Correlation Between Tissue Doppler Imaging Method (E/e′) and Invasive Measurements of Left Ventricular Filling Pressures: A Systematic Review, Meta-Analysis, and Meta-Regression

Objectives: Evaluation of pulmonary capillary wedge pressure (PCWP) through right heart catheterization can indirectly provide an estimation of the filling pressure of the left ventricle. Echocardiography can estimate left ventricular compliance using mitral annular tissue Doppler imaging (TDI). The E/e' ratio refers to the correlation between the peak mitral inflow (E-wave) velocity and early diastolic tissue Doppler mitral annular velocity (e'). The main purpose of this systematic review was to establish the correlation between echocardiographic E/e' ratio and PCWP. The correlation between E/e' and left ventricular end-diastolic pressure (LVEDP) was evaluated as a secondary objective. Design: A systematic review and meta-analysis of observational studies was conducted. The search was based on Medline (PubMed), Scopus, and Web of Science. Setting: Intensive care unit or cardiac intensive care unit. Participants: Adult patients. Interventions: Any study comparing the left ventricular filling pressure obtained by cardiac catheterization (reference) and echocardiographic evaluation, in particular TDI analysis (intervention), were included. Measurements and Main Results: The pooled analysis included 94 studies from the initially identified 7,304 records. The correlation was 0.48 (95% CI 0.42-0.54, Q = 420.52, I2 = 84.8%) for PCWP and 0.50 (95% CI 0.38-0.60, Q = 210.91, I2 = 89.1%) for LVEDP. Conclusions: The E/e' ratio moderately correlated with PCWP/LVEDP. The correlation was stable irrespective of the sites where e' was measured, but each site has its own limitations for specific patient subpopulations. The correlation was weak in patients with heart failure with a preserved ejection fraction.