Publications

Summary: Follow-up angiography at 6 months was obtained in 94% of the 693 patients (778 successfully dilated coronary lesions) enrolled in the Multicenter European Research trial with Cilazapril after Angioplasty to prevent Transluminal Coronary Obstruction and Restenosis (MERCATOR) trial—a double-blind, placebo-controlled trial—to study the effects of cilazapril 5 mg b.i.d. on restenosis [defined as the mean loss in minimal luminal diameter during follow-up, assessed by an interpolated edge detection technique (coronary angiography analysis system)] and long-term clinical outcome. No statistically significant difference could be detected between treatment and placebo groups with regard to clinical outcome or restenosis. The purpose of this ancillary study was to determine which, if any, patient, lesion, or procedural factors were predictive of restenosis. The identification of such factors could be helpful in the selection of lesions suitable for angioplasty and, if modifiable or controllable, potentially reduce restenosis. A stepwise multiple linear regression analysis was performed to identify independent predictors of restenosis. The following variables were retained in the model in order of significance: (a) relative gain (difference between the minimal luminal diameter pre- and post-percutaneous transluminal coronary angioplasty (PTCA), normalized for vessel size), (b) minimal luminal diameter post-PTCA, and (c) dilatation of another vessel than right coronary artery. The fit of the model was poor; where the predicted change in minimal luminal diameter was <0.1 mm, 0.1-0.3 mm, >0.3 mm, the corresponding percent correct classification was 30, 52, and 55%. The present study illustrates that the restenosis phenomenon cannot accurately be predicted by patient, lesion, and procedural variables.

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.

No abstract is provided for this article.

Aim The pathophysiological pattern of coronary artery disease (CAD) pre-procedure may affect the physiological response to percutaneous coronary intervention (PCI). The aim of this study was to evaluate whether the pathophysiological pattern of CAD, derived from virtual pullbacks of angiography-based fractional flow reserve, impacted the immediate hemodynamic outcome post-PCI. Methods and results Among 503 consecutive patients with chronic coronary syndrome and non-ST elevated acute coronary syndrome treated at least 1 vessel in the Multivessel TALENT trial, 826 quantitative flow ratio (QFR) analysable vessels were enrolled. Pre-procedural pathophysiological patterns in CAD were characterized by the physiological distribution and local severity of coronary atherosclerosis using QFR-derived indexes acquired from pre-PCI angiograms. The physiological distribution of CAD was defined as "predominant diffuse" or "focal" according to a QFR pullback pressure gradient (PPG) index &amp;lt;0.78 and ≥0.78, respectively. Physiological local severity was assessed using QFR gradient per 1 mm (dQFR/ds), with a value ≥ 0.025/mm defining the presence of a "major gradient". The optimal post-PCI QFR value was defined as QFR ≥0.91. Among the 826 vessels, 673 vessels were analysed (excluding vessels which have total occlusions, ostial lesions, and paired QFR not analysable). Mean pre-PCI PPG index was 0.70 with a nadir in the distribution curve. As per the definition, "focal" lesions were 30% of the total analysed vessels and 88% had a "major gradient". The majority of the vessels belong to predominantly diffuse disease with a major gradient (62.7%, Figure 1). Compared to predominantly focal disease with a major gradient, predominantly diffuse disease had a higher risk of a post-PCI QFR &amp;lt;0.91 (OR 1.78, 95%CI 1.23-2.58). The scatterplot between pre-procedural PPGI and post-procedural QFR showed positive correlation (Piason’s R=0.163, p&amp;lt;0.001, Figure 2). The correlation suggested that the vessels with focal lesions more frequently achieved optimal post-PCI QFR values compared to that with diffuse lesions. In multivariable analysis, low QFR PPG index (diffuse disease) was an independent factor for predicting a post-PCI QFR&amp;lt;0.91 (per 0.1 decreases of QFR PPG index, OR:10.3, 95% CI 1.7-63.3, p=0.012). The estimated 2-year VOCE, the powered secondary endpoint of this study, estimated by the post-QFR is 5.9% in treated vessels with predominant diffuse lesion, while 4.9% in that with predominant focal lesion based on the previous substudy of SYNTAX II trial.[1] Conclusions A physiological pattern of diffuse CAD pre-procedure was an independent factor in predicting an unfavourable immediate hemodynamic outcome post-PCI. Pre-procedural PPG index can be the predictor of not only post-PCI physiological value but also vessel base prognosis.pre-PCI pathophysiological patternScatterplot and correlation

Background There are different definitions of periprocedural myocardial infarction (PPMI) both in terms of thresholds for cardiac biomarkers and the ancillary criteria for myocardial ischemia. Cardiac Troponin I (cTnI) and cardiac Troponin T (cTnT) are used interchangeably to diagnose PPMI. Objectives This study evaluated the frequency of periprocedural myocardial injury and infarction as defined by the Society of Cardiovascular Angiography &amp; Interventions (SCAI), the Academic Research Consortium-2 (ARC-2), and the 4th Universal definition of MI (4UDMI) stratified using cTnT versus cTnI, among patients with chronic coronary syndrome (CCS) and unstable angina. Results Among 830 patients, PPMI rates according to the SCAI, ARC2 and 4UDMI criteria were 4.34%, 2.05%, and 4.94% respectively, with higher rates seen for all definitions when using cTnI versus cTnT (SCAI: 9.84% vs. 1.91%, p&amp;lt;0.001; ARC 2: 3.15% vs. 1.56%, p=0.136; and 4UDMI 5.91% vs. 4.51%, p=0.391). Minor and major periprocedural myocardial injury was respectively observed in 58.31% and 27.10% of patients, with rates of both significantly higher when using cTnI versus cTnT (Minor: 69.29% vs. 53.47%, p&amp;lt;0.001, Major: 49.21% vs. 17.36%, p&amp;lt;0.001). Conclusions Among patients with CCS and unstable angina, PPMIs defined by SCAI occurred more frequently when using cTnI as opposed to cTnT, whereas the type of troponin had no impact on the incidence of PPMIs according to the ARC-2 and 4UDMI

Introduction: Forced oscillation technique (FOT) is a method to estimate respiratory resistance (Rrs) and reactance (Xrs). However, some common artefacts may affect the accuracy of FOT readings. In particular, air leaks from lips not sealed around the mouthpiece, or those from the equipment. We studied the significance of this artefact and identified possible markers to detect it. Methods: 11 healthy subjects (33±7 years) underwent FOT measurements (Jaeger, Wurzburg, Germany) which generated 0.4 kPa peak-to-peak input signals. The Rrs and Xrs values at 5 and 20 Hz (R5, R20, X5) were registered in parallel with breathing volumes. To simulate air leaks, we applied artificial holes of increasing sizes (3.5 mm, 6 mm, and 8.5 mm diameters) on the breathing filter at 1 cm from the circumference. FOT data were compared to normal values obtained with no air leaks. Results: With increasingly bigger filter holes and resulting air leaks, we identified corresponding larger indentations in the descending limb of the breathing volume (ΔV (2.2±0.6 mL, 5.3±1.7 mL, 8.7±3.1 mL and 14.4±2.9 mL; respectively, p Conclusion: Indentations on the descending limb of the breathing volume may be used to detect the presence and magnitude of air leaks. Visual inspection of the data is required to exclude records where indentations are found. The first author is receiving an ERS Long Term Fellowship.

Although additive manufacturing (AM) has been maturing for some years, it has only recently started to capture the interest of the cost-sensitive construction industry. The research presented herein is seeking to integrate AM into the construction sector through the establishment of an automated end-to-end framework for the generation of high-performance AM structures, combining sophisticated optimization techniques with cutting edge AM methods. Trusses of tubular cross-section subjected to different load cases have been selected as the demonstrators of the proposed framework. Optimization studies, featuring numerical layout and geometry optimization techniques, are employed to obtain the topology of the examined structures, accounting for practical and manufacturing constraints. Cross-section optimization is subsequently undertaken, followed by a series of geometric operations for the design of free-form joints connecting the optimized members. Solid models of the optimized designs are then exported for wire arc additive manufacturing (WAAM). Following determination of the optimal printing sequence, the trusses are printed and inspected. The efficiency of the optimized designs has been assessed by means of finite element modelling and compared against equivalent conventional designs. More than 200% increases in efficiency (reflected in the capacity-to-mass ratios) were achieved for all optimized trusses (when compared to their equivalent reference designs), demonstrating the effectiveness of the proposed optimization framework.