Understanding the Outcome of Randomized Trials with Drug-Eluting Stents and Coronary Artery Bypass Graft in Patients with Multivessel Disease: A Review of a 25-Year Journey

Effects of pre-CABG program on discharge readiness and surgery outcomes for patients undergoing elective CABG surgery: a study protocol for a randomised control trial

INTRODUCTION

Cardiovascular diseases, a leading cause of death globally, impose significant health and economic burdens, particularly in countries like Iran. Coronary artery bypass grafting (CABG) is a common intervention for ischaemic heart disease, yet it entails a long recovery process with potential complications and psychological impacts. This study aims to evaluate the effectiveness of a prehabilitation programme (pre-CABG) on postoperative outcomes and discharge readiness in patients undergoing elective CABG.

METHODS AND ANALYSIS

This randomised controlled trial involves 60 patients diagnosed with coronary artery disease at Imam Khomeini Hospital Complex, Tehran. Participants will be randomly assigned to either the intervention group, receiving the pre-CABG programme, or the control group, receiving standard care. The pre-CABG programme includes patient education, stress management techniques, respiratory muscle training and nutritional guidance. Primary outcomes include discharge readiness, duration of intubation, Intensive Care Uniy (ICU) stay, occurrence of atelectasis, onset of mobility, hospital stay and levels of anxiety and depression. Secondary outcomes include the rate of 30-day readmissions. Data collection will involve standardised scales and checklists administered at various stages preoperation and postoperation.

ETHICS AND DISSEMINATION

The research study has received approval from the Research Ethics Committee at Tehran University of Medical Sciences' School of Nursing and Midwifery and Rehabilitation. All participants must provide written consent for their involvement in this study. The findings will be shared with appropriate groups and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

The study is registered with the Iranian Registry of Clinical Trials under the ID IRCT20231019059768N1.

Induction of Angiogenesis by Genetically Modified Human Umbilical Cord Blood Mononuclear Cells

Stimulating the process of angiogenesis in treating ischemia-related diseases is an urgent task for modern medicine, which can be achieved through the use of different cell types. Umbilical cord blood (UCB) continues to be one of the attractive cell sources for transplantation. The goal of this study was to investigate the role and therapeutic potential of gene-engineered umbilical cord blood mononuclear cells (UCB-MC) as a forward-looking strategy for the activation of angiogenesis. Adenovirus constructs Ad-VEGF, Ad-FGF2, Ad-SDF1α, and Ad-EGFP were synthesized and used for cell modification. UCB-MCs were isolated from UCB and transduced with adenoviral vectors. As part of our in vitro experiments, we evaluated the efficiency of transfection, the expression of recombinant genes, and the secretome profile. Later, we applied an in vivo Matrigel plug assay to assess engineered UCB-MC's angiogenic potential. We conclude that hUCB-MCs can be efficiently modified simultaneously with several adenoviral vectors. Modified UCB-MCs overexpress recombinant genes and proteins. Genetic modification of cells with recombinant adenoviruses does not affect the profile of secreted pro- and anti-inflammatory cytokines, chemokines, and growth factors, except for an increase in the synthesis of recombinant proteins. hUCB-MCs genetically modified with therapeutic genes induced the formation of new vessels. An increase in the expression of endothelial cells marker (CD31) was revealed, which correlated with the data of visual examination and histological analysis. The present study demonstrates that gene-engineered UCB-MC can be used to stimulate angiogenesis and possibly treat cardiovascular disease and diabetic cardiomyopathy.

Bioprinting small-diameter vascular vessel with endothelium and smooth muscle by the approach of two-step crosslinking process

Three‐dimensional bioprinting shows great potential for autologous vascular grafts due to its simplicity, accuracy, and flexibility. The 6‐mm‐diameter vascular grafts are used in clinic. However, producing small‐diameter vascular grafts are still an enormous challenge. Normally, sacrificial hydrogels are used as temporary lumen support to mold tubular structure which will affect the stability of the fabricated structure. In this study, we have developed a new bioprinting approach to fabricating small‐diameter vessel using two‐step crosslinking process. The ¼ lumen wall of bioprinted gelatin mechacrylate (GelMA) flat structure was exposed to ultraviolet (UV) light briefly for gaining certain strength, while ¾ lumen wall showed as concave structure which remained uncrosslinked. Precrosslinked flat structure was merged towards the uncrosslinked concave structure. Two individual structures were combined tightly into an intact tubular structure after receiving more UV exposure time. Complicated tubular structures were constructed by these method. Notably, the GelMA‐based bioink loaded with smooth muscle cells are bioprinted to form the outer layer of the tubular structure and human umbilical vein endothelial cells were seeded onto the inner surface of the tubular structure. A bionic vascular vessel with dual layers was fabricated successfully, and kept good viability and functionality. This study may provide a novel idea for fabricating biomimetic vascular network or other more complicated organs.

Gene Therapy: Targeting Cardiomyocyte Proliferation to Repopulate the Ischemic Heart

ABSTRACT

Adult mammalian cardiomyocytes show scarce division ability, which makes the heart ineffective in replacing lost contractile cells after ischemic cardiomyopathy. In the past decades, there have been increasing efforts in the search for novel strategies to regenerate the injured myocardium. Among them, gene therapy is one of the most promising ones, based on recent and emerging studies that support the fact that functional cardiomyocyte regeneration can be accomplished by the stimulation and enhancement of the endogenous ability of these cells to achieve cell division. This capacity can be targeted by stimulating several molecules, such as cell cycle regulators, noncoding RNAs, transcription, and metabolic factors. Therefore, the proposed target, together with the selection of the vector used, administration route, and the experimental animal model used in the development of the therapy would determine the success in the clinical field.

Increased incidence of serious late adverse events with drug-eluting stents when compared with coronary artery bypass surgery: a cause of concern

Percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) in pre-drug-eluting stents (DESs) era, randomized trials and meta-analysis showed that the extension of coronary artery disease was not associated with a better survival with CABG, and only diabetic patients had an inferior survival with PCI. After the introduction of DES, we would expect a substantial improvement in PCI results compared with CABG, narrowing the gap between both revascularization strategies, However, on the contrary, most randomized studies between DES and CABG showed that rate of recurrences remained and there is an unexpected increased of late serious adverse events including spontaneous myocardial infarction and death. In this review, we try to described each of these problems and find out explanations for these new findings searching for potential solutions.

A bioink blend for rotary 3D bioprinting tissue engineered small-diameter vascular constructs

3D bioprinted vascular constructs have gained increased interest due to their significant potential for creating customizable alternatives to autologous vessel grafts. In this study, we developed a new approach for biofabricating fibrin-based vascular constructs using a novel rotary 3D bioprinter developed in our lab. We formulated a new bioink by incorporating fibrinogen with gelatin to achieve a desired shear-thinning property for rotary bioprinting. The blending of heat-treated gelatin with fibrinogen turned unprintable fibrinogen into a printable biomaterial for vessel bioprinting by leveraging the favorable rheological properties of gelatin. We discovered that the heat-treatment of gelatin remarkably affects the rheological properties of a gelatin-fibrinogen blended bioink, which in turn influences the printability of the ink. Further characterizations revealed that not only concentration of the gelatin but the heat treatment also affects cell viability during printing. Notably, the density of cells included in the bioinks also influenced printability and tissue volumetric changes of the printed vessel constructs during cultures. We observed increased collagen deposition and construct mechanical strength during two months of the cultures. The burst pressure of the vessel constructs reached 1110 mmHg, which is about 52% of the value of the human saphenous vein. An analysis of the tensile mechanical properties of the printed vessel constructs unveiled an increase in both the circumferential and axial elastic moduli during cultures. This study highlights important considerations for bioink formulation when bioprinting vessel constructs. STATEMENT OF SIGNIFICANCE: There has been an increased demand for small-diameter tissue-engineered vascular grafts. Vascular 3D bioprinting holds the potential to create equivalent vascular grafts but with the ability to tailor them to meet patient's needs. Here, we presented a new and innovative 3D rotary bioprinter and a new bioink formulation for printing vascular constructs using fibrinogen, a favorable biomaterial for vascular tissue engineering. The bioink was formulated by blending fibrinogen with a more printable biomaterial, gelatin. The systematic characterization of the effects of heat treatment and gelatin concentration as well as bioink cell concentration on the printability of the bioink offers new insight into the development of printable biomaterials for tissue biofabrication.

One-Year Follow-Up Results From the Observational, Multicenter, Prospective, and Controlled Registry: The WALTZ All-Comers Study

The aim of this study was to evaluate 1-year follow-up results in an all “comers” population treated with a new cobalt chromium bare-metal stent (BMS) design. Since August 2016 to March 2017, 201 (9.7% of screening population) consecutive patients undergoing coronary stent implantation in 11 centers in Argentina were prospectively included in our registry. The inclusion criteria were multiple-vessel disease and/or unprotected left main disease, acute coronary syndromes (ACS) with at least one severe (⩾70%) stenosis in any of major epicardial vessel. In-stent restenosis, protected left main stenosis, or impossibility to receive dual-antiplatelet therapy was an exclusion criterion. Major adverse cardiac events (MACE) were the primary endpoint and included cardiac death, myocardial infarction (MI), and target lesion revascularization (TLR); also, all components of the primary endpoint were separately analyzed. Completeness of revascularization was analyzed as post hoc data using residual SYNTAX or ERACI risk scores. Demographic characteristics showed that 6.5% of patients were very elderly, 22.5% have diabetes, 47% have multiple-vessel disease, 67% have ACS, and 32% have ST elevation MI. At a mean of 376 ± 18.1 days of follow-up, MACE was observed in 10.4% of patients: death + MI + cardiovascular accident (CVA) in 3% (6 of 201) and cardiac death + MI + CVA in 1.5% (3 of 201). Residual ERACI score ⩽5 was associated with 98% of event-free survival (P < .04). In conclusion, this prospective, multicenter, and observational all-comers registry with this novel BMS design showed a low incidence of adverse events at 1 year mainly due to coronary restenosis.

Approaches to therapeutic angiogenesis for ischemic heart disease

Ischemic heart disease (IHD) is caused by the narrowing of arteries that work to provide blood, nutrients, and oxygen to the myocardial tissue. The worldwide epidemic of IHD urgently requires innovative treatments despite the significant advances in medical, interventional, and surgical therapies for this disease. Angiogenesis is a physiological and pathophysiological process that initiates vascular growth from pre-existing blood vessels in response to a lack of oxygen. This process occurs naturally over time and has encouraged researchers and clinicians to investigate the outcomes of accelerating or enhancing this angiogenic response as an alternative IHD therapy. Therapeutic angiogenesis has been shown to revascularize ischemic heart tissue, reduce the progression of tissue infarction, and evade the need for invasive surgical procedures or tissue/organ transplants. Several approaches, including the use of proteins, genes, stem/progenitor cells, and various combinations, have been employed to promote angiogenesis. While clinical trials for these approaches are ongoing, microvesicles and exosomes have recently been investigated as a cell-free approach to stimulate angiogenesis and may circumvent limitations of using viable cells. This review summarizes the approaches to accomplish therapeutic angiogenesis for IHD by highlighting the advances and challenges that addresses the applicability of a potential pro-angiogenic medicine.

Reduction of In-Stent Restenosis by Cholesteryl Ester Transfer Protein Inhibition

OBJECTIVE

Angioplasty and stent implantation, the most common treatment for atherosclerotic lesions, have a significant failure rate because of restenosis. This study asks whether increasing plasma high-density lipoprotein (HDL) levels by inhibiting cholesteryl ester transfer protein activity with the anacetrapib analog, des-fluoro-anacetrapib, prevents stent-induced neointimal hyperplasia.

APPROACH AND RESULTS

New Zealand White rabbits received normal chow or chow supplemented with 0.14% (wt/wt) des-fluoro-anacetrapib for 6 weeks. Iliac artery endothelial denudation and bare metal steel stent deployment were performed after 2 weeks of des-fluoro-anacetrapib treatment. The animals were euthanized 4 weeks poststent deployment. Relative to control, dietary supplementation with des-fluoro-anacetrapib reduced plasma cholesteryl ester transfer protein activity and increased plasma apolipoprotein A-I and HDL cholesterol levels by 53±6.3% and 120±19%, respectively. Non-HDL cholesterol levels were unaffected. Des-fluoro-anacetrapib treatment reduced the intimal area of the stented arteries by 43±5.6% (P<0.001), the media area was unchanged, and the arterial lumen area increased by 12±2.4% (P<0.05). Des-fluoro-anacetrapib treatment inhibited vascular smooth muscle cell proliferation by 41±4.5% (P<0.001). Incubation of isolated HDLs from des-fluoro-anacetrapib-treated animals with human aortic smooth muscle cells at apolipoprotein A-I concentrations comparable to their plasma levels inhibited cell proliferation and migration. These effects were dependent on scavenger receptor-B1, the adaptor protein PDZ domain-containing protein 1, and phosphatidylinositol-3-kinase/Akt activation. HDLs from des-fluoro-anacetrapib-treated animals also inhibited proinflammatory cytokine-induced human aortic smooth muscle cell proliferation and stent-induced vascular inflammation.

CONCLUSIONS

Inhibiting cholesteryl ester transfer protein activity in New Zealand White rabbits with iliac artery balloon injury and stent deployment increases HDL levels, inhibits vascular smooth muscle cell proliferation, and reduces neointimal hyperplasia in an scavenger receptor-B1, PDZ domain-containing protein 1- and phosphatidylinositol-3-kinase/Akt-dependent manner.

Downregulation of Cavin-1 Expression via Increasing Caveolin-1 Degradation Prompts the Proliferation and Migration of Vascular Smooth Muscle Cells in Balloon Injury-Induced Neointimal Hyperplasia

BACKGROUND

Percutaneous coronary intervention has been widely used in the treatment of ischemic heart disease, but vascular restenosis is a main limitation of percutaneous coronary intervention. Our previous work reported that caveolin-1 had a key functional role in intimal hyperplasia, whereas whether Cavin-1 (another important caveolae-related protein) was involved is still unknown. Therefore, we will investigate the effect of Cavin-1 on neointimal formation.

METHODS AND RESULTS

Balloon injury markedly reduced Cavin-1 protein and enhanced ubiquitin protein expression accompanied with neointimal hyperplasia in injured carotid arteries, whereas Cavin-1 mRNA had no change. In cultured vascular smooth muscle cells (VSMCs), Cavin-1 was downregulated after inhibition of protein synthesis by cycloheximide, which was distinctly prevented by pretreatment with proteasome inhibitor MG132 but not by lysosomal inhibitor chloroquine, suggesting that proteasomal degradation resulted in Cavin-1 downregulation. Knockdown of Cavin-1 by local injection of Cavin-1 short hairpin RNA (shRNA) into balloon-injured carotid arteries in vivo promoted neointimal formation. In addition, inhibition or overexpression of Cavin-1 in cultured VSMCs in vitro prompted or suppressed VSMC proliferation and migration via increasing or decreasing extracellular signal-regulated kinase phosphorylation and matrix-degrading metalloproteinases-9 activity, respectively. However, under basic conditions, the effect of Cavin-1 on VSMC migration was stronger than on proliferation. Moreover, our results indicated that Cavin-1 regulated caveolin-1 expression via lysosomal degradation pathway.

CONCLUSIONS

Our study revealed the role and the mechanisms of Cavin-1 downregulation in neointimal formation by promoting VSMC proliferation, migration, and synchronously enhancing caveolin-1 lysosomal degradation. Cavin-1 may be a potential therapeutic target for the treatment of postinjury vascular remodeling.

Recent Trends in Clinical Trials Related to Carrier-Based Drugs

Clinical trials related to carrier-based drugs have recently attracted attention because carrier-based drugs hold promise for high efficiency drug delivery and for reducing drug-related side effects. In this commentary, we introduce recent clinical trials involving the use of various carriers, including liposomes, nano and micro particles, micelles, emulsions, and polymeric carriers. Liposomal drug carriers are currently the most intensively tested carriers in clinical trials, but other carriers such as polymeric carriers, albumin-based carriers, and metal nanocarriers have also recently been studied in clinical trials. Each carrier has specific properties, advantages, and disadvantages. The recent clinical trials introduced herein provide information critical to understanding current trends in carrier-based drug research.