The efficacy and safety of coronary sinus reducer in refractory angina: a systematic review and meta-analysis.

BACKGROUND

Refractory angina is a challenging medical disorder associated with continuous anginal symptoms that do not respond to medical treatments or revascularization interventions. Coronary sinus reducer (CSR) has been introduced as a promising treatment option for patients with refractory angina. However, the avaliable evidence regarding the exact role of CSR in managing refractory angina is still inconclusive and limited by several factors, such as small sample size studies, and short follow up periods. Therefore, we conducted this study to evaluate the effectiveness and safety of CSR for managing patients with refractory angina.

METHODS

An extensive digital search of several databases encompassing PubMed, Scopus, Web of Science, and Cochrane Library was conducted from inception until August 2024. We included all studies that assessed the clinical and functional outcomes of CSR in treating patients with refractory angina. Our primary endpoint was ≥ 1 class improvement of the Canadian Cardiovascular Society (CCS) score. Secondary outcomes were implantation success, periprocedural complications, and cardiovascular mortality. We also assessed the functional outcomes, such as the six-minute walk distance (6MWD), CCS, and Seattle Angina Questionnaire (SAQ) scores.

RESULTS

20 studies comprising 1565 patients constituted our systematic review and meta-analysis. Our pooled analysis revealed that 70% (95% CI, [65-74%], P < 0.001) of the patients showed an improvement ≥ 1 class in CCS score after CSR. Additionally, the implantation success rate was 99% (95% CI [98-100%], P < 0.001), and the periprocedural complications were severely low and estimated at 2% with 95% CI of [1-3%]. The pooled analysis showed that CSR significantly improved the functional outcomes, including 6MWD, CCS score, and all SAQ domains.

CONCLUSION

CSR appears to be a safe and effective treatment for refractory angina, providing significant improvements in symptoms and quality of life. The significant success rate of implantation and very low complication rates support its use as an alternative therapy for patients not permitted for conventional revascularization.

CLINICAL TRIAL NUMBER

Not applicable.