The Coronary Sinus Reducer; 5-year Dutch experience

The Coronary Sinus Reducer Stent for the Treatment of Refractory Angina Pectoris: From the Conception of Innovation to Clinical Application

The Neovasc Coronary Sinus Reducer Stent (CSRS) was developed for the treatment of patients who continue to suffer from disabling symptoms despite optimal medical therapy. This patient population with refractory angina symptoms is expected to grow, since life expectancy of individuals with atherosclerotic coronary artery disease is increasing. In this paper, we discussed the development of a novel device the CSRS and the upside-down strategy to rebuild a retrograde coronary pressure that was attenuated by the atherosclerotic disease.

[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.

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.

Mechanisms of coronary sinus reducer for treatment of myocardial ischemia: in silico study

The coronary sinus reducer (CSR) is an emerging medical device for treating patients with refractory angina, often associated with myocardial ischemia. Patients implanted with CSR have shown positive outcomes, but the underlying mechanisms are unclear. This study sought to understand the mechanisms of CSR by investigating its effects on coronary microcirculation hemodynamics that may help explain the therapy's efficacy. We applied a validated computer model of the coronary microcirculation to investigate how CSR affects hemodynamics under different degrees of coronary artery stenosis. With moderate coronary stenosis, an increase in capillary transit time (CTT) [up to 69% with near-complete coronary sinus (CS) occlusion] is the key change associated with CSR. Because capillaries in the microcirculation can still receive oxygenated blood from the upstream artery with moderate stenosis, the increase in CTT allows more time for the exchange of gases and nutrients, aiding tissue oxygenation. With severe coronary stenosis; however, the redistribution of blood draining from the nonischemic region to the ischemic region (up to 96% with near-complete CS occlusion) and the reduction in capillary flow heterogeneity are the key changes associated with CSR. Because blood draining from the nonischemic region is not completely devoid of O2, the redistribution of blood to the capillaries in the ischemic region by CSR is beneficial especially when little or no oxygenated blood reaches these capillaries. This simulation study provides insights into the mechanisms of CSR in improving clinical symptoms. The mechanisms differ with the severity of the upstream stenosis.NEW & NOTEWORTHY Emerging coronary venous retroperfusion treatments, particularly coronary sinus reducer (CSR) for refractory angina linked to myocardial ischemia, show promise; however, their mechanisms of action are not well understood. We find that CSR's effectiveness varies with the severity of coronary stenosis. In moderate stenosis, CSR improves tissue oxygenation by increasing capillary transit time, whereas in severe stenosis, it redistributes blood from nonischemic to ischemic regions and reduces capillary flow heterogeneity.

A budget impact model and a cost-utility analysis of reducer device (Neovasc) in patients with refractory angina

Background

Refractory angina (RA) is a chronic condition characterized by the presence of debilitating angina symptoms due to established reversible ischemia in the presence of obstructive coronary artery disease (CAD). Treatments for this condition have undergone major developments in recent decades; however, the treatment for RA remains a challenge for medicine. In this sense, the Coronary Sinus Reducer System (CSRS) stands as the last line of therapy for ineligible patients for revascularization with reversible ischemia. The purpose of this report is to evaluate the potential burden on the National Health Service (NHS) and measure the health effects in terms of both quantity (life years) and quality-of-life aspects related to the reducer.

Methods

Two different economic evaluation models were developed as part of the analysis. The budget impact was developed to estimate the potential burden on the NHS from incremental uptake of the use of the reducer in the target population. The utility cost analysis compares and evaluates the quality of life and health resource use and costs between the two alternatives, based on the research of Gallone et al. A deterministic and probabilistic sensitivity analysis was carried out to characterize the uncertainty around the parameters of the model.

Results

In the budget impact analysis (BIA), the reducer is shown to be more expensive in the first 2 years of the model, due to the gradual uptake in the market and the cost of the device. Starting from the third year, assuming maintenance of effectiveness, there are savings in terms of resource absorption in direct healthcare costs arising from hospitalizations, emergency department accesses, coronarography, and visits avoided.

Conclusion

The BIA and cost-effectiveness model show that the reducer device, despite an increase in resources absorbed in the first years of implementation and use, has the potential to result in increased quality of life in patients with RA. These costs are largely offset in the short term by the improved clinical outcomes achievable leading to savings from the third year onward in the BIA and a dominance ratio in the cost-utility analysis.

The Efficacy of Coronary Sinus Reducer in Patients with Refractory Angina: A Systematic Review and Meta-Analysis

Background

Refractory angina is a frequently encountered phenomenon in patients with coronary artery disease, often presenting therapeutic challenges to the clinical cardiologist. Novel treatment methods have been explored in this direction, with the coronary sinus reducer (CSR) being among the most extensively-investigated.

Methods

We conducted a systematic review of the literature for studies assessing the efficacy of CSR in patients with refractory angina. The primary endpoints of interest were procedural success and the improvement in angina according to the Canadian Cardiovascular Society (CCS) by at least one class. Secondary endpoints were the rate of periprocedural adverse events, the improvement by at least 2 CCS classes, and the mean change in CCS class. A random-effects meta-analysis of proportions (procedural success, improvement by ≥ 1 or ≥ 2 classes, periprocedural adverse events) or means (mean CCS class change) were performed. I 2 was chosen as the metric for between-study heterogeneity. Publication bias was assessed by the inspection of funnel plots and Egger's regression test. We examined the risk of bias according to the Newcastle-Ottawa Scale.

Results

From a total of 515 studies identified from the original search, 12 studies were finally included for data extraction. Based on their meta-analysis, we observed a high CSR procedural success (98%, 95% confidence interval (CI) 96 to 99%) with a low rate of periprocedural complications (6%, 95% CI 5 to 7%), while most patients exhibited an improvement by at least 1 CCS class (75%, 95% CI 66 to 83%) after the intervention. A significant proportion of patients demonstrated an improvement by at least 2 CCS classes (39%, 95% CI 34 to 45%), with a mean change of -1.24 CCS class (95% CI -1.40 to -1.08).

Conclusions

CSR is associated with high implantation success rates and significant improvements in angina symptoms for patients with refractory angina.

Coronary sinus narrowing therapy: A "Reducer" for angina and beyond

Refractory Angina (RA) is an increasingly common clinical diagnosis, in which patients unsuitable for further percutaneous or surgical procedures experience anginal symptoms, despite receiving optimal medical therapy. This clinical condition challenges the everyday activities and diminishes the quality of life of these patients. A wide variety of novel therapies for this type of angina are being investigated for clinical use. One of them is coronary sinus narrowing, which is performed as a percutaneous interventional procedure using catheter-delivered device, the Reducer. The device is implanted in the coronary sinus creating a physical narrowing and a pressure gradient in the sinus. This intervention improves the impaired blood flow in the ischemic regions of the heart leading to the relief of the anginal symptoms and, therefore, the overall clinical improvement of these patients. Several clinical trials have established both the safety and efficacy of the coronary sinus Reducer, while ongoing trials are aiming to further establish the procedure's safety and efficiency in both RA and other cardiovascular diseases, such as coronary microvascular dysfunction. This review aims to discuss the pathophysiology and the role of the coronary sinus Reducer in RA, the clinical trials documenting its safety and efficacy, as well as the future perspectives of this procedure among cardiovascular diseases.

[Coronary sinus reducer : Literature review and issues surrounding the France Reducer registry]

Coronary sinus Reducer implantation is a percutaneous technique used to treat patients suffering from refractory angina pectoris. The device narrows the coronary sinus, increases the back pressure in the myocardial venous system and forces redistribution of coronary blood flow from less ischemic subepicardium to the more ischemic subendocardium. Multiple clinical studies had proven its efficacy to alleviate myocardial ischemia and related symptoms, and to improve the quality of life of patients with refractory symptomatic chronic coronary artery disease for whom coronary revascularization is deemed unsuitable. This literature review aims to expose the device design, its mechanisms of action, and the clinical data supporting its use. Since November 2021 Reducer's reimbursement has been granted in France by the national health authority. It is the first device to be approved under a newly established reimbursement approval process. A transitional coverage is provided with opportunities for renewal before applying for full-time reimbursement. To fulfill the requirements of the National Commission for Evaluation of Medical Devices and Health Technologies, the French Society of Cardiology has been creating the France Reducer registry. This clinical registry has been collecting data from patients undergoing coronary sinus Reducer implantation regarding their clinical situation, periprocedural information, and one-year follow-up. It is crucial for the future of this emerging therapeutic option in France. To date, 215 patients from 28 centers have been included between June 2022 and September 2023.

Coronary sinus Reducer device for the treatment of refractory angina: A multicenter initial experience

INTRODUCTION

The coronary sinus Reducer (CSR) device has emerged as a complementary therapy in patients with severe angina refractory to optimal medical therapy and not amenable to revascularization. Our aim was to assess the safety and efficacy of the CSR in a real-world setting.

METHODS

Twenty-six patients with refractory angina (RA) and evidence of myocardial ischemia attributable to the left coronary artery considered unsuitable for revascularization were treated with the CSR at two centers between May 2017 and July 2019. Safety endpoints were procedural success and complications. Efficacy endpoints, assessed at six-month follow-up, were reduction in CCS class, improvement in quality of life (QoL) assessed using the short version of the Seattle Angina Questionnaire (SAQ-7), and reduction in antianginal therapy.

RESULTS

Twenty-three patients had end-stage coronary artery disease without revascularization targets and three had microvascular disease without epicardial stenosis. Procedural success was achieved in 23 patients, with two device/procedure-related complications and one anatomically-related failure to deliver the device. A total of 25 patients had the device implanted and entered the efficacy analysis. Eighteen patients (75.0%) had a reduction of at least one CCS class, 41.7% had a reduction of at least two classes, and 16.7% became asymptomatic, with a mean reduction in CCS class of 1.3±0.2 (p=0.001) at six-month follow-up. All SAQ-7 domains improved, notably physical limitation (p=0.001), angina frequency (p=0.005) and QoL (p=0.006). There was a mean reduction in anti-ischemic drugs from 3.4±1.1 to 2.9±1.2 (p=0.010).

CONCLUSION

In this real-world, multicenter experience, implantation of the CSR was associated with improvement in angina and QoL in patients with RA.

Transcatheter Coronary Sinus Interventions

The coronary sinus has become a popular route for an increasing number of innovative transcatheter interventions to treat coronary and structural heart diseases. However, interventional cardiologists have limited experience with the cardiac venous system and its highly variable anatomy. In this paper, we review the anatomy of the cardiac veins as it relates to transcatheter interventions. We also provide a contemporary overview of the emerging coronary sinus-based transcatheter therapies and their growing literature.

Coronary sinus reducer for the treatment of chronic refractory angina pectoris

Refractory angina represents the final stage of chronic coronary artery disease, where anginal symptoms persist despite complete epicardial coronary artery revascularization and maximally tolerated pharmacological therapy. Percutaneous narrowing of the coronary sinus with the Coronary Sinus Reducer^® device was first attempted in humans in 2005 and has been shown to improve angina symptoms and the quality of life of patients suffering chronic refractory angina. It was recently included in the European guidelines for the management of chronic coronary syndrome and is progressively gaining popularity. The authors hereby provide a review of current literature on the topic, intending to facilitate insights and to promote further research on this device and its clinical applications.

The Effectiveness of CS Reducer for the treatment of Refractory Angina - a Meta-Analysis

BACKGROUND

Refractory angina is a debilitating condition that affects quality of life of patients worldwide, that after exhausting standard available therapies are regarded as "no option" patients. Recently, coronary sinus (CS) Reducer implantation became available and is gaining popularity in the treatment of refractory angina. The effectiveness of this therapy was demonstrated in one randomized sham-control trial and numerous uncontrolled prospective studies entailing altogether several hundred patients. We performed a meta-analysis to incorporate the data and elucidate its efficacy and safety.

METHODS

A meta-analysis of prospective studies assessing the effects of CS narrowing published in English until June 2021 was performed. The primary outcome was the proportion of patients improving ≥1 class in the Canadian Cardiovascular Society (CSS) angina score. Other endpoints included proportion of patients improving ≥2 CCS classes, procedural success, periprocedural complications, changes in Seattle Angina Questionnaire (SAQ) scores, and six-minute walk test (6MWT).

RESULTS

Data from 9 studies, including 846 patients was included. An improvement of ≥1 CSS class occurred in 76% [95% CI 73%- 80%] of patients. Improvement of ≥2 CSS classes was observed in 40% of patients (95% CI of 35-46%). Procedure success was 98%, with no major and 3% of non-major periprocedural complications. Post procedural SAQ scores and 6MWT distance were significantly improved.

CONCLUSIONS

In patients suffering from angina refractory to medical and interventional therapies, CS narrowing implantation improves symptoms and quality of life, with a low complication rate. These results are consistent in one randomized trial and in multiple prospective, uncontrolled studies.

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.