New Advances in the Management of Refractory Angina Pectoris

Research focus and theme evolution on enhanced external counterpulsation: A bibliometric analysis

Aims

The study delved into the identification of key research areas and evolving trends within the domain of Enhanced External Counterpulsation, aiming to gain comprehensive insights into the subject matter.

Methods

Utilizing the sophisticated search parameter of 'topic' (TS) on the Web of Science (WoS) database, the necessary information was retrieved. This research employed an array of tools for effective data extraction, analysis, and visualization, which included Microsoft Excel for tabular management, HistCite Pro for citation analysis, GunnMap for geographical mapping, BibExcel for bibliometric assessments, and VOSviewer for network visualization purposes.

Results

From its establishment up until March 31, 2024 a total of 535 entries were recorded in the WoS database, with 491 of these relevant to the specified subject matter. The USA was the most prolific country, and China ranked second. Sun Yat Sen University was the most productive institution, which was from China. And 80 % of the top 10 institutions were from the USA. A keyword co-occurrence analysis was conducted, revealing four distinct research foci. And they were the application of EECP in cardiovascular disease, the main indications of EECP, the mechanism of EECP and the therapeutic effect of EECP, respectively. Researchers paid the most attention to the application of EECP on the cardiac cardiovascular system. Professor Lawson WE, Hui JCK and Kennard ED were the top three prolific authors. Lawson WE, Henry TD, Braith RW and Zheng ZS were identified as the core authors in the author co-citation network analysis.

Conclusion

A comprehensive analysis was conducted on the literature surrounding improved enhanced external counterpulsation in this investigation, which can help researchers understand the theme trend better and grasp the research gap, to carry out further research and promote the progress of the topic.

Coronary Sinus Narrowing for Treating Refractory Angina: REDUCER-I Multicenter "Real-World" Observational Study Primary Endpoint Analysis

BACKGROUND

Patients with refractory angina are often ineligible for revascularization and have poor quality of life despite optimal medical therapy. The coronary sinus (CS) Reducer (Shockwave Medical Inc) was safe and effective in the treatment of refractory angina in the COSIRA (Coronary Sinus Reducer for Treatment of Refractory Angina) randomized sham-controlled trial.

OBJECTIVES

This study sought to perform the primary endpoint analysis of the complete REDUCER-I (An Observational Study of the Neovasc Reducer System) study cohort.

METHODS

REDUCER-I is a nonrandomized, "real-world" study of patients with refractory angina treated with the CS Reducer conducted at 25 centers from 9 European countries. The primary effectiveness endpoint was an improvement in Canadian Cardiovascular Society (CCS) class at 6 months. The primary safety endpoints were major adverse cardiac events and device- or procedure-related serious adverse events through 30 days. Study follow-up is planned through 5 years with some interim 3-year analyses included here.

RESULTS

From 2016 to 2023, 400 patients were enrolled, including 78.0% (312/400) male patients, 54.3% (216/398) with previous myocardial infarction, 73.6% (293/398) with previous revascularization, and 72.0% (280/389) CCS class III/IV. Major adverse cardiac event and serious adverse event rates were 1.6% (95% CI: 0.7-3.6) and 1.1% (4/371), respectively, with no deaths within 30 days. At 6 months, 69.8% (240/344) of patients improved by ≥1 CCS class. Six-minute walk distances improved by 34.1 ± 85.8 m at 6 months (P < 0.0001). Interim 3-year results showed CCS class and Seattle Angina Questionnaire quality of life improvements were sustained (P < 0.0001).

CONCLUSIONS

The complete primary endpoint analysis of the REDUCER-I study shows patients with refractory angina were safely and effectively treated with the CS Reducer. Improvements in angina and quality of life appear sustained through 3 years.

Procedural factors influencing successful coronary sinus reducer implantation for refractory angina: A single-centre experience

BACKGROUND

Coronary sinus reducer (CSR) implantation is emerging as a novel effective percutaneous therapy for patients with refractory angina. Limited data exists examining the factors influencing successful CSR implantation. As CSR implantation becomes more widely adopted, a greater understanding of the procedural challenges which operators encounter is required.

AIM

To evaluate the patient and procedural characteristics influencing successful CSR implantation.

METHODS

This was a retrospective cohort study of consecutive patients with refractory angina undergoing clinically indicated CSR implantation (February 2016 to August 2024) at a high-volume implanting centre in the UK. Patient and procedural characteristics affecting procedural difficulty were systematically analysed. Procedural difficulty was determined by 1) increasing total procedural time or 2) features of challenging equipment handling such as bellying, swan-necking or complete equipment fallout from the coronary sinus (CS).

RESULTS

102 out of 105 (97 %) patients underwent a successful CSR implant at the first attempt. Patients had a high rate of previous revascularisation (PCI: 85 %; CABG 64 %) and diabetes (58 %). Significant improvements in Canadian Cardiovascular Society (CCS) class were observed with 36 % of patients improving by ≥2 CCS classes and 71 % improving by ≥1 CCS class. A C- or non-C-shape of the CS was not associated with differences in procedural time (P = 0.52). However, the presence of both a valve and ridge in the CS was associated with significantly longer procedural times (P = 0.03). A ridge, alone or together with a valve, predicted features of procedural difficulty, such as bellying (ridge - OR: 2.69, P = 0.02; valve and ridge - OR: 4.58, P = 0.0006) and swan-necking (ridge - OR: 5.43, P = 0.001; valve and ridge - OR: 4.74, P = 0.002). Bellying, swan-necking, and complete fallout of equipment from the CS were associated with longer procedural times, but also with each other, suggesting their utility as indicators of procedural complexity.

CONCLUSION

In our experience, CSR implantation is safe and associated with high rates of procedural success. However, patient and procedural factors can influence the difficulty of CSR implantation. The presence of a ridge may make implantation more challenging. Bellying, swan-necking and complete equipment fallout may indicate increased procedural complexity. Greater awareness of these features will encourage operators to remain vigilant and adapt their implantation strategy when encountering challenging cases.

Coronary Sinus Reducer Therapy for Refractory Angina and its Role in Modern Interventional Practice: A Contemporary Review

Coronary sinus reducer (CSR) implantation is an emerging treatment option for patients with refractory angina. This condition represents a major global cardiovascular healthcare challenge, with patients experiencing chronic anginal symptoms that significantly impair their quality of life and for whom few effective treatments exist. The clinical burden of refractory angina is only set to grow because of improved survival from coronary artery disease, increased life expectancy and the presence of residual angina after percutaneous or surgical coronary revascularisation. Therefore, new, effective, evidence-based therapies are urgently needed. In this review, we highlight the unmet clinical needs of patients with refractory angina, discuss the development of the CSR device and review the preclinical and clinical evidence base underlying CSR implantation. In addition, we discuss the current role of CSR implantation in contemporary interventional practice, highlighting knowledge gaps and discussing areas of on-going research.

Safety and biodistribution of XC001 (encoberminogene rezmadenovec) gene therapy in rats: a potential therapy for cardiovascular diseases

Adenovirus-mediated gene therapy holds promise for the treatment of cardiovascular diseases such as refractory angina. However, potential concerns around immunogenicity and vector dissemination from the target injected tissue require evaluation. This study was undertaken to evaluate the safety and biodistribution of XC001, a replication-deficient adenovirus serotype 5 vector expressing multiple isoforms of human vascular endothelial growth factor (VEGF), following direct administration into normal rat myocardium. Animals received the buffer formulation or increasing doses of XC001 (1 × 107, 2.5 × 108 or 2.5 × 109 viral particles). Based on in-life parameters (general health, body weights, clinical pathology, serum cardiac troponin I, plasma VEGF, and gross necropsy), there were no findings of clinical concern. On Day 8, intramyocardial administration of XC001 was associated with dose-related, left ventricular myocardial inflammation at injection sites, resolving by Day 30. XC001 DNA was not detected in blood at any time but was present at Day 8 around the site of injection and to a much lesser extent in the spleen, liver, and lungs, persisting at low levels in the heart and spleen until at least Day 91. These findings demonstrate that intramyocardial injection of XC001 is supported for use in human studies.

Nonpharmacological interventions for 'no-option' refractory angina patients

Refractory angina pectoris (RAP) defined as chronic anginal chest pain because of coronary artery disease (CAD) is a major problem. The increase in the number of patients with RAP in recent years is because of the increasing aging population and improved survival rates among patients with CAD. Management of patients with RAP is often extremely challenging. In this review, we present several interventional approaches for RAP, including device therapies, lifestyle intervention, and cell therapies. Some of these treatments are currently used in the management of RAP, whereas other treatments are under investigation.

Coronary Sinus Reducer: A Solution for patients with Refractory Angina

Refractory Angina (RA) places a great burden on patients and the healthcare system, with reduced quality of life (QOL), increased hospital admissions, polypharmacy, and psychological effects. Patients with RA are limited in options for management and with the introduction of the coronary sinus reducer (CSR), a safe and effective option may be available for this group of patients. This review article seeks to understand the efficacy of coronary sinus implantation in the current literature.

External Counterpulsation Improves Angiogenesis by Preserving Vascular Endothelial Growth Factor-A and Vascular Endothelial Growth Factor Receptor-2 but Not Regulating MicroRNA-92a Expression in Patients With Refractory Angina

Objective: External counterpulsation (ECP) provides long-term benefits of improved anginal frequency and exercise tolerance in patients with refractory angina (RA). This is postulated as a result of improved angiogenesis and endothelial function through an increase in shear stress. Angiogenesis is mainly represented by vascular endothelial growth factor-A (VEGF-A) and its receptor, vascular endothelial growth factor receptor-2 (VEGFR-2). The microRNA-92a (miR-92a) is a flow-sensitive miRNA that regulates atherosclerosis and angiogenesis in response to shear stress. Thus, ECP beneficial effect might be achieved through interaction between VEGF-A, VEGFR-2, and miR-92a. This study aims to evaluate the ECP effect on VEGF-A, VEGFR-2, and miR-92a in patients with RA in a sham-controlled manner. Methods: This was a randomized sham-controlled trial, enrolling 50 patients with RA who have coronary artery disease (CAD). Participants were randomized (1:1 ratio) to 35 sessions of either ECP (n = 25) or sham (n = 25), each session lasting for 1 h. Plasma levels of VEGF-A and VEGFR-2 were assayed by the ELISA technique. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to measure miR-92a circulating levels in plasma. Result: External counterpulsation significantly preserved VEGF-A and VEGFR-2 level compared to sham [ΔVEGF-A: 1 (-139 to 160) vs.-136 (-237 to 67) pg/ml, p = 0.026; ΔVEGFR-2: -171(-844 to +1,166) vs. -517(-1,549 to +1,407) pg/ml, p = 0.021, respectively]. Circulating miR-92a increased significantly in ECP [5.1 (4.2-6.4) to 5.9 (4.8-6.4), p < 0.001] and sham [5.2 (4.1-9.4) to 5.6 (4.8-6.3), p = 0.008] post-intervention. The fold changes tended to be higher in ECP group, although was not statistically different from sham [fold changes ECP = 4.6 (0.3-36.5) vs. sham 2.8 (0-15), p = 0.33)]. Conclusion: External counterpulsation improved angiogenesis by preserving VEGF-A and VEGFR-2 levels. Both ECP and sham increased miR-92a significantly, yet the changes were not different between the two groups. (Study registered on www.clinicaltrials.gov, no: NCT03991871, August 8, 2019, and received a grant from the National Health Research and Development of Ministry of Health of Indonesia, No: HK.02.02/I/27/2020).

Adverse events and their management during enhanced external counterpulsation treatment in patients with refractory angina pectoris: observations from a routine clinical practice

AIMS 

Enhanced external counterpulsation (EECP) is a non-invasive treatment (35 one-hour sessions) for patients with refractory angina pectoris (RAP). To avoid interruption of treatment, more knowledge is needed about potential adverse events (AE) of EECP and their appropriate management. To describe occurrence of AE and clinical actions related to EECP treatment in patients with RAP and compare the distribution of AE between responders and non-responders to treatment.

METHODS AND RESULTS 

A retrospective study was conducted by reviewing medical records of 119 patients with RAP who had undergone one EECP treatment and a 6-min-walk test pre- and post-treatment. Sociodemographic, medical, and clinical data related to EECP were collected from patients' medical records. An increased walking distance by 10% post-treatment, measured by 6-min-walk test, was considered a responder. The treatment completion rate was high, and the occurrence of AE was low. Adverse events occurred more often in the beginning and gradually decreased towards the end of EECP treatment. The AE were either device related (e.g. muscle pain/soreness) or non-device related (e.g. bradycardia). Medical (e.g. medication adjustments) and/or nursing (e.g. extra padding around the calves, wound dressing) actions were used. The AE distribution did not differ between responders (n = 49, 41.2%) and non-responders. Skin lesion/blister occurred mostly in responders and paraesthesia occurred mostly in non-responders.

CONCLUSION 

Enhanced external counterpulsation appears to be a safe and well-tolerated treatment option in patients with RAP. However, nurses should be attentive and flexible to meet their patients' needs to prevent AE and early termination of treatment.

Extracorporeal cardiac shock waves therapy promotes function of endothelial progenitor cells through PI3K/AKT and MEK/ERK signaling pathways

Previous studies have demonstrated extracorporeal cardiac shock waves (ECSW) could induce angiogenesis and improves myocardial function in patients with coronary heart diseases as a safe, effective, and non-invasive angiogenic approach. The endothelial progenitor cells (EPCs) can migrate to the ischemic myocardium and differentiate into vascular endothelial cells, thus promoting the angiogenesis. Whether ECSW can improve the angiogenic ability of EPCs is unclear. This topic studied the effects of ECSW Therapy on EPCs functions and related signal transduction pathways. The bone marrow-derived EPCs of SD rats were isolated by the density centrifugation method. After treatment with ECSW (500 shots at 0.09 mJ/mm²), the cell viability, anti-apoptosis, migration, and tube formation of EPCs were significantly improved. In addition, the expressions of phosphorylated AKT and ERK were increased after ECSW treatment, the expressions of downstream signaling molecules eNOS and Bcl-2 were also increased, but the expressions of Bax and Caspase3 were decreased. However, these beneficial effects can be inhibited by PI3K/AKT inhibitor LY294002 and MEK/ERK inhibitor PD98059. Together, ECSW can promote the cell viability, migration, and angiogenic ability of EPCs and inhibit the apoptosis of EPCs through the PI3K/AKT and MEK/ERK signaling pathways. The mechanism may be related to promoting the expressions of downstream p-eNOS and anti-apoptotic protein Bcl-2 and inhibiting the expressions of pro-apoptotic protein Bax and Caspase3 through the PI3K/AKT and MEK/ERK signaling pathways.

Implantation of a Coronary Sinus Reducer to Treat Refractory Angina in a 38-Year-Old with an Anomalous Left Coronary Artery and No Revascularization Options

A 38-year-old female with anomalous left coronary artery from the pulmonary artery presented with refractory angina (Canadian Cardiovascular Society [CCS] class 4). Having failed two previous internal mammary artery grafts to the left anterior descending artery and with no percutaneous revascularization options, she underwent coronary sinus reducer implantation, which improved her symptoms (CCS 0), quality of life, and corresponded to an improvement in ischemia on myocardial perfusion scanning. This case report describes an unusual case of refractory angina in the context of congenital heart disease, illustrates the benefit of this novel hourglass-shaped stent in improving ischemia, quality of life, depression and anxiety, and highlights the importance of managing these patients in multidisciplinary teams.