Value of low-dose dobutamine stress echocardiography on defining true severe low gradient aortic stenosis in patients with preserved left ventricular ejection fraction

Low-dose dobutamine stress echocardiography (DSE) is a valuable tool to distinguish true-severe (TS) from pseudo-severe (PS) low gradient aortic valve stenosis (LGAS) in patients with reduced left ventricular ejection fraction (LVEF). However, only scanty studies reported the clinical utility of DSE in differentiating TS-LGAS patients with preserved LVEF. We investigated the clinical utility of DSE in LGAS patients with preserved LVEF and the echocardiographic determinants suggestive of TS-LGAS. 130 consecutive LGAS patients [indexed aortic valve area (AVA) ≤ 0.6cm2/m2 and mean trans-aortic pressure gradient (PGmean) < 40mmHg] with preserved (≥ 50%, n = 63) and reduced (< 50%, n = 67) LVEF were included. DSE defined TS-LGAS (projected AVA ≤ 1 cm2) in 61.2% patients with reduced LVEF and in 68.3% patients with preserved LVEF. Multivariate logistic regression analysis showed that baseline AVA was an independent determinant of TS-LGAS both in LVEF ≥ 50% (OR 0.45, P = 0.004) and LVEF < 50% groups (OR 0.55, P = 0.005). Reduced septal and lateral mitral annular plane systolic excursion (MAPSE, OR 0.72 and 0.75, P = 0.013 and 0.016) and septal TDI-s´ were significantly associated with TS-LGAS in patients with LVEF ≥ 50%. Higher systolic pulmonary artery pressure (SPAP, OR 1.43, P = 0.045) was associated with TS-LGAS in patients with LVEF < 50%. DSE is useful to define TS-LGAS also in patients with preserved LVEF. Lower baseline AVA values are linked with TS-LGAS in both patients with reduced and preserved LVEF. Reduced MAPSE and septal TDI-s´ are suggestive of TS-LGAS in patients with preserved LVEF, while higher SPAP is associated with TS-LGAS in patients with reduced LVEF.