What is the clinical evidence from this study?

Study design: Observational. Population: Normal left ventricular ejection fraction (LVEF ≥ 50%) with suspected left ventricular diastolic dysfunction (n=55). Intervention: Left atrial strain via speckle tracking echocardiography vs. E/e' ratio. Primary outcome: Prediction of elevated left ventricular end-diastolic pressure (> 16 mmHg) by left atrial reservoir strain (LASr) (OR 0.75, 95% CI 0.64-0.88, p=0.001).

May 3, 2020Open Access

Correlation of left atrial strain with left ventricular end-diastolic pressure in patients with normal left ventricular ejection fraction

Key Result

Left atrial reservoir strain independently predicted elevated left ventricular end-diastolic pressure (OR 0.75) with high diagnostic accuracy (AUC 0.914) in patients with normal ejection fraction.

Study Design

Type

Observational (n=55)

Blinding

Blinded assessors

Multicenter

Structured PICO

Does left atrial strain measured by echocardiography correlate with invasively measured left ventricular end-diastolic pressure in patients with normal left ventricular ejection fraction?

Population

55 consecutive individuals with normal left ventricular ejection fraction (LVEF > 50%) undergoing invasive left-heart catheterization.

Intervention

Left atrial strain measurement (reservoir, conduit, and contraction strain) by speckle tracking echocardiography

Comparator

Invasive left ventricular end-diastolic pressure (LVEDP) measurement and standard echocardiographic E/e' ratio

Outcome

Correlation between left atrial strain parameters and invasively measured left ventricular end-diastolic pressure (LVEDP)surrogate

Left atrial reservoir strain is a strong non-invasive predictor of elevated left ventricular end-diastolic pressure in patients with normal ejection fraction, outperforming the traditional E/e' ratio.

Main Result

Effect estimate: OR 0.75 (95% CI 0.64-0.88)

p-value: p=0.001

Limitations

Limited sample size leading to potential selection bias
Conducted at a single medical center
Left atrium imaging is difficult to obtain with poor image definition in some cases
Poor repeatability in some echocardiographic images for left atrial strain

Abstract

Left ventricular diastolic dysfunction (LVDD) remains challenging to be assessed by echocardiography. We sought to explore the relationship between left atrial strain and left ventricular (LV) diastolic function in patients with normal left ventricular ejection fraction (LVEF) by invasive left-heart catheterization. 55 consecutive individuals with LVEF > 50% underwent LV catheterization. Standard transthoracic echocardiography was performed during 12 h before or after the procedure. Left atrial (LA) strain were obtained by speckle tracking echocardiography. When LVEF ≥ 50%, the group with elevated left ventricular end-diastolic pressure (LVEDP) (n = 35) showed decreased left atrial reservoir strain (LASr) (35.2 ± 7.7% vs 21.3 ± 7.2%, p < 0.001), left atrial conduit strain (LASct) (17.6 ± 6.3% vs 11.9 ± 4.1%, p < 0.001), left atrial contraction strain (LAScd) (16.6 ± 7.2% vs 9.5 ± 5.0%, p < 0.001) and increased E/e' ration(8.9 ± 2.6 vs 10.1 ± 3.5, p = 0.17). LVEDP negatively correlated with LASr (R = 0.662, p < 0.001), LASct (R = 0.575, p < 0.001) and LAScd (R = 0.456, p < 0.001), but not with E/e'. LASr, LASct and LAScd were all independent predictors of elevated LVEDP (p < 0.05), with a higher C-statistic for the model including LASr (0.95, 0.86 and 0.93 respectively). The area under the curve (AUC) for LASr is 0.914 (cutoff value is 26.7%, sensitivity is 90%, specificity is 82.9%). In patients with normal LV ejection fraction, left atrial strain presented good correlation with LVEDP, and LASr was superior to LASct and LAScd to predict LVEDP. LA strain demonstrated better agreement with the invasive reference than E/e'.

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