UNMET MEDICAL NEED
Calcified aortic stenosis (CAS) affects 3 to 12% of the population aged 65 and over: it has become a major public health concern because of the ageing Western population population (by 2030, 1 person out of 3 will be over 65 in Europe). There are 5 million patients currently affected in Europe, of which 1.3 million have developed a severe case which requires a valve replacement surgery, as the survival rate is 2 to 5 years following diagnosis.
CAS is caused by the narrowing of the opening of the aortic valve which is the “gateway” from the heart to the body. It is made up of three flexible leaflets that need to open completely to allow oxygened blood to exit from the heart towards the vital organs. With age, the aortic valve calcifies and stiffens, it is less elastic. It fails to open fully leading to poor blood perfusion of the body.
About 20% to 30% of affected patients are not eligible to current medical response which is surgery or they refuse the surgery
CURRENT MEDICAL RESPONSE
The only medical response to CAS is currently a valve replacement surgery, either by open-heart surgery or by a less-invasive procedure called TAVR or TAVI:
The standard treatment consists in replacing the aortic valve with an artificial tissue or mechanical valve during an open-heart surgery, with extracorporeal circulation and the heart stopped – the patient is clinically dead. This surgery is a serious, expensive and risky operation. A third of diagnosed patients are ineligible to this surgery because they are too weak, there are contraindications or the risks outweigh the benefits.
Since 2007, a new technique for minimally invasive endovascular surgery called TAVR (Trans Aortic Valve Replacement) has been used with spectacular results. This surgery consists in replacing the aortic valve via a percutaneous route passing through either the aorta or the femoral artery. It allows almost half the patients for whom open-heart surgery is contraindicated to be treated, but it has an incidence of vascular and haemorrhagic complications of over 20% and causes a significant number of cerebrovascular accidents and kidney injury.
The morbidity associated with both surgeries remains high: 3-7% of patients die during surgery, 24-26% die within 1 year, 44% within 3 years. These surgeries also cause numerous complications (CVA, infections and infarctions).
Finally, these procedures represent a significant cost to public health systems, for reference US$100,000 per patient in the United States. Overall costs associated with aortic valve disease exceeds $50 billion in Western countries.