Noninvasive estimation of pulmonary capillary wedge pressure using speckle tracking echocardiography in patients with preserved or reduced ejection fraction

Abstract

Purpose: Echocardiographic parameters such as a ratio of early mitral inflow velocity (E) to atrial contraction flow velocity (A) and a ratio of E to mitral annular tissue velocity (e') were proposed to estimate left ventricular (LV) diastolic function and pulmonary capillary wedge pressure (PCWP). However, E/A and E/e' have limitations to use in various conditions. Noninvasive estimation of PCWP has not been elucidated. We have recently developed a novel index to estimate PCWP using left atrial (LA) emptying function (EF) and volume (LAV) assessed by speckle tracking echocardiography (STE) and named it kinetics-tracking (KT) index: log (active LAEF/ minimum LAV index). The estimated PCWP (ePCWP) was determined as 10.7 – 12.4 × KT index. The aim was to examine the usefulness of KT index in patients with preserved or reduced ejection fraction to estimate PCWP measured by cardiac catheterization. Methods: We measured phasic LAV and EF obtained from time-LA volume curves by STE during sinus rhythm in consecutive 128 patients (age 67±12, 80 men, 77 patients with LV ejection faction ≥55%) just before cardiac catheterization. Patients with atrial fibrillation, severe mitral regurgitation and mitral stenosis were excluded. LA volume and EF and E/e' were compared with PCWP measured by cardiac catheterization. Moreover, ePCWP estimated by 4 combinations of LA maximum or minimum volume and LA total or active EF was compared with PCWP by cardiac catheterization. Results: The maximum and minimum LAV index were correlated with PCWP (r=0.71 and r=0.78, respectively, p 15 mmHg were 95 and 88%, respectively (AUC = 0.97) using KT index of 17.8 as an optimal cutoff value. In multivariate regression analysis, only KT index was an independent parameter to estimate PCWP by cardiac catheterization in 128 subjects. Conclusions: For noninvasive estimation of LV diastolic function, the KT index is a novel and more accurate predictor of PCWP than LA function, volume solely or E/e'. KT index have an incremental value in routine clinical practice.