Coronary sinus reducer for the treatment of refractory angina (ORBITA-COSMIC): a randomised, placebo-controlled trial

An updated review on therapeutic strategies in coronary microvascular dysfunction

Coronary microvascular dysfunction (CMD) is well-known cause of angina, yet treatment options remain limited. This systematic review and meta-analysis examines the current literature and provides a contemporary evaluation of treatments using a stringent definition for CMD with accurate methods of microvascular assessment in accordance with recent consensus guidelines. Methods and Results: A search strategy was conducted independently by two authors (CK and RR). Studies were required to be prospective trials in adult patients with documented CMD by IC doppler wire, thermodilution techniques, or perfusion imaging via PET/MRI. CMD was defined as either coronary flow reserve (CFR)/myocardial perfusion reserve (MPR) < 2.5, and/or index of microvascular resistance (IMR) > 25. Methodological quality of studies was assessed via the Cochrane Risk of Bias tool. The primary and secondary endpoints were change in CFR/MPR/IMR and change in Seattle Angina Questionnaire (SAQ) scores respectively. Two-sided p-values were used and considered significant if p < 0.05. A total of 11,360 records were identified, from which 14 were included in this review covering 9 different treatments. Two treatments (quinapril and ranolazine) showed significant improvement in both CFR and angina. Three ranolazine trials were pooled in meta-analysis. The standardised mean difference showed a weak positive effect (0.24) with wide intervals (-0.21 to 0.26) which was not statistically significant (p = 0.20). We subsequently reviewed all treatments as mentioned in recent European consensus statements. Conclusions: The overall quality of evidence surrounding treatments for CMD is of "low", with lack of robust data highlighting the dire need for higher quality trials in this area.

Efficacy and safety of coronary sinus reducer for refractory angina: a systematic review and meta-analysis of randomized controlled trials

Refractory angina affects patients' quality of life around the world. Coronary sinus reducer (CSR) is a new therapeutic approach that has been investigated in recent years. We aimed to investigate the efficacy and safety of CSR for refractory angina. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) from PubMed, Web of Science, Scopus, Embase, and CENTRAL searches until May 2024. Dichotomous data were pooled using risk ratio (RR), and continuous data were pooled using mean difference (MD), both with a 95% confidence interval (CI), using (R version 4.3). With the inclusion of three RCTs, our cohort comprised a total of 180 patients. Compared with the control group, after 6 months, CSR was significantly associated with a decreased mean change of Canadian Cardiovascular Society (CCS) class [MD: -0.54 with 95% CI (-0.80 to -0.27), P  < 0.01], a decreased number of patients in the CCS class III/IV [RR: 0.56 with 95% CI (0.38-0.84), P  < 0.01], and increased exercise time [MD: 50.46 with 95% CI (9.47-91.45), P  = 0.02]. However, there was no significant difference between CSR and the control group in double products, all Seattle Angina Questionnaire domains, and safety outcomes. CSR has been shown to reduce angina severity by lowering CCS class scores and increasing exercise time. Large-scale RCTs are needed to confirm its effectiveness in patients with refractory angina.

Advances in Clinical Cardiology 2024: A Summary of Key Clinical Trials

INTRODUCTION

In 2024, numerous key clinical trials in the field of clinical cardiology have been published or presented at major international conferences. This review seeks to collate and summarise these trials and reflect on their clinical context.

METHODS

The authors evaluated all clinical trials presented at major cardiology conferences during 2024 with a focus on clinical trials which would influence and/or change current clinical practice. We reviewed clinical trials presented at all major international conferences including the American College of Cardiology (ACC), European Association for Percutaneous Cardiovascular Interventions (EuroPCR), European Society of Cardiology (ESC), Transcatheter Cardiovascular Therapeutics (TCT), American Heart Association (AHA), European Heart Rhythm Association (EHRA), Society for Cardiovascular Angiography and Interventions (SCAI), TVT-The Heart Summit (TVT) and Cardiovascular Research Technologies (CRT). Trials considered to have highest impact and/or broad relevance across the field of clinical cardiology, with a high likelihood to change or impact upon clinical practice were included.

RESULTS

Over 90 key cardiology clinical trials were identified across the spectrum of clinical cardiology. Important updates in percutaneous coronary intervention were reviewed including new ESC guidance and several key trials in the field of coronary physiology (FAVOR III), drug-coated balloons (REGCAGE-FREE, AGENT-IDE), shock, and acute coronary syndromes (SENIOR-RITA, DanGer-Shock). Structural trials included major updates in transcatheter aortic valve replacement (TAVR) from EARLY-TAVR, TAVR-UNLOAD and NOTION 3, as well as seminal trials in tricuspid (TRISCEND II) and mitral intervention (MATTERHORN). Key updates in preventative cardiology included new data in lipoprotein (a) pharmacotherapy, low-density lipoprotein (LDL) cholesterol reduction and hypertension management (BPROAD, BedMed, KRAKEN), as well as several key trials in heart failure (SUMMIT, FINEARTS) hypertrophic cardiomyopathy (SEQUOIA-HCM) and cardiac amyloid (HELIOS-B).

CONCLUSION

The review presents a concise summary of the key clinical cardiology trials published or presented during the past year and should be of interest to clinicians and researchers in the field of cardiology.

Focusing on microvascular function in heart failure with preserved ejection fraction

Heart failure is a prevalent global health issue. Heart failure with preserved ejection fraction (HFpEF), which already represents half of all heart cases worldwide, is projected to further increase, driven by aging populations and rising cardiovascular risk factors. Effective therapies for HFpEF remain limited, particularly due to its pathophysiological heterogeneity and incomplete understanding of underlying pathomechanisms and implications. Coronary microvascular dysfunction (CMD), characterized by structural and functional changes in the coronary microcirculation, is increasingly recognized as a significant factor in HFpEF even though the exact nature of their causal relationship is still unclear. This review explores prevalence, prognostic implications, and potential therapeutic targets for CMD in HFpEF. CMD's role in HFpEF might involve impaired coronary blood flow regulation, leading to myocardial ischemia, impaired relaxation, and/or adverse remodeling. Vice versa, increased wall stress in patients with HFpEF might elevate coronary resistances, further worsening microvascular perfusion. Finally, abnormalities in substrate metabolism might cause both CMD and HFpEF. Current treatments, including pharmacotherapy and device-based therapies, show limited success, highlighting the need for more targeted approaches. New possible therapies, such as the coronary sinus reducer device, may show promise in improving myocardial perfusion and function. However, further large-scale studies are required to elucidate the mechanistic links between CMD and HFpEF and to develop specialized treatments for distinct heart failure phenotypes.

The comprehensive clinical benefits of digital phenotyping: from broad adoption to full impact

Digital phenotyping collects health data digitally, supporting early disease diagnosis and health management. This paper systematically reviews the diversity of research methods in digital phenotyping and its clinical benefits, while also focusing on its importance within the P4 medicine paradigm and its core role in advancing its application in biobanks. Furthermore, the paper envisions the continued clinical benefits of digital phenotyping, driven by technological innovation, global collaboration, and policy support.

Patient-centric no-option refractory angina management: establishing comprehensive angina relief (CARE) clinics

INTRODUCTION

Refractory angina (RA) is a debilitating condition characterized by persistent angina despite optimized medical therapy and limited options for further revascularization, leading to diminished quality of life and increased healthcare utilization. The RA patient population is rapidly expanding with significant unmet needs. Specialty clinics should be developed to focus on the long-term efficacy and safety of clinically available and novel treatment strategies, emphasizing quality of life.

AREAS COVERED

Patient-focused Comprehensive Angina Relief (CARE) clinics can enhance care and outcomes by providing individualized management for complex RA. This review summarizes peer-reviewed articles from PubMed and trial data from ClinicalTrials.gov. We discuss the epidemiology and pathophysiology of RA, introduce standardized tools for evaluating angina and psychosocial factors, and address symptom management. We also review treatment options such as risk factor modification, medication, and complex revascularization. Additionally, we explore emerging therapies, including coronary sinus occlusion, regenerative therapy, and neuromodulation for 'no-option' RA.

EXPERT OPINION

In the next five years, patients with refractory chest pain with or without coronary artery disease will increasingly be referred to specialty clinics for follow-up. Conducting more randomized control clinical trials with larger population subsets will bring novel therapies to the forefront.

The Novel A-Flux Coronary Sinus Reducer Normalizes Coronary Microvascular Function in a Persistently Symptomatic Patient

Coronary microvascular dysfunction (CMD) contributes to persistent angina/anginal equivalent symptoms and is associated with adverse outcomes. Coronary sinus reduction (CSR) is a device-based therapy with the potential to improve outcomes by reducing symptom burden and improving coronary flow reserve. A patient with CMD underwent CSR with the next-generation A-Flux device.

Management of angina pectoris

Angina pectoris, a primary manifestation of ischemic heart disease, imposes a significant clinical and economic burden globally. This review highlights recent advancements in the management of angina, emphasizing a patient-centred approach that integrates pharmacological, interventional, and lifestyle strategies to reduce cardiovascular risk and improve patient outcomes. For obstructive coronary artery disease, optimal medical therapy represents the cornerstone of treatment. Individualized regimens should be tailored to clinical factors such as blood pressure, heart rate, left ventricular function, comorbidities like heart failure and diabetes, concomitant medications, patient preferences, and drug availability. Myocardial revascularization is reserved for select cases to alleviate symptoms or improve prognosis. For angina or ischemia with non-obstructive coronary arteries (ANOCA/INOCA), precise endotype classification, differentiating microvascular angina, vasospastic angina, mixed type and non-coronary chest pain, enables personalized treatment strategies. Lifestyle interventions, including smoking cessation, weight management, adherence to Mediterranean diet, and exercise therapy, are essential components of care, promoting improved cardiovascular outcomes and quality of life. Structured exercise programs, particularly within cardiac rehabilitation settings, have demonstrated efficacy in enhancing functional capacity and reducing adverse events. Emerging therapies, including pharmacological agents and novel interventional approaches such as the coronary sinus reducer, hold promise for addressing unmet needs in refractory angina and challenging ANOCA/INOCA cases. Future directions should prioritize the integration of precision medicine, digital health technologies, and multidisciplinary care to optimize outcomes and advance personalized angina management.

Quantitative Stress First-Pass Perfusion Cardiac MRI: State of the Art

Quantitative stress perfusion (qPerf) cardiac magnetic resonance (CMR) imaging is a noninvasive approach used to quantify myocardial blood flow (MBF). Compared with visual analysis, qPerf CMR has superior diagnostic accuracy in the detection of myocardial ischemia and assessment of ischemic burden. In the evaluation of epicardial coronary artery disease (CAD), qPerf CMR improves the distinction of single-vessel from multivessel disease, yielding a more accurate estimate of the ischemic burden, and in turn improving patient management. In patients with chest pain without epicardial CAD, the findings of lower stress MBF and myocardial perfusion reserve (MPR) allow the diagnosis of microvascular dysfunction (MVD). Given its accuracy, MBF quantification with stress CMR has been introduced into the most recent recommendations for diagnosis in patients who have ischemia with nonobstructive CAD. Recent studies have shown a greater decrease in stress MBF and MPR in patients with three-vessel CAD compared with those in patients with MVD, demonstrating an important role that quantitative stress CMR can play in differentiating these etiologies in patients with stable angina. In cases of hypertrophic cardiomyopathy and cardiac amyloidosis, qPerf CMR aids in early diagnosis of ischemia and in risk assessment. Ischemia also results from alterations in hemodynamics that may occur with valve disease such as aortic stenosis or in cases of heart failure. qPerf CMR has emerged as a useful noninvasive tool for detection of cardiac allograft vasculopathy in patients who have undergone heart transplant. The authors review the basic principles and current primary clinical applications of qPerf CMR. ©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Leung and Ng in this issue.

Segmental redistribution of myocardial blood flow after coronary sinus reducer implantation demonstrated by quantitative perfusion cardiovascular magnetic resonance

BACKGROUND

The coronary sinus reducer (CSR) is a novel percutaneous treatment for patients with refractory angina. Increasing evidence supports its clinical efficacy in patients with advanced epicardial coronary artery disease. However, its mechanism of action and its effects on myocardial perfusion remain undefined. Using quantitative stress perfusion cardiovascular magnetic resonance (CMR), this study assessed changes in myocardial perfusion in patients with refractory angina undergoing CSR implantation.

METHODS

This single-center retrospective observational cohort study included 16 patients. Rest and adenosine stress perfusion CMR was performed before and at median 5 months after CSR implantation. Perfusion images were acquired using a dual-sequence quantitative protocol with automated generation of myocardial blood flow (MBF; mL/min/g). In addition to visual assessment of ischemic segments, changes in absolute MBF across myocardial segments and between myocardial layers were analyzed.

RESULTS

A high proportion of myocardial segments had visually adjudicated ischemia at baseline (208 out of 254: 81.9%), which significantly reduced after CSR implantation (175 out of 254: 68.9%; P = 0.001). There were no changes in global MBF or strain values. Changes in myocardial perfusion reserve (MPR) correlated with baseline MPR with more ischemic segments at baseline improving to a greater extent at follow-up. Similar patterns were observed in both the left and right coronary artery territories. Changes in endocardial/epicardial MBF ratio at stress were similarly dependent on baseline values.

CONCLUSION

In patients with refractory angina undergoing CSR implantation, quantitative stress perfusion CMR demonstrated redistribution of myocardial perfusion across segments, from less ischemic to more ischemic myocardium, and across myocardial layers with greatest improvements in endocardial perfusion observed in the most ischemic myocardium. Further studies are needed to validate the different patterns of MBF redistribution that may occur after CSR implantation and correlate with clinical outcomes.

Coronary Microvascular Dysfunction and Vasospastic Angina-Pathophysiology, Diagnosis and Management Strategies

Coronary artery disease is one of the leading public health problems in the world in terms of mortality and economic burden from the disease. Traditionally, the focus of research and clinical pathways leading to the diagnosis and treatment of coronary artery disease was on the more common variant of the disease resulting from atherosclerosis in the epicardial coronary arteries. However, coronary microvasculature, representing the vast majority of the total heart circulation, has the greatest influence on overall coronary resistance and, therefore, blood flow. Coronary microvascular dysfunction (CMD), characterized by structural or functional abnormalities in the microvasculature, significantly impacts myocardial perfusion. Endothelial dysfunction results in inadequate coronary dilation during exercise or spontaneous spasm in the microvasculature or epicardial arteries. A significant proportion of people presenting for coronary angiography in the context of angina have unobstructed epicardial coronary arteries yet are falsely reassured about the benign nature of their condition. Meanwhile, increasing evidence indicates that patients diagnosed with CMD as well as vasospastic angina (VSA) face an increased risk of Major Adverse Cardiovascular Events (MACEs), including death. The aim of this review is to outline the current practice with regard to invasive and non-invasive methods of CMD and VSA diagnosis and assess the evidence supporting the existing treatment strategies. These include endotype-specific pharmacological therapies, a holistic approach to lifestyle modifications and risk factor management and novel non-pharmacological therapies. Furthermore, the review highlights critical gaps in research and suggests potential areas for future investigation, to improve understanding and management of these conditions.

Coronary Microvascular Dysfunction: Insights on Prognosis and Future Perspectives

Coronary microvascular dysfunction (CMD) comprises a wide spectrum of structural and/or functional abnormalities of coronary microcirculation that can lead to myocardial ischemia. Emerging evidence has indicated that CMD is a relevant cause of morbidity and mortality and is associated with a high risk of major adverse cardiovascular events (MACEs) and heart failure with preserved ejection fraction as well as poor quality of life. This review aims to elucidate briefly the pathogenesis and diagnostic modalities of CMD and to shed light on contemporary evidence on the prognostic impact of CMD. Finally, we will provide an overview of novel emerging therapeutic strategies for CMD.

Bayesian Analytical Methods in Cardiovascular Clinical Trials: Why, When, and How

The Bayesian analytical framework is clinically intuitive, characterised by the incorporation of previous evidence into the analysis and allowing an estimation of treatment effects and their associated uncertainties. The application of Bayesian statistical inference is not new to the cardiovascular field, as illustrated by various recent randomised trials that have applied a primary Bayesian analysis. Given the guideline-shaping character of trials, a thorough understanding of the concepts and technical details of Bayesian statistical methodology is of utmost importance to the modern practicing cardiovascular physician. This review presents a step-by-step guide to interpreting and performing a Bayesian (re)analysis of cardiovascular clinical trials, while highlighting the main advantages of Bayesian inference for the clinical reader. After an introduction of the concepts of frequentist and Bayesian statistical inference and reasons to apply Bayesian methods, key steps in performing a Bayesian analysis are presented, including verification of the clinical appropriateness of the research question, quality and completeness of the trial design, and adequate elicitation of the prior (ie, one's belief toward a certain treatment before the current evidence becomes available); identification of the likelihood; and their combination into a posterior distribution. Examination of this posterior distribution offers not only the possibility of determining the probability of treatment superiority, but also the probability of exceeding any chosen minimal clinically important difference. Multiple priors should be transparently prespecified, limiting post hoc manipulations. Using this guide, 3 cardiovascular randomised controlled trials are reanalysed, demonstrating the clarity and versatility of Bayesian inference.

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.

REGENERATE-COBRA: A phase II randomized sham-controlled trial assessing the safety and efficacy of intracoronary administration of autologous bone marrow-derived cells in patients with refractory angina

AIMS

The REGENERATE-COBRA trial (NCT05711849) will assess the safety and efficacy of an intracoronary infusion of autologous bone marrow-derived mononuclear cells in refractory angina patients with no revascularization options who are symptomatic despite optimal medical and device therapy.

METHODS

REGENERATE-COBRA is a single site, blinded, randomized, sham-controlled, Phase II clinical trial enrolling 110 refractory angina patients with no revascularization options who are symptomatic despite optimal medical and device therapy. Patients will be randomized to either autologous bone marrow derived-mononuclear cells or a sham procedure. Patients in the cell-treated arm will undergo a bone marrow aspiration and an intracoronary infusion of autologous bone marrow derived-mononuclear cells. Patients in the control arm will undergo a sham bone marrow aspiration and a sham intracoronary infusion. The trial's primary endpoint is an improvement in Canadian Cardiovascular Society (CCS) angina class by 2 classes between baseline and 6 months. Secondary endpoints include change in: CCS class at 12 months, myocardial ischemic burden (as measured by perfusion imaging) at 6 months, quality of life at 6 and 12 months (as measured by EQ-5D-5L, EQ-5D-VAS and Seattle Angina Questionnaire), angina frequency at 6 and 12 months, total exercise time (as measured by a modified Bruce protocol) and major adverse cardiovascular events at 6 and 12 months.

CONCLUSIONS

This is the first trial to assess the safety and efficacy of an intracoronary infusion of autologous bone marrow-derived unfractionated mononuclear cells in symptomatic refractory angina patients who have exhausted conventional therapeutic options.

[Coronary sinus reducer : Technical aspects, prevention and management of potential complications]

Coronary sinus reducer implantation is a percutaneous technique creating a narrowing in the coronary sinus through the implantation of an hourglass-shaped endoprosthesis. It is proposed to reduce symptoms in patients suffering from refractory angina pectoris. This innovative treatment is experiencing a major craze among interventional cardiologists. It is associated with very high procedural success rates. Complications are rare and include coronary sinus dissection or perforation and migration of the device. This review exposes the device implantation technique, the potential anatomical difficulties, the tips and tricks to overcome challenging situations. It also focuses on the prevention and management of potential complications.

Safety and Effectiveness of Coronary Sinus Reducer in the Therapy of Refractory Angina Pectoris-Mid-Term Results of the Real-Life Cohort

Background: Despite continuous improvements in revascularization techniques, refractory angina without potential revascularization options remains a relevant clinical issue with significant impact on the patient's quality of life. Recently, a novel device, the Coronary Sinus Reducer (CSR), has been introduced into clinical practice as a therapeutic option for patients with disabling angina pectoris. In this single-center, observational study, we evaluated the mid-term (3-month) safety and efficacy of the CSR in a real-world cohort. Methods: The study population consisted of 55 patients with refractory angina without potential revascularization options, who were predominantly men (87.3%) with a high cardiovascular risk factor burden and advanced angina (baseline CCS angina class 3.15 ± 0.6). In terms of procedure safety, all patients underwent successful device deployment with only one periprocedural complication. Results: At the 3-month follow-up, we observed a statistically significant improvement in angina control measured CCS class and SAQ-7 total questionnaire along with increased abolition of physical limitation-6-MWT (233.3 ± 107.1 vs. 305.2 ± 126.8; p < 0.0001). Additionally, we observed significant improvement in terms of quality of life measurements SF-36, the EQ-5D-5L questionnaire, and the EQ-VAS. Conclusions: Our real-world data suggest that CSR implantation is a relatively safe procedure and appears to be particularly effective in relieving angina symptoms and improving quality of life in subjects with refractory angina.

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.

Evaluating the Efficacy of Coronary Sinus Reducer Implantation in the Management of Refractory Angina: A Systematic Review and Meta-Analysis

The coronary sinus reducer (CSR), a minimally invasive device, has emerged as a promising alternative for improving myocardial perfusion in these patients. This meta-analysis evaluated the effectiveness of CSR implantation in patients with refractory angina. A comprehensive search of PubMed, EMBASE, and Web of Science databases identified 10 relevant studies with a pooled sample size of 799 patients. The analysis focused on changes in the Canadian Cardiovascular Society (CCS) classification score, Seattle Angina Questionnaire (SAQ) score, and six-minute walk distance (6MWD) from baseline to follow-up. Results showed significant improvements across all measured outcomes. CCS scores decreased significantly post-CSR implantation, indicating reduced angina severity. SAQ scores improved across all domains, including physical limitation, anginal stability, anginal frequency, treatment satisfaction, and quality of life, suggesting enhanced overall well-being. The 6MWD also increased significantly, reflecting improved functional capacity. These findings highlight CSR's potential as an effective treatment option for patients with refractory angina who have exhausted traditional therapies. CSR implantation appears to alleviate angina symptoms, improve quality of life, and enhance exercise tolerance. Future research should prioritize larger, multi-center randomized controlled trials to validate these findings. Long-term follow-up studies are needed to assess sustained benefits and potential risks.

Managing chronic coronary syndrome: how do we achieve optimal patient outcomes?

INTRODUCTION

Chronic coronary syndrome (CCS) remains the leading cause of death worldwide with high admission/re-admission rates. Medical databases were searched on CCS & its management.

AREAS COVERED

This review discusses phenotypes per stress-echocardiography, noninvasive/invasive testing (coronary computed-tomography angiography-CCTA; coronary artery calcium - CAC score; echocardiography assessing wall-motion, LV function, valvular disease; biomarkers), multidisciplinary management (risk factors/anti-inflammatory/anti-ischemic/antithrombotic therapies and revascularization), newer treatments (colchicine/ivabradine/ranolazine/melatonin), cardiac rehabilitation/exercise improving physical activity and quality-of-life, use of the implantable-defibrillator, and treatment with extracorporeal shockwave-revascularization for refractory symptoms.

EXPERT OPINION

CCS is age-dependent, leading cause of death worldwide with high hospitalization rates. Stress-echocardiography defines phenotypes and guides prophylaxis and management. CAC is a surrogate for atherosclerosis burden, best for patients of intermediate/borderline risk. Higher CAC-scores indicate more severe coronary abnormalities. CCTA is preferred for noninvasive detection of CAC and atherosclerosis burden, determining stenosis' functional significance, and guiding management. Combining CAC score with CCTA improves diagnostic yield and assists prognosis. Echocardiography assesses LV wall-motion and function and valvular disease. Biomarkers guide diagnosis/prognosis. CCS management is multidisciplinary: risk-factor management, anti-inflammatory/anti-ischemic/antithrombotic therapies, and revascularization. Newer therapies comprise colchicine, ivabradine, ranolazine, melatonin, glucagon-like peptide-1-receptor antagonists. Cardiac rehabilitation/exercise improves physical activity and quality-of-life. An ICD protects from sudden death. Extracorporeal shockwave-revascularization treats refractory symptoms.