Assessment of left atrial reservoir function in rheumatic mitral stenosis with pulmonary hypertension

Abstract

The pathophysiology triggering dyspnea in rheumatic MS patients remains not fully understood. Recently introduced echocardiographic techniques allowed the study of left atrial reservoir function (LASr) notably in patients with PH. The objective of this study was to assess the correlation between LASr determined by 2D STE derived from global LA strain and PH. We performed prospective 2D TTE in patients with rheumatic MS. 2D and doppler TTE parameters, including indexed LA volume, maximal trans tricuspid velocity (TRVmax), mean trans-mitral gradient (MTMG), valve area (MVA) using pressure half time (PHT), 2D and 3D planimetry and left ventricular index stroke volume, were recorded. Doppler parameters are determined as the mean of three measurements. Maximal TRVmax was used as an indicator of the degree of PH to ignore assumptions on the right atrial pressure. A TRVmax cut-off value ≥ 2.9 m/s was retained to determine an intermediate to high probability of PH. NYHA functional status was determined moments before performing the scan. We enrolled 195 patients with rheumatic MS, with a mean age of 50.55 ± 12.07 years (between February 2018 and October 2021). Patients were divided into two groups: group 1 had TRVmax ≥ 2.9 m/s and group 2 had TRVmax < 2.9 m/s. There was no difference in age (52 ± 12 vs. 49 ± 11, P = 0.16) and in sex (respectively 69.8% and 76.1% were female, P = 0.3). AF was comparable between the two groups (69.8 vs. 65.7%, P = 0.5). There was no difference in the incidence of severe dyspnea (48.8% vs. 43.1%, P = 0.5 had NYHA class III or I symptoms). Incidence of diabetes mellitus was significantly higher among patients with PH (24.4 vs. 10.6%, P = 0.02). Patients in the PH group had significantly higher MTMG (13 ± 6 vs. 8 ± 3 mmHg, P < 0.001) and significantly lower MVA (1.1 ± 0.5 vs. 1.5 ± 0.5 cm2, P < 0.001). LASr was significantly higher in patients without PH (11.1 ± 7 vs. 8.9 ± 5%, P = 0.05). LASr was associated with a lower incidence of pulmonary hypertension in patients with MS.