Coronary sinus stent insertion for refractory angina

The condition

2.1 Angina is pain or constricting discomfort that typically occurs in the front of the chest (but may radiate to the neck, shoulders, jaw or arms), and is brought on by physical exertion or emotional stress. Some people can have atypical symptoms, such as gastrointestinal discomfort, breathlessness or nausea. Angina is the main symptom of myocardial ischaemia. It is usually caused by atherosclerotic obstructive coronary artery disease restricting blood flow and therefore oxygen delivery to the heart muscle. Being diagnosed with angina can have a significant impact on a person's quality of life, restricting daily work and leisure activities.

Current treatments

2.2 NICE's guideline on stable angina describes recommendations on managing stable angina. Options include lifestyle advice, drug treatment and revascularisation using percutaneous or surgical techniques.

2.3 For patients with refractory angina, these treatments do not control symptoms or are not clinically suitable. Coronary sinus stent insertion is indicated for those patients in whom other treatment options (medical or surgical) have failed or are not possible. The aim is to reduce symptoms, and to improve quality of life and long-term morbidity and mortality.

The procedure

2.4 The coronary sinus is a large venous structure formed by the merging of veins that drain blood away from the myocardium. It receives most of cardiac venous blood, which then flows into the right atrium (along with deoxygenated blood from the superior and inferior venae cavae).

2.5 This procedure uses a percutaneously inserted balloon-expandable stent device to narrow the coronary sinus. In current practice the device used is a stainless-steel mesh hourglass-shaped device. The stent device is usually inserted via the right jugular vein or femoral vein under local anaesthesia. A catheter is introduced through the vein, then the superior or inferior vena cava to the right atrium and into the main vessel of the coronary sinus. Injected contrast is used to visualise the anatomy of the coronary sinus, to define and measure the most suitable position for implanting the stent device. A guiding catheter is then used to advance the device to the implantation site. The device is mounted on a balloon, which is inflated to expand it. Imaging is used to confirm full occlusion of the coronary sinus by the balloon which is then deflated and the catheter pulled back.

2.6 The device becomes the sole path for blood flow through the coronary sinus, leading to development of an upstream pressure gradient that results in redistribution of blood from the less ischaemic epicardium to the ischaemic endocardium.