The 2010s in clinical drug-eluting stent and bioresorbable scaffold research: a Dutch perspective.

Dutch researchers were among the first to perform clinical studies in bare metal coronary stents, the use of which was initially limited by a high incidence of in-stent restenosis. This problem was greatly solved by the introduction of drug-eluting stents (DES). Nevertheless, enthusiasm about first-generation DES was subdued by discussions about a higher risk of very-late stent thrombosis and mortality, which stimulated the development, refinement, and rapid adoption of new DES with more biocompatible durable polymer coatings, biodegradable polymer coatings, or no coating at all. In terms of clinical DES research, the 2010s were characterised by numerous large-scale randomised trials in all-comers and patients with minimal exclusion criteria. Bioresorbable scaffolds (BRS) were developed and investigated. The Igaki-Tamai scaffold without drug elution was clinically tested in the Netherlands in 1999, followed by an everolimus-eluting BRS (Absorb) which showed favourable imaging and clinical results. Afterwards, multiple clinical trials comparing Absorb and its metallic counterpart were performed, revealing an increased rate of scaffold thrombosis during follow-up. Based on these studies, the commercialisation of the device was subsequently halted. Novel technologies are being developed to overcome shortcomings of first-generation BRS. In this narrative review, we look back on numerous devices and on the DES and BRS trials reported by Dutch researchers.

Effect of technique on outcomes following bioresorbable vascular scaffold implantation: analysis from the ABSORB trials

BACKGROUND: Procedural technique may affect clinical outcomes after bioresorbable vascular scaffold (BVS) implantation. Prior studies suggesting such a relationship have not adjusted for baseline patient and lesion characteristics that may have influenced operator choice of technique and outcomes. OBJECTIVES: This study sought to determine whether target lesion failure (TLF) (cardiac death, target-vessel myocardial infarction, or ischemia-driven target lesion revascularization) and scaffold thrombosis (ScT) rates within 3 years of BVS implantation are affected by operator technique (vessel size selection and pre- and post-dilation parameters). METHODS: TLF and ScT rates were determined in 2,973 patients with 3,149 BVS-treated coronary artery lesions from 5 prospective studies (ABSORB II, ABSORB China, ABSORB Japan, ABSORB III, and ABSORB Extend). Outcomes through 3 years (and between 0 to 1 and 1 to 3 years) were assessed according to pre-specified definitions of optimal technique (pre-dilation, vessel sizing, and post-dilation). Multivariable analysis was used to adjust for differences in up to 18 patient and lesion characteristics...

Are BVS suitable for ACS patients? Support from a large single center real live registry.

OBJECTIVES: To investigate one-year outcomes after implantation of a bioresorbable vascular scaffold (BVS) in patients presenting with acute coronary syndrome (ACS) compared to stable angina patients. BACKGROUND: Robust data on the outcome of BVS in the setting of ACS is still scarce. METHODS: Two investigator initiated, single-center, single-arm BVS registries have been pooled for the purpose of this study, namely the BVS Expand and BVS STEMI registries. RESULTS: From September 2012-October 2014, 351 patients with a total of 428 lesions were enrolled. 255 (72.6%) were ACS patients and 99 (27.4%) presented with stable angina/silent ischemia. Mean number of scaffold/patient was 1.55±0.91 in ACS group versus 1.91±1.11 in non-ACS group (P=0.11). Pre- and post-dilatation were performed less frequent in ACS patients, 75.7% and 41.3% versus 89.0% and 62.0% respectively (P=0.05 and P=0.001). Interestingly, post-procedural acute lumen gain and percentage diameter stenosis were superior in ACS patients, 1.62±0.65mm (versus 1.22±0.49mm, P<0.001) and 15.51±8.47% (versus 18.46±9.54%, P=0.04). Major adverse cardiac events (MACE) rate at 12months was 5.5% in the ACS group (versus 5.3% in stable group, P=0.90). One-year definite scaffold thrombosis rate was comparable: 2.0% for ACS population versus 2.1% for stable population (P=0.94), however, early scaffold thromboses occurred only in ACS patients. CONCLUSIONS: One-year clinical outcomes in ACS patients treated with BVS were similar to non-ACS patients. Acute angiographic outcomes were better in ACS than in non-ACS, yet the early thrombotic events require attention and further research.

Novel bioresorbable scaffolds technologies: current status and future directions.

Over the past century, coronary artery disease (CAD) has remained a leading cause of death worldwide, managed with enormous progress by medicine, from the development of advanced drugs to highly sophisticated revascularization modalities. Among them, as confirmed by recent studies, bioresorbable scaffolds (BRSs) have shown to have the potential to overtake conventional stents. This review presents their material composition and properties, those currently used in clinical evaluation, and their current limitations and potential improvements.

Relation between bioresorbable scaffold sizing using QCA-Dmax and clinical outcomes at 1 year in 1,232 patients from 3 study cohorts (ABSORB Cohort B, ABSORB EXTEND, and ABSORB II)

BACKGROUND:Assessment of pre-procedural Dmax of proximal and distal sites has been used for Absorb scaffold size selection in the ABSORB studies.METHODS:A total of 1,248 patients received Absorb scaffolds in the ABSORB Cohort B (ABSORB Clinical Investigation, Cohort B) study (N = 101), ABSORB EXTEND (ABSORB EXTEND Clinical Investigation) study (N = 812), and ABSORB II (ABSORB II Randomized Controlled Trial) trial (N = 335). The incidence of major adverse cardiac events (MACE) (a composite of cardiac death, any myocardial infarction [MI], and ischemia-driven target lesion revascularization) was analyzed according to the Dmax subclassification of scaffold oversize group versus scaffold nonoversize group...

1-Year clinical outcomes of diabeticpatients treated with everolimus-elutingbioresorbable vascular scaffolds: a pooled analysis of the ABSORB and the SPIRIT trials

Objectives The aim of this study was to evaluate 1-year clinical outcomes of diabetic patients treatedwith the Absorb bioresorbable vascular scaffold (BVS).Background Clinical outcomes of diabetic patients after BVS implantation have been unreported.Methods This study included 101 patients in the ABSORB Cohort B trial and the first consecutive 450patients with 1 year of follow-up in the ABSORB EXTEND trial. A total of 136 diabetic patients werecompared with 415 nondiabetic patients. In addition, 882 diabetic patients treated with everolimuselutingmetal stents (EES) in pooled data from the SPIRIT trials (SPIRIT FIRST [Clinical Trial of the AbbottVascular XIENCE V Everolimus Eluting Coronary Stent System], SPIRIT II [A Clinical Evaluation of the XIENCEV Everolimus Eluting Coronary Stent System], SPIRIT III [Clinical Trial of the XIENCE V Everolimus ElutingCoronary Stent System (EECSS)], SPIRIT IV Clinical Trial [Clinical Evaluation of the XIENCE V EverolimusEluting Coronary Stent System]) were used for the comparison by applying propensity score matching.The primary endpoint was a device-oriented composite endpoint (DoCE), including cardiac death, targetvessel myocardial infarction, and target lesion revascularization at 1-year follow-up.Results The cumulative incidence of DoCE did not differ between diabetic and nondiabetic patientstreated with the BVS (3.7% vs. 5.1%, p » 0.64). Diabetic patients treated with the BVS had a similarincidence of the DoCE compared with diabetic patients treated with EES in the matched study group(3.9% for the BVS vs. 6.4% for EES, p » 0.38). There were no differences in the incidence of definite orprobable scaffold/stent thrombosis (0.7% for both diabetic and nondiabetic patients with the BVS; 1.0%for diabetic patients with the BVS vs. 1.7% for diabetic patients with EES in the matched study group).Conclusions In the present analyses, diabetic patients treated with the BVS showed...

Long-term outcome of the unrestricted use of everolimus-eluting stents compared to sirolimus-eluting stents and paclitaxel-eluting stents in diabetic patients: the Bern-Rotterdam diabetes cohort study.

BACKGROUND: Newer generation everolimus-eluting stents (EES) improve clinical outcome compared to early generation sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES). We investigated whether the advantage in safety and efficacy also holds among the high-risk population of diabetic patients during long-term follow-up. METHODS: Between 2002 and 2009, a total of 1963 consecutive diabetic patients treated with the unrestricted use of EES (n=804), SES (n=612) and PES (n=547) were followed throughout three years for the occurrence of cardiac events at two academic institutions. The primary end point was the occurrence of definite stent thrombosis. RESULTS: The primary outcome occurred in 1.0% of EES, 3.7% of SES and 3.8% of PES treated patients ([EES vs. SES] adjusted HR=0.58, 95% CI 0.39-0.88; [EES vs. PES] adjusted HR=0.29, 95% CI 0.13-0.67). Similarly, patients treated with EES had a lower risk of target-lesion revascularization (TLR) compared to patients treated with SES and PES ([EES vs. SES], 5.6% vs. 11.5%, adjusted HR=0.68, 95% CI: 0.55-0.83; [EES vs. PES], 5.6% vs. 11.3%, adjusted HR=0.51, 95% CI: 0.33-0.77). There were no differences in other safety end points, such as all-cause mortality, cardiac mortality, myocardial infarction (MI) and MACE. CONCLUSION: In diabetic patients, the unrestricted use of EES appears to be associated with improved outcomes, specifically a significant decrease in the need for TLR and ST compared to early generation SES and PES throughout 3-year follow-up.

Adherence to patient selection criteria in patients undergoing transcatheter aortic valve implantation with the 18F CoreValve ReValving System.

BACKGROUND: Anecdotal evidence suggests that transcatheter aortic valve implantation (TAVI) is being used beyond pre-market label indications. METHODS: To assess the frequency and outcomes associated with "off-label" use of TAVI, we conducted a retrospective study, examining adherence to patient selection criteria in 63 patients undergoing implantation with the 18F CoreValve ReValving System (CRS). Label status (on-label vs off-label) was determined by following (1) inclusion/exclusion criteria indicated in the 18F CRS safety and efficacy trial and (2) a patient selection matrix indicating anatomical boundaries to guide patient selection. Off-label use was defined as the presence of at least one exclusion criterion or "non-acceptable" criteria based on the patient selection matrix. RESULTS: Off-label implantation was identified in 42 patients (67%)-40% had one, 19% had two and 8% had three or more off-label criteria. Baseline demographics were similar between the groups except for a higher logistic EuroSCORE in the on-label group (19.8 (11.2) vs 14.5 (7.3), p = 0.029). There was no significant difference in the procedural success rates between the on-label and off-label groups (91% vs 95%, respectively, p = 0.47). The frequency of angiographic moderate-severe aortic regurgitation, post-implant dilatation or implantation of a second valve was also similar between the groups. At 30 days, the cumulative death rate was 10%; there were four deaths in the "on-label" and three deaths in the "off-label" group. CONCLUSION: In this study we found that "off-label" implantation of the CRS was common. Further studies are needed to evaluate the consequences of "label status" for patients undergoing TAVI.

Optical coherence tomography assessment of the acute effects of stent implantation on the vessel wall: a systematic quantitative approach.

OBJECTIVE: To observe and characterise vessel injury after stenting using optical coherence tomography (OCT), to propose a systematic OCT classification for periprocedural vessel trauma, to evaluate its frequency in stable versus unstable patients and to assess its clinical impact during the hospitalisation period. SETTING: Stenting causes vessel injury. DESIGN AND INTERVENTIONS: All consecutive patients in whom OCT was performed after stent implantation were included in the study. Qualitative and quantitative assessment of tissue prolapse, intra-stent dissection and edge dissection were performed. RESULTS: Seventy-three patients (80 vessels) were analysed. Tissue prolapse within the stented segment was visible in 78/80 vessels (97.5%). Median number of tissue prolapse sites was 8 (IQR 4-19), mean (SD) area 1.04 (0.9) mm(2). Intra-stent dissection flaps were visible in 69/80 vessels (86.3%) (median number 3 (IQR 1.25-6), maximum flap length 450 (220) microm). Fifty-five out of 80 vessels (68.8%) showed dissection cavities (median number 2 (IQR 0-4.75), maximum depth 340 (170) microm). Edge dissection was visible in 20 vessels (mean (SD) length flap 744 (439) microm). The frequency of tissue prolapse or intra-stent dissection was similar in stable and unstable patients (95.6% vs 100%, p = 0.5 for tissue prolapse; 91.1% vs 82.9%, p = 0.3 for intra-stent dissection). There were no events during the hospitalisation period. CONCLUSIONS: OCT allows a detailed visualisation of vessel injury after stent implantation and enables a systematic classification and quantification in vivo. In this study, frequency of tissue prolapse or intra-stent dissections after stenting was high, irrespective of the clinical presentation of the patients, and was not associated with clinical events during hospitalisation.

Revascularization in the high-risk patient: multivessel disease.

The aim of this article is to review the treatment of patients with multi-vessel coronary artery disease. Percutaneous coronary intervention (PCI) has been challenging coronary artery bypass grafting (CABG) as the gold standard of care for patients with multi-vessel disease; however, the application of PCI to these patients has been mainly limited by restenosis. Up to the late 1990s, numerous large-scale, randomized trials addressed this issue comparing CABG to PCI with balloon angioplasty or bare-metal stents. These studies demonstrated similar rates of death and myocardial infarction in both groups, while the need for revascularization remained significantly lower in the CABG group. Drug-eluting stents (DES) have dramatically reduced restenosis and repeat revascularization rates. CABG has also progressed with improvements in perioperative management, a higher use of arterial grafting, and advanced techniques with the implementation of minimally invasive and off-pump surgery as options. Therefore, the results of previous trials in the pre-DES era can no longer be extrapolated into the ''real world''. As intermediate steps preceding a fully-fledged, randomized trial, several trials have compared PCI with DES and the historical control of CABG, but the results are still inconclusive. Several dedicated randomized trials are currently ongoing to compare PCI with DES and CABG using contemporary techniques. Until the results of these randomized trials are presented, the choice for each strategy should be based on the patients' individual risk and anatomy.

Two novel nodal-related genes initiate early inductive events in Xenopus Nieuwkoop center.

In vertebrates, Nodal-related protein plays crucial roles in mesoderm and endoderm induction. Here we describe two novel Xenopus nodal-related genes, Xnr5 and Xnr6, which are first zygotically expressed at the mid-blastula transition, in the dorsal-vegetal region including the Nieuwkoop center. Xnr5 and Xnr6 were isolated by expression screening of a library enriched with immediate-early-type transcripts, and are strong inducers of both mesoderm and endoderm. They also induce the other nodal-related genes in the animal cap. In embryos, cerberus-short (nodal-specific inhibitor) can inhibit Xnr1 and Xnr2 express to the same extent goosecoid, but not Xnr5 and Xnr6 transcription. Xnr5 and Xnr6 are regulated completely cell autonomously, differently from other Xnrs in the cell-dissociated embryos. The expression of Xnr5 and Xnr6 is regulated by maternal VegT and (beta)-catenin, but does not require TGF-(beta) signaling. Therefore, expression of Xnr5 and Xnr6 is controlled by different mechanisms from other Xnr family genes.

Expression of the Xenopus GTP-binding protein gene Ran during embryogenesis.

The Ran gene family encodes small GTP binding proteins that are associated with a variety of nuclear processes. We isolated a Xenopus Ran cDNA and analyzed the pattern of expression of this gene during embryogenesis. Ran is expressed maternally and later in the CNS, neural crest, mesenchyme, eyes, and otic vesicles. However, expression is not detected in the somites or the notochord.

Molecular cloning of a novel Xenopus spalt gene (Xsal-3).

The sal (spalt) gene family is characterized by unique double zinc finger motifs and is conserved among various species from Drosophila to humans. Here we report a new Xenopus member of this family, Xsal-3. It is 38% homologous at the amino acid level to the previously reported Xenopus homologue of the spalt gene, Xsal-1. Alternatively spliced Xsal-3 transcripts give rise to RNAs coding either two or three double zinc fingers, and the longer form is expressed maternally. Xsal-3 is expressed in the neural tube, the mandibular, hyoid, and branchial arch, and the pronephric duct, which is different from the expression pattern of Xsal-1. These findings suggest that Xsal-3 may have distinct roles in early Xenopus development.

Molecular cloning of the cone-rod homeobox gene (Crx) from the rat and its temporal expression pattern in the retina under a daily light-dark cycle.

The primary structure of the cone-rod homeobox protein (CRX), a member of the OTX-like homeobox protein family, in the rat was deduced from the cDNA nucleotide sequence. The deduced protein consisted of 299 amino acid residues with motifs conserved in mammalian CRXs, and was 98% identical to mouse CRX. Northern blot analysis showed that Crx mRNA levels in the rat retina were constant under a daily light-dark cycle. These findings suggest that the expression mechanism of rat Crx in the retina was different from that in the pineal, where Crx mRNA exhibits a daily expression rhythm.

Identification of putative palytoxin as the cause of clupeotoxism.

In 1994 in Madagascar a woman died after eating a sardine, Herklotsichthys quadrimaculatus. Two heads removed, respectively, from a toxic and a nontoxic fish before cooking were retrieved, kept frozen, and used for toxin analysis. The causative toxin was identified as palytoxin or its analogs based on its cytotoxicity, delayed hemolysis, neutralization with an anti-palytoxin antibody, chromatographic properties on different columns, and MS data. The gill and esophagus of the fish contained large amount of bottom sediments indicating that the fish had fed on the bottom and thus probably obtained the toxin from a benthic organism. The benthic dinoflagellate Ostreopsis siamensis that produces palytoxin and its analogs was inferred as the probable toxin source. This is the first study to shed light on clupeotoxism, a highly fatal form of human intoxication due to ingestion of clupeoid fish.

cDNA cloning and distribution of the Xenopus follistatin-related protein.

Recently, several proteins which have a follistatin module have been isolated. One of them, the follistatin-related protein (FRP), is encoded by TSC-36 (TGF-beta-stimulated clone 36) in mouse, originally isolated as a cDNA clone up-regulated by TGF-beta1 in mouse osteogenic MC3T3E1 cells. To determine the physiological role of FRP in early Xenopus embryonic development, we cloned the Xenopus FRP (xFRP) cDNA. The resulting cDNA clone was a secreted glycoprotein consisting of 299 amino acid residues with about 70% similarity to the mammalian and avian FRPs. Northern blotting analysis revealed that xFRP gene expression started at stage 10, the onset of gastrulation, gradually increased during the blastula and neurula stages and was sustained through the tail-bud stage. Whole-mount in situ hybridization analysis showed the localization of xFRP mRNAs in the Spemann organizer, notochord, neural floor plate, hypochord and somite. The similarities with the pattern of expression of Xenopus follistatin mRNA suggests that xFRP may play a role in neuralization.

Usefulness of magnetic resonance imaging with dynamic contrast enhancement and fat suppression in detecting a pancreatic tumor.

The purpose of this study was to compare the value of dynamic magnetic resonance imaging (MRI) and fat suppression in detecting a pancreatic tumor. The subjects were 19 patients with invasive ductal adenocarcinoma and six patients with islet cell tumor where diagnosis was established pathologically. Breath-hold gradient echo images, breath-hold gradient echo images with fat suppression and breath-hold gradient echo images with dynamic enhancement at 1.5 T were obtained for all patients. The efficacies of these three imaging techniques were compared by calculating the contrast-to-noise ratio, as indicative of conspicuousness between a tumor-affected and a normal pancreas. As for adenocarcinoma, our results indicated that the usefulness in detecting the tumor was high, decreasing in the order dynamic contrast images > fat suppression images > plain images, and that the difference between any two of these three types of image was statistically significant. On the other hand, these imaging techniques showed no statistically significant difference in detecting islet cell tumors. In conclusion, dynamic MRI is the best method for detecting pancreatic adenocarcinoma. As the fat suppression technique has the advantage of being non-invasive, this method is suitable for screening studies of pancreatic adenocarcinoma. However, no advantage was recognized in using the fat suppression technique for detecting an islet cell tumor in comparison with plain MRI.

Concentration of levofloxacin in cervical mucus and its clinical effects on cervicitis.

An investigation was made on the concentration of levofloxacin (LVFX) in cervical mucus and its clinical effects on cervicitis. The results were as follows: 1) The concentrations of orally administered LVFX in the cervical mucus of 110 subjects were determined by HPLC. During 1-4 hour after the administration the mean concentration of LVFX in the cervical mucus reached a level of 2 micrograms/g, which was higher than the serum level. The transfer of LVFX to the cervical mucus was almost the same as that to other genital organs. 2) When LVFX was given to 102 patients at a dose of 100-200 mg, t.i.d for 4-5 days and the efficacy was evaluated with clinical improvement, the clinical efficacy rate of LVFX was 72/102 (70.6%). Significant bacteriological effects were observed in 70/73 (95.9%), especially, the disappearance rate of C. trachomatis was 18/18 (100%). 3) The administration LVFX did not cause any subjective or objective side effects and any abnormalities were not detected in the laboratory test done in this study. These results demonstrate that LVFX can be sufficiently transferred to the cervical mucus for the treatment of cervicitis due to the infection of C. trachomatis etc.