Onyx stents were the most flexible devices. The Xience Alpine and Absorb stents had the highest longitudinal and radial resistances. Conclusions Drug-eluting coronary stents used in current clinical practice have very different biomechanical characteristics, which should be taken into consideration to select the most appropriate device for each clinical situation

Effect and Safety of Morphine Use in Acute Anterior ST‐Segment Elevation Myocardial Infarction

International audienceBackground: Morphine is commonly used to treat chest pain during myocardial infarction, but its effect on cardiovascular outcome has never been directly evaluated. The aim of this study was to examine the effect and safety of morphine in patients with acute anterior ST‐segment elevation myocardial infarction followed up for 1 year.Methods and Results: We used the database of the CIRCUS (Does Cyclosporine Improve Outcome in ST Elevation Myocardial Infarction Patients) trial, which included 969 patients with anterior ST‐segment elevation myocardial infarction, admitted for primary percutaneous coronary intervention. Two groups were defined according to use of morphine preceding coronary angiography. The composite primary outcome was the combined incidence of major adverse cardiovascular events, including cardiovascular death, heart failure, cardiogenic shock, myocardial infarction, unstable angina, and stroke during 1 year. A total of 554 (57.1%) patients received morphine at first medical contact. Both groups, with and without morphine treatment, were comparable with respect to demographic and periprocedural characteristics. There was no significant difference in major adverse cardiovascular events between patients who received morphine compared with those who did not (26.2% versus 22.0%, respectively; P=0.15). The all‐cause mortality was 5.3% in the morphine group versus 5.8% in the no‐morphine group (P=0.89). There was no difference between groups in infarct size as assessed by the creatine kinase peak after primary percutaneous coronary intervention (4023±118 versus 3903±149 IU/L; P=0.52).Conclusions: In anterior ST‐segment elevation myocardial infarction patients treated by primary percutaneous coronary intervention, morphine was used in half of patients during initial management and was not associated with a significant increase in major adverse cardiovascular events at 1 year

Adhesion forces and percentage of non-adhesive, non-specific adhesive and specific adhesive events obtained using AFM force spectroscopy in milliQ-grade water on TIL448, TIL1230, TIL1289 and TIL1290 lacto-probes in contact with PGM-coated polystyrene.

a<p>NA: non-adhesive event.</p>b<p>NSA: non-specific adhesive event.</p>c<p>SA: specific adhesive event.</p

AFM force spectroscopy for the wild-type TIL448 and the plasmid-cured derivative TIL1230.

<p>(A, D) Representative SEM images of <i>L. lactis</i> bacterial cells immobilized onto AFM tip and cantilever; (B, E) histograms of adhesion forces and (C, F) typical force-distance curves obtained when probing interactions between the wild-type TIL448 (A, B, C) and the plasmid-cured derivative TIL1230 (D, E, F) and PGM-coated polystyrene using AFM force spectroscopy in milliQ-grade water. One representative experiment (1024 force curves) is shown.</p

AFM blocking assays with free PGM for the wild-type TIL448.

<p>(A, B) Histograms of adhesion forces and (C, D) typical force-distance curves for wild-type TIL448 lacto-probe in interaction with PGM-coated polystyrene, using AFM force spectroscopy in milliQ-grade water, before (A, C) and after (B, D) incubation with free PGM. One representative experiment (1024 force curves) is shown.</p

Composition of the acidic fraction of O-glycans released from PGM.

<p>Monosaccharide composition of individual glycans was established by MALDI-TOF-MS based on the <i>m/z</i> values of monosaccharides.</p><p>Nature of monosaccharides (Gal, GlcNAc and Fuc) was based on GC composition analysis and on previous reports <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079850#pone.0079850-Karlsson1" target="_blank">[48]</a>. <i>m/z</i> values of sialylated glycans correspond to [M+Na]⁺ adducts whereas sulphated glycans exhibited [M+2Na-H]⁺ adducts.</p

Composition of the neutral fraction of O-glycans released from PGM. Monosaccharide composition of individual glycans was established by MALDI-TOF-MS based on the <i>m/z</i> values of monosaccharides.

<p>Nature of monosaccharides (Gal, GlcNAc and Fuc) was based on GC composition analysis and on previous reports <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079850#pone.0079850-Karlsson1" target="_blank">[48]</a>. <i>m/z</i> values of neutral glycans correspond to [M+Na]⁺ adducts.</p

Bacterial strains used in this study.

a<p>Micalis, INRA, Jouy-en-Josas, France.</p

Detachment under shear flow of the wild-type TIL448, the pilin mutant TIL1289 and the mucus-binding protein mutant TIL1290.

<p>Shear-flow induced detachment profiles of <i>L. lactis</i> bacterial cells attached to PGM-coated polystyrene in PBS; wild-type TIL448 (black square); pilin mutant TIL1289 (white square) and mucus-binding protein mutant TIL1290 (light grey square). The given results are the average values and standard deviations over at least three different coupons and independently grown cultures.</p