Original Research
Layer-Specific Quantification of Myocardial Deformation by Strain Echocardiography May Reveal Significant CAD in Patients With Non–ST-Segment Elevation Acute Coronary Syndrome

https://doi.org/10.1016/j.jcmg.2013.01.009Get rights and content
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Objectives

Our objective was to assess whether patients with significant coronary artery disease (CAD) had reduced endocardial function assessed by layer-specific strain compared with patients without significant CAD.

Background

The left ventricular (LV) wall of the heart comprises 3 myocardial layers. The endocardial layer is most susceptible to ischemic injury.

Methods

Seventy-seven patients referred to coronary angiography due to suspected non–ST-segment elevation-acute coronary syndromes (NSTE-ACS) were prospectively included. Coronary occlusion was found in 28, significant stenosis in 21, and no stenosis in 28 patients. Echocardiography was performed 1 to 2 h before angiography. Layer-specific longitudinal and circumferential strains were assessed from endocardium, mid-myocardium, and epicardium by 2-dimensional (2D) speckle-tracking echocardiography (STE). Territorial longitudinal strain (TLS) was calculated based on the perfusion territories of the 3 major coronary arteries in a 16-segment LV model, whereas global circumferential strain (GCS) was averaged from 6 circumferential LV segments in all 3 layers.

Results

Patients with significant CAD had worse function in all 3 myocardial layers assessed by TLS and GCS compared with patients without significant CAD. Endocardial TLS (mean –14.0 ± 3.3% vs. –19.2 ± 2.2%; p < 0.001) and GCS (mean –19.3 ± 4.0% vs. –24.3 ± 3.4%; p < 0.001) were most affected. The absolute differences between endocardial and epicardial TLS and GCS were lower in patients with significant CAD (Δ2.4 ± 3.6% and Δ6.7 ± 3.8%, respectively) than in those without significant CAD (Δ5.3 ± 2.1% and Δ10.4 ± 3.0%; p < 0.001). This reflects a pronounced decrease in endocardial function in patients with significant CAD. A receiver-operating characteristic curve analysis showed that endocardial and mid-myocardial TLS were superior to identify significant CAD compared with epicardial TLS (p < 0.05), wall motion score index (p < 0.01), and ejection fraction (EF) (p < 0.001).

Conclusions

Assessment of layer-specific strain by 2D-STE might identify NSTE-ACS patients with significant CAD. Endocardial function was more affected in patients with significant CAD compared with epicardial function and EF.

Key Words

coronary artery disease
echocardiography
myocardial function
myocardial layers
strain

Abbreviations and Acronyms

2D
2-dimensional
CAD
coronary artery disease
EF
ejection fraction
GCS
global circumferential strain
GLS
global longitudinal strain
LV
left ventricular
NSTE-ACS
non–ST-segment elevation-acute coronary syndrome(s)
STE
speckle-tracking echocardiography
TLS
territorial longitudinal strain

Cited by (0)

This work was supported by the South-Eastern Norway Regional Health Authority, the Norwegian Research Council, and the Inger and John Fredriksen Foundation. Dr. Sarvari has received honoraria from Toshiba for a lecture at one occasion. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.