A Comparison of the Strain and Tissue Doppler-Based Indices as Echocardiographic Correlates of the Left Ventricular Filling Pressures.

OBJECTIVES: Diastolic strain and strain rate, combined with E (peak transmitral velocity), have been proposed as novel noninvasive predictors of left ventricle (LV) filling pressures, avoiding angulation errors inherent to tissue Doppler indices (TDI). The primary objective was to study the correlation of strain-based indices (SBI) and TDI with pulmonary artery catheter-derived LV end-diastolic pressures (LVEDP). The secondary aim was to determine appropriate cut-off of indices to predict LVEDP ≥15 mmHg.

DESIGN: A prospective observational clinical study.

SETTING: Single university hospital.

PARTICIPANTS: One hundred twenty adults with preserved ejection fraction (EF) undergoing coronary artery bypass grafting.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Two-dimensional speckle-tracking echocardiography estimated global longitudinal diastolic strain (Ds) and strain rate (DSr) at peak mitral filling to compute E/Ds and E/10DSr. TDI was measured as the ratio of E and e' (mitral annular diastolic velocity). E/e', E/Ds, and E/10DSr were significantly higher (p < 0.001) in patients with LVEDP ≥15 mm Hg (31/120). Correlation of E/Ds, E/10DSr with LVEDP was R = 0.86 and 0.88 (p < 0.001), respectively, compared with a correlation of R = 0.63 (p < 0.001) for E/e'. SBI correlated well with LVEDP ≥15 mm Hg compared with TDI. E/Ds ≥11 and E/10DSr ≥12 had higher sensitivity and specificity (96.77%, 93.26%; 100%, 96.63%, respectively; area under the curve [AUC] = 0.99) than E/e'≥13 (74%,75%; AUC = 0.84) for prediction of LVEDP ≥15 mmHg. SBI accurately predicted elevated LVEDP in the indeterminate zone of 8<E/e' <13.

CONCLUSIONS: SBI were better predictors of LVEDP, compared with TDI, in patients with preserved EF and indeterminate E/e' values.