Clinical outcome and functional characteristics of patients with asymptomatic low-flow low-gradient severe aortic stenosis with preserved ejection fraction are closer to high-gradient severe than to moderate aortic stenosis.

Asymptomatic "paradoxic" severe low-flow low-gradient aortic stenosis with preserved ejection fraction (PAS) constitutes a challenging condition where the optimal management and follow-up remain elusive. We evaluated the clinical outcome in patients with PAS as compared to asymptomatic patients with moderate (MAS) or classical severe aortic stenosis (CAS). Consecutive asymptomatic moderate or severe aortic stenosis patients without concomitant other heart or lung disease (n = 121) were invited. Participants (n = 74) were assigned to three subgroups with regard to degree of aortic stenosis: MAS (n = 25), CAS (n = 22) and PAS (n = 27). Echocardiographic parameters at baseline and clinical outcome data after > 3 years of follow-up time were obtained. Patients with PAS had the smallest stroke volumes and the highest relative wall thickness (p < 0.05). Left ventricular mass index was highest in subjects with CAS, followed closely by PAS and eventually MAS subjects. Whereas ejection fraction was similar amongst the subgroups, a stepwise decrease in global longitudinal left ventricular strain with increasing degree of aortic stenosis was observed, with CAS patients displaying the lowest mean global longitudinal strain, followed by PAS and MAS. A trend towards increasing mortality rate by increasing degree of stenosis was observed. Patients with CAS underwent aortic valve replacement surgery more frequently than both PAS and MAS (p < 0.001). These data suggest that echocardiographic parameters and clinical outcome in patients with PAS bear closer resemblance to CAS than to MAS, but management of PAS is more conservative than in CAS.