Left atrial longitudinal strain by speckle tracking echocardiography correlates well with left ventricular filling pressures in patients with heart failure

Abstract

Background: The combination of early transmitral inflow velocity and mitral annular tissue Doppler imaging (E/Em ratio) is widely applied to noninvasively estimate left ventricular (LV) filling pressures. However E/Em ratio has a significant gray zone and its accuracy in patients with heart failure is debated. Left atrial (LA) deformation analysis by speckle tracking echocardiography (STE) was recently proposed as an alternative approach to estimate LV filling pressures. This study aimed at exploring the correlation of LA longitudinal function by STE and Doppler measurements with direct measurements of LV filling pressures in patients with heart failure.

Methods: A total of 36 patients with advanced systolic heart failure (ejection fraction < or = 35%), undergoing right heart catheterization, were studied. Simultaneously to pulmonary capillary wedge pressure (PCWP) determination, peak atrial longitudinal strain (PALS) and mean E/Em ratio were measured in all subjects by two independent operators. PALS values were obtained by averaging all segments (global PALS), and by separately averaging segments measured in the 4-chamber and 2-chamber views.

Results: Not significant correlation was found between mean E/Em ratio and PCWP (R = 0.15). A close negative correlation between global PALS and the PCWP was found (R = -0.81, p < 0.0001). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.93) and excellent sensitivity and specificity of 100% and 93%, respectively, to predict elevated filling pressure using a cutoff value less than 15.1%. Bland-Altman analysis confirmed this close agreement between PCWP estimated by global PALS and invasive PCWP (mean bias 0.1 +/- 8.0 mmHg).

Conclusion: In a group of patients with advanced systolic heart failure, E/Em ratio correlated poorly with invasively obtained LV filling pressures. However, LA longitudinal deformation analysis by STE correlated well with PCWP, providing a better estimation of LV filling pressures in this particular clinical setting.

Figure 1

Measurement of peak atrial longitudinal strain (PALS) from an apical two-chamber view. The dashed curve represents the average atrial longitudinal strain along the cardiac cycle. (PALS, peak atrial longitudinal strain; AVC, aortic valve closure).

Figure 2

Correlation between global peak atrial longitudinal strain (PALS) and pulmonary capillary wedge pressure. R = -0.8070; p < 0.0001. (PALS, peak atrial longitudinal strain).

Figure 3

Correlation between global peak atrial longitudinal strain (PALS) and mean E/Em ratio. R = 0.1487; p = ns. (PALS, peak atrial longitudinal strain; E, early transmitral flow velocity; Em, early diastolic mitral annular velocity).

Figure 4

Diagnostic accuracy of noninvasive estimate of elevated filling pressure. Receiving operating characteristic (ROC) curves for global peak atrial longitudinal strain (PALS), left atrial (LA) volume indexed and mean E/Em ratio for prediction of pulmonary capillary wedge pressure ≥18 mmHg in patients with advanced systolic heart failure. (PALS, peak atrial longitudinal strain; LA, left atrial; E, early transmitral flow velocity; Em, early diastolic mitral annular velocity; AUC, area under the curve).

Figure 5

Bland-Altman analysis. Bland-Altman agreement plot comparing pulmonary papillary wedge pressure (PCWP) estimated by global peak atrial longitudinal strain (PALS) and invasive PCWP in the 36 patients. Bias (0.1); 95% Limits of agreement (-8.0 to 8.0). (PALS, peak atrial longitudinal strain; PCWP, pulmonary capillary wedge pressure).