The history of interventional cardiology: cardiac catheterization, angioplasty, and related interventions

Randomized study for a novel elbow joint fixation device on postoperative complications in patients undergoing percutaneous coronary diagnostic or therapeutic procedures through the brachial artery

Brachial artery access for coronary diagnostic or therapeutic procedures is associated with a greater risk of vascular complications. To determine whether 3D printing of a novel elbow joint fixation device could reduce postoperative complications after percutaneous coronary diagnostic or therapeutic procedures through the brachial artery. Patients who underwent percutaneous coronary diagnostic or therapeutic procedures by brachial access were randomly assigned to receive either a 3D-printed elbow joint fixation device (brace group) or traditional compression (control group) from March 2023 to December 2023. The severity of puncture site-related discomfort at 24 h postsurgery was significantly lower in the brace group (P = 0.014). Similarly, the upper arm calibration rate at 24 h postsurgery was significantly lower in the brace group [0.024 (0.019-0.046) vs. 0.077 (0.038-0.103), P < 0.001], as was the forearm calibration rate [0.026 (0.024-0.049) vs. 0.050 (0.023-0.091), P = 0.007]. The brace group had a significantly lower area of subcutaneous hemorrhage at 24 h postsurgery [0.255 (0-1.00) vs. 1 (0.25-1.75) cm2]. In patients who underwent percutaneous coronary diagnostic or therapeutic procedures by brachial access after manual compression hemostasis, the novel elbow joint fixation device was effective at reducing puncture site-related discomfort, alleviating the degree of swelling, and minimizing the subcutaneous bleeding area. Additionally, no significant complications were observed.Trial registration: China Clinical Trial Registration on 01/03/2023 (ChiCTR2300068791).

Concordance between Coronary Artery Computed Tomography and Invasive Coronary Angiography in a Real-World Population with Suspected Chronic Coronary Syndrome

BACKGROUND

Coronary computed tomographic angiography (CCTA) is a non-invasive imaging technique that possesses the ability to provide detailed anatomical information about coronary arteries, avoiding unnecessary invasive procedures. Our aim was to assess the ability of CCTA to identify coronary artery disease compared to invasive coronary angiography (ICA) in a real-life setting.

METHODS

We examined 137 consecutive patients who underwent ICA after CCTA. The latter was conducted in various non-selected centers, and data regarding stenosis were taken from individual reports without further analysis.

RESULTS

A total of 60.5% of patients who underwent CCTA were found to have at least one critical stenosis, while the remaining 39.5% underwent ICA due to concurrent clinical or instrumental indications. Among these, 29.5% had angiographically critical pathology, 20.3% underwent a percutaneous coronary intervention (PCI), and 1.8% had coronary artery bypass grafting. Among the 83 patients with positive CCTA results, 34.9% had negative ICA findings. CCTA demonstrated low sensitivity (57.8%) and a positive predictive value of 42.6%. However, it retained high specificity (83.6%) and a negative predictive value of 90.4% for identifying critical stenosis. Among the 18.2% of patients who underwent CCTA without a specific indication, 60% had critical coronary lesions on their ICA and 86.6% of these subsequently underwent a PCI.

CONCLUSIONS

CCTA performed in non-selective centers has a low concordance with ICA.

A multicenter prospective observational study appraising the effectiveness of the Supera stent after subintimal recanalization of femoro-popliteal artery occlusion: The SUPERSUB II study

BACKGROUND

Complex femoropopliteal artery disease represents a challenge. The Supera stent holds the promise of improving the results of endovascular therapy for complex femoropopliteal disease.

AIMS

We aimed at appraising the early and long-term effectiveness of the Supera stent after successful subintimal angioplasty (SuperSUB strategy) for complex femoropopliteal lesions.

METHODS

We conducted a multicenter, prospective, single-arm observational study including consecutive patients at participating centers in whom Supera was implanted after successful subintimal angioplasty for complex femoropopliteal lesions.

RESULTS

A total of 92 patients were included Femoropopliteal arteries were the most common target, and lesion length was 261 ± 102 mm. Most procedures were technically demanding, with antegrade femoral access in 35 (38%) and retrograde distal access in 55 (60%). Supera stent length was 281 ± 111 mm, with 4, 5, and 6 mm devices being most commonly used: 32 (35%), 35 (38%), and 23 (25%), respectively. Technical success was achieved in 100% of subjects, as was clinical success (per subject), whereas procedural success (per subject) was obtained in 98%. At 24 months, freedom from clinically driven target lesion revascularization was 93%, whereas primary patency was 87%. When compared with a similar historical cohort, Supera stent use appeared to be associated with a reduction in resources.

CONCLUSION

Use of Supera stent after successful subintimal recanalization of complex lower limb arterial lesions yields favorable procedural results, which are maintained over follow-up, and are associated also with a favorable resource use profile.

An unusual no-reflow phenomenon due to neointimal tissue embolization during drug eluting balloon intervention in stent restenosis: A case report

Acute coronary syndrome is one of the leading causes of death worldwide. Percutaneous coronary intervention (PCI), along with various devices, have been technically developed to dramatically improve mortality risk in patients with acute myocardial infarction. However, no-reflow phenomenon still remains a problematic complication during a PCI, even in the era of drug eluting stents. There are various hypotheses and mechanisms for no-reflow phenomenon, but none have been confirmed. Treatment for no-reflow phenomenon also depends on various underlying conditions, but have not yet shown effective improvement. We presented a case of no-reflow phenomenon caused by an unusual cause.

Impact of mechanical stress on flexible tubing used for biomedical applications: Characterization of the damages and impact on the patient's health

Flexible tubing is a key part of a lot of medical devices used in hospital, but may be subjected to a lot of various mechanical stresses that can led to the failure or to complications for the patients. The nature and causes of these mechanical stresses were listed for peristaltic pump tubing, infusion set tubing and catheters. Their consequences in term of tubing damages and particular contamination were reported. The impact of the chemical nature of the tubing, of its size and also the impact of various parameters of the clinical acts were reviewed. Last the consequences for the patient's health were discussed.

Effects of Sevoflurane on Apoptosis of Myocardial Cells in IRI Rats

Background

Cardiomyocyte apoptosis functions essentially in ischemia/reperfusion- (I/R-) induced myocardial injury. It is suggested that autophagy is widely implicated in the regulation of cell survival and death. Sevoflurane, as a largely used inhalational general anesthetic, has been shown to have a protective effect on cardiomyocytes. However, it was yet elusive on the underlying mechanisms.

Aim

The objective of this study is to investigate the association of sevoflurane-mediated cardioprotective effects with autophagy regulation.

Methods

An in vitro hypoxia model was established in primary cardiomyocytes from fresh myocardial tissue of the rats. The apoptosis rate of myocardial cells treated with hypoxia and treated with sevoflurane was measured. Western blot and immunocytochemical assay were used to measure the protein expression. The cell proliferation rate and cell apoptosis were measured using the MTT assay and flow cytometry, respectively.

Results

The expression of apoptotic proteins including B cell lymphoma-2 (Bcl-2), CCAAT/enhancer-binding protein homologous protein (CHOP), glucose-regulated protein 78 (GRP78), and Bcl-2-associated X protein (BAX) in myocardium treated with sevoflurane was significantly lower than that in myocardium treated with hypoxia. The expression of adhesion proteins such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in myocardium treated with sevoflurane was higher than that in myocardium treated with hypoxia, suggesting better connectivity of the myocardium.

Conclusion

Sevoflurane treatment reduced the apoptosis of myocardial cells after hypoxia treatment.

[Coronary angiography my false friend]

Coronary angiography has been a long-standing friend since the first selective injection by Sones in 1958. More than 400,000 coronary angiographies are performed each year in France for the diagnosis and treatment of ischemic heart disease. In just over 60 years, examinations have become simpler, with imaging that has considerably progressed. Nevertheless, it remains an invasive and radiating examination and requires an injection of a potentially nephrotoxic contrast medium. It is a two-dimensional projection of a luminogram of small arteries, in perpetual movement. The technical realization must be perfect, the analysis of the images must be careful. It is important to be aware of the pitfalls and limitations of the examination, and to rely on complementary techniques to resolve ambiguities, whether functional (FFR, IMR) or morphological (IVUS, OCT). Although non-invasive explorations, such as coroscanner, are in full development, these alternative methods have other limitations (lack of resolution, artifacts related to calcifications) which mean that angiography often remains essential for the diagnosis of coronary artery disease, indispensable for deciding on treatment and guiding revascularization. All of these elements make coronary angiography the definition of a friend: someone you know well... but you love anyway.

Hemodynamic alternations following stent deployment and post-dilation in a heavily calcified coronary artery: In silico and ex-vivo approaches

In this work, hemodynamic alterations in a patient-specific, heavily calcified coronary artery following stent deployment and post-dilations are quantified using in silico and ex-vivo approaches. Three-dimensional artery models were reconstructed from OCT images. Stent deployment and post-dilation with various inflation pressures were performed through both the finite element method (FEM) and ex vivo experiments. Results from FEM agreed very well with the ex-vivo measurements, interms of lumen areas, stent underexpansion, and strut malapposition. In addition, computational fluid dynamics (CFD) simulations were performed to delineate the hemodynamic alterations after stent deployment and post-dilations. A pressure time history at the inlet and a lumped parameter model (LPM) at the outlet were adopted to mimic the aortic pressure and the distal arterial tree, respectively. The pressure drop across the lesion, pertaining to the clinical measure of instantaneous wave-free flow ratio (iFR), was investigated. Results have shown that post-dilations are necessary for the lumen gain as well as the hemodynamic restoration towards hemostasis. Malapposed struts induced much higher shear rate, flow disturbances and lower time-averaged wall shear stress (TAWSS) around struts. Post-dilations mitigated the strut malapposition, and thus the shear rate. Moreover, stenting induced larger area of low TAWSS (<0.4 Pa) and lager volume of high shear rate (>2000 s^-1), indicating higher risks of in-stent restenosis (ISR) and stent thrombosis (ST), respectively. Oscillatory shear index (OSI) and relative residence time (RRT) indicated the wall regions more prone to ISR are located near the malapposed stent struts.

Real-World Clinical Outcomes of Indigenous Biodegradable Polymer Drug-Eluting Stents

Introduction

The durable polymer has been shown to cause neoatherosclerosis, and chronic local inflammation, predisposing individuals to in-stent restenosis and stent thrombosis (ST). The biodegradable polymer stents, which degrade after the desired function of drug release is achieved, allow for endothelial healing. Indigenous coronary stent manufacturing and its use are on the rise nowadays, and their safety and efficacy have been studied in well-structured clinical trials. However, data are scarce on their safety and efficacy in the real-world clinical setting. In this study, we examine the real-world one-year performance of bioresorbable or polymer-free stents manufactured in India.

Materials and methods

This was a single-center, single-arm prospective observational study involving 210 patients undergoing intracoronary stenting using bioabsorbable or polymer-free drug-eluting stents (DES) from Indian manufacturers. All patients were followed up for 12 months prospectively for any major clinical events.

Results

The mean age of the enrolled patients was 57.04 years (IQR: 34-84 years), among which 159 (75.7%) were male; 99 (43.8%) patients had presented with acute myocardial infarction (MI). A total of 294 stents were deployed with a mean diameter of 3.1 ±0.4 mm, and a mean length of 29.4 ±9.1 mm. Two patients had experienced major adverse cardiovascular events (MACE). After three months of follow-up, one patient developed ST, and the same patient developed a cerebrovascular accident (CVA) after six months. After one year of follow-up, one patient died of cardiac causes.

Conclusion

Based on our findings, in the real-world clinical setting, the indigenously made biodegradable polymer DES are both safe and effective.

Evolution of the fabric of cardiovascular science: Saga of an enduring process of refinement

BACKGROUND

The core elements of cardiovascular science have been established by scholarly pursuits of numerous scientists across centuries. In this article, we have tried to trace the evolutionary journey of cardiovascular science from a rudimentary form in ancient period to a robust scientific discipline in modern times.

METHODS

A literature search of relevant, peer-reviewed, published articles was undertaken from indexed databases (Medline & Pubmed, Scopus, Embase, CINAHL Plus, Web of Science and Google Scholar).

RESULTS

Cardiovascular science has its roots in antiquity, when Greek scholars mostly relied on philosophical thoughts and ancient texts. This was followed by addition of few structural details to the theory of circulation by Galen based on animal dissection. Arab scholar Ibn al-Nafis provided new insights regarding circulation pathway in humans. Nevertheless, an erroneous concept prevailed into the onset of European Renaissance. Even with legalization of human dissection, little headway could be made till sixteenth century due to persistent reliance of anatomists on ancient Galenic principles. During seventeenth century, the circulatory pathway (as we know it today) was established due to significant contributions from scholars like Harvey and Malpighi. Their efforts were based on findings from experiments and logical conclusions. Eighteenth century witnessed the emergence of autopsy based methods which led to valuable contributions from Vieussens, Thebesius, Morgagni and Hunter regarding normal and pathologic anatomy of cardiovascular system. With structural details mostly established, researchers during nineteenth century focussed on innovations in diagnostic methods based on human experiments. Further development of advanced human experiment models during twentieth century led to emergence of contemporary treatment methods for various cardiac conditions. In the twenty-first century, cardiovascular science is undergoing comprehensive progress at an exponential rate due to technological advances.

CONCLUSION

The evolutionary journey of cardiovascular science as a discipline across centuries has been intriguing and eventful.

Left distal radial artery approach versus conventional radial artery for coronary angiography

We aimed to evaluate feasibility, contrast utilization and complications of trans-radial approach comparing the left distal trans-radial artery (lt. dTRA) access versus conventional right trans-radial artery (rt. TRA) access in coronary angiography. Subjects and Methods: This study was conducted on (100) patients who underwent coronary angiography (50 patients via lt. dTRA & 50 patients via rt. TRA) and was performed in the department of cardiology, Benha University Hospital. All patients performed ECG, echocardiography, arterial doppler pre and post procedures.

Degradation behaviors and in-vivo biocompatibility of a rare earth- and aluminum-free magnesium-based stent

Biodegradable stents can provide scaffolding and anti-restenosis benefits in the short term and then gradually disappear over time to free the vessel, among which the Mg-based biodegradable metal stents have been prosperously developed. In the present study, a Mg-8.5Li (wt.%) alloy (RE- and Al-free) with high ductility (> 40%) was processed into mini-tubes, and further fabricated into finished stent through laser cutting and electropolishing. In-vitro degradation test was performed to evaluate the durability of this stent before and after balloon dilation. The influence of plastic deformation and residual stress (derived from the dilation process) on the degradation was checked with the assistance of finite element analysis. In addition, in-vivo degradation behaviors and biocompatibility of the stent were evaluated by performing implantation in iliac artery of minipigs. The balloon dilation process did not lead to deteriorated degradation, and this stent exhibited a decent degradation rate (0.15 mm/y) in vitro, but divergent result (> 0.6 mm/y) was found in vivo. The stent was almost completely degraded in 3 months, revealing an insufficient scaffolding time. Meanwhile, it did not induce possible thrombus, and it was tolerable by surrounding tissues in pigs. Besides, endothelial coverage in 1 month was achieved even under the severe degradation condition. In the end, the feasibility of this stent for treatment of benign vascular stenosis was generally discussed, and perspectives on future improvement of Mg-Li-based stents were proposed.

Vascular Access for Large Bore Access

Recent advances in the field of interventional cardiology have allowed for more complex procedures to be performed percutaneously. Ability to obtain safe large bore vascular access is frequently the key factor to procedural success. Meticulous technique for successful vascular access incorporates the understanding of anatomic landmarks, ultrasound, fluoroscopy, and micropuncture. Adequate hemostasis at the end of the case can be achieved through careful use of commercially available vascular closure devices. Although access-related vascular complications are uncommon, early recognition is key to successful management. Arterial tortuosity and calcification can present a significant challenge to successful common femoral artery access.

Endothelial Dysfunction and Coronary Vasoreactivity - A Review of the History, Physiology, Diagnostic Techniques, and Clinical Relevance

The fervency for advancement and evolution in percutaneous coronary intervention has revolutionised the treatment of coronary artery disease. Historically, the focus of the interventional cardiologist was directed at the restoration of luminal patency of the major epicardial coronary arteries, yet whilst this approach is evolving with much greater utilisation of physiological assessment, it often neglects consideration of the role of the coronary microcirculation, which has been shown to clearly influence prognosis. In this review, we explore the narrative of the coronary circulation as more than just a simple conduit for blood but an organ with functional significance. We review organisation and physiology of the coronary circulation, as well as the current methods and techniques used to examine it. We discuss the studies exploring coronary artery endothelial function, appreciating that coronary artery disease occurs on a spectrum of disorder and that percutaneous coronary intervention has a latent effect on the coronary circulation with long-term consequences. It is concluded that greater recognition of the coronary artery endothelium and mechanisms of the coronary circulation should further guide revascularisation strategies.

Comparison of survival rate and complications of percutaneous coronary intervention, coronary artery bypass graft, and medical treatment in patients with left main and/or three vessel diseases

BACKGROUND

The probable complications of 3 different cardiovascular diseases treatment options including percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG), and medical therapy (MT), especially in individuals suffering from left main (LM) and/or three vessel diseases (3VDs), have received less attention. Thus, the aim of this study was to compare the complications of the aforementioned therapeutic strategies in patients admitted with LM coronary artery disease (CAD) and/or having 3VDs.

METHODS

From March 2018 to March 2019, a total number of 251 eligible individuals (87, 86, and 78 subjects treated with PCI, CABG, and MT, respectively) were recruited in this cohort study. After the initiation of treatment, all individuals were followed for 6 months. Occurrence of any complications including chest pain (CP), re-hospitalization due to cardiac problems, heart failure (HF), death, myocardial infarction (MI), and stroke as well as major adverse cardiac events (MACE) were assessed.

RESULTS

Significantly lower percentages of CP, readmission, and HF were observed in the CABG group compared to the PCI and MT groups (24.4% vs. 47.1% and 53.9%, P < 0.001; 3.5% vs. 13.8% and 5.1%, P = 0.020; 1.2% vs. 2.3% and 9%; P = 0.040, respectively). Further analysis revealed an increased likelihood of hospitalization in the PCI group (OR: 3.82, 95% CI: 1.01-14.41, P = 0.040), and a lower risk of CP and HF occurrence in the CABG group subjects compared to the MT group (OR: 0.28, 95% CI: 0.13-0.62, P = 0.002 and OR: 0.05, 95% CI: 0.004-0.71, P = 0.030, respectively). This pattern was also observed in the PCI group in terms of HF (OR: 0.12, 95% CI: 0.02-0.83, P = 0.030).

CONCLUSION

Patients suffering from LM and/or 3VDs would most likely benefit from CABG followed by PCI, rather than MT. Further large-scale studies are required to confirm these results.

Cardiac catherization in Austria : Results from the Austrian National Cardiac Catheterization Laboratory Registry (ANCALAR) 2012-2018

Background

Cardiac catheterization is one of the most widely performed cardiac interventional procedures worldwide. The Austrian National Catheterization Laboratory Registry (ANCALAR), started in 1992, collects annual data on cardiac catheterization in Austria. The registry enables in-depth understanding of the dynamics of cardiac catheterization procedures and their use across 34 cardiac catheterization laboratories in Austria.

Methods

Data from ANCALAR on cardiac catheterization including the latest data for 2017, voluntarily provided by centers with cardiac catheterization laboratories, were analyzed. Where possible, international comparisons in therapeutic and interventional cardiac procedures are made with Switzerland and Germany.

Results

Internationally, Austria ranks alongside the top countries in Europe. Whilst the number of people undergoing routine percutaneous coronary interventions (PCI) remains stable, complex and acute interventions are increasing year by year in Austria.

Conclusion

Evidence from ANCALAR revealed that Austria is another example of the difficulties of weighing current guidelines with new emerging evidence and resulting real-life clinical practice in the dynamic world of interventional cardiology.

Electronic supplementary material

The online version of this article (10.1007/s00508-019-01599-4) contains supplementary material, which is available to authorized users.

Endovascular Approach to Cerebral Revascularization: Historical Vignette

From their origins as cardiovascular research tools, endovascular techniques have evolved to provide a minimally invasive means of diagnosis and therapy for individuals suffering from occlusive artery disease. The techniques were pioneered by William Harvey, whose work set the stage for all subsequent endovascular experiments. These included the bold self-catheterization procedure performed by Werner Forssmann in 1929, which would lead to his dismissal by his superiors, only to regain respect within the medical community in 1956 on receiving the Nobel Prize. Charles Dotter was the first to understand the true potential of endovascular approaches after a chance recanalization that would catapult arterial catheterization first into the cardiovascular surgical arena, then into neurosurgery for intracranial stenoses. Having been meticulously evaluated and compared with open vascular procedures, endovascular neurosurgery has continued to be refined and optimized. Understanding the history and development of these techniques and their applications in neurosurgery is necessary to appreciate the current clinical utility of these procedures, serving to provide the vascular neurosurgeon a greater array of treatment options for patients. Here we explore the major scientific and technological advancements that facilitated the development of the endovascular approach to cerebral revascularization, as well as current indications and ongoing clinical trials.

A Review of the Ultrathin Orsiro Biodegradable Polymer Drug-eluting Stent in the Treatment of Coronary Artery Disease

Drug-eluting stents (DES) have revolutionised the treatment of coronary artery disease (CAD) in patients undergoing percutaneous coronary intervention. In recent years, there has been a focus on a new generation of DES, such as biodegradable polymer DES (BP-DES). This novel stent platform was developed with the hope of eliminating the risk of very late stent thrombosis associated with the current gold-standard durable polymer DES (DP-DES). Ultrathin Orsiro BP-DES (Biotronik, Bülach, Switzerland) are based on a cobalt-chromium stent platform that is coated with a bioresorbable polymer coating containing sirolimus. These devices have one of the thinnest struts available in the current market and have the theoretical benefit of reducing a chronic inflammatory response in the vessel wall. In 2019, the United States Food and Drug Administration (FDA) approved the use of Orsiro BP-DES in patients with CAD based on promising results in recent landmark trials, such as BIOFLOW V and BIOSTEMI. The aim of the present review article was to discuss the history of stent technology and the continued opportunities for improvements, focusing on the potential benefits of Orsiro BP-DES.

Structural and Hemodynamic Analyses of Different Stent Structures in Curved and Stenotic Coronary Artery

Coronary artery stenting is commonly used for the treatment of coronary stenosis, and different stent structures indeed have various impacts on the stress distribution within the plaque and artery as well as the local hemodynamic environment. This study aims to evaluate the performance of different stent structures by characterizing the mechanical parameters after coronary stenting. Six stent structures including three commercially-shaped stents (Palmaz-Schatz-shaped, Xience Prime-shaped, and Cypher-shaped) and three author-developed stents (C-Rlink, C-Rcrown, and C-Astrut) implanted into a curved stenotic coronary artery were investigated. Structural analyses of the balloon-stent-plaque-artery system were first performed, and then followed by hemodynamic analyses. The results showed that among the three commercially-shaped stents, the Palmaz-Schatz-shaped had the least stent dogboning and recoiling, corresponding to the greatest maximum plastic strain and the largest diameter change, nevertheless, it induced the highest maximum von Mises stress on plaque, arterial intima and media. From the viewpoint of hemodynamics, the Palmaz-Schatz-shaped displayed smaller areas of adverse low wall shear stress (<0.5 Pa), low time-averaged wall shear stress (<0.5 Pa), and high oscillating shear index (>0.1). Compared to the Cypher-shaped, the C-Rcrown and C-Astrut had smaller recoiling, greater maximum plastic stain and larger diameter change, which indicated the improved mechanical performance of the Cypher-shaped stent. Moreover, both C-Rcrown and C-Astrut exhibited smaller areas of adverse low wall shear stress, and low time-averaged wall shear stress, but only the C-Rcrown displayed a smaller area of adverse high oscillating shear index. The present study evaluated and compared the performance of six different stents deployed inside a curved artery, and could be potentially utilized as a guide for the selection of suitable commercially-shaped stent for clinical application, and to provide an approach to improve the performance of the commercial stents.

Unobtrusive Estimation of Cardiovascular Parameters with Limb Ballistocardiography

This study investigates the potential of the limb ballistocardiogram (BCG) for unobtrusive estimation of cardiovascular (CV) parameters. In conjunction with the reference CV parameters (including diastolic, pulse, and systolic pressures, stroke volume, cardiac output, and total peripheral resistance), an upper-limb BCG based on an accelerometer embedded in a wearable armband and a lower-limb BCG based on a strain gauge embedded in a weighing scale were instrumented simultaneously with a finger photoplethysmogram (PPG). To standardize the analysis, the more convenient yet unconventional armband BCG was transformed into the more conventional weighing scale BCG (called the synthetic weighing scale BCG) using a signal processing procedure. The characteristic features were extracted from these BCG and PPG waveforms in the form of wave-to-wave time intervals, wave amplitudes, and wave-to-wave amplitudes. Then, the relationship between the characteristic features associated with (i) the weighing scale BCG-PPG pair and (ii) the synthetic weighing scale BCG-PPG pair versus the CV parameters, was analyzed using the multivariate linear regression analysis. The results indicated that each of the CV parameters of interest may be accurately estimated by a combination of as few as two characteristic features in the upper-limb or lower-limb BCG, and also that the characteristic features recruited for the CV parameters were to a large extent relevant according to the physiological mechanism underlying the BCG.

Invited Article: Emerging soft bioelectronics for cardiac health diagnosis and treatment

Cardiovascular diseases are among the leading causes of death worldwide. Conventional technologies for diagnosing and treating lack the compliance and comfort necessary for those living with life-threatening conditions. Soft electronics presents a promising outlet for conformal, flexible, and stretchable devices that can overcome the mechanical mismatch that is often associated with conventional technologies. Here, we review the various methods in which electronics have been made flexible and stretchable, to better interface with the human body, both externally with the skin and internally with the outer surface of the heart. Then, we review soft, wearable, noninvasive heart monitors designed to be attached to the chest or other parts of the body for mechano-acoustic and electrophysiological sensing. A common method of treatment for various abnormal heart rhythms involves catheter ablation procedures and we review the current soft bioelectronics that can be placed on the balloon or head of the catheter. Cardiac mapping is integral to determine the state of the heart; we discuss the various parameters for sensing aside from electrophysiological sensing, such as temperature, pH, strain, and tactile sensing. Finally, we review the soft devices that harvest energy from the natural and spontaneous beating of the heart by converting its mechanical motion into electrical energy to power implants.

Coronary angiography using the left distal radial approach - An alternative site to conventional radial coronary angiography

Objective:

To share our experience with the left distal radial approach for transradial coronary angiography and interventions. By performing the radial puncture in the fossa radialis or the so called anatomical “Snuffbox” we aimed to present the feasibility and complications of this new technique.

Methods:

Left distal radial artery was used as an access site in 54 patients admitted to our clinic for coronary angiography and intervention between May 25^th and October 20^th 2017. All of them had pulse in their left distal radial artery. In the laboratory, they had their left arm gently flexed at the shoulder so that the hand was placed over their right groin. The operator stood on the right side of the patient and performed coronary angiography and interventions. During the hospital stay, demographic features and complications were recorded.

Results:

Mean age of patients was 59.3 years and 80% were male. We used Judkins 6 French catheters for the procedures. Seventeen patients admitted with acute coronary syndrome. They all underwent successful left distal transradial coronary angiography and intervention. Primary angioplasty was performed in 10 patients. In total, 20 patients had coronary intervention. Left anterior descending artery was the artery requiring most intervention (11 patients). Two patients experienced brachial spasm requiring crossover to right femoral artery. There were no cases of radial artery occlusion, hematoma, or hand numbness. The radial sheath was removed at procedure termination. Hemostasis was achieved with manual compression.

Conclusion:

Left distal radial approach is safe and feasible as a new technique for coronary angiography and interventions.

Invasive Hemodynamics of Pulmonary Disease and the Right Ventricle

Pulmonary hypertension (PH) falls into 5 groups, as defined by the World Health Organization. Swan-Ganz catheters determine precapillary versus postcapillary PH. The hemodynamic values of PH at rest and with vasodilatory challenge categorize the etiology of PH and guide treatment. RV maladaptations to increased pulmonary vascular resistance (PVR) and the chronicity of the right ventricle's (RV) response to increased PH and/or increased PVR can be understood with pressure-volume (PV) loops constructed with use of conductance catheters. These PV loops demonstrate the RV's ability to increase stroke volume in acutely and chronically increased PVR.

Achieving Multidisciplinary Collaboration for the Creation of a Pulmonary Embolism Response Team: Creating a "Team of Rivals"

Pulmonary embolism response teams (PERTs) have recently been developed to streamline care for patients with life-threatening pulmonary embolism (PE). PERTs are unique among rapid response teams, in that they bring together a multidisciplinary team of specialists to care for a single disease for which there are novel treatments but few comparative data to guide treatment. The PERT model describes a process that includes activation of the team; real-time, multidisciplinary consultation; communication of treatment recommendations; mobilization of resources; and collection of research data. Interventional radiologists, along with cardiologists, emergency physicians, hematologists, pulmonary/critical care physicians, and surgeons, are core members of most PERTs. Bringing together such a wide array of experts leverages the expertise and strengths of each specialty. However, it can also lead to challenges that threaten team cohesion and cooperation. The purpose of this article is to discuss ways to integrate multiple specialists, with diverse perspectives and skills, into a cohesive PERT. The authors will discuss the purpose of forming a PERT, strengths of different PERT specialties, strategies to leverage these strengths to optimize participation and cooperation across team members, as well as unresolved challenges.

From Femoral to Radial Approach in Coronary Intervention

Since the first cardiac catheterization in 1929, this procedure has evolved considerably. Historically performed via the transfemoral access, in the last years, the transradial access has been spreading gradually due to its many advantages. We have conducted a review of published literature concerning efficacy, safety, and cost-effectiveness, and we analyzed our patients' data, including the results of the recently published Minimizing Adverse hemorrhagic events by TRansradial access site and systemic implementation of angioX (MATRIX) study. This review confirmed the superiority of the transradial access compared to the femoral access, especially regarding complications related to the access site, duration of hospitalization, and comfort for the patient. The transradial approach is an excellent option for coronary angiography, and the procedure's risks are reduced by increased operator experience.

Biodegradable Metals for Cardiovascular Stents: from Clinical Concerns to Recent Zn-Alloys

Metallic stents are used to promote revascularization and maintain patency of plaqued or damaged arteries following balloon angioplasty. To mitigate the long-term side effects associated with corrosion-resistant stents (i.e., chronic inflammation and late stage thrombosis), a new generation of so-called "bioabsorbable" stents is currently being developed. The bioabsorbable coronary stents will corrode and be absorbed by the artery after completing their task as vascular scaffolding. Research spanning the last two decades has focused on biodegradable polymeric, iron-based, and magnesium-based stent materials. The inherent mechanical and surface properties of metals make them more attractive stent material candidates than their polymeric counterparts. A third class of metallic bioabsorbable materials that are based on zinc has been introduced in the last few years. This new zinc-based class of materials demonstrates the potential for an absorbable metallic stent with the mechanical and biodegradation characteristics required for optimal stent performance. This review compares bioabsorbable materials and summarizes progress towards bioabsorbable stents. It emphasizes the current understanding of physiological and biological benefits of zinc and its biocompatibility. Finally, the review provides an outlook on challenges in designing zinc-based stents of optimal mechanical properties and biodegradation rate.

Modelling pH-Optimized Degradation of Microgel-Functionalized Polyesters

We establish a novel mathematical model to describe and analyze pH levels in the vicinity of poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate-co-N-vinylimidazole) (VCL/AAEM/VIm) microgel-functionalized polymers during biodegradation. Biodegradable polymers, especially aliphatic polyesters (polylactide/polyglycolide/polycaprolactone homo- and copolymers), have a large range of medical applications including delivery systems, scaffolds, or stents for the treatment of cardiovascular diseases. Most of those applications are limited by the inherent drop of pH level during the degradation process. The combination of polymers with VCL/AAEM/VIm-microgels, which aims at stabilizing pH levels, is innovative and requires new mathematical models for the prediction of pH level evaluation. The mathematical model consists of a diffusion-reaction PDE system for the degradation including reaction rate equations and diffusion of acidic degradation products into the vicinity. A system of algebraic equations is coupled to the degradation model in order to describe the buffering action of the microgel. The model is validated against the experimental pH-monitored biodegradation of microgel-functionalized polymer foils and is available for the design of microgel-functionalized polymer components.

The metamorphosis of vascular stents: passive structures to smart devices

The role of nanotechnology enabled techniques in the evolution of vascular stents.

Nobel prizes: contributions to cardiology

The Nobel Prize was created by Alfred Nobel. The first prize was awarded in 1901 and Emil Adolf von Behring was the first laureate in medicine due to his research in diphtheria serum. Regarding cardiology, Nobel Prize's history permits a global comprehension of progress in pathophysiology, diagnosis and therapeutics of various cardiac diseases in last 120 years. The objective of this study was to review the major scientific discoveries contemplated by Nobel Prizes that contributed to cardiology. In addition, we also hypothesized why Carlos Chagas, one of our most important scientists, did not win the prize in two occasions. We carried out a non-systematic review of Nobel Prize winners, selecting the main studies relevant to heart diseaseamong the laureates. In the period between 1901 and 2013, 204 researches and 104 prizes were awarded in Nobel Prize, of which 16 (15%) studies were important for cardiovascular area. There were 33 (16%) laureates, and two (6%) were women. Fourteen (42%) were American, 15 (45%) Europeans and four (13%) were from other countries. There was only one winner born in Brazil, Peter Medawar, whose career was all in England. Reviewing the history of the Nobel Prize in physiology or medicine area made possible to identify which researchers and studies had contributed to advances in the diagnosis, prevention and treatment of cardiovascular diseases. Most winners were North Americans and Europeans, and male.

A novel photochemical cross-linking technology to improve luminal gain, vessel compliance, and buckling post-angioplasty in porcine arteries

Development of substituted 1,8-naphthalimides for photochemical cross-linking of biomolecules is the focus of this research. This study describes limited cross-linking of collagen in the artery wall to control recoil and buckling in arteries following balloon angioplasty. Isolated porcine arteries were overstretched (25%) with balloon angioplasty (BA) +/- light-activated naphthalimide treatment (NVS). Lumen size and recoil were measured as retention of stretch after angioplasty. Cross-sectional compliance and distensibility coefficients were measured as slope of cross-sectional area versus increasing hydrostatic pressure. Buckling was measured, with 30% axial pre-stretch and 200 mmHg, as deviation from the center line. Electron microscopy evaluation of collagen fibers was conducted.

RESULTS

Uninjured arteries have low compliance and low levels of buckling, whereas the BA-injured arteries demonstrated much greater compliance and buckling behavior. Treatment of the injured artery with NVS reduced buckling and demonstrated compliance midway between the two groups while retaining the increased luminal diameter imparted by angioplasty compared to untreated vessels. In summary, limited collagen cross-linking with NVS treatment resulted in lumen retention, as well as improved compliance without the accompanying rigidity and stiffness of conventional stent therapy or current cross-linking materials. This treatment shows great promise for dilation, repair and strengthening of arteries damaged by injury or vascular disease.

Progress in interventional cardiology: challenges for the future

Cardiovascular disease is the leading cause of death in the western and developing countries. Percutaneous transluminal coronary interventions have become the most prevalent treatment option for coronary artery disease; however, due to serious complications, such as stent thrombosis and in-stent restenosis (ISR), the efficacy and safety of the procedure remain important issues to address. Strategies to overcome these aspects are under extensive investigation. In this review, we summarise relevant milestones during the time to overcome these limitations of coronary stents, such as the development of polymer-free drug-eluting stents (DES) to avoid pro-inflammatory response due to the polymer coating or the developement of stents with cell-directing drugs to, simultaneously, improve re-endothelialisation and inhibit ISR amongst other techniques most recently developed, which have not fully entered the clinical stage. Also the novel concept of fully biodegradable DES featured by the lack of a permanent foreign body promises to be a beneficial and applicable tool to restore a natural vessel with maintained vasomotion and to enable optional subsequent surgical revascularisation.

Balloon Angioplasty - The Legacy of Andreas Grüntzig, M.D. (1939-1985)

In 1974, at the Medical Policlinic of the University of Zürich, German-born physician-scientist Andreas Grüntzig (1939-1985) for the first time applied a balloon-tipped catheter to re-open a severely stenosed femoral artery, a procedure, which he initially called "percutaneous transluminal dilatation". Balloon angioplasty as a therapy of atherosclerotic vascular disease, for which Grüntzig and Charles T. Dotter (1920-1985) received a nomination for the Nobel Prize in Physiology or Medicine in 1978, became one of the most successful examples of translational medicine in the twentieth century. Known today as percutaneous transluminal angioplasty (PTA) in peripheral arteries or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI) in coronary arteries, balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. On the occasion of the 40(th) anniversary of balloon angioplasty, we summarize Grüntzig's life and career in Germany, Switzerland, and the United States and also review the developments in vascular medicine from the 1890s to the 1980s, including Dotter's first accidental angioplasty in 1963. The work of pioneers of catheterization, including Pedro L. Fariñas in Cuba, André F. Cournand in France, Werner Forssmann, Werner Porstmann and Eberhard Zeitler in Germany, António Egas Moniz and Reynaldo dos Santos in Portugal, Sven-Ivar Seldinger in Sweden, and Barney Brooks, Thomas J. Fogarty, Melvin P. Judkins, Richard K. Myler, Dickinson W. Richards, and F. Mason Sones in the United States, is discussed. We also present quotes by Grüntzig and excerpts from his unfinished autobiography, statements of Grüntzig's former colleagues and contemporary witnesses, and have included hitherto unpublished historic photographs and links to archive recordings and historic materials. This year, on June 25, 2014, Andreas Grüntzig would have celebrated his 75(th) birthday. This article is dedicated to his memory.

Transradial approach to cardiovascular interventions: an update

Background Since the first cardiac catheterization in 1929, the procedure has continually evolved with advances in understanding, capabilities, and ease of operation. Though historically performed by cut down of the brachial artery, cardiologists soon learned that transfemoral access was both easier to perform and more efficacious with regard to patient outcome. In the last 20 years, the transradial approach has been adopted, and is being utilized with increasing frequency. Methods We conducted a survey of literature published concerning safety, efficacy, cost-effectiveness, and global uptake of transradial catheterization with specific attention to how transradial interventions compare with transfemoral interventions. Results This review of literature indicates that when performed by an experienced interventionalist, radial catheterization is as effective as femoral catheterization and has additional benefits of shorter length of hospital stay and reduced patient costs. Transradial access is superior to transfemoral access in some, but not all, clinical scenarios; in addition, it is an effective alternative for catheterization in patients contraindicated for transfemoral procedures. Adoption of radial access in the United States is at a faster rate than previously expected, though rate of use varies drastically worldwide. Conclusion The transradial approach is an excellent option for carrying out cardiovascular interventions, and will be adopted by more cardiologists in the upcoming years.

Clinicians' contributions to the development of coronary artery stents: a qualitative study of transformative device innovation

Background

Medical device innovation remains poorly understood, and policymakers disagree over how to incentivize early development. We sought to elucidate the components of transformative health care innovation by conducting an in-depth case study of development of a key medical device: coronary artery stents.

Methods and Findings

We conducted semi-structured interviews with the innovators whose work contributed to the development of coronary artery stents who we identified based on a review of the regulatory, patent, and medical literature. Semi-structured interviews with each participant covered the interviewee’s personal involvement in coronary artery stent development, the roles of institutions and other individuals in the development process, the interplay of funding and intellectual property in the interviewee’s contribution, and finally reflections on lessons arising from the experience. Transcripts were analyzed using standard coding techniques and the constant comparative method of qualitative data analysis.

Conclusions

We found that the first coronary artery stents emerged from three teams: Julio Palmaz and Richard Schatz, Cesare Gianturco and Gary Roubin, and Ulrich Sigwart. First, these individual physician-inventors saw the need for coronary artery stents in their clinical practice. In response, they developed prototypes with the support of academic medical centers leading to early validation studies. Larger companies entered afterwards with engineering support. Patents became paramount once the technology diffused. The case of coronary stents suggests that innovation policy should focus on supporting early physician-inventors at academic centers.