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

Femoro-popliteal endovascular interventions

Peripheral artery disease (PAD) is a worldwide major health challenge, and it is a strong predictor of mortality and morbidity. The advances in PAD treatment have resulted in many therapeutic options or endovascular interventions (EVIs) for endovascular revascularization if drug therapy does not lead to substantial improvement. Randomized controlled trials (RCTs) have reported the efficacy of various EVIs such as atherectomy, stents, and medicated balloons over the traditional transluminal angioplasty; however, the standard treatment for PAD remains unclear due to the lack of head-to-head comparative studies between different EVIs. Additionally, the variable outcomes between clinical trials regarding the functional capacity and quality of life (QoL) make it difficult to ascertain the superiority of one particular EVI over another. Therefore, the latest PAD clinical trials should include head-to-head comparisons between different EVIs, and this review aimed to highlight the femoro-popliteal EVIs, evidence supporting each intervention and why those EVIs are used.

Drug-Coated Balloons in the Management of Coronary Artery Disease

Drug-coated balloons (DCBs) are specialized coronary devices comprised of a semicompliant balloon catheter with an engineered coating that allows the delivery of antiproliferative agents locally to the vessel wall during percutaneous coronary intervention. Although DCBs were initially developed more than a decade ago, their potential in coronary interventions has recently sparked renewed interest, especially in the United States. Originally designed to overcome the limitations of conventional balloon angioplasty and stenting, they aim to match or even improve upon the outcomes of drug-eluting stents without leaving a permanent implant. Presently, in-stent restenosis is the condition with the most robust evidence supporting the use of DCBs. DCBs provide improved long-term vessel patency compared with conventional balloon angioplasty and may be comparable to drug-eluting stents without the need for an additional stent layer, supporting their use as a first-line therapy for in-stent restenosis. Beyond the treatment of in-stent restenosis, DCBs provide an additional tool for de novo lesions for a strategy that avoids a permanent metal scaffold, which may be especially useful for the management of technically challenging anatomies such as small vessels and bifurcations. DCBs might also be advantageous for patients with high bleeding risk due to the decreased necessity for extended antiplatelet therapy, and in patients with diabetes and patients with diffuse disease to minimize long-stented segments. Further studies are crucial to confirm these broader applications for DCBs and to further validate safety and efficacy.

From Palm Leaves to Thermoplastic Polyurethanes-The History of Vascular Catheter Development and Use

Vascular catheterization procedures are performed on millions of patients in the United States annually. Diagnostic and therapeutic, these procedures allow for the detection and treatment of diseased vessels. The use of catheters, however, is no new phenomenon. Ancient Egyptians, Greeks, and Romans constructed tubes from hollow reeds and palm leaves to be tunneled through the vasculature of cadavers to study cardiovascular system function, while eighteenth century English physiologist Stephen Hales used a brass pipe cannula to perform the first central vein catheterization on a horse. In 1963, American surgeon Thomas Fogarty developed a balloon embolectomy catheter, while in 1974, German cardiologist Andreas Grüntzig developed a more refined angioplasty catheter using polyvinyl chloride with improved rigidity. Vascular catheter material has since continued to evolve and is tailored to the specific needs of the procedure but would not have been possible without its rich and diverse history of development.

Polyphenol-mediated sandwich-like coating promotes endothelialization and vascular healing

Drug-eluting stents have become one of the most effective methods to treat cardiovascular diseases. However, this therapeutic strategy may lead to thrombosis, stent restenosis, and intimal hyperplasia and prevent re-endothelialization. In this study, we selected 3-aminophenylboronic acid-modified hyaluronic acid and carboxylate chitosan as polyelectrolyte layers and embedded an epigallocatechin-3-gallate-tanshinone IIA sulfonic sodium (EGCG-TSS) complex to develop a sandwich-like layer-by-layer coating. The introduction of a functional molecular EGCG-TSS complex improved not only the biocompatibility of the coating but also its stability by enriching the interaction between the polyelectrolyte coatings through electrostatic interactions, hydrogen bonding, π-π stacking, and covalent bonding. We further elucidated the effectiveness of sandwich-like coatings in regulating the inflammatory response, smooth muscle cell growth behavior, stent thrombosis and restenosis suppression, and vessel re-endothelialization acceleration via in vivo and in vitro. Conclusively, we demonstrated that sandwich-like coating assisted by an EGCG-TSS complex may be an effective surface modification strategy for cardiovascular therapeutic applications.

Is Intravascular Lithotripsy (IVL) Alone a Therapy for the Treatment of Aortoiliac Occlusive Disease (AIOD)?

We present a rare case in which a 63-year-old male with a history of hypertension, diabetes mellitus, hyperlipidemia, and previous coronary artery bypass graft (CABG) presented with bilateral external iliac artery near occlusion. We describe the utilization of lithotripsy balloon angioplasty as opposed to the traditional double-barrel stenting method or modified endovascular repair (EVAR) to treat the occlusion. Pre-operative computed tomography (CT) angiography demonstrated a 90 percent occlusion of both the distal aorta and right external iliac artery, and 99 percent occlusion of the left external iliac. The patient remains symptom-free three years post-intervention with normal right and left ankle-brachial indices, 1.34 and 1.32 respectively. We review the available literature regarding aortoiliac occlusive disease (AIOD) and discuss the advantages and disadvantages of novel and traditional treatment modalities. Understanding all treatment options is crucial for physicians who are presented with similar cases.

Revascularization Modalities in Acute Coronary Syndrome: A Review of the Current State of Evidence

Acute coronary syndrome (ACS) stands as a leading global cause of mortality, underscoring the importance of effective prevention, early diagnosis, and timely intervention. While medications offer benefits to many patients, revascularization procedures such as coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), and emerging hybrid approaches remain pivotal for ACS management. This review delves into the 2018 ESC/EACTS guidelines alongside an analysis of existing literature to shed light on the spectrum of revascularization methods. While both CABG and PCI demonstrate promising outcomes, the optimal choice between the two hinges on a comprehensive assessment of individual patient factors, anatomical complexity guided by advanced imaging, comorbidities, and age. The determination of whether to pursue culprit or total revascularization, as well as immediate or staged revascularization, is contingent upon various factors, including age, disease complexity, and clinical outcomes. This evidence-based decision-making process is orchestrated by a multidisciplinary heart team grounded in ongoing clinical evaluation. The primary objective of this review is to provide valuable insights into revascularization strategies and scrutinize the congruence of current guidelines with recent advancements in the field.

Design of percutaneous transluminal coronary angioplasty balloon catheters

BACKGROUND

Eight commercially available percutaneous transluminal coronary angioplasty (PTCA), including semi-compliant and non-compliant balloons, have been assessed in detail on their tip, balloon, shaft, RX-Port, and hypotube design. Important performance characteristics such as tip deformation, balloon elongation, and deflation rate have been quantified.

METHODS

Five catheters of each model were evaluated during various tests. The robustness of the tips was evaluated through compression, measuring any occurrence of damage. The longitudinal growth of the balloons was recorded during inflation up to Rated Burst Pressure (RBP). The forces required to move the catheter forward and retract it into the guide catheter were measured in a simulated use test setup. The deflation behavior was studied by measuring extracted contrast media over time. Furthermore, balloon compliance and catheter dimensions were investigated.

RESULTS

The outer dimensions of the catheter were found to be smallest at the hypotube (0.59-0.69 mm) and highest at the balloon, respectively, the crossing profile (0.9-1.2 mm). The tip diameter increased after compression by 1.7-22%. Cross-sections of the folded balloons revealed a tri- and two-fold, respectively. The measured balloon elongation ranged from 0.6 to 2.0 mm. After the inflation of the balloon, an increase in friction between the guide wire and the catheter was observed on four catheters. A maximum increase of 0.12 N to 1.07 N was found. Cross-sections of the RX-Port revealed a semicircular-shaped inflation lumen and a circular guide wire lumen. The measured deflation rate ranged from 0.004 to 0.013 µL/s, resulting in an estimated balloon deflation time of 10.2-28.1 s.

CONCLUSION

This study provides valuable insights into the design characteristics of RX PTCA balloon catheters, which can contribute to facilitating the development of improved catheter designs and enhancing clinical outcomes. Distinctions between SC and NC catheters, such as balloon performance and dimensions, are evident. It is important to note that no single catheter excels in all aspects, as each possesses unique strengths. Therefore, it is essential to consider individual intervention requirements when selecting a catheter. The research also identifies specific catheter weaknesses, such as reduced wall thickness, fringes at the tip, and reduced performance characteristics.

Balloon rupture with eversion during innominate vein angioplasty requiring surgical retrieval

Balloon rupture during angioplasty can with calcified or recalcitrant lesions. A 61-year-old woman presented with worsening arm and facial swelling. She had a history of left upper extremity thrombolysis and stenting of the innominate vein 6 years prior. Venography showed severe in-stent stenosis. After crossing the lesion, a 12-mm balloon was inflated, which ruptured at nominal pressure. The balloon became stuck and could not be moved over the wire even after retraction of the sheath. A limited surgical cutdown was performed, and the balloon and the wire were removed together. The ruptured balloon part was found to be everted and circumferentially wrapped around the wire, preventing the wire exchange. After cutting the everted portion of the balloon, the catheter was removed without losing wire access. A high-pressure balloon was subsequently used to treat the lesion successfully. Her symptoms had resolved on follow-up, and the stent remained patent after 6 months.

Selection criteria in the era of perfect competition for drug-eluting stents - a survey of interventional cardiologists in Japan: the selection-DES study

BACKGROUND

More than 20 years have passed since the first company introduced drug-eluting stent (DES) in 2002, but competing companies still have improved their DESs under regulatory approval. This study aimed to investigate the criteria for interventional cardiologists performing percutaneous coronary intervention (PCI) in selecting a DES.

RESEARCH DESIGN AND METHODS

From 10 April 2023, to 30 April 2023, 3,422 cardiologists were requested to complete a questionnaire, of whom 126 responded to the survey.

RESULTS

Overall, 86.5% of the respondents used Xience cobalt-chromium everolimus-eluting stent (Xience) in > 10% of PCI procedures. For Xience, brand loyalty and calcified lesions were important independent variables for the DES selection criteria. Ultimaster sirolimus-eluting stent (Ultimaster) was not affected by the clinical data delivered by the company, whereas the respondents were shown to seek support for their activities from the Ultimaster supplier. The relationship with the company and/or sales representative and the planned surgical procedure affected the use of Coroflex ISAR NEO sirolimus-eluting polymer-free stent.

CONCLUSIONS

Patient background and lesion characteristics had little impact on the DES selection criteria, suggesting that DES performance has already reached its physical limitations to the extent that respondents may not value further improvements in performance or characteristics of DES.

Choosing the right treatment for the right lesion, part I: a narrative review of the role of plain balloon angioplasty in dialysis access maintenance

Background and Objective

The majority of patients with end-stage renal disease (ESRD) requiring hemodialysis (HD) do so via an arteriovenous fistula (AVF) or graft. Both of these accesses are complicated by dysfunction related to neointimal hyperplasia (NIH) and subsequent stenosis. Percutaneous balloon angioplasty using plain balloons is the first line treatment for clinically-significant stenosis, with excellent initial response rates, however, with poor long-term patency and need for frequent reintervention. Recent research has sought to improve patency rates utilizing antiproliferative drug-coated balloons (DCBs), however, their role in treatment has not yet been fully determined. In part one of this two-part review, we aim to provide a comprehensive overview of the mechanisms of arteriovenous (AV) access stenosis, the evidence behind their treatment with high-quality plain balloon angioplasty techniques, and treatment considerations for specific stenotic lesions.

Methods

An electronic search was performed on PubMed and EMBASE to identify relevant articles from 1980 to 2022. The highest available level of evidence regarding stenosis pathophysiology, angioplasty techniques, and approaches to treating different types of lesions within fistulas and grafts were included as part of this narrative review.

Key Content and Findings

NIH, and subsequent stenoses, develop via a combination of upstream events, causing vascular damage, and downstream events, representing the subsequent biologic response. The large majority of stenotic lesions can be treated utilizing high-pressure balloon angioplasty, with the addition of ultra-high pressure balloon (UHPB) angioplasty for resistant lesions and prolonged angioplasty with progressive balloon upsizing for elastic lesions. Additional treatment considerations must be taken into account when treating specific lesions, including cephalic arch and swing point stenoses in fistulas and graft-vein anastomotic stenoses in grafts, amongst others.

Conclusions

High-quality plain balloon angioplasty, performed utilizing the available evidence-basis regarding technique and considerations for specific lesion locations, is successful in treating the large majority of AV access stenoses. While initially successful, patency rates remain non-durable. Part two of this review will discuss the evolving role of DCBs, which seek to improve angioplasty outcomes.

Transformation of the Cardiovascular Clinics in Japan - How to Overcome Crisis Due to Changes in the External Environment

The first percutaneous coronary intervention (PCI) was performed in September 1977, and after 1980 this minimally invasive treatment was established in Japan. To deliver this treatment to a larger population, a number of cardiovascular clinics emerged across the country in the 2000s, and the number of PCI cases performed has been steadily increasing, to >250,000 cases per year. In the early 2000s, a single catheterization unit was profitable, if it performed a certain number of treatments and was adequately staffed without excessive capital investment. In the late 1990s, the price of a balloon catheter medical device used for PCI was approximately JPY300,000, although the price was reduced to JPY32,000, almost one-tenth in price, in the April 2022 revision of the National Health Insurance. The reimbursement of the mainstream drug-eluting stent has also decreased from JPY421,000, when it was first introduced, to JPY136,000 currently. In addition, the consumption tax and reforms in working hours will have a major impact on clinic management. We present a history of cardiovascular clinics in Japan and their present and future positions under the variable external environment.

Clinical Outcomes of a Non-Compliant Balloon Dilatation Catheter: MOZEC™ NC Study

The present study sought to assess the clinical outcomes of the Mozec™ Non-compliant (NC) Rx PTCA balloon dilatation catheter (BDC) (Meril Life Sciences Pvt. Ltd., Vapi, India) for dilatation of coronary lesions. This was a post-marketing, single-centre, single-arm, retrospective study. In total, 57 patients who had undergone post-dilatation with the Mozec™ NC Rx PTCA balloon dilatation catheter were evaluated. The primary endpoint was procedural success defined as (i) successful delivery of the investigational device to and across the target lesion; (ii) successful inflation, deflation, and withdrawal of the investigational device; (iii) absence of vessel perforation, flow-limiting vessel dissection, increase in thrombolysis in myocardial infarction (TIMI) flow from baseline, clinically significant arrhythmia requiring medical treatment; and (iv) achievement of final TIMI flow grade 3 after percutaneous coronary intervention of the target lesion after single or multiple attempts to cross the target lesion. Procedural success was achieved in 57 (100%) patients. There were no incidences of major adverse cardiac events (MACE)/target lesion failure (TLF). Mozec™ NC Rx PTCA balloon dilatation catheter has demonstrated favourable outcomes for the dilatation of routine and complex coronary lesions in a small cohort, as evidenced by its 100% procedural success rate and absence of MACE.

Development of Innovative Biomaterials and Devices for the Treatment of Cardiovascular Diseases

Cardiovascular diseases have become the leading cause of death worldwide. The increasing burden of cardiovascular diseases has become a major public health problem and how to carry out efficient and reliable treatment of cardiovascular diseases has become an urgent global problem to be solved. Recently, implantable biomaterials and devices, especially minimally invasive interventional ones, such as vascular stents, artificial heart valves, bioprosthetic cardiac occluders, artificial graft cardiac patches, atrial shunts, and injectable hydrogels against heart failure, have become the most effective means in the treatment of cardiovascular diseases. Herein, an overview of the challenges and research frontier of innovative biomaterials and devices for the treatment of cardiovascular diseases is provided, and their future development directions are discussed.

Development of Biodegradable Polymeric Stents for the Treatment of Cardiovascular Diseases

Cardiovascular disease has become the leading cause of death. A vascular stent is an effective means for the treatment of cardiovascular diseases. In recent years, biodegradable polymeric vascular stents have been widely investigated by researchers because of its degradability and clinical application potential for cardiovascular disease treatment. Compared to non-biodegradable stents, these stents are designed to degrade after vascular healing, leaving regenerated healthy arteries. This article reviews and summarizes the recent advanced methods for fabricating biodegradable polymeric stents, including injection molding, weaving, 3D printing, and laser cutting. Besides, the functional modification of biodegradable polymeric stents is also introduced, including visualization, anti-thrombus, endothelialization, and anti-inflammation. In the end, the challenges and future perspectives of biodegradable polymeric stents were discussed.

Evolution of drug-eluting coronary stents: a back-and-forth journey from the bench-to-bedside

Coronary stents have revolutionized the treatment of coronary artery disease. Compared with balloon angioplasty, bare-metal stents effectively prevented abrupt vessel closure but were limited by in-stent restenosis due to smooth muscle cell proliferation and neointimal hyperplasia. The first-generation drug-eluting stent (DES), with its antiproliferative drug coating, offered substantial advantages over bare-metal stents as it mitigated the risk of in-stent restenosis. Nonetheless, they had several design limitations that increased the risk of late stent thrombosis. Significant advances in stent design, including thinner struts, enhanced polymers' formulation, and more potent antiproliferative agents, have led to the introduction of new-generation DES with a superior safety profile. Cardiologists have over 20 different DES types to choose from, each with its unique features and characteristics. This review highlights the evolution of stent design and summarizes the clinical data on the different stent types. We conclude by discussing the clinical implications of stent design in high-risk subsets of patients.

Efficacy and Safety of a Polytetrafluoroethylene Membrane Wrapped a Single Layer of Sirolimus-Eluting Stent in a Porcine Coronary Perforation Model

Background

Covered stents are effective in treating coronary artery perforation (CAP), however, the high rate of immediate device deployment failure and in-stent restenosis have limited the application of the currently covered stents.

Methods

We designed a covered stent system consisting of a single layer of drug-eluting stent and a layer of polytetrafluoroethylene (PTFE) membrane wrapped at the outer layer of the stent. The immediate sealing effect of our novel covered stent was observed by using an Ellis type III CAP model. The device's success was defined as its ability to seal the perforation, assessed by visual estimation and final thrombolysis in myocardial infarction (TIMI) 3 flow. The antiproliferative effect was evaluated in 12 swine, which were randomly assigned to treatment (sirolimus-eluting covered stents) and control (bare metal covered stents) groups. Coronary angiography and optical coherence tomography (OCT) were performed at index procedure, 1- and 6-month after stent implantation. All swine were sacrificed for histopathological analyses at 6-month.

Results

The device success rate was 100%. All swine were alive at 6-month follow-up. At 1-month, the treatment group had a larger minimal luminal diameter (MLD) (1.89 ± 0.29 mm vs. 0.63 ± 0.65 mm, p = 0.004) and lower late luminal loss (LLL) (0.47 ± 0.15 mm vs. 1.80 ± 0.34 mm, p < 0.001) compared with control group. At 6-month, the treatment group had a numerically higher MLD (0.94 ± 0.75 mm vs. 0.26 ± 0.46 mm; p = 0.230) and lower LLL (1.43 ± 0.85 mm vs. 2.17 ± 0.28 mm; p = 0.215) compared with control group. Histological analyses revealed the mean plaque area was lower in the treatment group (2.99 ± 0.81 mm 2 vs. 4.29 ± 0.77 mm 2 , p = 0.035) than in the control group. No in-stent thrombosis was observed in either group.

Conclusions

In the porcine model of coronary perforation, the PTFE membrane wrapped sirolimus-eluting stent showed a high device success rate in sealing the perforation. The drug-eluting covered stent demonstrated a relatively sustained antiproliferative effect up to 6 months post-implantation.

Catheter based interventions for lower extremity peripheral artery disease

The field of peripheral arterial intervention has exploded over the past 20 years. Current knowledge includes a growing evidence base for treatment as well as a myriad of new interventional approaches to complex disease. This review seeks to outline the current state of the art for interventional approaches to lower extremity peripheral arterial disease.

Temperature-dependent tensile properties of polyamide 12 for the use in percutaneous transluminal coronary angioplasty balloon catheters

BACKGROUND

Percutaneous transluminal coronary angioplasty (PTCA) balloon catheters must withstand high pressures required for the lesion treatment, pushing loads during insertion, and pulling loads during withdrawal. These loads pose a challenge especially for polymeric tubular shafts with small cross sections. In order to enable new design innovations and to better understand the mechanics of current catheter technologies, the tensile properties of polyamide (PA) 12 were investigated. PA 12 dog bone specimens and medical PA 12 tubes were either stored at ambient temperature and humidity or conditioned in water, and subjected to tensile loads at different temperatures. In addition, the effect on the tensile properties of the necking process, a forming process to reduce the wall thickness of the tubes, was determined.

RESULTS

The tested tubes showed a reduction in both Young's Modulus (- 41.5%) and yield stress (- 29.2%) compared to standardized specimens. Furthermore, an increase in temperature and water absorption softens the material and reduces the mechanical properties like the Young's Modulus and the yield stress. It was found that the material strengthens during the necking process. Likely due to the orientation of the polymers chain molecules in load direction (Rösler et al., 2007), the Young's Modulus of the material could be increased by 43.5%. Furthermore, the absence of a yield point after necking allows for a greater loading capacity of the material without unstable neck growth. Besides the strengthening, the ultimate strain is reduced by 50%. This indicates that the necking process induces plastic deformation.

CONCLUSION

The investigation showed that the environmental conditions like temperature and humidity can influence mechanical properties. It could also be shown that pre-forming processes such as necking can enhance the mechanical properties, such as the Young's Modulus, while reducing the wall thickness. These findings suggest possible further development of catheters with a small cross section and higher mechanical strength and highlight the importance to account for the targeted operating temperature during the design process.

United States Investigational Device Exemption study of the Revolution™ Peripheral Atherectomy System

OBJECTIVE

Atherectomy has become commonplace as an adjunct to interventional treatments for peripheral arterial disease, but the procedures have been complicated by risks including distal embolization and arterial perforation. This study aimed to examine the safety and effectiveness of a novel atherectomy system to treat femoropopliteal and below-knee peripheral arterial disease.

METHODS

The Revolution Peripheral Atherectomy System (Rex Medical LP, Conshohocken, Pa) was studied in 121 patients with 148 femoropopliteal and below-knee lesions, enrolled at 17 United States institutions. Technical success was defined when the post-atherectomy angiographic stenosis was ≤50%, as assessed by an independent core laboratory. Major adverse events were adjudicated by an independent Clinical Events Committee.

RESULTS

Among 148 site-identified target lesions in 121 patients, 21.4% were in the superficial femoral artery, 13.7% involved the popliteal artery, and 67.9% were in tibial arteries; 3.1% involved more than one segment. Technical success was 90.2%, with stenoses decreasing from 73% ± 19% at baseline to 42% ± 14% after atherectomy. Adjunctive treatment after atherectomy included angioplasty with uncoated balloons in 91%, drug-coated balloons in 11%, bare stent deployment in 8%, and drug-eluting stent placement in 3%. Procedural success (<30% residual stenosis) was achieved in 93.7% of target lesions. Complications during the procedure included one target vessel perforation and two distal embolizations; each of which were adjudicated by the Clinical Events Committee as unrelated to the device and were not visualized angiographically by the core laboratory. Freedom from major adverse events was 97.3% through 30 days. The Kaplan-Meier estimates of primary, assisted primary, and secondary patency were 81.6%, 87.7%, and 91.6% at 6 months, respectively.

CONCLUSIONS

The use of the Revolution Peripheral Atherectomy System was associated with few procedural complications and a high rate of success at the index procedure and through 6 months.

Implications of the Landmark ISCHEMIA Trial on the Initial Management of High-Risk Patients with Stable Ischemic Heart Disease

PURPOSE OF THE REVIEW

In the decades following the advent of percutaneous coronary intervention, the optimal treatment strategy for managing stable ischemic heart disease has remained a topic of debate. The purpose of this review is to discuss current literature that provides insight into preferred treatment strategies for managing stable coronary artery disease.

RECENT FINDINGS

The COURAGE trial (2007) compared patients with stable coronary artery disease treated with percutaneous coronary intervention plus optimal medical therapy versus optimal medical therapy alone and found no difference in death from any cause and non-fatal myocardial infarction at 4.6 years. The more recent ISCHEMIA trial (2020) compared an initial invasive revascularization strategy with optimal medical therapy to optimal medical therapy alone and similarly found no difference in death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest at 5 years. When applied to a broad population with stable coronary artery disease, evidence suggests there is no benefit to an initial invasive revascularization strategy relative to optimal medical therapy alone. Further investigation is warranted to determine whether there are subgroups of individuals that may benefit from earlier revascularization.

Medical Journals Should Be a Forum for Disruptive Research

Disruptive innovation completely changes the traditional way that we operate and may only be realized in retrospect. For example, shoulder superior capsule reconstruction (SCR) is a complete change from the traditional methods of treating massive, irreparable rotator cuff tears and pseudoparalysis. Classic examples of disruptions in orthopaedic surgery include distraction osteogenesis, total hip joint replacement arthroplasty, and modern orthopaedic trauma care. Orthopaedic technologies that promise future disruption include artificial intelligence, surgical simulation, and orthopaedic biologics, including mesenchymal stromal cell (MSC) and gene therapy. Most of all, arthroscopic surgery completely changed the way we operate by using new methods and technology. Many never saw it coming. The challenge going forward is to motivate and foster new ideas and research that result in innovation and progress. Skepticism has a place, but not at the expense of transformative ideas, particularly as medical journals offer the alternative of prospective hypothesis testing using the scientific method, followed by unbiased peer review, and publication. Medical journals should be a forum for disruptive research.

OCT Findings in MINOCA

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a working diagnosis for patients presenting with acute myocardial infarction without obstructive coronary artery disease on coronary angiography. It is a heterogenous entity with a number of possible etiologies that can be determined through the use of appropriate diagnostic algorithms. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection, coronary artery spasm, and coronary thromboembolism. Optical coherence tomography (OCT) is an intravascular imaging modality which allows the differentiation of coronary tissue morphological characteristics including the identification of thin cap fibroatheroma and the differentiation between plaque rupture or erosion, due to its high resolution. In this narrative review we will discuss the role of OCT in patients presenting with MINOCA. In this group of patients OCT has been shown to reveal abnormal findings in almost half of the cases. Moreover, combining OCT with cardiac magnetic resonance (CMR) was shown to allow the identification of most of the underlying mechanisms of MINOCA. Hence, it is recommended that both OCT and CMR can be used in patients with a working diagnosis of MINOCA. Well-designed prospective studies are needed in order to gain a better understanding of this condition and to provide optimal management while reducing morbidity and mortality in that subset patients.

Who is who in cardiovascular research? What a review of Nobel Prize nominations reveals about scientific trends

Background

Since 1901, at least 15 scholars who contributed to cardiovascular research have received a Nobel prize in physiology or medicine.

Methods

Using the Nobel nomination database (nobelprize.org), which contains 5950 nominations in the accessible period from 1901 to 1953 in physiology or medicine, we listed all international nominees who contributed to cardiovascular research. We subsequently collected nomination letters and jury reports of the prime candidates from the archive of the Nobel Committee in Sweden to identify shortlisted candidates.

Results

The five most frequently nominated researchers with cardiovascular connections from 1901 to 1953 were, in descending order, the surgeon René Leriche (1879–1955) (FR) with a total of 79 nominations, the physiologist and 1924 Nobel laureate Willem Einthoven (1860–1927) (NL) (31 nominations), the surgeon Alfred Blalock (1899–1964) (US) (29 nominations), the pharmacologist and 1936 Nobel laureate Otto Loewi (1873–1961) (DE, AT, US) (27 nominations) and the paediatric cardiologist Helen Taussig (1898–1986) (US) (24 nominations). The research of these scholars merely hints at the width of topics brought up by nominators ranging from the physiological and pathological basics to the diagnosis and (surgical) interventions of diseases such as heart malformation or hypertension.

Conclusion

We argue that an analysis of Nobel Prize nominations can reconstruct important scientific trends within cardiovascular research during the first half of the twentieth century.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01813-2.

Predictor of in-stent restenosis in patients with drug-eluting stent (PRIDE)- a retrospective cohort study

BACKGROUND

It is a fact that coronary artery disease (CAD) is more prevalent in India as compared to western countries. The major risk factors associated with the early CAD are a high prevalence of diabetes mellitus, atherogenic lipid profile, smoking habits, sedentary lifestyle, low socioeconomic condition and high prevalence of obesity. Is this true for restenosis after drug-eluting stent (DES) implantation and factors associated with it? The main objective of the study was to determine the rate of in-stent restenosis (ISR) in patients with DES and risk factors associated with it from our region.

METHODS

It was a single-center, retrospective cohort study in which 550 patients who underwent DES implantation were included. Patient's demographic data, coronary angiography findings, procedural characteristics and development of ISR were noted.

RESULTS

Out of 550 patients, 31 developed ISR with a rate of restenosis of 5.63% and target lesion revascularization (TLR) of 5.63%. On multiple Cox-regression analysis, only diabetes mellitus (DM) (p=0.008, adjusted hazard ratio (HR): 2.757, 95% confidence interval (CI): 1.296-5.863), deployment of stent in the left anterior descending (LAD) artery (p=0.031, adjusted HR: 3.342, 95% CI: 1.115-10.017) and periprocedural complication during percutaneous coronary intervention (p=0.040, adjusted HR: 2.824, 95% CI: 1.049-7.603) were found to be significantly associated with increased risk of ISR. Kaplan-Meier survival analysis of event-free survival for restenosis showed patients with DM had significantly lower event-free survival compared to patients without DM (p=0.005 by log-rank test).

CONCLUSIONS

In our study, the rate of restenosis after DES implantation was 5.63%. The presence of DM, the stent in the LAD territory and the periprocedural complication is strongly associated with the development of ISR.

The impact of advances in percutaneous catheter interventions on redo cardiac surgery

Toward the end of the twentieth century, redo cardiac surgery accounted for approximately 15-20% of total cardiac surgical volume. Major risk factors for redo cardiac surgery include young age at time of the first operation, progression of native coronary artery disease (CAD), vein graft atherosclerosis, bioprosthetic valve failure and endocarditis, and transplantation for end stage heart failure. Historically, redo coronary artery bypass grafting (CABG) alone carried a mortality risk of around 4%. Factors such as older age, female sex, comorbidities, combined procedures, hemodynamic instability, and emergency procedures contributed to even higher mortality and morbidity. These poor outcomes made it necessary to look for less invasive alternate methods of treatment. Advances in catheter-based interventions have made a major impact on redo cardiac surgeries, making it no longer the first option in a majority of cases. Percutaneous interventions for recurrence following CABG, transcutaneous aortic valve replacement (TAVR) for calcific aortic stenosis, valve in valve (VIV) implantations, device closure of paravalvular leaks (PVL), and thoracic endovascular aortic repair (TEVAR) for residual and recurrent aneurysms and mitral clip to correct mitral regurgitation (MR) in heart failure are rapidly developing or developed, obviating the need for redo cardiac surgery. Our intent is to review these advances and their impact on redo cardiac surgery.

The Biolimus A9-coated BioFreedom™ stent: from clinical efficacy to real-world evidence

In this state-of-the-art review, we present the findings and a critical analysis of the Leaders Free trial program, evaluating outcomes of a new stent-generation based on polymer-free technology, in this case the BioFreedom^™ (Biosensors Europe, Switzerland), in patients at high bleeding risk (HBR). Polymer-free drug-coated stents were designed to obtain a device with the antirestenotic benefits of drug-eluting stents but without the polymer coating as potential trigger for delayed arterial wall healing and subsequent late ischemic adverse events, causing a prolonged dependence on dual antiplatelet therapy after stenting. This offers therefore the potential of a promising device-based strategy in a complex growing population of patients with combined HBR and high thrombosis risk, due to the possible reduction of antithrombotic duration.

Advances in IVUS/OCT and Future Clinical Perspective of Novel Hybrid Catheter System in Coronary Imaging

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed and improved as both diagnostic and guidance tools for interventional procedures over the past three decades. IVUS has a resolution of 100 μm with a high tissue penetration and capability of assessing the entire structure of a coronary artery including the external elastic membrane, whereas OCT has a higher resolution of 10–20 μm to assess endoluminal structures with a limited tissue penetration compared to IVUS. Recently, two companies, CONAVI and TERUMO, integrated IVUS and OCT into a single catheter system. With their inherent strength and limitations, the combined IVUS and OCT probes are complementary and work synergistically to enable a comprehensive depiction of coronary artery. In this review, we summarize the performance of the two intracoronary imaging modalities—IVUS and OCT—and discuss the expected potential of the novel hybrid IVUS–OCT catheter system in the clinical field.

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.

Endothelin: 30 Years From Discovery to Therapy

Discovered in 1987 as a potent endothelial cell-derived vasoconstrictor peptide, endothelin-1 (ET-1), the predominant member of the endothelin peptide family, is now recognized as a multifunctional peptide with cytokine-like activity contributing to almost all aspects of physiology and cell function. More than 30 000 scientific articles on endothelin were published over the past 3 decades, leading to the development and subsequent regulatory approval of a new class of therapeutics-the endothelin receptor antagonists (ERAs). This article reviews the history of the discovery of endothelin and its role in genetics, physiology, and disease. Here, we summarize the main clinical trials using ERAs and discuss the role of endothelin in cardiovascular diseases such as arterial hypertension, preecclampsia, coronary atherosclerosis, myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) caused by spontaneous coronary artery dissection (SCAD), Takotsubo syndrome, and heart failure. We also discuss how endothelins contributes to diabetic kidney disease and focal segmental glomerulosclerosis, pulmonary arterial hypertension, as well as cancer, immune disorders, and allograft rejection (which all involve ET_A autoantibodies), and neurological diseases. The application of ERAs, dual endothelin receptor/angiotensin receptor antagonists (DARAs), selective ET_B agonists, novel biologics such as receptor-targeting antibodies, or immunization against ET_A receptors holds the potential to slow the progression or even reverse chronic noncommunicable diseases. Future clinical studies will show whether targeting endothelin receptors can prevent or reduce disability from disease and improve clinical outcome, quality of life, and survival in patients.

Transradial approach for coronary angiography and percutaneos coronary intervention: personal experience

BACKGROUND

The transradial approach (TRA) has already become popular worldwide, but only recently has gained acceptance among Iraqi interventional cardiologists. The aim of this study is to document single operator experience with TRA and to test the benefit of assessing dual hand circulation before the TRA. It was an observational prospective study. Over a 2-year period (Jan 1, 2015, to Dec 31, 2016), 1561 patients underwent transradial coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) by a single operator. Patients were divided into two groups: A (the first 450 patients), in which dual hand circulation was assessed by Allen's test or plethysmography/oximetry test before TRA, and B (1111 patients) in which TRA was done without assessing dual hand circulation.

RESULTS

A total of 1561 patients were included, 69.1% males and 30.9% females. The mean age was (57 ± 10.0) years. We performed 1684 procedures (1005 CAG and 679 PCIs). The total transradial success rate was 95.6%, and PCI procedural success rate was 96.5%. The crossover rate from radial to femoral access was 4.4%. The primary causes for crossover were severe tortuosity of the aorta and brachiocephalic trunk, radial artery spasm, puncture failure, and radial loop. The main complication was radial artery occlusion (RAO) (3.7%). There were no cases of hand ischemia or complications that need surgical repair or blood transfusion. No statistically significant difference between groups A and B was observed regarding hand ischemia, the incidence of RAO, or the crossover rate.

CONCLUSIONS

TRA is safe and can be applied in the majority of cases. The routine assessment of dual hand circulation before TRA might not be necessary.

Endovascular treatment of femoro-popliteal lesions

Peripheral artery disease (PAD) is a major health concern affecting more than 200 million people worldwide and studies have shown PAD to be a strong predictor of mortality, morbidity, and disability. The management of PAD is multi-tiered and advancements in technology have given physicians more options for endovascular revascularization if medical therapy does not result in substantial improvement. Many randomized controlled trials have reported efficacy of various therapies including laser atherectomy, stent technology, and drug-coated balloons over standard percutaneous transluminal angioplasty; however, uncertainty regarding the best standard of care remains unclear because of a lack of head to head comparisons between novel therapies. Furthermore, variability in the reported clinical outcomes exists and makes it difficult to evaluate the superiority of any specific treatment modality, especially for functional capacity and quality of life. Recently established consensus definitions for clinical outcomes coupled with investigators incorporating direct comparisons within clinical trials will be crucial to establish consistent care and meaningful gain in treatment for these patients. This review will highlight the treatment modalities, literature supporting each treatment modality, and insight into why they are being used and why variation exists around the United States.

Applications and challenges of using 3D printed implants for the treatment of birth defects

Pediatric implants are a special subclass of a vast number of clinically used medical implants, uniquely designed to address the needs of young patients who are at the onset of their developmental growth stage. Given the vulnerability of the implant receiver, it is crucial that the implants manufactured for small children with birth-associated defects be given careful considerations and great attention to design detail to avoid postoperative complications. In this review, we focus on the most common types of medical implants manufactured for the treatment of birth defects originating from both genetic and environmental causes. Particular emphasis is devoted toward identifying the implant material of choice and manufacturing approaches for the fabrication of pediatric prostheses. Along this line, the emerging role of 3D printing to enable customized implants for infants with congenital disorders is presented, as well as the possible complications associated with prosthetic-related infections that is prevalent in using artificial implants for the treatment of birth malformations.

Percutaneous Coronary Intervention in the Elderly: Are Drug-coated Balloons the Future?

Background:

Balloon angioplasty revolutionised percutaneous treatment for coronary ar-tery disease four decades ago, but vessel-threatening dissections, elastic recoil and restenosis were major drawbacks to an otherwise successful long-lasting intervention. Subsequent advances with bare metal stents and then drug eluting stents followed, aiming to mitigate the risks of acute vessel closure and restenosis. However, stent implantation often necessitates dual antiplatelet therapy for a pro-longed period of time, which in itself can lead to adverse outcomes, especially in the frail elderly pop-ulation at higher risk of bleeding. More recently, bioabsorbable stents have been implemented in clini-cal practice enabling earlier intimal coverage of the stent and apposition.

However, another addition to the armamentarium of percutaneous coronary intervention is the use of drug-coated balloons without the need for deploying any coronary stents or scaffolds. Drug-coated balloons are semi-compliant balloons coated with an antiproliferative agent that is rapidly released on contact with the vessel intima exerting an anti-restenotic effect. The absence of a metallic scaffold means that the need for antiplatelet therapy can potentially be negated in the longer term if required. In this article, we will review the history of percutaneous coronary intervention and the available evi-dence for the appropriate use of drug-coated balloons especially in the elderly population.

Conclusion:

We will conclude this review by demonstrating the potential use of drug-coated balloon rather percutaneous stenting through case examples.

Drug-eluting balloon: design, technology and clinical aspects

A drug-eluting balloon is a non-stent technology in which the effective homogenous delivery of anti-proliferative drugs is processed by the vessel wall through an inflated balloon. This is done to restore luminal vascularity in order to treat atherosclerosis, in-stent restenosis and reduce the risk of late thrombosis without implanting a permanent foreign object. The balloon technology relies on the concept of targeted drug delivery, which helps in the rapid healing of the vessel wall and prevents the proliferation of smooth muscle cells. Several drug eluting devices in the form of coated balloons are currently in clinical use, namely DIOR^®, PACCOCATH^®, SeQuent^®Please and IN.PACT™. The device varies in terms of the material used for making the balloon, the coating techniques, the choice of coated drug and the release pattern of the drug at the site. This review gives an insight into the evolution, rationale and comparison of the marketed drug-eluting balloons. Here, different coating techniques have been analysed for the application and critical analysis of available DEB technologies, and a technical comparison has been done.

Twenty years of the G protein-coupled estrogen receptor GPER: Historical and personal perspectives

Estrogens play a critical role in many aspects of physiology, particularly female reproductive function, but also in pathophysiology, and are associated with protection from numerous diseases in premenopausal women. Steroids and the effects of estrogen have been known for ∼90 years, with the first evidence for a receptor for estrogen presented ∼50 years ago. The original ancestral steroid receptor, extending back into evolution more than 500 million years, was likely an estrogen receptor, whereas G protein-coupled receptors (GPCRs) trace their origins back into history more than one billion years. The classical estrogen receptors (ERα and ERβ) are ligand-activated transcription factors that confer estrogen sensitivity upon many genes. It was soon apparent that these, or novel receptors may also be responsible for the "rapid"/"non-genomic" membrane-associated effects of estrogen. The identification of an orphan GPCR (GPR30, published in 1996) opened a new field of research with the description in 2000 that GPR30 expression is required for rapid estrogen signaling. In 2005-2006, the field was greatly stimulated by two studies that described the binding of estrogen to GPR30-expressing cell membranes, followed by the identification of a GPR30-selective agonist (that lacked binding and activity towards ERα and ERβ). Renamed GPER (G protein-coupled estrogen receptor) by IUPHAR in 2007, the total number of articles in PubMed related to this receptor recently surpassed 1000. In this article, the authors present personal perspectives on how they became involved in the discovery and/or advancement of GPER research. These areas include non-genomic effects on vascular tone, receptor cloning, molecular and cellular biology, signal transduction mechanisms and pharmacology of GPER, highlighting the roles of GPER and GPER-selective compounds in diseases such as obesity, diabetes, and cancer and the obligatory role of GPER in propagating cardiovascular aging, arterial hypertension and heart failure through the stimulation of Nox expression.

The future of interventional and neurointerventional radiology: learning lessons from the past

The rapid progression of medical imaging technology and the ability to leverage knowledge from non-invasive imaging means that Interventional Radiologists (IRs) and Interventional Neuroradiologists are optimally placed to incorporate minimally invasive interventional paradigms into clinical management to advance patient care. There is ample opportunity to radically change the management options for patients with a variety of diseases through the use of minimally invasive interventional procedures. However, this will need to be accompanied by an increased clinical role of IRs to become active partners in the clinical management of patients. Unfortunately, the development of IR clinical presence has lagged behind and is reflected by declining rates of IR involvement in certain areas of practice such as vascular interventions. Current and future IRs must be willing to take on clinical responsibilities; reviewing patients in clinic to determine suitability for a procedure and potential contraindications, rounding on hospital inpatients and be willing to manage procedure related complications, which are all important parts of a successful IR practice. Increasing our clinical presence has several advantages over the procedure-driven model including enhanced patient knowledge and informed consent for IR procedures, improved rapport with patients and other clinical colleagues through active participation and engagement in patient care, visibility as a means to facilitate referrals and consistency of follow-up with opportunities for further learning. Many of the solutions to these problems are already in progress and the use of IR as a "hired gun" or "technician" is a concept that should be relegated to the past, and replaced with recognition of IRs as clinicians and partners in delivering modern high quality multidisciplinary team-based patient care. The following article will review the history of IR, the challenges facing this rapidly evolving profession and discuss recent developments occurring globally that are essential in maintaining expertise, securing future growth and improving patient outcomes in the modern multidisciplinary practice of medicine.

Transradial vs. Transfemoral Approach in Cardiac Catheterization: A Literature Review

The main objective of this review paper is to study the comparison between transradial and transfemoral approach in catheterization. Transradial and transfemoral are two main approaches which are used as a diagnostic and therapeutic purpose in catheterization. The transradial approach in interventional cardiology is safe, effective, and feasible as compared to the transfemoral approach. The aim of this study is to compare pros and cons of transradial vs. transfemoral approach in catheterization.

We conducted this systematic review on the role of transradial vs. transfemoral catheterization. The articles included real human data on interventional approaches. Reviews on these strategies were conducted in PubMed, medical literature analysis and retrieval system online (MEDLINE), Cochrane, Medscape and National Institute of Health. To maintain a high standard of review, studies published in all non-famous journals were excluded.

Data collected from the studies have suggested that transradial approach has less bleeding complications, cost effective, decreased hospital mortality rate, and less access site complications as compared to transfemoral approach. However, longer procedural duration and radiation exposure are still concerns regarding transradial approach.

The findings of the present study show that transradial approach in catheterization is safe, effective, and feasible as compared to the transfemoral approach. However, duration and radiation exposure are higher in the transradial access. Several studies suggest that the modern approach overweight in benefits with the comparison to the classical approach.

Fractional flow reserve in 2017: current data and everyday practice

INTRODUCTION

Fractional flow reserve (FFR) is an objective physiological index utilized in coronary angiography. It expresses the blood flow in the presence of a coronary artery stenosis as a fraction of the normal blood flow and gives information regarding the functional significance of the lesion. FFR guided percutaneous coronary intervention (PCI) has been shown to be superior to angiography guided PCI in several trials and registries. In addition, it appears that the use of FFR may also be preferable from an economic perspective. Areas covered: This article will cover the physiological principles underpinning FFR, the landmark clinical trials that have established its diagnostic utility and the current recommendations for the use of the procedure in daily practice. We will also examine potential future directions for the technology and try to predict how its use will evolve in the next five years. Expert commentary: We see FFR as an essential diagnostic tool in the modern catheterization laboratory, enabling physicians to make optimal decisions regarding percutaneous coronary intervention for an individual patient. It must be stated however that FFR is an adjunctive invasive functional tool that must be used in conjunction with sensible clinical history and exam findings pertaining to the individual patient. We expect that the results of FAME3 will further establish the role of FFR in risk stratifying patients with 3 vessel disease by utilizing a functional SYNTAX score.