Abstract Body (Do not enter title and authors here): Introduction: Despite the continuous development of the medical therapeutic revolution, there are many conditions that pose a great challenge and are still spreading at increasing rates, such as refractory angina (RA), which is considered a burden on patients and on the health systems. However, with the emergence of effective treatment options such as a coronary sinus reducer (CSR) that works to narrow the coronary sinus in controlled manner aiming to restore efficient blood flow and reduce symptoms.
Purpose: We aimed to study the effectiveness of CSR in patients with refractory angina (RA), and give a comprehensive appraisal from the published records.
Methods: A comprehensive search was done on PubMed, Cochrane Library, Scopus, and WOS until Feb 2024. We included studies that assessed the effectiveness of CSR in patients with RA. Clinical improvement, implantation success, periprocedural complications, revascularization, 6MWT distance and change in SAQ score were our outcomes of interest.
Results: 18 studies comprising 1149 patients were included in the analysis. The pooled implantation success was 98% (95% CI: 97% to 99%), clinical improvement > 1 class was 63% (95% CI: 52% to 72%), and clinical improvement > 2 class was 37% (95% CI: 32% to 41%). The incidence rate of periprocedural complications and PCI was reported as follows, respectively (OR: 0.05, 95% CI: 0.03 to 0.08, and 0.37, 95% CI: 0.18 to 0.61). Moreover, the incidence rate of all-cause mortality was low (OR: 0.06, 95% CI: 0.03 to 0.11). Regarding physical activity and quality of life, CSR improved 6MWT distance (MD = 323.82, 95% CI: 273.52 to 372.13), and all categories of SAQ score either angina frequency, angina stability, physical limitation, quality of life, or treatment satisfaction.
Conclusion: Coronary Sinus Reducer is a promising treatment for the management of refractory angina, as it showed clinical improvement with higher implantation success. It also improved the physical activity and quality of life scores. Large-volume RCTs are warranted to test the efficacy of CSR in a long-term manner.