Key result
Transmural global longitudinal strain was significantly impaired in unstable angina patients with obstructive coronary artery disease compared to those without (-18.2% vs -20.4%, p=0.001), though its overall diagnostic accuracy was modest (AUC 0.683).
Why the study?
Longitudinal strain by speckle tracking echocardiography is established in NSTEMI/STEMI and stable CAD, but its accuracy for diagnosing and predicting CAD severity in unstable angina patients without regional wall motion abnormalities required evaluation.
Does 2-D Speckle Tracking Echocardiography derived longitudinal strain accurately diagnose obstructive CAD in patients with low-risk unstable angina and normal LVEF?
Observational (n=124)
Single-blind
No
Does 2-D Speckle Tracking Echocardiography derived longitudinal strain accurately diagnose obstructive CAD in patients with low-risk unstable angina and normal LVEF?
Effect estimate: AUC 0.683
Absolute Event Rate: -18.2% vs -20.4%
p-value: p=0.001
In low-risk unstable angina patients with normal LVEF, 2D speckle-tracking echocardiography has modest overall diagnostic accuracy for obstructive CAD, but a grossly abnormal GLS (>-16.1%) strongly predicts obstructive and multivessel disease.
Suggests speckle tracking echocardiography may help risk-stratify low-risk.
Longitudinal strain (LS) measurements by Speckle Tracking Echocardiography (STE) is a point of care imaging modality that had been documented to have a role in NSTEMI/STEMI and stable Coronary artery disease (CAD). This study aims to determine the accuracy of LS parameters in diagnosis and predicting severity of CAD in unstable angina patients with no regional wall motion abnormalities. It was a prospective analytical study in which 143 low-risk Unstable angina patients underwent STE. Based on Coronary angiogram results, the study participants were divided into obstructive CAD and control group. Patients with obstructive CAD (n ¼ 79) had significantly higher GLS Trans and GLS12 (¡18.2 ± 3.5% Vs ¡20.4 ± 3.2%, p ¼ 0.001 and ¡16.0 ± 3.5% Vs ¡18.1 ± 3.0, p ¼ 0.001 respectively) compared to patients with normal/non-obstructive coronaries (n ¼ 45). Both GLS trans and GLS12 were independent predictors of obstructive CAD by multivariate logistic regression. However, the diagnostic accuracy of GLS Trans (AUC ¼ 0.683) and GLS12 (AUC ¼ 0.687) were only modest. But the positive predictive value of grossly altered GLS >-16.1% was high (92.1%). Regional longitudinal strain (RLS) parameters were noted to be significantly higher in obstructive CAD group compared to the control one (RLSLAD: ¡18.8 ± 4.8 Vs ¡21.2 ± 4.5, p ¼ 0.007; RLSLCX: ¡16.0 ± 4.8 Vs ¡18.6 ± 3.5, p ¼ 0.001; RLSRCA: ¡18.8 ± 3.6 Vs ¡20.2 ± 3.4, p ¼ 0.031). Diagnostic accuracy of GLS in patients with low-risk UA is only modest. However, the subgroup of patients with GLS >16.1% have a high probability of having obstructive CAD and in particular multivessel disease and hence these patients can be subjected to CAG without further ischemic testing.
No takes yet. Share an insight, caveat, or question.
Giridharan et al. (2021) conducted an observational in Unstable angina with normal left ventricular ejection fraction (n=124). Two-dimensional Speckle-Tracking Echocardiography (Global Longitudinal Strain) vs. Normal or non-obstructive coronary arteries was evaluated on Presence of obstructive coronary artery disease (>70% stenosis) (AUC 0.683, p=0.001). Transmural global longitudinal strain was significantly impaired in unstable angina patients with obstructive coronary artery disease compared to those without (-18.2% vs -20.4%, p=0.001), though its overall diagnostic accuracy was modest (AUC 0.683).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: