Severe low-gradient aortic stenosis, with preserved ventricular function: should it be treated?

Exists a group of patients with small AVA (<0,6 cm/m), and normal LVEF (≥50%) who display a low transvalvular flow (LF) [index stroke volume (SVi)<35 ml/m2] and/or low transvalvular gradient (LG). This condition is called severe paradoxical aortic stenosis (SAO) LFLG. In many studies this condition was associated to increased mortality both with medical therapy and with surgical intervention. Crucial is define correctly the diagnostical criteria of this condition. Indeed there are several specific anatomical and functional characteristics useful in differentiating paradoxical severe aortic stenosis from the other forms of aortic stenosis. In case of doubt in the diagnostical process, the Multidetector Computed Tomography (MDCT) could be useful in quantifying calcificazions of the aortic valve. The guidelines European Society of Cardiology (ESC) and American College of Cardiology (ACC) recomended aortic valve replacement for symptomatic patients with paradoxical LFLG severe aortic stenosis, recommending to accurately measure the flow in these patients as to differentiate them from those with NFLG and better prognosis.