Usefulness of layer-specific strain for identifying complex CAD and predicting the severity of coronary lesions in patients with non-ST-segment elevation acute coronary syndrome: Compared with Syntax score

Prevalence and Predictors of Occlusive Myocardial Infarction in Patients Presenting With Non-ST-Elevation Acute Coronary Syndrome in Duhok, Iraq: A Cross-Sectional Study

Background and aim Myocardial infarction is a major global health issue and the leading cause of death. Non-ST segment elevation acute coronary syndrome (NSTE-ACS) could behave like ST-segment elevation ACS in terms of causing total or near total occlusion of the coronary artery and leading to occlusive myocardial infarction (OMI). This study aims to assess OMI prevalence and associated factors in NSTE-ACS patients in Duhok, Iraq, to improve diagnosis and treatment outcomes. Materials and methods This prospective cross-sectional study, conducted at Azadi Heart Center and Zakho Teaching Hospital from March 2023 to March 2024, included 189 NSTE-ACS patients undergoing coronary angiography. Data collection encompassed demographics, clinical profiles, electrocardiographic (ECG) patterns, cardiac biomarkers, and angiographic outcomes. Patients were categorized into those with and without occlusive myocardial infarction (OMI). Results A total of 189 NSTE-ACS patients with a mean age of 58.65 (±10.38 SD) years were enrolled in the study. The overall OMI rate was 29.63%. OMI patients were older and had a higher prevalence of hypertension, dyslipidemia, and a family history of ischemic heart disease (IHD). Significant ECG changes associated with OMI included biphasic T-wave inversion and ST depression in specific leads. Marked elevation in troponin levels was also noted in OMI patients. The left anterior descending (LAD) artery was the most common culprit artery. Conclusions About one-quarter of our study cohort exhibited OMI. The condition was linked to clinical, ECG, and elevated troponin levels. The study underscores the importance of promptly recognizing occlusive myocardial infarction (OMI) in NSTE-ACS patients for better outcomes. Regular audits are imperative to augment awareness among healthcare professionals at cardiac centers regarding updated protocols and guidelines.

Artificial intelligence calculated global longitudinal strain and left ventricular ejection fraction predicts cardiac events and all-cause mortality in patients with chest pain

BACKGROUND

Assessment of left ventricular ejection fraction (LVEF) and myocardial deformation with global longitudinal strain (GLS) has shown promise in predicting adverse cardiovascular events. The aim of this study was to evaluate whether artificial intelligence (AI) calculated LVEF and GLS is associated with major adverse cardiac events (MACE) and all-cause mortality in patients presenting with chest pain.

METHODS

We studied 296 patients presenting with chest pain, who underwent transthoracic echocardiography (TTE). Clinical data, downstream clinical investigations and patient outcomes were collected. Resting TTE images underwent AI contouring for automated calculation of LVEF and GLS with Ultromics EchoGo Core 2.0. Regression analysis was performed to identify clinical and AI calculated parameters associated with MACE and all-cause mortality.

RESULTS

During a median follow-up period of 7.8 years (IQR 6.4, 8.8), MACE occurred in 34 (11.5%) patients and all-cause mortality in 60 (20%) patients. AI calculated LVEF (Odds Ratio [OR] .96; 95% CI .93-.99 and .96; 95% CI .93-.99) and GLS (1.11; 95% CI 1.01-1.21 and 1.08; 95% CI 1.00-1.16) were independently associated with MACE and all-cause mortality, respectively. According to Cox proportional hazards, a LVEF < 50% was associated with a 3.7 times MACE and 2.8 times all-cause mortality hazard rate compared to those with a LVEF ≥ 50%. Those with a GLS ≥ 15% was associated with a 2.5 times MACE and 2.3 times all-cause mortality hazard rate compared to those with a GLS ≤ 15.

CONCLUSION

AI calculated resting LVEF and GLS is independently associated with MACE and all-cause mortality in high CVD risk patients. These results may have significant clinical implications through improved risk stratification of patients with chest pain, accelerated workflow of labour-intensive technical measures, and reduced healthcare costs.

The diagnostic accuracy of two-dimensional strain imaging echocardiography to detect the severity of coronary artery disease in non-ST segment elevation acute coronary syndrome

OBJECTIVE

Strain imaging by two-dimensional speckle tracking echocardiography can detect severe coronary artery disease (CAD). This study aims to assess the diagnostic accuracy of various strain parameters in patients with non-ST segment acute coronary syndrome to detect the angiographic severity of CAD and also to compare among them.

METHODS

This hospital-based observational study was conducted on 178 patients with NSTEACS and preserved left ventricular ejection fraction who presented in emergency or outdoor from July 2021 to December 2022. We excluded patients with prior coronary revascularization, heart failure, arrhythmia, more than trivial valvular heart disease, or poor acoustic window. Global longitudinal strain (GLS), peak systolic strain (SS), post systolic index (PSI), and systolic strain rate (SR) were calculated by speckle tracking with automated function imaging. Coronary angiography was done in all patients, and the syntax score was calculated.

RESULTS

The strain parameters showed a significant correlation with the syntax score. There was a statistically significant difference in strain parameters between patients with left main (LM) or triple vessel disease (TVD) and others. Receiver operating characteristic (ROC) curve analysis showed that GLS had a better diagnostic accuracy for detecting LM or TVD than other strain parameters. GLS with a cut-off value of -11.2% had a sensitivity of 85.7% and specificity of 53.5% for detecting LM or TVD.

CONCLUSION

Strain imaging can be a helpful bedside adjunct to conventional investigations for detecting severe CAD in patients with NSTEACS.

Multiaxial pressure-strain analysis of regional myocardial work in the setting of graded coronary stenoses and dobutamine stress

We present a detailed analysis of regional myocardial blood flow and work to better understand the effects of coronary stenoses and low-dose dobutamine stress. Our analysis is based on a unique open-chest model in anesthetized canines that features invasive hemodynamic monitoring, microsphere-based blood flow analysis, and an extensive three-dimensional (3-D) sonomicrometer array that provides multiaxial deformational assessments in the ischemic, border, and remote vascular territories. We use this model to construct regional pressure-strain loops for each territory and quantify the loop subcomponent areas that reflect myocardial work contributing to the ejection of blood and wasted work that does not. We demonstrate that reductions in coronary blood flow markedly alter the shapes and temporal relationships of pressure-strain loops, as well as the magnitudes of their total and subcomponent areas. Specifically, we show that moderate stenoses in the mid-left anterior descending coronary artery decrease regional midventricle myocardial work indices and substantially increase indices of wasted work. In the midventricle, these effects are most pronounced along the radial and longitudinal axes, with more modest effects along the circumferential axis. We further demonstrate that low-dose dobutamine can help to restore or even improve function, but often at the cost of increased wasted work. This detailed, multiaxial analysis provides unique insight into the physiology and mechanics of the heart in the presence of ischemia and low-dose dobutamine, with potential implications in many areas, including the detection and characterization of ischemic heart disease and the use of inotropic support for low cardiac output.NEW & NOTEWORTHY Our unique experimental model assesses cardiac pressure-strain relationships along multiple axes in multiple regions. We demonstrate that moderate coronary stenoses decrease regional myocardial work and increase wasted work and that low-dose dobutamine can help to restore myocardial function, but often with further increases in wasted work. Our findings highlight the significant directional variation of cardiac mechanics and demonstrate potential advantages of pressure-strain analyses over traditional, purely deformational measures, especially in characterizing physiological changes related to dobutamine.

Role of two-dimensional strain echocardiographic parameters in suspected acute coronary syndrome patients with initial non-diagnostic electrocardiogram and troponins: An observational study

INTRODUCTION

Diagnosis of acute coronary syndrome (ACS) is often challenging especially in presence of initial normal troponins and non-specific electrocardiogram. The index study aimed at determining the diagnostic value of strain echocardiography in patients with suspected ACS but with non-diagnostic electrocardiogram and echocardiography findings.

METHODS

The study was conducted on 42 patients with suspected ACS and non-diagnostic electrocardiograms, normal quantitative troponin-T levels, and left ventricular function. All patients underwent conventional and 2D-strain echocardiography followed by coronary angiography, within 24 h of admission. Patients with regional wall motion abnormalities (RWMA), valvular heart disease, suspected myocarditis, and past coronary artery disease (CAD) were excluded.

RESULTS

Amongst the global strains, the global circumferential strain (GCS) was significantly reduced (p = .014) amongst those with significant CAD on angiography as opposed to global longitudinal strain (GLS) which was similar in the two groups (p = .33). The GCS/GLS ratio was also significantly reduced in patients with significant CAD compared to those with normal/mild disease on coronary angiography (p = .025). Both the parameters had good accuracy in predicting significant CAD. GCS displayed a sensitivity of 80% and a specificity of 86% at an optimal cut-off 31.5% (AUROC: .93, 95% CI: .601-1.000; p = .03), and likewise GCS/GLS ratio had a sensitivity of 80% and a specificity and 86% at a cut-off of 1.89% (AUROC: .86, 95% CI: .592-1.000; p = .049). GLS and peak atrial longitudinal strain (PALS) did not differ significantly in patients with/without significant CAD (p = .32 and .58, respectively).

CONCLUSION

GCS and GCS/GLS ratio provides incremental value in comparison to GLS, PALS, and tissue Doppler indices (E/e') in patients with suspected ACS and non-diagnostic electrocardiogram and troponins. GCS at cut-off of >31.5% and GCS/GLS ratio >1.89 can reliably exclude patients with significant CAD in this setting.

Link between myocardial deformation phenotyping using longitudinal and circumferential strain and risk of incident heart failure and cardiovascular death

AIMS

Left ventricular (LV) systolic deformation is altered early in the ventricular disease process despite normal LV ejection fraction (LVEF). These alterations seem to be characterized by decreased global longitudinal strain (GLS) and augmented global circumferential strain (GCS). This study aimed to investigate the link between myocardial deformation phenotyping using longitudinal and circumferential strain and risk of incident heart failure (HF) and cardiovascular death (CD).

METHODS AND RESULTS

The study sample was based on the prospective cohort study the 5th Copenhagen City Heart Study (2011-15). All participants were examined with echocardiography following a pre-defined protocol. A total of 2874 participants were included. Mean age was 53±18 years and 60% were female. During a median follow-up of 3.5 years, a total of 73 developed HF/CD. A U-shaped relationship between GCS and HF/CD was observed. LVEF significantly modified the association between GCS and HF/CD (P for interaction <0.001). The optimal transition point for the effect modification was LVEF < 50%. In multivariable Cox regressions, increasing GCS was significantly associated with HF/CD in participants with LVEF ≥ 50% (hazard ratio [HR]=1.12 [95% confidence interval (CI): 1.02; 1.23] per 1% increase), while decreasing GCS was associated with a higher risk of HF/CD in individuals with LVEF < 50% [HR=1.18 (95% CI: 1.05; 1.31) per 1% decrease].

CONCLUSIONS

The prognostic utility of GCS is modified by LVEF. In participants with normal LVEF, higher GCS was associated with increased risk of HF/CD, while the opposite was observed in participants with abnormal LVEF. This observation adds important information to our understanding of the pathophysiological evolution of myocardial deformation in cardiac disease progression.

The potential of HEART score to detect the severity of coronary artery disease according to SYNTAX score

Clinical scoring systems such as the HEART score can predict major adverse cardiovascular events, but they cannot be used to demonstrate the degree and severity of coronary artery disease. We investigated the potential of HEART Score in detecting the existence and severity of coronary artery disease based on SYNTAX score. This multi-centric cross-sectional study investigated patients referred to the cardiac emergency departments of three hospitals between January 2018 and January 2020. Data including age, gender, risk factors, comorbidities, 12-lead ECG, blood pressure and echocardiogram were recorded for all the participants. Serum troponin I level was measured on admission and 6 h later. Coronary angiography was done via the femoral or radial route. HEART and SYNTAX scores were calculated for all patients and their association was assessed. 300 patients (65% female) with mean age of 58.42 ± 12.42 years were included. mean HEART Score was 5.76 ± 1.56 (min = 3, max = 9), and mean SYNTAX score was 14.82 ± 11.42 (min = 0, max = 44.5). Pearson correlation coefficient was 0.493 between HEART Score and SYNTAX score which was statistically significant (P < 0.001). We found that HEART Score of more than 6 is 52% sensitive and 74.7% specific to detect extensive coronary artery involvement (SNTAX score ≥ 23). The present study showed that the HEART score has a moderate and positive correlation with the SYNTAX score and HEART score with a cut-off value of 6 is a predictor for SYNTAX score of ≥ 23.

The clinical application of longitudinal layer specific strain as a diagnostic and prognostic instrument in ischemic heart diseases: A systematic review and meta-analysis

Background

2-dimensional Speckle-Tracking Echocardiography, to obtain longitudinal layer specific strain (LSS), has recently emerged as a novel and accurate non-invasive imaging technique for diagnosis as well as for prediction of adverse cardiac events. This systematic review and meta-analysis aimed to give an overview of the possible clinical implication and significance of longitudinal LSS.

Methods

We conducted a systematic review and meta-analysis with all the studies involving layer specific strain in patients with ischemic heart disease (IHD). Of 40 eligible studies, 9 met our inclusion criteria. Studies that were included either investigated the prognostic value (n = 3) or the diagnostic value (n = 6) of longitudinal LSS.

Results

The pooled meta-analysis showed that longitudinal LSS is a significant diagnostic marker for coronary artery disease (CAD) in patients with IHD. Endocardial LSS was found to be a good diagnostic marker for CAD in IHD patients (OR: 1.28, CI95% [1.11–1.48], p &lt; 0.001, per 1% decrease). Epicardial (OR: 1.34, CI95% [1.14–1.56], p &lt; 0.001, per 1% decrease), Mid-Myocardial (OR: 1.24, CI95% [1.12–1.38], p &lt; 0.001, per 1% decrease) and endocardial (OR: 1.21, CI95% [1.09–1.35], p &lt; 0.001, per 1% decrease) LSS all entailed diagnostic information regarding CAD, with epicardial LSS emerging as the superior diagnostic marker for CAD in patients with SAP. Endocardial LSS proved to be the better diagnostic marker of CAD in patients with non-ST elevation acute coronary syndrome (NSTE-ACS). LSS was shown to be a good prognostic maker of adverse cardiac events in IHD patients. Two studies found endocardial circumferential strain to be the good predictor of outcome in CAD patients and when added to baseline characteristics. Epicardial LSS emerged as best predictor in acute coronary syndrome (ACS) patients.

Conclusion

In patients with SAP, epicardial LSS was the stronger diagnostic marker while in NSTE-ACS patients, endocardial LSS was the stronger diagnostic marker. In addition, endocardial circumferential strain is the better predictor of adverse outcome in CAD patients whilst in ACS patients, epicardial LSS was found to be a better predictor of outcome.

Application of Layered Strain Technique in NSTE-ACS

Background

To explore the application value of layered strain technique in non-ST elevation acute coronary syndrome (NSTE-ACS).

Methods

120 patients with suspected NSTE-ACS undergoing coronary angiography in our hospital from December 2018 to December 2019 were prospectively selected. According to the results of coronary angiography, the patients were divided into the significant CAD group and the nonsignificant CAD group. Echocardiography was performed 1-2 hours before invasive coronary angiography. The long axis and circumferential strain of the endocardium, myocardial layer, and epicardium were evaluated by the layered strain technique. The territorial longitudinal strain (TLS), the global longitudinal strain (GLS) of the three myocardial layers, and the global circumferential strain (GCS) were calculated based on the perfusion region of the three coronary arteries and the 17-segment model of the left ventricle. The primary endopoints were TLS and GCS of the three-layer myocardium.

Results

Compared with the nonsignificant CAD patients, the TLS and GCS of three-layer myocardium in significant CAD patients were decreased, especially in the endocardium. The absolute values of TLS and GCS of the endocardium and epicardium in significant CAD patients were lower than those in nonsignificant CAD patients. This indicates a significant decrease in endocardial function. Receiver operating characteristic (ROC) curve analysis showed that endocardial TLS was superior to LVEF, Troponin I (TnI), and other strain parameters in evaluating the extent of coronary lesions.

Conclusions

The layered strain technique of 2D-STE can evaluate the severity of coronary lesions in patients with NSTE-ACS, and for significant CAD patients, endocardial function is significantly more impaired than epicardial function.

The utility of SYNTAX score predictability by electrocardiogram parameters in patients with unstable angina

Background

SYNTAX score is one of the risk assessment systems to predict cardiac events in acute coronary syndrome patients. Despite the large number of SYNTAX score benefits, invasive methods such as coronary angiography are necessary to perform the scoring. We hypothesized that ECG parameters could predict the SYNTAX score in unstable angina patients.

Methods

During the retrospective cohort study, a total number of 876 patients were diagnosed with unstable angina. After applying the exclusion criteria, 600 patients were divided into tertiles based on the SYNTAX scores as low (0–22), intermediate (23–32), and high (≥ 33). The association between ECG parameters and SYNTAX score was investigated.

Results

The study included 65% men and 35% women with a mean age of 62.4 ± 9.97 years. The delayed transition zone of QRS complex, ST-depression in inferior-lateral territories or/and in all three territories, and T-wave inversion in lateral territory were significant (p < 0.05) independent predictors of intermediate SYNTAX score. High SYNTAX score was predicted by the presence of prolonged P wave duration, ST-depression in lateral territory or/and anterior-lateral territories, ST-elevation in aVR–III leads or/and aVR–III–V1 leads. Among those, all three territories ST-depression (AUC: 0.611, sensitivity: 75%, specificity: 51%) and aVR + III ST-elevation (AUC: 0.672, sensitivity: 50.12%, specificity: 80.50%) were the most accurate parameters to predict intermediate and high SYNTAX scores, respectively.

Conclusion

The present study demonstrates that accompanying the STE in the right side leads (aVR, III, V1) with ST-depression in other leads indicates the patients with high SYNTAX score; meanwhile, diffuse ST-depression without ST-elevation is a marker for intermediate SYNTAX score in unstable angina patients and can be applied for early risk stratification and intervention.

Value of GRACE and SYNTAX scores for predicting the prognosis of patients with non-ST elevation acute coronary syndrome

BACKGROUND

GRACE and SYNTAX scores are important tools to assess prognosis in non-ST-elevation acute coronary syndrome (NSTE-ACS). However, there have been few studies on their value in patients receiving different types of therapies.

AIM

To explore the value of GRACE and SYNTAX scores in predicting the prognosis of patients with NSTE-ACS receiving different types of therapies.

METHODS

The data of 386 patients with NSTE-ACS were retrospectively analyzed and categorized into different groups. A total of 195 patients who received agents alone comprised the medication group, 156 who received medical therapy combined with stents comprised the stent group, and 35 patients who were given agents and underwent coronary artery bypass grafting (CABG) comprised the CABG group. General information was compared among the three groups. GRACE and SYNTAX scores were calculated. The association between the relationship between GRACE and SYNTAX scores and the occurrence of major adverse cardiovascular events (MACEs) was analyzed. Pearson’s correlation analysis was used to determine the factors influencing prognosis in patients with NSTE-ACS. Univariate and multivariate analyses were conducted to analyze the predictive value of GRACE and SYNTAX scores for predicting prognosis in patients with NSTE-ACS using the Cox proportional-hazards model.

RESULTS

The incidence of MACE increased with the elevation of GRACE and SYNTAX scores (all P < 0.05). The incidence of MACE was 18.5%, 36.5%, and 42.9% in the medication group, stent group, and CABG group, respectively. By comparison, the incidence of MACE was significantly lower in the medication group than in the stent and CABG groups (all P < 0.05). The incidence of MACE was 6.2%, 28.0% and 40.0% in patients with a low GRACE score in the medication group, stent group, and CABG group, respectively (P < 0.05). The incidence of MACE was 31.0%, 30.3% and 42.9% in patients with a medium GRACE score in the medication group, stent group, and CABG group, respectively (P > 0.05). The incidence of MACE was 16.9%, 46.2%, and 43.8% in patients with a high GRACE score in the medication group, stent group, and CABG group, respectively (P < 0.05). The incidence of MACE was 16.2%, 35.4% and 60.0% in patients with a low SYNTAX score in the medication group, stent group, and CABG group, respectively (P < 0.05). The incidence of MACE was 37.5%, 40.9%, and 41.7% in patients with a medium SYNTAX score in the medication group, stent group, and CABG group, respectively (P > 0.05). MACE incidence was 50.0%, 75.0%, and 25.0% in patients with a high SYNTAX score in the medication group, stent group, and CABG group, respectively (P < 0.05). Univariate Cox regression analyses showed that both GRACE score (hazard ratio [HR] = 1.212, 95% confidence interval [CI]: 1.083 to 1.176; P < 0.05) and SYNTAX score (HR = 1.160, 95%CI: 1.104 to 1.192; P < 0.05) were factors influencing MACE (all P < 0.05). Multivariate Cox regression analyses showed that GRACE (HR = 1.091, 95%CI: 1.015 to 1.037; P < 0.05) and SYNTAX scores (HR = 1.031, 95%CI: 1.076 to 1.143; P < 0.05) were independent predictors of MACE (all P < 0.05).

CONCLUSION

GRACE and SYNTAX scores are of great value for evaluating the prognosis of NSTE-ACS patients, and prevention and early intervention strategies should be used in clinical practice targeting different risk scores.

Quantitative evaluation of fetal ventricular function by speckle tracking echocardiography

METHODS

The study included 59 patients with normal fetal heart structure, blood flow, and heart rhythm (fetal abnormality-negative group) and 50 patients with abnormal fetal heart structure, blood flow, and/or heart rhythm (fetal abnormality-positive group). Automated Cardiac Motion Quantification (aCMQ) was performed in both groups to obtain left and right ventricular endocardial global longitudinal strain (GLSendo), mid-myocardial global longitudinal strain (GLSmid), and epicardial global longitudinal strain (GLSepi). Parameters between the two groups were compared and correlation analyses performed. A deformation analysis was performed by two trained observers, and reproducibility was assessed.

RESULTS

The fetal left ventricular and right ventricular global longitudinal strain (LV-GLS and RV-GLS, respectively) decreased in a gradient from the endocardium to the epicardium. LV-GLS and RV-GLS of all myocardial layers were lower in the fetal abnormality-positive than -negative group (all P < 0.05). Correlation analysis showed that neither LV-GLS nor RV-GLS was significantly correlated with gestational age in the fetal abnormality-negative group (all P > 0.05), whereas left ventricular GLSendo, GLSmid, and GLSepi were negatively correlated with gestational age in the fetal abnormality-positive group (r = -.39 to -.44, all P < 0.05). Repeatability testing showed that the inter-observer and intra-observer intra-class correlation coefficients for LV-GLS and RV-GLS in each myocardial layer were >.75 (all P < 0.001).

CONCLUSIONS

As a new speckle tracking echocardiography tool, aCMQ has feasibility and repeatability in evaluating myocardial deformation of the fetal ventricle. This technique might provide helpful information on ventricular myocardial deformation in fetal hearts with abnormal structure or rhythm for clinical guidance in pregnancy.

Layer-specific and whole wall global longitudinal strain predict major adverse cardiovascular events in patients with stable angina pectoris

Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of layer-specific GLS has not yet been investigated in patients with suspected stable angina pectoris (SAP). We sought to investigate the prognostic value of layer-specific and whole wall GLS in patients with suspected SAP. From September 2008 to March 2011, 296 consecutive patients with clinically suspected SAP, normal ejection fraction, and no previous cardiac history were enrolled in a prospective cohort study. Patients underwent echocardiography including two-dimensional speckle tracking at rest, exercise stress test, and coronary angiography. The end-point was a composite of incident heart failure, acute myocardial infarction, and cardiovascular death (MACE). Out of the 285 included patients (mean age 61 years, 50% male), 24 (8%) developed MACE during a median follow-up of 3.5 years. Both endocardial [hazard ratio (HR) 1.21, 95% CI 1.08-1.35, p = 0.001], epicardial (HR 1.29, 95% CI 1.12-1.50, p = 0.001) and whole wall GLS (HR 1.25, 1.10-1.42, p = 0.001) were significantly associated with an increased risk of developing MACE during follow-up in univariable Cox regression analysis. In multivariable analysis, only epicardial (HR 1.23, 95% CI 1.00-1.51, p = 0.046) and whole wall GLS (HR 1.20, 95% CI 1.00-1.43, p = 0.049) remained significantly associated with an increased risk of MACE independent of various baseline clinical variables, left ventricular ejection fraction (LVEF), E/e' and Duke Score. Layer-specific and whole wall GLS were significant predictors of MACE in this cohort of patients with suspected SAP independent of various baseline clinical variables, LVEF, E/e' and Duke Score.

Prognostic Value of Multilayer Left Ventricular Global Longitudinal Strain in Patients with ST-segment Elevation Myocardial Infarction with Mildly Reduced Left Ventricular Ejection Fractions

Multilayer (epi-, mid- and endocardium) left ventricular (LV) global longitudinal strain (GLS) reflects the extent of myocardial damage after ST-segment myocardial infarction (STEMI). However, the prognostic implications of multilayer LV GLS remain unclear. We studied the association between multilayer LV GLS and prognosis in patients with mildly reduced or preserved LV ejection fraction (EF) after STEMI. Patients with first STEMI and LVEF>45% were evaluated retrospectively. Baseline multilayer (endocardial, mid-myocardial and epicardial) LV GLS were measured on 2-dimensional speckle tracking echocardiography. Patients were followed up for of all-cause mortality. A total of 569 patients (77% male, 60 ± 11 years) were included. After a median follow-up of 117 (interquartile range 106-132) months, 95 (17%) patients died. We observed no differences in baseline LVEF and peak troponin levels between survivors and non-survivors. However, non-survivors showed more impaired GLS at all layers (epicardium: -11.9 ± 2.8% vs. -13.4 ± 2.8%; mid-myocardium: -14.2 ± 3.2% vs. -15.6 ± 3.2%; endocardium: -16.5 ± 3.7% vs. -17.7 ± 3.6%, p <0.05, for all). On multivariable analysis, increasing age (hazard ratio 1.095; p<0.001) and impaired LV GLS of the epicardial layer (hazard ratio 1.085; p = 0.047) were independently associated with higher risk of all-cause mortality. In addition, LV GLS at the epicardium had incremental prognostic value for all-cause mortality (χ² = 114, p = 0.044). In conclusion, in contemporary STEMI patients with mildly reduced or preserved LVEF, ageing and reduced LV GLS of the epicardium (reflecting transmural scar formation) were independently associated with all-cause mortality after adjusting for clinical and echocardiographic variables.

Layer-specific global longitudinal strain and the risk of heart failure and cardiovascular mortality in the general population: the Copenhagen City Heart Study

AIMS

Layer-specific global longitudinal strain (GLS) has been demonstrated to predict outcome in various patient cohorts. However, little is known regarding the prognostic value of layer-specific GLS in the general population and whether different layers entail differential prognostic information. The aim of the present study was to investigate the prognostic value of whole wall (GLS_WW ), endomyocardial (GLS_Endo ), and epimyocardial (GLS_Epi ) GLS in the general population.

METHODS AND RESULTS

A total of 4013 citizens were included in the present study. All 4013 had two-dimensional speckle tracking echocardiography performed and analysed. Outcome was a composite endpoint of incident heart failure and/or cardiovascular death. Mean age was 56 years and 57% were female. During a median follow-up time of 3.5 years, 133 participants (3.3%) reached the composite outcome. Sex modified the relationship between all GLS parameters and outcome. In sex-stratified analysis, no GLS parameter remained significant predictors of outcome in females. In contrast, GLS_WW [hazard ratio (HR) 1.16, 95% confidence interval (CI) 1.02-1.31, per 1% decrease] and GLS_Epi (HR 1.19, 95% CI 1.04-1.38, per 1% decrease) remained as significant predictors of outcome in males after multivariable adjustment (including demographic, clinical, biochemistry, and echocardiographic parameters). Lastly, only in males did GLS parameters provide incremental prognostic information to general population risk models.

CONCLUSIONS

In the general population, sex modifies the prognostic value of GLS resulting in GLS_Epi being the only layer-specific prognosticator in males, while no GLS parameter provides independent prognostic information in females.

Ensemble machine learning approach for screening of coronary heart disease based on echocardiography and risk factors

BACKGROUND

Extensive clinical evidence suggests that a preventive screening of coronary heart disease (CHD) at an earlier stage can greatly reduce the mortality rate. We use 64 two-dimensional speckle tracking echocardiography (2D-STE) features and seven clinical features to predict whether one has CHD.

METHODS

We develop a machine learning approach that integrates a number of popular classification methods together by model stacking, and generalize the traditional stacking method to a two-step stacking method to improve the diagnostic performance.

RESULTS

By borrowing strengths from multiple classification models through the proposed method, we improve the CHD classification accuracy from around 70-87.7% on the testing set. The sensitivity of the proposed method is 0.903 and the specificity is 0.843, with an AUC of 0.904, which is significantly higher than those of the individual classification models.

CONCLUSION

Our work lays a foundation for the deployment of speckle tracking echocardiography-based screening tools for coronary heart disease.

The Relationship Between the Severity of Coronary Artery Disease and Erythrocyte Morphology Parameters Measured by New-Generation Hematology Analyzer

BACKGROUND

There is a possible relation between red blood cell distribution width (RDW) and various clinical conditions. These conditions can render RDW disadvantageous in its relation with cardiovascular disease. There may be a relation between the severity of acute coronary syndrome (ACS) and the percentage of hypochromia (hypo%), percentage of hyperchromia (hyper%), percentage of macrocytosis (MAC%), and percentage of microcytosis (MIC%) values measured using new-generation hematological devices.

OBJECTIVE

We aimed to examine the relation between the SYNTAX score and the hypo%, hyper%, MAC%, and MIC% values in patients admitted with ACS.

METHOD

A group of 55 patients who underwent coronary angiography with diagnosis of ACS (STEMI and NSTEMI) and a control group of 48 patients with normal coronary arteries were included in the study. Venous blood samples were collected in the morning after a fasting of at least 8 h and analyzed using standard laboratory methods. Hemogram parameters were studied using Alinity HQ (Abbott, USA) a completely automated hemogram autoanalyzer. Biochemical parameters were studied using Architect c16000 (Abbott, USA) a completely automated biochemistry autoanalyzer.

RESULTS

Significant difference was observed in erythrocyte morphology-related tests (mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, RDW, hypo%, hyper%, MIC%, and MAC%) between the groups. Correlation analysis showed a positive correlation between the SYNTAX score and MAC% (r = 0.315, p = 0.019). Multivariate logistic regression analysis was performed for MAC% to identify the independent predictors of the SYNTAX score (β = 0.315, p = 0.019).

CONCLUSION

Changes in MAC% test can be measured in emergencies with new-generation hematological devices and used as independent predictors of presence of severe coronary artery disease.

Layer-specific global longitudinal strain obtained by speckle tracking echocardiography for predicting heart failure and cardiovascular death following STEMI treated with primary PCI

The aim of this study was to evaluate layer-specific global longitudinal strain (GLS), obtained by speckle tracking, in predicting outcomes following ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). Echocardiography, including layer-specific GLS, was performed at median two days after the STEMI in a prospective study of STEMI patients treated with pPCI between September 2006 and December 2008. The outcome was the composite of heart failure hospitalization and/or cardiovascular death (HF/CVD). A total of 349 patients were included. Mean age was 62.2 ± 11.5 years, 76% were male, and mean ejection fraction (LVEF) was 46 ± 9. Seventy-seven (22%) patients developed HF/CVD during median follow-up 5.4 years. Patients with HF/CVD had lower absolute values for all GLS-layers: endocardial (GLS_Endo) 11.4%vs 14.5% (p < 0.001), midmyocardial (GLS_Mid) 9.8% vs 12.5% (p < 0.001) and epicardial (GLS_Epi) 8.5% vs 10.9% (p < 0.001). In unadjusted analysis, all layers were significant predictors of HF/CVD; hazard ratio (HR) per 1% decrease for GLS_Endo: HR 1.18 (95%CI 1.11-1.25), GLS_Mid: HR 1.22 (95%CI 1.14-1.30) and GLS_Epi: HR 1.26 (95%CI 1.16-1.36), p < 0.0001 for all. The risk of HF/CVD increased incrementally with increasing tertiles for all layers, being more than three times higher in 3rd tertile compared to 1st tertile. In multivariable models, including baseline clinical and echocardiographic parameters, only GLS_Mid and GLS_Epi remained independent predictors of HF/CVD. Global longitudinal strain obtained from all myocardial layers were significant predictors of incident HF and CVD following STEMI, however, only GLS_Mid and GLS_Epi remained independent predictors after multivariable adjustment.

Layer-specific strain echocardiography may reflect regional myocardial impairment in patients with hypertrophic cardiomyopathy

Our study aimed to determine whether layer-specific strain (LSS) could reflect regional myocardial impairment in patients with hypertrophic cardiomyopathy (HCM). The study enrolled 50 patients with HCM and 30 age-matched healthy controls. Transmural gradient of longitudinal strain (TGLS), defined as the difference between the longitudinal strain of the endocardium and epicardium in a left ventricular segment, was used to reflect layer-specific myocardial impairment. Negative TGLS was consistently observed in healthy controls. The TGLS was relatively consistent within the basal, middle, and apical levels in healthy controls,but showed a significant gradient from the base towards the apex. In patients with HCM, the hypertrophic segments had significantly higher TGLS than the relatively normal segments or healthy controls at all 3 levels (0.14 % ± 3.48 % vs. -2.65 % ± 4.44 % vs. -2.17 % ± 1.66 % for basal, - 0.72 % ± 3.71 % vs. -4.02 % ± 4.00 % vs. -3.58 % ± 2.29 % for middle, and - 8.69 % ± 7.96 % vs. -11.44 % ± 6.65 % vs. -10.04 % ± 3.20 % for apex). Abnormal TGLS, defined as positive TGLS, in patients with HCM was associated with chest pain. In receiver operating characteristic curve analysis, a large area of abnormal TGLS (> 4 segments) had moderate accuracy for predicting chest pain (sensitivity, 73.3 %; specificity, 70.0 %). TGLS, a novel LSS derived parameter, may reflect regional myocardial impairment in patients with HCM.

Two-Dimensional Speckle Tracking Echocardiography Identifies Coronary Artery Disease in 690 Patients: A Retrospective Study from a Single Center

BACKGROUND Two-dimensional speckle tracking echocardiography (2D-STE) is a novel and non-invasive technique for the diagnosis of coronary artery disease (CAD). This retrospective study from a single center aimed to identify myocardial ischemia using 2D-STE in CAD patients identified by angiography. MATERIAL AND METHODS From March 1 to November 30, 2019, 690 patients in Beijing Hospital were enrolled. After angiography, 346 patients were diagnosed with CAD. Reduction in vessel diameter of ≥50% by stenosis in at least 1 major coronary artery or its main branch was considered CAD. Analysis of 2D-STE was performed using EchoPAC version 201. RESULTS The global strain was significantly impaired in CAD patients (P<0.01). Global longitudinal peak strain (GLPS) was analyzed in layers. For GLPS of the epicardium, the odds ratio (OR) was 1.297 (1.217-1.382; P=0.002), the area under the curve (AUC) was 0.727, and the cut-off value was -16.95; sensitivity and specificity were 73.7% and 63.0%, respectively. For GLPS of the middle layer, the OR was 1.260 (1.192-1.333; P<0.001), the AUC was 0.732, and the cut-off value was -20.95; sensitivity and specificity were 82.4% and 56.2%, respectively. For GLPS of the endocardium, the OR was 1.193 (1.137-1.251; P<0.001), the AUC was 0.708, and the cut-off value was -22.95; sensitivity and specificity were 82.9% and 52.9%, respectively. CONCLUSIONS The findings from this study support the clinical application of 2D-STE in patient populations with suspected myocardial ischemia due to CAD. Therefore, 2D-STE combined with ECG monitoring may have a future role for early screening of CAD patients.

Detection of cardiac allograft vasculopathy by multi-layer left ventricular longitudinal strain in heart transplant recipients

Cardiac allograft vasculopathy (CAV) is an obliterative and diffuse type of coronaropathy that develops in the transplanted human heart, representing a major cause of graft failure and mortality. Nowadays the gold standard for the diagnosis of CAV is coronary angiography (CA). Non-invasive CAV detection, especially in the early stages of the disease, is still challenging. Our study aimed to investigate the role of speckle tracking echocardiography (STE), in particular three-layer STE, in predicting CAV at early stages, and if other traditional echocardiographic, clinical or biochemical parameters could relate to CAV. The study population was composed of a total of 33 heart transplanted patients, divided accordingly to the presence or absence of CAV (12 CAV+ , 22 CAV-). All subjects underwent a complete transthoracic echocardiographic examination on the same day of the CA, and all conventional parameters of myocardial function were obtained, including strain values assessed by STE. Strain values were significantly reduced in presence of CAV, at each myocardial layer but in particular the endocardial-epicardial gradient (- 4.15 ± 1.6 vs - 1.7 ± 0.4% < .0001) that was also highly predictive of CAV (AUC at ROC curve 0.97). Among diastolic parameters, the E wave deceleration time (DT) and the mean E/e' ratio were strongly positively associated with CAV. In our population, left ventricular global longitudinal strain (GLS), layer-specific GLS and the endocardial-epicardial LS gradient, E wave DT and E/e' ratio were the best independent non-invasive predictors of CAV.

Comparison of mitral annular displacement and global longitudinal strain imaging for predicting significant coronary atherosclerotic disease in patients of chronic stable angina pectoris

Myocardial strain by two-dimensional speckle-tracking echocardiography (2D-STE) is a validated clinical index of myocardial deformation, for predicting CAD in patients with chronic stable angina pectoris (CSAP) with preserved ejection fraction (EF). However, it is complex, imaging dependant with intra and intervendor variability. The mitral annulus displacement (MAD) has been correlated to left ventricular (LV) longitudinal deformation and may be interchanged with strain imaging. This cross-sectional study was conducted on patients with suspected CSAP (n = 146) and preserved LVEF without wall motion abnormalities. We excluded patients with prior heart disease, ACS, arrhythmia, heart failure or poor imaging. GLS, Average MAD and normalized MAD were calculated using 2D-STE by automated function imaging. CAG was gold standard. MAD had significantly lesser dropout due to suboptimal imaging. Receiver operating characteristic (ROC) analysis showed that GLS had significantly better area under curve (AUC) compared to Normalised MAD and Average MAD (P = 0.035) in predicting significant CAD in patients of CSAP. The optimal cut-off of GLS, normalized MAD and Average MAD were ≥  - 20.67% (sensitivity 94.2%, specificity 86.7%), ≤ 15.22% (sensitivity 90.7%, specificity 80%) and ≤ 11.18 mm (sensitivity 83.7%, specificity 71.1%) respectively. GLS showed strong correlation with Normalised MAD (R = 0.669, P < 0.001) and good correlation to Average MAD (R 0.572, P < 0.001). Absolute GLS and Normalised MAD showed significant inverse correlation to SYNTAX score. GLS is a more accurate measure for predicting presence and severity of CAD then MAD however latter is a reliable simpler, robust, and expeditious tool with lesser dropouts. It can be at least of complementary value to other imaging markers for myocardial function when LV curvatures are poorly visualized or in busy outdoors with time constraint.

New Ultrasound Technologies for Ischemic Heart Disease Assessment and Monitoring in Cardiac Rehabilitation

Owing to its ease of application, noninvasive nature, and safety, echocardiography is an essential imaging modality to assess cardiac function in patients affected by ischemic heart disease (IHD). Over the past few decades, we have witnessed a continuous series of evolutions in the ultrasound field that have led to the introduction of innovative echocardiographic modalities which allowed to better understand the morphofunctional abnormalities occurring in cardiovascular diseases. This article offers an overview of some of the newest echocardiographic modalities and their promising application in IHD diagnosis, risk stratification, management, and monitoring after cardiac rehabilitation.

Does layer-specific strain using speckle tracking echocardiography improve the assessment of left ventricular myocardial deformation? A review

An increasing number of studies of left ventricular myocardial deformation have been published. Layer-specific strain using speckle tracking echocardiography to evaluate left ventricular function is not recommended in clinical practice. However, evaluation of myocardial mechanics using longitudinal and circumferential layer-specific strain enables the detection of subclinical impairment of myocardial deformation in various diseases. Unfortunately, normal values for longitudinal and circumferential strain have not been clearly defined. In normal subjects, layer-specific strain decreases from the endocardial to the epicardial layer, and from the apex to the base of the left ventricle. Although various studies have tried to define normal values for each layer in healthy subjects, studies with more subjects are needed. This tool has good reproducibility in terms of intraobserver and interobserver variability, but, as with monolayer strain, it has poor intervendor variability. Efforts that aim for standardization between vendors will be required before widespread use of this technique can be advocated.

Echocardiographic reference ranges for normal left ventricular layer-specific strain: results from the EACVI NORRE study

AIMS

To obtain the normal range for 2D echocardiographic (2DE) measurements of left ventricular (LV) layer-specific strain from a large group of healthy volunteers of both genders over a wide range of ages.

METHODS AND RESULTS

A total of 287 (109 men, mean age: 46 ± 14 years) healthy subjects were enrolled at 22 collaborating institutions of the EACVI Normal Reference Ranges for Echocardiography (NORRE) study. Layer-specific strain was analysed from the apical two-, three-, and four-chamber views using 2DE software. The lowest values of layer-specific strain calculated as ±1.96 standard deviations from the mean were -15.0% in men and -15.6% in women for epicardial strain, -16.8% and -17.7% for mid-myocardial strain, and -18.7% and -19.9% for endocardial strain, respectively. Basal-epicardial and mid-myocardial strain decreased with age in women (epicardial; P = 0.008, mid-myocardial; P = 0.003) and correlated with age (epicardial; r = -0.20, P = 0.007, mid-myocardial; r = -0.21, P = 0.006, endocardial; r = -0.23, P = 0.002), whereas apical-epicardial, mid-myocardial strain increased with the age in women (epicardial; P = 0.006, mid-myocardial; P = 0.03) and correlated with age (epicardial; r = 0.16, P = 0.04). End/Epi ratio at the apex was higher than at the middle and basal levels of LV in men (apex; 1.6 ± 0.2, middle; 1.2 ± 0.1, base 1.1 ± 0.1) and women (apex; 1.6 ± 0.1, middle; 1.1 ± 0.1, base 1.2 ± 0.1).

CONCLUSION

The NORRE study provides useful 2DE reference ranges for novel indices of layer-specific strain.

New Myocardial Deformation by 2D Multi-layer Speckle-Tracking Analysis in Healthy Patients: Normal Reference Values and Their Physiologic Determinants

There are limited data regarding intrinsic changes of the left (LV) and right ventricular (RV) deformation assessed layer-by-layer. We designed a prospective multi-centric study, using a new multi-layer 2D-speckle-tracking-echo (MSTE). We investigated the impact of different physiologic parameters on layer-specific LV/RV myocardial deformation and synchrony, in a large group of healty subjects. 151 subjects were feasible for MSTE, divided in 4 groups: <40 yrs, 41 to 50 yrs, 51 to 60, and >61 yrs. We found a significant higher LV dyssynchrony index with age. In all groups, an endo-epicardial gradient was present in longitudinal LV/RV and circumferential deformation, with higher values in endocardial layer (p<0.001). There were no differences in deformation with age in all layers. We provided normal reference values for a new index of LV dyssynchrony, and also for RV longitudinal, LV circumferential and longitudinal layer-specific deformation, which can be further used when assessing subclinical dysfunction in myocardial diseases.

Layer-specific distribution of myocardial deformation from anthracycline-induced cardiotoxicity in patients with breast cancer-From bedside to bench

BACKGROUND

Anthracycline anticancer drugs such as epirubicin and doxorubicin may induce myocardial dysfunction, leading to poor prognosis. Early detection of minor left ventricular (LV) myocardial dysfunction is important for the prevention of anthracylcine-induced cardiotoxicity. Using layer-specific speckle tracking echocardiography (STE), we investigated the progressive distribution of myocardial dysfunction in both breast cancer patients and an animal toxicity model.

METHODS

Patients with preserved LV ejection fraction (LVEF) preparing for epirubicin chemotherapy (N = 125) were prospectively enrolled. Layer-specific STE, including LV longitudinal and circumferential strains on subepicardium and subendocardium, were evaluated at baseline and after the first cycle, third cycle and six months of epirubicin therapy. A decline of LVEF above 10% to <55% at six months was defined as cardiotoxicity. These same strain measures were obtained in doxorubicin-treated rats and the distribution of myocardial fibrosis evaluated.

RESULTS

In patients developing cardiotoxicity, LV longitudinal strain on subendocardium (LVLSendo) was significantly reduced after three cycles of therapy despite no significant changes in conventional LV systolic, diastolic parameters as well as LV circumferential strains at that moment. Compared to conventional echocardiographic parameters, LVLSendo was significantly predictive of cardiotoxicity. Declines in LVLSendo were also observed in doxorubicin-treated rats at an early stage. These reductions also predicted significant fibrosis in the subendocardial layer.

CONCLUSION

LVLSendo is useful for the early detection of minor cardiac dysfunction during chemotherapy, thereby implicating endocardial involvement in the development of cardiotoxicity.

Multilayer longitudinal strain can help predict the development of no-reflow in patients with acute coronary syndrome without ST elevation

No-reflow (NR) is one of the major complications of primary percutaneous coronary intervention (PCI) in patients with non-ST-segment elevation myocardial infarction (NSTEMI). We aim to assess the value of multilayer longitudinal strain parameter to predict NR in patients with NSTEMI and preserved ejection fraction. 230 consecutive patients who were admitted to the emergency department and diagnosed with NSTEMI were prospectively included in this study. Echocardiography was performed 1 h before angiography. Specific analysis for endocardial, mid-myocardial and epicardial layers were performed by two-dimensional (2D) speckle tracking echocardiography (STE) for multilayer longitudinal strain. NR was described as flow grade of ≤ TIMI 2 when mechanical occlusions like dissection, intimal tear, arterial spasm and thromboembolism during angiography were excluded. 49 of 168 patients admitted to the study had NR. No significant differences were observed between the groups regarding age and gender. Multilayer longitudinal strain imaging (endocard, midmyocard and epicard) revealed lower strain values particularly in endocardial layer in patients with NR (GLS-endocard: - 14.14 ± 1.39/- 17.41 ± 2.34, p < 0.001; GLS-midmyocard: - 14.81 ± 1.40/17.81 ± 2.22, p < 0.001; GLS-epicard: - 16.14 ± 1.38/18.22 ± 2.00, p < 0.001). GLS-endocard, GLS-midmyocard, GLS-epicard and ST depression were found to be statistically significant independents parameters respectively to predict NR phenomenon (GLS-endocard: OR: 2.193, p < 0.001; GLS-midmyocard: OR: 1.510, p: 0.016; GLS-epicard: OR: 1.372, p: 0.035; ST depression: OR: 3.694, p: 0.014). We revealed that left ventricular strain study with speckle tracking echocardiography predicts NR formation. This noninvasive method may be useful for detecting NR formation in patients with NSTEMI.

Speckle Tracking Echocardiography in Non-ST-Segment Elevation Acute Coronary Syndromes

Non-ST-segment elevation acute coronary syndromes (NSTE-ACSs) are a group of clinical conditions characterized by acute myocardial ischemia. Conventional echocardiography is generally used to evaluate cardiac function using wall motion analysis and left ventricular ejection fraction but may be insufficient to explore all the complex features of NSTE-ACSs, which may vary substantially from patient to patient in terms of severity of ischemia and extent of involved myocardium. In the last years, speckle tracking echocardiography (STE) has become a widely available technique for the non-invasive assessment of cardiac function and has been repeatedly applied in the setting of NSTE-ACSs. In this review we summarize current evidence about the use of STE in patients with NSTE-ACSs, trying to underline advantages and limitations in comparison with conventional echocardiography for: diagnosis of NSTE-ACS, differential diagnosis, identification of high-risk patients, and prediction of outcome.

Early Changes of Myocardial Function After Transcatheter Aortic Valve Implantation Using Multilayer Strain Speckle Tracking Echocardiography

Transcatheter aortic valve implantation (TAVI) is an effective therapeutic option for severe symptomatic aortic valve stenosis (AS) with intermediate or high surgical risk. The purpose of this study was to examine the effects of TAVI on left ventricular (LV) mechanics using multilayer global longitudinal strain (GLS) by 2D speckle-tracking echocardiography. A total of 119 patients (mean age 83 ± 7.0 years, male 54%) with severe symptomatic AS and normal LV ejection fraction (LVEF) underwent echocardiography at baseline and 1 month after TAVI. Global longitudinal strain was measured from the endocardial layer (GLSendo), mid-ventricular layer (GLSmyo), epicardial layer (GLSepi) and full thickness of myocardium (GLSwhole). There was significant improvement in all 3 layers of GLS after TAVI compared with baseline, but there was no significant change in LVEF. The relative % increment in GLS in each layer strain were 11.2 ± 23.4% (GLSendo), 13.4 ± 33.0% (GLSmyo) and 18.0 ± 46.6% (GLSepi) with significant difference between GLSendo and GLSepi (p < 0.05). In conclusion, multilayer GLS is more sensitive than conventional LVEF to detect early improvement in LV systolic function after TAVI in patients with severe AS. There is a disproportional improvement in different layers with least improvement in the endocardium. Multilayer strain analysis may provide new insights into understanding mechanics of AS.

Value of layer-specific strain distribution patterns in hypertrophied myocardium from different etiologies

BACKGROUND

Intrinsic myocardial mechanics might have different patterns because of the different etiologies of myocardial hypertrophy. We used layer-specific strain to compare those with aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM) and examined the differences in strain distribution pattern and for their clinical implications.

METHODS

Comprehensive echocardiography was done in 3 groups: 129 with moderate-to-severe AS, 172 consecutive patients with HCM, and 58 healthy controls. Left ventricle (LV) layer-specific deformation parameters were obtained using two-dimensional speckle tracking echocardiography. The transmural strain gradient was defined as the strain difference between subendocardial and subepicardial myocardium. Both diseased groups were further divided based on the median value of transmural strain gradient for the hemodynamics correlation.

RESULTS

Compared with the HCM group, the AS group had more preserved transmural longitudinal strain gradient (4.49 ± 1.3% vs. 3.61 ± 1.2%, p < 0.001), which was not significantly different from that of the healthy controls (4.49 ± 1.3% vs. 4.54 ± 1.0%, p = 0.975). And only in AS group the transmural circumferential strain correlated with myocardium mass index (r = -0.237, p = 0.008), and the hemodynamic profiles (LV ejection fraction and LA pressure) were correlated well with transmural strain gradient, in that the lower subgroup had a significantly lower LV ejection fraction and higher average E/E'.

CONCLUSIONS

Myocardium hypertrophy from different etiology resulted in different layer-specific strain distribution pattern. The loss of an adequate transmural strain gradient correlated with hemodynamics and might reflect intrinsic myocardial dysfunction.

Evaluation of myocardial viability in patients with acute myocardial infarction: Layer-specific analysis of 2-dimensional speckle tracking echocardiography

BACKGROUND

The value of layer-specific two-dimensional speckle tracking echocardiography (LS2D-STE) for evaluating viable myocardium (VM) in patients with acute myocardial infarction (AMI) was unclear, this study provides new insights into it and to make a comparison with dualisotope simultaneous acquisition single photon emission computed tomography ( DISA-SPECT).

METHODS

Forty hospitalized patients with AMI and left ventricular systolic dysfunction (left ventricular ejection fraction <50%) underwent LS2D-STE and DISA-SPECT before percutaneous coronary intervention (PCI). The longitudinal, circumferential, and radial peak systolic strains and the peak systolic strain rates of 3 myocardiallayers (endocardium, mid-myocardium, and epicardium), as well as the total wall thickness, were determined by LS2D-STE. Routine echocardiography was followedup at 1, 3, 6 months after PCI, with the improvement of the wall motion as the goldenstandard for evaluating VM.

RESULTS

The sensitivity, specificity and accuracy of DISA-SPECT for evaluating VM were 82.1%, 74.3%, and 79.3%, respectively. Among the layer-specific parameters, only endocardial (endo-) longitudinal strain (LS) and endo- longitudinal strain rate (LSr) were used as independent parameters for evaluating VM (P < .05), and the sensitivity, specificity and accuracy of endo-LS and endo-LSr in evaluation of VM were 77.1%, 65.4%, and 72.9% vs 72.9%, 65.4%, and 69.7%. Endo-LS and endo-LSr were superior to total wall thickness LS and LSr (AUC endo-LS 0.767 vs total-LS 0.669; endo-LSr 0.743 vs total-LSr 0.682). The parallel test and the serial test of combination of endo-LS and endo-LSr showed similar sensitivity, specificity and accuracy to DISA-SPECT (P > .05).

CONCLUSION

The endo-LS and endo-LSr analysis of LS2D-STE can evaluate the VM well, and its sensitivity, specificity and accuracy in detection of VM are similar to those of DISA-SPECT, resulting in LS2D-STE being a good option for the assessment of VM.

Subclinical myocardial dysfunction in coronary slow flow phenomenon: Identification by speckle tracking echocardiography

OBJECTIVE

This study aimed to determine whether STE could help detect subclinical myocardial dysfunction in patients with CSFP.

METHODS

Sixty patients with CSFP confirmed by CAG and 51 controls with normal coronary flow were prospectively enrolled. Coronary angiographic data and conventional and speckle tracking echocardiographic parameters of the LV and RV were obtained for every subject.

RESULTS

Compared with controls, CSFP patients presented with higher BMI and TG levels, but lower HDL-C levels. Conventional echocardiographic parameters of biventricular systolic and diastolic function did not differ between the two groups (all P > 0.05). The GLS of the LV and RV was significantly impaired in CSFP patients compared with that in controls (-19.03% vs -21.42%, P < 0.001 and -19.72% vs -22.96%, P = 0.001, respectively). The myocardial impairment pattern of CSFP patients was homogenous in the RV and heterogeneous in the LV, where only endo- and mid-myocardial layers were affected. LV-GLS and RV-GLS were found to be well correlated with mTFC and HDL-C in CSFP groups (r = 0.463 vs r = 0.439; r = -0.569 vs r = -0.552, all P < 0.05). ROC curve analysis demonstrated that LV-GLS-endo had the highest AUC (0.867, P < 0.001) for predicting subclinical myocardial impairment in CSFP patients.

CONCLUSIONS

Subclinical myocardial systolic dysfunction occurs in both ventricles, and GLS could be an effective method to detect early-stage myocardial impairment in patients with CSFP.

Layer-specific strain analysis in patients with suspected stable angina pectoris and apparently normal left ventricular wall motion

BACKGROUND

Non-invasive imaging tests are widely used in the evaluation of stable angina pectoris (SAP). Despite these tests, non-significant coronary lesions are not a rare finding in patients undergoing elective coronary angiography (CAG). Two-dimensional (2D) speckle tracking global longitudinal strain (GLS) imaging is a more sensitive and accurate technique for measuring LV function than conventional 2D methods. Layer-specific strain analysis is a relatively new method that provides endocardial and epicardial myocardial layer assessment. The aim of the present study was to evaluate longitudinal layer-specific strain (LSS) imaging in patients with suspected SAP.

METHODS

Patients who underwent CAG for SAP were retrospectively screened. A total of 79 patients with no history of heart disease and wall motion abnormalities were included in the study. Forty-three patients with coronary lesions > 70% constituted the coronary artery disease (CAD) group and 36 patients without significant CAD constituted the control group. Layer-specific GLS transmural, endocardium, and epicardium values (GLS-trans, GLS-endo, and GLS-epi, respectively) were compared between the groups.

RESULTS

Patients in the CAD group had significantly lower GLS values in all layers (GLS-trans: -18.2 + 2.4% vs -22.2 + 2.2% p < .001; GLS-endo: -20.8 + 2.8% vs -25.3 + 2.6%, p < .001; GLS-epi: 15.9 + 2.4% vs -19.5 + 1.9%, p < .001). Multivariate adjustment demonstrated GLS-trans as the only independent predictor of CAD [OR:0.472, CI (0.326-0.684), p < .001]. Additionally, the GLS values were all lower in myocardial perfusion scintigraphy (MPS) true-positive patients compared with MPS false-positive patients (GLS-trans: -17.7 ± 2.4 vs. -21.9 ± 2.4%, p < .001; GLS-endo: -20.2 ± 2.9% vs -24.9 ± 2.9%, P < .001; GLS-epi: 15.4 ± 2.6% vs. -19.2 ± 1.8%, P < .001).

CONCLUSION

Resting layer-specific strain as assessed by 2D speckle tracking analysis demonstrated that GLS values were reduced in all layers of myocardium with SAP and with no wall motion abnormalities. LSS analysis can improve the identification of patients with significant CAD but further prospective larger scale studies are needed to put forth the incremental value of LSS analysis over transmural GLS.

An introduction to left ventricular strain

PURPOSE OF REVIEW

The assessment of left ventricular function by two-dimensional (2D) transthoracic echocardiography (TTE) is conventionally performed by measuring the ejection fraction, which has been shown to have important prognostic implications. However, left ventricular ejection fraction (LVEF) has notable shortcomings, including limited reproducibility, suboptimal inter/intraobserver variability and dependence on load/volume. Furthermore, subclinical left ventricular dysfunction cannot be measured with LVEF. With the advent of left ventricular deformation (strain) analysis, a new and robust means for assessing left ventricular function has emerged.

RECENT FINDINGS

Contemporary research and guidelines have attempted to standardize the definition, acquisition and measurement of left ventricular strain. In addition, multiple studies have sought to establish normal values for left ventricular strain in addition to evaluating the benefits and prognostic value of strain assessment.

SUMMARY

This article reviews the definition of left ventricular strain, outlines the types of strain and reviews how strain is acquired and measured. In addition, the advantages of strain analysis over LVEF as well as the incremental prognostic value of strain are examined. We further review the challenges associated with strain imaging as well as outline the future of strain imaging.

Speckle tracking analysis in intensive care unit: A toy or a tool?

The use of conventional echocardiography in the intensive care unit (ICU) is today established to assess left and right ventricular systolic function, for preload determination and procedural guidance. Next step in ICU echocardiography could be the use of novel ultrasound techniques such as strain echocardiography to assist in the management of patients with acute coronary syndrome, heart failure, or pulmonary embolism. This review has gathered the available evidence supporting the incremental value of strain in the diagnostic workup of cardiac diseases treated in ICU.

Does Masked Hypertension Cause Early Left Ventricular Impairment in Youth?

Objectives: Masked hypertension (MH) is not uncommon in the youth and may increase risks of long-term cardiovascular impairment. However, little is known about the subclinical heart damage in this group of patients. Currently, 3-layer speckle tracking imaging based on two-dimensional echocardiography is feasible to detect the early signs of myocardial damage. We therefore aimed to investigate whether subtle changes of cardiac function occurred in the young MH patients by using advanced quantification with layer-specific speckle tracking. Methods: A total of 40 adolescents with MH (age 18 ± 3 years, 73% males) and 40 age-, gender-, race-, and height-matched normotensive volunteers were enrolled in our study. MH was defined as one or more of the ambulatory blood pressure (BP) parameters (24-h, daytime and night-time average BPs) higher than ≥ 95th percentile for gender and height according to the local reference. Both comprehensive two-dimensional echocardiography with layer-specific strain analysis and 24-h ambulatory BP monitoring were performed. Longitudinal strain and circumferential strain in endocardial, mid-myocardial, and epicardial layers were determined accordingly with the dedicated software (EchoPAC software version 201, GE Healthcare, Horten, Norway). Results: Compared with normotensive controls, youths with MH had higher ambulatory pulse rate and left ventricular mass index, and were more obese. Interestingly, similar ventricular volumes and ejection fraction were observed in the study groups, but further analysis with layer-specific strains revealed that endocardial and mid-myocardial longitudinal and circumferential mechanical function were decreased in the young MH subjects when compared to normotensive individuals (all p < 0.05). However, there were no difference regarding radial strain and apical rotation derived from traditional speckle tracking analysis. Conclusion: Subclinical change of LV mechanic function assessed by layer-specific speckle tracking is present in youth with MH despite considered as normal with conventional ways.Thus, MH in youth should be monitored closely instead of labeling as an entirely benign entity.

Normal range of myocardial layer-specific strain using two-dimensional speckle tracking echocardiography

Background

Newer 2D strain software has a potential to assess layer-specific strain. However, normal reference values for layer-specific strain have not been established. We aimed to establish the normal ranges of layer-specific longitudinal and circumferential strain (endocardial global longitudinal strain (GLS), transmural GLS, epicardial GLS, endocardial global circumferential strain (GCS), transmural GCS, and epicardial GCS).

Methods and results

We retrospectively analyzed longitudinal and circumferential strain parameters in 235 healthy subjects, with use of layer-specific 2D speckle tracking software (GE). The endocardial strain/epicardial strain (Endo/Epi) ratio was also measured to assess the strain gradient across the myocardium. The endocardial, transmural, and epicardial GLS values and the Endo/Epi ratio in the normal subjects were -23.1±2.3, -20.0±2.0, -17.6±1.9, and 1.31±0.07, respectively. The corresponding values of GCS were -28.5±3.0, -20.8±2.3, -15.3±2.0, and 1.88±0.17, respectively. The layer-specific global strain parameters exhibited no age dependency but did exhibit gender dependency except for endocardial GCS. A subgroup analysis revealed that basal and middle levels of endocardial LS was decreased in the middle and elderly aged group. However, apical endocardial LS was preserved even in the elderly subjects.

Conclusions

We proposed normal reference values for layer-specific strain based on both age and gender. This detailed strain analysis provides layer-oriented information with the potential to characterize abnormal findings in various cardiovascular diseases.