Coronary Sinus Reducer: History, Current Applications, and Future Perspectives

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology

Background:

• Refractory angina significantly impacts quality of life, particularly in patients with severe coronary artery disease (CAD) ineligible for revascularization.
• The coronary sinus reducer (CSR) is a percutaneous device derived from surgical coronary sinus ligation (CSL).

Purpose of the Study:

• To evaluate the efficacy of CSR in improving coronary blood flow and alleviating angina symptoms.
• To explore the mechanism of action of CSR, including its effects on microvascular function.
• To assess the potential of CSR for patients with angina/ischemia and non-obstructive coronary arteries (ANOCA/INOCA).

Main Methods:

• Percutaneous implantation of the CSR device to narrow the coronary sinus.
• Assessment of myocardial perfusion, microvascular resistance, and capillary recruitment.
• Clinical evaluation of angina symptom reduction and patient outcomes.

Main Results:

• CSR effectively enhances perfusion in ischemic myocardial territories, particularly subendocardial regions.
• The device reduces microvascular resistance and promotes capillary recruitment.
• Emerging evidence suggests CSR improves microvascular function in patients with coronary microvascular dysfunction.

Conclusions:

• CSR is an effective treatment for chronic refractory angina in patients with severe CAD unsuitable for revascularization.
• CSR demonstrates potential therapeutic benefits beyond obstructive CAD, including for ANOCA/INOCA.
• Further research is expanding the understanding of CSR's mechanism and clinical applications.