Everolimus- vs. novolimus-eluting bioresorbable scaffolds in patients with acute coronary syndrome.

BACKGROUND: Limited data exist on bioresorbable scaffolds (BRS) in patients with acute coronary syndrome (ACS). The aim of the present study was to evaluate novolimus-eluting BRS (DESolve) as interventional treatment for patients with ACS, and to compare its 12-month outcomes with the everolimus-eluting bioresorbable scaffolds (Absorb). METHODS: In this retrospective study, patients with ACS (including unstable angina pectoris, ST-segment elevation myocardial infarction, or non-ST-segment elevation myocardial infarction) treated with either the Absorb or the DESolve BRS were evaluated in a 1:1 matched-pair analysis. Major adverse cardiac events (MACE), including death, myocardial infarction, and target lesion revascularization, were evaluated as a major endpoint. The occurrence of scaffold thrombosis was also assessed. RESULTS: A total of 102 patients were eligible for this analysis. The rate of MACE at 12 months was comparable between the Absorb and the DESolve group (8.3% vs. 6.8%, p = 0.738). The occurrence of target lesion revascularization (6.2% vs. 4.7%; p = 0.700) and scaffold thrombosis (4.1% vs. 2.1%; p = 0.580) was comparable as well. All instances of scaffold thrombosis occurred within 30 days of the index procedure. CONCLUSION: In this study, similar 12-month event rates were observed for both BRS types after implantation for the treatment of ACS.

New strategies in the treatment of coronary bifurcations.

Despite major improvements in stent technology (i.e., drug-eluting stents, DES), treatment of coronary bifurcations is an ever occurring problem of the interventional cardiology. While stenting the main branch with provisional side branch stenting seems to be the prevailing approach, in the era of DES various two-stent techniques emerged (crush) or were re-introduced (V or simultaneous kissing stents, crush, T, culottes, etc.) to allow stenting in the side branch when needed. New techniques in imaging like optical coherence tomography help in better understanding bifurcation anatomy and, thus, have the potential to help us better treat this challenging subset of lesions. In addition, new dedicated bifurcation stents have been proposed in an attempt to overcome limitations associated with current approaches, and they showed promising results in early studies; however, the safety and the efficacy of these devices remain to be seen in the ongoing and upcoming trials. This review focuses on the current approaches and the development of new techniques employed for the treatment of bifurcation disease.

[Purpuric contact dermatitis from Agave Americana]. / Dermatite purpurique de contact au suc d'Agave americana.

BACKGROUND: Irritant papulovesicular dermatitis after cutaneous exposure to the sap of Agave Americana, which contains chemical irritants such as calcium oxalate and saponins, is well known, but purpuric dermatitis is rare in such cases. CASE REPORT: We report the case of a 52 year-old man with purpuric dermatitis of the legs mimicking purpura vasculitis that appeared a few hours after he had cut down a large Agave with a chain-saw. DISCUSSION: Our case is quite similar to three other cases found in the literature. In all four cases the patients had been using machines causing projections of plant fragments (chain-saw, trimmer). This may have promoted vascular damage, either by direct traumatism or by embedding oxalate crystals and saponins in the skin close to small vessels.

[Acne in adult women: data from a national study on the relationship between type of acne and markers of clinical hyperandrogenism]. / Acné de la femme adulte.

INTRODUCTION: The role of hyperandrogenism in acne occurring or persisting in adult women is controversial. Studies reported have often been carried out in hospital settings. The aim of this nationwide prospective and descriptive study was to evaluate the frequency of clinical hyperandrogenism in a large number of adult acneic women visiting dermatologists in a non-hospital setting. PATIENTS AND METHODS: Three hundred and fifteen dermatologists completed clinical questionnaires concerning the next five female patients with acne at their private practices. These patients had to be between 25 and 45 years of age. The questionnaire covered patients' demographic characteristics, medical history, gynaecological status and acne history. Patients' acne, seborrhea and cycle disorders were described, as well as other signs suggesting hyperandrogenism, such as hirsutism and alopecia. RESULTS: A total of 1 135 questionnaires were analyzed. Nearly 50 p. 100 of the patients had major scalp or facial seborrhea, 18.4 p. 100 hirsutism, 7 p. 100 alopecia and 32.2 p. 100 menstrual cycle abnormalities. When these signs were present, acne was more often retentional, with more scarring and more widespread. CONCLUSION: This prospective study in a large number of patients in a non-hospital setting shows that acne in adult women is frequently associated with clinical hyperandrogenism.

Optical coherence tomography in bioabsorbable stents: mechanism of vascular response and guidance of stent implantation.

Fully biodegradable L-polylactic acid stents (biodegradable vascular scaffold, BVS), the latest breakthrough in the area of coronary implants, entered clinical trials in 2005 and became commercially available in 2011. Optical coherence tomography (OCT) was used from the first implants to study the vessel wall response and the timing of the resorption process in man. Analysis of BVS with OCT has several advantages over that of metallic stents. BVS polymeric struts are transparent to the light so that scaffold integrity, apposition to the underlying wall, presence of thrombus and hyperplasia, and changes in the strut characteristics over time can be easily studied. We present a comprehensive review of the findings OCT provided when used as a research tool in serial examination up to five years for investigation of the mechanism of resorption, neointimal coverage, shrinkage and late lumen enlargement. We also report our experience with OCT in 47 lesions of various complexity as a practical means of percutaneous coronary intervention guidance during BVS implantation.

Patient-specific coronary stenoses can be modeled using a combination of OCT and flow velocities to accurately predict hyperemic pressure gradients.

Computational fluid dynamics (CFD) is increasingly being developed for the diagnostics of arterial diseases. Imaging methods such as computed tomography (CT) and angiography are commonly used. However, these have limited spatial resolution and are subject to movement artifact. This study developed a new approach to generate CFD models by combining high-fidelity, patient-specific coronary anatomy models derived from optical coherence tomography (OCT) imaging with patient-specific pressure and velocity phasic data. Additionally, we used a new technique which does not require the catheter to be used to determine the centerline of the vessel. The CFD data were then compared with invasively measured pressure and velocity. Angiography imaging data of 21 vessels collected from 19 patients were fused with OCT visualizations of the same vessels using an algorithm that produces reconstructions inheriting the in-plane (10 µm) and longitudinal (0.2 mm) resolution of OCT. Proximal pressure and distal velocity waveforms ensemble averaged from invasively measured data were used as inlet and outlet boundary conditions, respectively, in CFD simulations. The resulting distal pressure waveform was compared against the measured waveform to test the model. The results followed the shape of the measured waveforms closely (cross-correlation coefficient = 0.898 ± 0.005, ), indicating realistic modeling of flow resistance, the mean of differences between measured and simulated results was -3. 5 mmHg, standard deviation of differences (SDD) = 8.2 mmHg over the cycle and -9.8 mmHg, SDD = 16.4 mmHg at peak flow. Models incorporating phasic velocity in patient-specific models of coronary anatomy derived from high-resolution OCT images show a good correlation with the measured pressure waveforms in all cases, indicating that the model results may be an accurate representation of the measured flow conditions.

Stent flexibility versus concertina effect: mechanism of an unpleasant trade-off in stent design and its implications for stent selection in the cath-lab.

The "concertina effect", longitudinal deformation of the proximal segments of a deployed stent when force is applied from a guide catheter or other equipment, is a recently recognised problem which seems to particularly affect more recent stent designs. Until now, flexibility and deliverability have been paramount aims in stent design. Developments have focussed on optimising these features which are commonly evaluated by clinicians and demanded by regulatory bodies. Contemporary stent designs now provide high flexibility by reducing the number of connecting links between stent segments and by allowing the connecting links to easily change their length. These design evolutions may, however, simultaneously reduce longitudinal strength and have the unintended effect of inducing some risk of longitudinal compression of the stent (the "concertina effect") during difficult clinical cases. Progress in stent design and elimination of restenosis by drug coating has improved PCI outcome and enabled new applications. Here we discuss design trade-offs that shaped evolution and improvement in stent design, from early bare metal designs to the latest generation of drug eluting stent (DES) platforms. Longitudinal strength was not recognised as a critical parameter by clinicians or regulators until recently. Measurements, only now becoming publically available, seem to confirm vulnerability of some modern designs to longitudinal deformation. Clinicians could be more guarded in their assumption that changes in technology are beneficial in all clinical situations. Sometimes a silent trade-off may have taken place, adopting choices that are favourable for the vast majority of patients but exposing a few patients to unintended hazard.

Location of side branch access critically affects results in bifurcation stenting: Insights from bench modeling and computational flow simulation.

BACKGROUND: The aim of this study was to evaluate the impact of stent design and side branch access on final strut apposition during bifurcation stenting. METHODS AND RESULTS: A series of 6 different commercially available Drug Eluting Stents (DES) (n=42) were deployed in an identical model of a coronary bifurcation. Kissing Balloon (KB) optimization was performed after either proximal or distal recrossing of the guidewire and results were analyzed by micro-Computed-Tomography. Stent design only had a minor impact on side branch lumen area free of stent struts. Similar rate of strut malapposition was observed within the bifurcation when a consistent KB optimization protocol and an optimal distal recrossing of the wire to reaccess the side branch (SB) are followed. Conversely, proximal instead of distal cell recrossing toward the side branch produced a significant lower area of the side branch lumen free of struts than an optimal distal recrossing (60.3±7.1% versus 81.1±8.0%, p<0.0001), as well as a higher rate of strut malapposed toward the SB ostium (40.6±6.0% versus 26.0±5.7%, p=0.0005). CONCLUSIONS: Optimal cell recrossing of the guidewire may be critical to ensure successful stent optimization in bifurcation PCI.

How to optimize the percutaneous treatment of bifurcated lesions: dedicated stents vs. provisional stenting.

Although provisional T-stenting with stenting of the main branch and optional side branch stenting is nowadays the default strategy generally preferred for simple bifurcation lesions, percutaneous coronary intervention (PCI) of complex true bifurcation lesions remains a difficult task to achieve also with modern second generation drug eluting stents. Treatment of complex bifurcational lesions is not only more time consuming but can lead to significantly higher rate of periprocedural myocardial infarction and late estenosis, stent thrombosis and target lesion revascularization. These clinical complications may be at least in part be due to the fact that current bifurcation techniques often fail to ensure continuous stent coverage of the SB ostium and the bifurcation branches and often leave a significant number of malapposed struts. Struts left unapposed in the lumen are not efficient for drug delivery to the vessel wall, disturb blood flow and may increase the risk of restenosis and stent thrombosis. This article summarises the various techniques of bifurcation stenting, highlighting their relative merits and disadvantages. In addition, the role of newer dedicated bifurcation stent devices, as well as the role of imaging in guiding optimal stent deployment will be discussed.