Cardiovascular disease
Aortic Valve Disease
Aortic Stenosis (AS) is the most common valvular heart disease in both the EU and the USA. It is predominantly a disease associated with calcification of the aortic valve in old age (estimated 2% – 7 % of the population over 65). For younger patients the most common underlying factor is congenital bicuspid valve disease.
Echocardiography is the primary tool to confirm the presence of AS and the degree of calcification, to assess LV function and wall thickness and to provide prognostic information. Doppler echocardiology provides information on severity.
Valve area is theoretically the best measure of AS but may be operator dependant. Therefore, it should be considered in the light of other factors such as; degree of calcification, flow rate, pressure gradient, LV function, size and wall-thickness, blood pressure and functional status.
Once symptoms become apparent, mortality in patients without surgical treatment may be as high as 10–20% per year. According to the ESC guidelines, in asymptomatic patients a LV end-systolic diameter (LVESD) is 50 mm is an indication for valve intervention. In patients with bicuspid aortic valve the size of the aorta is additional indication for operation (at the level of the ascending aorta).
Aortic valve replacement is the standard therapy for severe AS. Early replacement is recommended for all symptomatic patients with severe AS who are considered suitable for surgery as the disease is progressive and there is no medical therapy that is able to improve outcome.
Operative mortalities range from ~1-8 % depending on age.
Other factors, relevant to the timing of intervention, that increase risk include
increased age
functional class
emergency operation
LV dysfunction
pulmonary hypertension
Whilst surgery has been shown to prolong life and improve quality of life many patients are not offered it.
Types of surgical intervention
Read about the types of valve intervention.
Balloon valvuloplasty alone has a very limited role in treatment of adults with AS as the risk of complications and the reoccurrence of disease is high. Transcatheter aortic valve implantation (TAVI) is usually beneficial for high risk patients but is not available at all centres and the long-term durability of TAVI valves has yet to be established.
Management of asymptomatic patients with severe AS is controversial, and there is no data to support early replacement in asymptomatic patients with very severe AS.
Aortic regurgitation (AR) is the second most common form of aortic valve disease. In many patients (eg with bicuspid aortic valves) AS is combined with AI Patients with AS. Chronic and severe volume overload due to AR and symptoms has, if left untreated, poor long-term prognosis.
Mitral Valve Disease
Mitral regurgitation (MR) is the second most frequent valve disease in the EU.
There are two types
primary which relates to pathology of the valve components
secondary in which the valve is in a normal state but the supporting apparatus – the annulus or papillary muscles – are damaged by disease.
Degenerative MR has now become the most common.
For asymptomatic patients, an estimated five year rate of death from any cause has been reported in 22% of cases [Ref 1].
There is a trend that valve repair is preferred over valve replacement in surgical therapies. In addition, transcatheter valve repair techniques are increasingly used that were also pioneered by our institutions.
As stated, many variations of repair/replacement techniques have been used with varying success rates in terms of perioperative mortality, preservation of postoperative ventricular function or long-term morbidity [Ref 2].
More recently, percutaneous methods for replacement of the mitral valve [Ref 3] have been successfully introduced. There is consensus, that different types of valve prosthesis (size, shape) or repair techniques will have different functional results [Ref 4], [Ref 5].
The planned DSS will allow for in-silico simulation of different treatment options and thus allow comparing their immediate hemodynamic outcome.
In addition, the DSS is also expected to simulate the outcome in complex cases of mitral disease, eg in patients that have combined AS and MR. We expect that in our study population (see work package four) approximately 30% of the patients will have combined AS-MR.
References
[Ref 1] Enriquez-Sarano M, Akins CW, Vahanian A. Mitral regurgitation. Lancet 2009;373:1382–1394.
[Ref 2] Lung et al. 2003
[Ref 3] Gaemperli et al. 2012
[Ref 4] Carlsson et al.2012
[Ref 5] Mahedevia et al. 2014