Grant: Operating Grant

Patients with narrowing of the aortic cardiac valve (i.e. aortic stenosis, AS) and concomitantly a reduced cardiac output (i.e. low blood flow across the valve) represent the most challenging subset among patients with valvular heart disease. In the setting of a low cardiac output, it is often difficult to separate patients with true severe AS (TS AS) from those with pseudosevere AS (PS AS). The distinction between these 2 subgroups is essential because the patients with TSAS will generally benefit of aortic valve replacement surgery (AVR), whereas the patients with PS AS will not. Beyond the distinction between TS AS and PS AS, it is also important to assess the extent of impairment of the cardiac muscular function because patients with more severe impairment of muscular function undergoing AVR have a very high risk of operative mortality regardless of the degree of valve stenosis. Unfortunately, the diagnostic tools (echocardiography) currently used to assess the severity of valvular obstruction and the cardiac function in patients with low-output AS are far from being optimal, and as a consequence, several patients are misdiagnosed and thus do not receive the appropriate therapies. The objective of this prospective multicenter study is to develop and validate new indices and criteria based on echocardiography, magnetic resonance imaging (MRI), computed tomography (CT) imaging, and blood cardiac hormones (BNP) that will contribute: (1) to better separate TS AS from PS AS, (2) to accurately assess the extent of cardiac function impairment, and (3) to better predict the operative risk for AVR and the evolution of cardiac function and symptoms after AVR. We believe that a strategy based on echo, MRI, CT, and BNP will contribute to improve the risk stratification and the clinical decision making in these high-risk patients with AS and low cardiac output.