Mitral annular plane systolic excursion to left atrial volume ratio – a strainless relation with left ventricular filling pressures

Left atrial reservoir strain (LASr) offers diagnostic and prognostic value in patients with heart failure. However, LASr may be technically challenging and is not available to all clinical echocardiographers. Since LASr is a consequence of left atrial (LA) stretch during apical descent of the mitral annulus, we hypothesized that a ratio between mitral annular plane systolic excursion (MAPSE) and LA volume (LAV) may offer similar diagnostic value as LASr. We aimed to investigate the relationship between MAPSE/LAV and LASr and evaluate the diagnostic performance of MAPSE/LAV to identify patients with elevated LV filling pressure. MAPSE/LAV and LA strain measures were obtained in patients referred for echocardiography due to aortic stenosis, and in patients who had undergone clinically indicated right heart catheterization (RHC) with simultaneous echocardiography. In 93 patients with moderate aortic stenosis, MAPSE/LAV was moderately correlated with LASr (r = 0.57) but was lower in patients with elevated compared to normal LV filling pressure by echocardiography (0.11 vs. 0.16 mm/mL, p < 0.001). In 72 patients who had undergone RHC and simultaneous echocardiography, MAPSE/LAV and LASr correlated weakly with pulmonary artery wedge pressure (PAWP) (r=-0.44 and r = 0.37). MAPSE/LAV was lower in patients with elevated (> 15 mmHg) vs. normal PAWP (0.14 mm/mL vs. 0.27 mm/mL). Accuracy for detection of elevated PAWP was similar for MAPSE/LAV (area under the curve MAPSE/LAV: 0.75 [0.58-0.92] and LASr: 0.75 [0.57-0.90]). Despite a moderate correlation with LASr, MAPSE/LAV provided similar diagnostic value as LASr in predicting elevated LV filling pressures as determined by echocardiography and RHC.