Transcoronary Sinus Therapy for Coronary Microvascular Dysfunction.

Coronary microvascular disease has been found to increase the incidence of the composite endpoint for cardiovascular events and affect coronary revascularization. Coronary microvascular disease is often accompanied by epicardial disease, and despite successful revascularization and optimal medications, coronary microvascular disease may lead to reduced exercise tolerance and worsening clinical symptoms. Moreover, despite advances in percutaneous coronary intervention for coronary revascularization, the management of microvascular obstruction in reperfused myocardial tissue remains challenging and is a high-risk procedure. Previous studies have identified the coronary venous system as a new avenue for treating coronary microvascular obstructions associated with revascularization. Current data suggest that coronary sinus interventions, which primarily include coronary sinus reducer and pressure-controlled intermittent coronary sinus occlusion interventions, can provide significant clinical aid in 70-80% of patients with refractory angina pectoris and acute myocardial infarction who suffer from microvascular disease with no possibility of revascularization by modulating coronary venous pressures. However, a recent randomized trial demonstrated no difference in infarct size reduction between the pressure-controlled intermittent coronary sinus occlusion-assisted and conventional primary percutaneous coronary intervention groups. This article reviews recent advancements in coronary sinus-based therapeutic approaches for coronary microvascular disease.