Coronary artery disease is a chronic disease, characterized by the formation of atherosclerotic plaque in the coronary arteries, which causes inflammation and can lead to narrowing or even obstruction of the vessel, and to major cardiac events such as heart attacks. Vulnerable plaque, or high-risk plaque, is a particular type of plaque that has a rich necrotic and lipid content in its core within the vessel wall, and a thin cap separating the necrotic core from the bloodstream. This plaque which may not be restricting blood flow, is called high risk plaque because it is at high risk of rupturing, at which point a large amount of the core material would be released in the bloodstream and cause acute thrombus formation, resulting in a heart attack. There are currently no dedicated device treatments available for vulnerable plaque. Current treatments being used such as stents do not address the underlying pathophysiology of the lesion and are commonly associated with a number of problems such as re-narrowing of the vessel and also a future significant risk of a major cardiac events.

Cryotherapy has been shown to be safe, and in applications such as the treatment of atherosclerotic disease in the peripheral vessels (outside of the heart) it has been shown to be effective. CryoTherapeutics has developed a patented console and balloon cryo-catheter to be used by interventional cardiologists to treat areas of vulnerable plaque in the coronary arteries.  The catheter can be inserted in to the coronary artery to position the balloon in the vulnerable plaque lesion. The system will deliver local cryotherapy, and has the advantage that it does not involve leaving in place a permanent implant in non-significantly narrowed arteries. The treatment is applied at temperatures of –10° to – 20°C. The cryotherapy is expected to reduce the inflammatory process and to stabilize the vulnerable plaque, aiming to prevent rupture of the plaque. The treatment does not involve ablation of tissue but rather enhances the vessel healing response.