Page 115 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

wave Doppler echocardiography.12 Finally, LV diastolic function was assessed with transmitral flow pulsed-wave recordings and the peak early (E) and late (A) diastolic velocities as well as the E-wave deceleration time were measured. The measurement of e´ was performed with tissue Doppler imaging at the septal and lateral mitral annulus in the apical 4-chamber view.13
2D-speckle tracking echocardiography STE was applied to perform a layer-specific analysis (endocardial, mid-myocardial and epicardial) of GLS from the apical 2- and 4-chamber views, as well as the long-axis view of the left ventricle.14 The software allows for analysis of the global LV longitudinal strain of the 3 different layers: endomyocardial, mid-myocardial and epicardial. As described previously, layer-specific GLS values were obtained as the average of longitudinal strain of 17 LV segments at each individual layer.15
Survival data were complete for all study subjects and collected from the departmental 6 cardiology information system, which is linked with the municipal civil registries and
contains up to date mortality data. Patients were followed for the occurrence of all-
cause mortality which is defined as cardiac and non-cardiac mortality.
All statistical analysis were performed with the Software Package for Social Sciences for Windows v23.0 (IBM, Armonk, New York). Categorical data are presented as frequencies and percentages. Continuous data are presented as mean ± standard deviation or median and interquartile range, as appropriate. To compare categorical data between groups, χ2-tests were performed. Continuous data were compared using the unpaired Student t-test or Mann-Whitney U test, as appropriate. Furthermore, Kaplan-Meier analysis was performed for survival rates. The study population was divided into two groups according to the median of each individual layer. Survival rates were compared with log-rank tests. The association of clinical and echocardiographic variables with all- cause mortality were tested using the Cox proportional hazards analysis. The hazard ratio (HR) and 95% confidence interval (CI) were calculated. Statistically significant predictors in univariable Cox regression analysis (p<0.05) were included in multivariable models. To avoid multicollinearity, a correlation coefficient of >0.7 was set. Finally, to evaluate the incremental value of layer-specific LV GLS over clinical and conventional echocardiographic parameters, layer-specific LV GLS was introduced to a baseline Cox regression model in a stepwise manner. Global χ2 values were calculated for all individual models. A 2-tailed p-value <0.05 was considered statistically significant.
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