Unidimensional longitudinal strain in moderate-severe aortic stenosis with low flow and preserved systolic function.

Purpose : Low flow (LF) (stroke volume index (SVI) < 35ml/m ) is a prognostic marker in aortic stenosis (AS). Longitudinal strain evaluated with speckle tracking is related to LF. Unidimensional strain derived from Mitral Annular Plane Systolic Excursion (MAPSE) is a surrogate of longitudinal strain. The objective was to evaluate the relationship of the unidimensional longitudinal strain (LVSTRAIN) with the LF in moderate (MAS) or severe (SAS) AS. Methods: Patients with MAS (aortic valve area < 1.50 cm ) or SAS (aortic valve area ≤ 1 cm ) and ejection fraction ≥50% were evaluated. LVSTRAIN was calculated using the average of lateral and medial MAPSE, and divided by the length of the left ventricle (LV) in diastole. In SAS four groups were substratified, depending on LV flow status: normal flow (NF) vs. LF and mean pressure gradient levels: low gradient (LG) (<40 mmHg) vs. high gradient (HG) (≥40 mmHg). Results: One hundred and fifty-nine patients were evaluated. LF was 20.14%. LVSTRAIN was 16.74% (±2.45) in NF and 12.28% (±3.06) in LF (p=<0.001). A correlation was observed between the LVSTRAIN and the SVI (r=0.47-p=<0.001), both in MAS (r= 0.51-p<0.001) and in SAS (r=0.45-p=<0.001). Patients with LF and MAS had lower LVSTRAIN than those with NF, 11.39% (±2.51) and (16.75% (±2.05), respectively (p=0.007). Patients with SAS with both LFHG and LFLG had lower LVSTRAIN than those with NF (p=<0.001). Conclusion: LVSTRAIN is decreased in patients with MAS or SAS and LF. A significant correlation was observed between SVI and LVSTRAIN in both SAS and MAS.