Background: Global longitudinal strain (GLS) is a useful marker for the echocardiographic evaluation of left ventricular (LV) systolic dysfunction. Presently GLS is derived from speckle tracking of LV images, but speckle tracking software is not always available. We seek to determine if manually measured GLS (MM-GLS) by assessing mid-myocardial lengths can be a reliable alternative to speckle tracking GLS (ST-GLS). Methods: Transthoracic echocardiogram images of a tertiary hospital in Australia were retrospectively analyzed to study the relationships between ST-GLS, MM-GLS, and LV ejection fraction (LVEF). We further evaluated the impact of image quality and regional wall motion abnormalities on those relationships. Results: Echocardiography studies from 154 patients were included (female sex, 36%; mean age, 61.7 ± 14.8 years).The average LVEF was 51.3% ± 11.3% and the average ST-GLS was 16.7 ± 3.8. MM-GLS strongly correlated with ST-GLS (intraclass correlation coefficient, 0.986; P < 0.001) and with LVEF regardless of the presence of regional wall motion abnormalities. If using GLS cutoff of more than 18% as normal, 97.5% of studies with normal ST-GLS had normal MM-GLS. If using GLS cutoff as less than 16% as abnormal, 95.5% of studies with abnormal ST-GLS had abnormal MM-GLS. There was no case with ST-GLS > 18% and MM-GLS < 16%, nor were there any case in with ST-GLS < 16% and  MM-GLS > 18%. Conclusions MM-GLS correlates strongly with ST-GLS. If ST-GLS cannot be accurately assessed, MM-GLS may be a useful alternative to provide GLS values in both clinical and research studies.

Background: Global longitudinal strain (GLS) is a useful marker for the echocardiographic evaluation of left ventricular (LV) systolic dysfunction. Presently GLS is derived from speckle tracking of LV images, but speckle tracking software is not always available. We seek to determine if manually measured GLS (MM-GLS) by assessing mid-myocardial lengths can be a reliable alternative to speckle tracking GLS (ST-GLS). Methods: Transthoracic echocardiogram images of a tertiary hospital in Australia were retrospectively analyzed to study the relationships between ST-GLS, MM-GLS, and LV ejection fraction (LVEF). We further evaluated the impact of image quality and regional wall motion abnormalities on those relationships. Results: Echocardiography studies from 154 patients were included (female sex, 36%; mean age, 61.7 ± 14.8 years).The average LVEF was 51.3% ± 11.3% and the average ST-GLS was 16.7 ± 3.8. MM-GLS strongly correlated with ST-GLS (intraclass correlation coefficient, 0.986; P < 0.001) and with LVEF regardless of the presence of regional wall motion abnormalities. If using GLS cutoff of more than 18% as normal, 97.5% of studies with normal ST-GLS had normal MM-GLS. If using GLS cutoff as less than 16% as abnormal, 95.5% of studies with abnormal ST-GLS had abnormal MM-GLS. There was no case with ST-GLS > 18% and MM-GLS < 16%, nor were there any case in with ST-GLS < 16% and  MM-GLS > 18%. Conclusions MM-GLS correlates strongly with ST-GLS. If ST-GLS cannot be accurately assessed, MM-GLS may be a useful alternative to provide GLS values in both clinical and research studies.

Background: Global longitudinal strain (GLS) is a useful marker for the echocardiographic evaluation of left ventricular (LV) systolic dysfunction. Presently GLS is derived from speckle tracking of LV images, but speckle tracking software is not always available. We seek to determine if manually measured GLS (MM-GLS) by assessing mid-myocardial lengths can be a reliable alternative to speckle tracking GLS (ST-GLS). Methods: Transthoracic echocardiogram images of a tertiary hospital in Australia were retrospectively analyzed to study the relationships between ST-GLS, MM-GLS, and LV ejection fraction (LVEF). We further evaluated the impact of image quality and regional wall motion abnormalities on those relationships. Results: Echocardiography studies from 154 patients were included (female sex, 36%; mean age, 61.7 ± 14.8 years).The average LVEF was 51.3% ± 11.3% and the average ST-GLS was 16.7 ± 3.8. MM-GLS strongly correlated with ST-GLS (intraclass correlation coefficient, 0.986; P < 0.001) and with LVEF regardless of the presence of regional wall motion abnormalities. If using GLS cutoff of more than 18% as normal, 97.5% of studies with normal ST-GLS had normal MM-GLS. If using GLS cutoff as less than 16% as abnormal, 95.5% of studies with abnormal ST-GLS had abnormal MM-GLS. There was no case with ST-GLS > 18% and MM-GLS < 16%, nor were there any case in with ST-GLS < 16% and  MM-GLS > 18%. Conclusions MM-GLS correlates strongly with ST-GLS. If ST-GLS cannot be accurately assessed, MM-GLS may be a useful alternative to provide GLS values in both clinical and research studies.

BACKGROUND: We aimed to compare the diagnostic accuracy of the Alere Triage Cardio3 Tropinin I (TnI) assay (Alere, Inc., USA) and the PathFast cTnI-II (Mitsubishi Chemical Medience Corporation, Japan) against the central laboratory assay Singulex Erenna TnI assay (Singulex, USA). METHODS: Using the Markers in the Diagnosis of Acute Coronary Syndromes (MIDAS) study population, we evaluated the ability of three different assays to identify patients with acute myocardial infarction (AMI). The MIDAS dataset, described elsewhere, is a prospective multicenter dataset of emergency department (ED) patients with suspected acute coronary syndrome (ACS) and a planned objective myocardial perfusion evaluation. Myocardial infarction (MI) was diagnosed by central adjudication. RESULTS: The C-statistic with 95% confidence intervals (CI) for diagnosing MI by using a common population (n=241) was 0.95 (0.91-0.99), 0.95 (0.91-0.99), and 0.93 (0.89-0.97) for the Triage, Singulex, and PathFast assays, respectively. Of samples with detectable troponin, the absolute values had high Pearson (R(P)) and Spearman (R(S)) correlations and were R(P)=0.94 and R(S)=0.94 for Triage vs Singulex, R(P)=0.93 and R(S)=0.85 for Triage vs PathFast, and R(P)=0.89 and R(S)=0.73 for PathFast vs Singulex. CONCLUSIONS: In a single comparative population of ED patients with suspected ACS, the Triage Cardio3 TnI, PathFast, and Singulex TnI assays provided similar diagnostic performance for MI.
Acute Coronary Syndrome/*diagnosis ; Biomarkers/analysis ; Emergency Service, Hospital ; Humans ; Laboratories/standards ; Myocardial Infarction/diagnosis ; *Point-of-Care Systems ; Prospective Studies ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; Troponin I/*analysis