<International Circulation>: Improvements in heathcare actually leads to the increase in the incidence of some conditions， such as aortic valve calcification. Aortic valve calcification in elderly patients can cause aortic stenosis and because age has increased risk for all kinds of complications and multiple organ dysfunctions， the risk of surgery is very high. Recently， percutaneous aortic valve implantation has presented itself as an appropriate therapy for these special patients. Can you outline the indications and contraindications for the procedure?

    Dr Ussia: Aortic stenosis is the most frequent valvulopathy in the elderly population in Western countries. So there is a large need to be able to treat these patients with less risk. Most of the elderly patients have higher cardiac surgery risk for several reasons due specifically to age: frailty and because very often they have co-morbidities. Additionally very often they are anxious and afraid of the prospect of surgery.
    This new device， the transcatheter aortic valve prosthesis， is a biological valve， and in Europe is available for clinical use as two types.  The technology is  young having appeared on the market only three years ago and for this reason at the moment the indication for its use is in patients judged at high risk for surgical aortic valve replacement.
So the indications would be patients around 75 years of age with a EuroSCORE more than 20% or an STS-PROM score more than 10% or patients with porcelain aorta，  liver cirrhosis， hostile thorax， with previous coronary artery bypass operation， or those that are very frail assessed by the frailty index score.
    There is also indication for patients who have already had an aortic valve replacement with a biological prosthesis which is dysfunctional. We have seen with both types of valves that are available – the self-expanding and the balloon expandable – we can treat with very good results， previous surgical aortic biological valve malfunction due to restenosis or regurgitation.
    There are few contraindications to this procedure mainly for unfavorable anatomy assessed during the screening phase with echocardiography， angiography， and angio CT scan.