Global longitudinal strain by speckle tracking for infarct size estimation

A new protocol for a single-stage combined cardiopulmonary and echocardiography exercise test: a pilot study

Aims

The value of cardiopulmonary exercise testing (CPET) and exercise stress echocardiography (ESE) in managing cardiac disease is well known, but no standard CPET-ESE protocol is currently recommended. This pilot study aims to compare feasibility and cardiac function responses between a new high-intensity single-stage combined test (CPET-hiESE) and a standard maximal ESE (smESE).

Methods and results

After screening and maximal CPET, all volunteers (n = 21) underwent three ESE modalities: (i) based on the gas exchange threshold (hiESE-GET, 40% of peak-GET, 6 min), (ii) based on heart rate (HR) (hiESE-HR, 80% of peak HR, 6 min), and (iii) smESE (85% of predicted peak HR for age, 3 min). Speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI) were measured at each step. There was superior image quality and data completeness for the right ventricle strain for both hiESE modalities compared with smESE (71.4 and 76.2 vs. 42.9%, P = 0.07). Left ventricular STE data completeness was similar for all three conditions. Despite systematically higher HR, work rate and levels of exertion in the smESE compared with hiESE, STE and TDI parameters were not systematically different. Concordance correlation coefficients ranged from 0.56 to 0.88, lowest for strain rate parameters and mean difference from -0.34 to 1.53, highest for TDI measurements.

Conclusion

The novel CPET-hiESE protocol allowed for better data completeness, at lower levels of exertion compared with smESE, without systematically different cardiac reserve measurements in healthy participants. This single-stage protocol can be individualized to clinical populations, which would provide practical advantages to standard testing.

Strain Imaging and Ventricular Arrhythmia

Ventricular arrhythmia is one of the main causes of sudden cardiac death. Hence, identifying patients at risk of ventricular arrhythmias and sudden cardiac death is important but can be challenging. The indication for an implantable cardioverter defibrillator as a primary preventive strategy relies on the left ventricular ejection fraction as a measure of systolic function. However, ejection fraction is flawed by technical constraints and is an indirect measure of systolic function. There has, therefore, been an incentive to identify other markers to optimize the risk prediction of malignant arrhythmias to select proper candidates who could benefit from an implantable cardioverter defibrillator. Speckle-tracking echocardiography allows for a detailed assessment of cardiac mechanics, and strain imaging has repeatedly been shown to be a sensitive technique to identify systolic dysfunction unrecognized by ejection fraction. Several strain measures, including global longitudinal strain, regional strain, and mechanical dispersion, have consequently been proposed as potential markers of ventricular arrhythmias. In this review, we will provide an overview of the potential use of different strain measures in the context of ventricular arrhythmias.

Antiquated ejection fraction: Basic research applications for speckle tracking echocardiography

For years, ejection fraction has been an essentially ubiquitous measurement for assessing the cardiovascular function of animal models in research labs. Despite technological advances, it remains the top choice among research labs for reporting heart function to this day, and is often overstated in applications. This unfortunately may lead to misinterpretation of data. Clinical approaches have now surpassed research methods, allowing for deeper analysis of the tiers of cardiovascular performance (cardiovascular performance, heart performance, systolic and diastolic function, and contractility). Analysis of each tier is crucial for understanding heart performance, mechanism of action, and disease diagnosis, classification, and progression. This review will elucidate the differences between the tiers of cardiovascular function and discuss the benefits of measuring each tier via speckle tracking echocardiography for basic scientists.

Left Ventricular Strain Is Associated With Myocardial Recovery Following ST-Elevation Myocardial Infarction, a Prospective Longitudinal CMR Study

Background

Infarct size following ST-elevation myocardial infarction (STEMI) is an important determinate of left ventricular (LV) dysfunction and cardiovascular morbidity and mortality. Cardiac magnetic resonance feature tracking (CMR-FT) is a technique that allows for the assessment of myocardial function via quantification of longitudinal, radial, and circumferential strain. We investigated the association between CMR-FT-derived myocardial global strain and myocardial recovery.

Methods

A prospective study on patients presenting with STEMI treated with primary percutaneous coronary intervention (PCI) was conducted. CMR imaging was obtained at two interval time points, the baseline within 2 weeks of hospital discharge and follow-up at 6 months. Strain analysis was performed via FT-CMR, and recovery was quantified by the area of late gadolinium enhancement (LGE).

Results

A total of n = 14 patients met inclusion and exclusion criteria and were analyzed. There was a significant reduction in the infarct size, as measured by LGE mass percentage of the left ventricular muscle mass, between the initial and follow-up CMR (19.7%, IQR 12.2-23.9 vs. 17.1%, IQR 8.3-22.5, p = 0.04). Initial strain parameters were inversely correlated with the initial edema mass and the decrease in LGE mass between the initial and follow-up CMR. All LV global strains had high accuracy for the prediction of a reduction in LGE mass by 50% or more.

Conclusions

LV global strains measured after primary PCI can predict the extent of myocardial recovery.

Tissue Mitral Annular Displacement in Patients With Myocardial Infarction - Comparison With Global Longitudinal Strain

Background: Global longitudinal strain (GLS) can predict prognosis after myocardial infarction (MI). Tissue mitral annular displacement (TMAD) is another index of longitudinal left ventricular deformity, and is less dependent on image quality than GLS. We investigated the relationship between TMAD and GLS, and their ability to predict outcomes after MI. Methods and Results: GLS and TMAD were measured on echocardiograms 2 weeks after MI in 246 consecutive patients (median age 62 years, 85.7% male). TMAD was measured from apical 4- and 2-chamber views (TMAD4ch and TMAD2ch, respectively), and a mean value (TMADav) was calculated. TMAD4ch, TMAD2ch, and GLS were successfully measured in 240 (97.5%), 210 (85.3%) and 214 patients (87.0%), respectively. All TMAD parameters were significantly correlated with GLS (R=0.71-0.75) and left ventricular ejection fraction (LVEF; R=0.48-0.53). TMAD parameters were weakly correlated with peak creatine kinase (CK; R=0.20) and CK-MB (R=0.21-0.25). GLS and TMADav were significantly associated with LVEF after 6 months (R=0.48-0.53) and all-cause mortality during the follow-up period (median 1,242 days). TMADav discriminated patients with higher all-cause mortality when patients were divided into 3 groups, namely upper 25%, middle range, and lower 25% of TMADav (P=0.041, log-rank test). GLS detected high-risk patients using 15.0% as a cut-off value. Conclusions: TMAD could be a simple and reliable alternative to GLS for predicting outcomes in patients with MI.

Evaluating the role of left ventricle global longitudinal strain in myocardial perfusion defect assessment

Myocardial perfusion defect, assessed with single photon emission computed tomography (SPECT), is useful for patient management and risk stratification. Left ventricle Global Longitudinal Strain (LV GLS) has gained interest for observing subclinical LV dysfunction. We aimed to investigate the utility of LV GLS in evaluating myocardial perfusion defect. A retrospective study of all patients who underwent SPECT and LV GLS at Tel Aviv Sourasky medical center. Overall, 86 patients were included. LV GLS and SPECT correlated in the base and apex sections for infraction, and in the apex only for ischemia. Adjusted analysis showed a significant correlation between LV GLS of both the mid and apical section and infarction by SPECT, but no association with ischemia. No associations were found by arterial supply territory. A sub-analysis of patients without left bundle branch block (LBBB) strengthened the correlations, with a 58-70% higher chance of both fixed and reversible defects for every 1-unit decrease LV GLS in the mid and apical sections. LV GLS effectively evaluated the presence of infarction by SPECT in the mid and apical sections, particularly in patients without LBBB. Due to its high availability, LV GLS may have a role in evaluating myocardial perfusion defect.

Global longitudinal strain predicts cardiovascular events after coronary artery bypass grafting

OBJECTIVE

To determine the prognostic value of global longitudinal strain (GLS) after coronary artery bypass grafting (CABG).

METHODS

We performed a retrospective cohort study on patients undergoing CABG between 2006 and 2011 who had an echocardiogram available for strain analysis. The patients were followed up through nationwide registries for development of all-cause mortality, cardiovascular death (CVD) and major adverse cardiovascular events (MACEs) defined as heart failure hospitalisation and/or CVD. Multivariable Cox regression was applied to adjust for the European System for Cardiac Operative Risk Evaluation II (EuroSCORE-II). Additive value was assessed by Net Reclassification Index (NRI) improvement.

RESULTS

Of the 709 patients included, 80 died during a median follow-up of 3.8 years. Of these, 45 had CVD, and 72 patients experienced MACE. Mean age was 68 years and 85% were men. Left ventricular ejection fraction (LVEF) was 50% and GLS was -13%.GLS was an independent predictor when adjusted for the EuroSCORE-II (all-cause mortality: HR=1.07 (1.01-1.13), p=0.018; CVD: HR=1.11 (1.03-1.20), p=0.007; MACE: HR=1.12 (1.06-1.19), p<0.001, per 1% absolute decrease). GLS significantly improved the NRI score by 0.30 when added to the EuroSCORE-II for predicting MACE, but not significantly for the other endpoints.LVEF modified the association between GLS and outcomes (p for interaction<0.05 for CVD and MACE). GLS remained an independent predictor of outcomes in patients with preserved LVEF (LVEF≥50%) and improved the NRI score when added to the EuroSCORE-II for predicting CVD and MACE, but not all-cause mortality in these patients.

CONCLUSION

GLS is an independent predictor of long-term outcomes after CABG. The predictive value appears strongest among patients with preserved LVEF.

Copeptin levels predict left ventricular systolic function in STEMI patients: A 2D speckle tracking echocardiography-based prospective observational study

In the present study, we aimed to investigate whether copeptin values on admission are related to left ventricle (LV) systolic function and its improvement at 6 months in ST-segment elevation myocardial infarction (STEMI) patients.In this single-center, prospective observational study, we included 122 STEMI patients from January 2016 to November 2016. LV systolic functions in the form of global longitudinal strain (GLS) in addition to conventional echocardiography parameters were evaluated on admission and at 6-month. Serum copeptin levels were determined using an ultrasensitive immunofluorescence assay.The study population was divided into 2 groups according to median values of copeptin. GLS was significantly lower in patients with high copeptin levels compared to those with low copeptin levels at early stage and 6-month (-16% (16-16.5) vs -15% (15-15.5), P < .001 and -18% (18-19) vs -16% (16-16.25), P < .001, respectively). Copeptin values were negatively correlated with an early and 6-month GLS (r = -0.459 at early stage and r = -0.662 at 6-month). In addition, we observed that copeptin values were negatively correlated with the improvement of GLS at 6-month follow-up (r = -0.458, P < .001 and r = -0.357, P = .005, respectively).Serum copeptin levels in STEMI patients at the time of admission may predict early and 6-month LV systolic function assessed by two-dimensional GLS. To the best of our knowledge, this study is the first to specifically address the relationship between copeptin values and GLS in STEMI patients.

Impaired left ventricular global longitudinal strain is associated with elevated left ventricular filling pressure after myocardial infarction

Left ventricular (LV) global longitudinal strain (GLS) has emerged as a significant prognostic marker in patients after myocardial infarction (MI). Although elevated LV filling pressure after MI might alter GLS, direct evidence for this is lacking. This study aimed to clarify the association between GLS and LV filling pressure in a large animal MI model. A total of 104 Yorkshire pigs underwent both echocardiographic and hemodynamic assessments 1-4 wk after induction of large anterior MI. GLS was measured in the apical four-chamber view using a semiautomated speckle-tracking software. LV pressure-volume relationship was invasively measured using a high-fidelity pressure-volume catheter. GLS >-14% was considered impaired. Compared with pigs with LV ejection fraction (LVEF) >40% and preserved GLS (n = 29), those with LVEF >40% and impaired GLS (n = 37) and those with LVEF ≤40% (n = 38) had significantly higher LV end-diastolic pressure (15.5 ± 5.5 vs. 19.7 ± 5.8 and 19.6 ± 6.6 mmHg; P = 0.008 and P = 0.026, respectively) and higher LV mean diastolic pressure (7.1 ± 2.9 vs. 10.4 ± 4.5 and 11.1 ± 5.4 mmHg; P = 0.013 and P = 0.002, respectively). GLS was modestly correlated with τ (r = 0.21, P = 0.039) and slope of LV end-diastolic pressure-volume relationship (r = 0.43, P < 0.001). Impaired GLS was associated with higher LV end-diastolic and mean-diastolic pressures after adjusting for LVEF and baseline characteristics (P = 0.026 and P = 0.001, respectively). Impaired GLS assessed by speckle-tracking echocardiography was associated with elevated LV filling pressure after MI. GLS has an incremental diagnostic value for detecting elevated LV filling pressure and may be particularly useful for evaluating post-MI patients with preserved LVEF.NEW & NOTEWORTHY Strain analysis was performed in 104 pigs after MI, and its relationship to invasive hemodynamic measurements was studied. Impaired longitudinal strain was associated with high ventricular filling pressure independent of LVEF in post-MI setting. Global longitudinal strain is a potential prognostic marker after MI.

Correlates and Long-Term Implications of Left Ventricular Mechanical Dispersion by Two-Dimensional Speckle-Tracking Echocardiography in Patients with ST-Segment Elevation Myocardial Infarction

BACKGROUND

Left ventricular (LV) mechanical dispersion (LVMD), measured with speckle-tracking echocardiography (STE) after ST-segment elevation myocardial infarction (STEMI), has been proposed as a measurement of regional heterogeneity of myocardial contraction and may reflect changes in the myocardial structure (e.g., fibrosis or edema). Further insight into this parameter may aid in the risk stratification of STEMI patients.

METHODS

A total of 1,000 STEMI patients (77% male, 60 ± 12 years) treated with primary percutaneous coronary intervention were retrospectively analyzed. The LVMD was assessed with two-dimensional STE within 48 hours following the index infarction. Patients were followed for the occurrence of all-cause mortality.

RESULTS

After a median follow-up of 117 months, 229 (23%) patients died. Nonsurvivors showed worse LV ejection fraction (43% ± 10% vs 48% ± 9%; P < .001) and global longitudinal strain (-12.0% ± 3.5% vs -14.2% ± 3.5%; P = .001) and prolonged LVMD (63 [interquartile range, 50-85] msec vs 52 [interquartile range, 42-63] msec; P < .001) compared with survivors. Increasing age, systolic blood pressure, and heart rate at discharge as well as diabetes mellitus, anterior STEMI, TIMI flow < 2, less usage of angiotensin converter enzyme inhibitors or angiotensin receptor blockers, and impaired LV global longitudinal strain were independently associated with more prolonged LVMD. On multivariable analysis, prolonged LVMD was independently associated with increased risk of all-cause mortality (hazard ratio = 1.012; 95% CI, 1.005-1.018; P = .001) and had incremental value for all-cause mortality over clinical and echocardiographic parameters.

CONCLUSIONS

In contemporary STEMI patients, prolonged LVMD was associated with various clinical and echocardiographic parameters. Prolonged LVMD was associated with worse long-term outcome.

[The Role of Residual Stenosis of the Coronary Arteries in the Dynamics Systolicdiastolic Left Ventricular Function after Acute Coronary Syndrome]

OBJECTIVE

The aim of the research under consideration was to study the dynamics of a local systolic-diastolic function of patients with various ischemic heart disease (IHD) progressions after survival of an acute coronary syndrome (ACS) provided there are residual stenoses of coronary arteries.

MATERIALS AND METHODS

 There were 112 patients suffering from ACS who took part in the research. The diagnosis was verified (acute myocardial infarction or unstable angina) in accordance with the recommendations of European Society of Cardiology (ESC). All patients were divided into two groups depending on the occurrence of major acute cardiac events (MACE): 59 patients with aggravated IHD progression and 152 patients with non-aggravated course. Echo-cardiography was performed on a scanner Philips iE33 (the Netherlands) with a consideration to systolic and diastolic functions parameters of a left ventricle. Quantitative analysis of the left ventricle was executed in the mode of Tissue Doppler Imaging (TDI) and according to the method of tracing the patches of the ultra-sound image gray scale (ST).

RESULTS

In the course of the aggravated IHD a decrease in systolic-diastolic function of left ventricle has been discovered. It has been found out that the amount of the systolic peak of longitudinal strain of the left ventricle anteroseptal wall less than 12% is associated with a greater extent of coronary atherosclerosis and aggravated progression of IHD. TDI and ST methods have enabled to reveal that in the course of non-aggravated IHD the contractility and the diastolic function of the left ventricle anteroseptal wall improve in combination with the increase in the contractility of the left ventricle inferolateral wall. During an aggravated IHD progression the contractility and diastolic function of the left ventricle anteresoptal wall decreases without an increase in contractility and diastolic function of the inferior and inferolateral walls of the left ventricle. The reason for such results might be a progressing myocardial ischemia of the left ventricle anteroseptal wall despite the sufficient anterior interventricular artery stenting. The presence of the relevant residual stenoses of the circumflex and right coronary arteries increases the possibility of the aggravated IHD progressing especially by the end of the fourth year of observation.

CONCLUSION

The disbalance of the local contractility of anterior, inferior and inferolateral left ventricle walls in the course of aggravated IHD is connected with the CA residual stenoses presence and forwards the decrease in global systolic-diastolic function of the left ventricle. The final results can serve as a foundation for optimization of recommendations for performing PCI on the patients with multivessel disease of CA.

Usefulness of Myocardial Longitudinal Strain in Prediction of Heart Failure in Patients with Successfully Reperfused Anterior Wall ST-segment Elevation Myocardial Infarction

Background and Objectives

Acute myocardial infarction-related heart failure (HF) is associated with poor outcome. This study was designed to investigate the usefulness of global longitudinal strain (GLS), global circumferential strain (GCS) and mean longitudinal strain of left anterior descending artery territory (LS_ant) measured by 2-dimensional speckle tracking echocardiography (2D STE) in prediction of acute anterior wall ST-segment elevation myocardial infarction (ant-STEMI)-related HF.

Methods

A total of 171 patients with ant-STEMI who underwent successful primary coronary intervention and had available 2D STE data were enrolled. Patients were divided into 3 groups: in-hospital HF, post-discharge HF, and no-HF groups.

Results

In-hospital and post-discharge HF developed in 39 (22.8%) and 13 (7.6%) of patients, respectively and 113 patients (69.6%) remained without HF. Multivariate analysis showed that GLS was the only factor significantly associated with the development of in-hospital HF. For post-discharge HF, LS_ant was the only independent predictor. Other echocardiographic or laboratory parameters did not show independent association with the development of ant-STEMI-related HF.

Conclusions

GLS is a powerful echocardiographic parameter related to development of in-hospital HF and LS_ant was significantly associated with post-discharge HF in patients with successfully reperfused ant-STEMI.

Identification of significant coronary artery disease in patients with non-ST segment elevation acute coronary syndrome by myocardial strain analyses using three dimensional speckle tracking echocardiography

BACKGROUND

Speckle-tracking imaging is a novel method for assessing left ventricular function and ischemic changes. This study aimed to predict the presence of significant coronary artery stenosis in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) by 3D strain analysis using speckle tracking echocardiography (3DSTE) at rest.

METHODS

This cross-sectional study included a total 60 patients with NSTE-ACS who underwent 3DSTE immediately prior to coronary angiography. Subsequently, patients undergone coronary angiogram (CAG) and divided into two groups; group- I: significant stenosis (n = 36), group-II: non-significant stenosis (n = 24).

RESULTS

Global peak systolic longitudinal strain (GPSLS), circumferential strain (CS), area strain (AS), and radial strain (RS) were obtained successfully in 60 patients. All strain parameters were significantly reduced in patient group of significant stenosis. Receiver operating characteristic (ROC) curve analysis demonstrated that GPSLS could effectively detect patients with significant stenosis (area under ROC curve = 0.840, 95% CI = 0.735-0.945). GPSLS with a cutoff value of -13.50% showed good sensitivity and specificity for predicting significant stenosis (sensitivity 88.9% and specificity 70.8%).

CONCLUSION

Global peak systolic longitudinal strain using 3D speckle tracking echocardiography at rest was significantly lower in patients with significant stenosis and might be useful for identifying patients with a significant stenosis with good degree of sensitivity and specificity.

Predictors of myocardial functional recovery following successful reperfusion of acute ST elevation myocardial infarction

BACKGROUND

Following acute ST elevation myocardial infarction (STEMI), restoration of large-vessel patency does not mean complete perfusion recovery. Little is known regarding the predictors of successful myocardial reperfusion for the STEMI patients undergoing pharmacologic and mechanical reperfusion strategies.

AIM OF THE WORK

The aim of this clinical study was to find out the predictors of myocardial functional recovery following reperfusion of acute STEMI, represented by 3-month global longitudinal strain (GLS) value assessed by speckle tracking echocardiography.

MATERIAL/METHODS

The study population included 400 patients presented with first acute STEMI with successful reperfusion by thrombolysis (group I) or primary percutaneous coronary intervention (PPCI) (group II). Electrocardiography (ECG) at baseline and 90 minutes after coronary reperfusion was performed with assessment of ST resolution. Basal and 3-month follow-up echocardiography was performed with assessment of ejection fraction (EF), myocardial performance index (MPI), systolic myocardial excursion (S'), and GLS.

RESULTS

There was nonsignificant difference between patients of both groups regarding age (P = 0.422) and gender (P = 0.272). Also, there was a nonsignificant difference between both groups regarding the risk factors of coronary artery disease like hypertension (P = 0.511), diabetes mellitus (P = 0.332), and smoking (P = 0.381). But there was significant statistical difference between both groups regarding dyslipidemia (P = 0.012). Ninety-minute ST resolution was significantly higher in PPCI group (P = 0.042). Moreover, PPCI group had significant improvement of EF (P = 0.013) during follow-up, and highly significant improvement of MPI, S' and GLS (P ˂ 0.001) compared to the basal echocardiographic study. The percentage of change (∆) of each of the echocardiographic parameter was compared between both groups and revealed statistically significant improvement regarding EF, highly significant improvement of MPI, S' and GLS in favor of PPCI arm (group II). Multivariate regression analysis demonstrated that pain to reperfusion time, MI territory, ST resolution, and basal GLS value are the most important predictors for LV functional recovery.

CONCLUSION

The study found pain to reperfusion time, MI territory, ST resolution, basal GLS value are the most important predictors of myocardial functional recovery. Regular follow-up with echocardiography for STEMI patients with different reperfusion strategies has informative impact on long-term clinical outcome. Also the study confirmed that PPCI is better than thrombolysis not only in restoring epicardial coronary flow but also in restoring microvascular and tissue perfusion assuring better myocardial functional recovery and better long-term clinical outcomes.

Assessment of LVEF using a new 16-segment wall motion score in echocardiography

Background

Simpson biplane method and 3D by transthoracic echocardiography (TTE), radionuclide angiography (RNA) and cardiac magnetic resonance imaging (CMR) are the most accepted techniques for left ventricular ejection fraction (LVEF) assessment. Wall motion score index (WMSI) by TTE is an accepted complement. However, the conversion from WMSI to LVEF is obtained through a regression equation, which may limit its use. In this retrospective study, we aimed to validate a new method to derive LVEF from the wall motion score in 95 patients.

Methods

The new score consisted of attributing a segmental EF to each LV segment based on the wall motion score and averaging all 16 segmental EF into a global LVEF. This segmental EF score was calculated on TTE in 95 patients, and RNA was used as the reference LVEF method. LVEF using the new segmental EF 15-40-65 score on TTE was compared to the reference methods using linear regression and Bland–Altman analyses.

Results

The median LVEF was 45% (interquartile range 32–53%; range from 15 to 65%). Our new segmental EF 15-40-65 score derived on TTE correlated strongly with RNA-LVEF (r = 0.97). Overall, the new score resulted in good agreement of LVEF compared to RNA (mean bias 0.61%). The standard deviations (s.d.s) of the distributions of inter-method difference for the comparison of the new score with RNA were 6.2%, indicating good precision.

Conclusion

LVEF assessment using segmental EF derived from the wall motion score applied to each of the 16 LV segments has excellent correlation and agreement with a reference method.

Comparison of Left Ventricular Function and Myocardial Infarct Size Determined by 2-Dimensional Speckle Tracking Echocardiography in Patients With and Without Chronic Obstructive Pulmonary Disease After ST-Segment Elevation Myocardial Infarction

Patients with chronic obstructive pulmonary disease (COPD) have a high risk of mortality after acute ST-segment elevation myocardial infarction (STEMI). We compared STEMI patients with versus without COPD in terms of infarct size and left ventricular (LV) systolic function using advanced 2-dimensional speckle tracking echocardiography. Of 1,750 patients with STEMI (mean age 61 ± 12 years, 76% male), 133 (7.6%) had COPD. With transthoracic echocardiography, left ventricular ejection fraction (LVEF) and wall motion score index were measured. Infarct size was assessed using biomarkers (creatine kinase and troponin T). LV global longitudinal strain (GLS), reflecting active LV myocardial deformation, was measured with 2-dimensional speckle tracking echocardiography to estimate LV systolic function and infarct size. STEMI patients with COPD were significantly older, more likely to be former smokers, and had worse renal function compared with patients without COPD. There were no differences in infarct size based on peak levels of creatine kinase (1315 [613 to 2181] vs 1477 [682 to 3047] U/l, p = 0.106) and troponin T (3.3 [1.4 to 7.3] vs 3.9 [1.5 to 7.8] µg/l, p = 0.489). Left ventricular ejection fraction (46% vs 47%, p = 0.591) and wall motion score index (1.38 [1.25 to 1.66] vs 1.38 [1.19 to 1.69], p = 0.690) were comparable. In contrast, LV GLS was significantly more impaired in patients with COPD compared with patients without COPD (-13.9 ± 3.0% vs -14.7 ± 3.9%, p = 0.034). In conclusion, despite comparable myocardial infarct size and LV systolic function as assessed with biomarkers and conventional echocardiography, patients with COPD exhibit more impaired LV GLS on advanced echocardiography than patients without COPD, suggesting a greater functional impairment at an early stage after STEMI.

Influence of Myocardial Ischemia Extent on Left Ventricular Global Longitudinal Strain in Patients After ST-Segment Elevation Myocardial Infarction

Two-dimensional echocardiographic left ventricular (LV) global longitudinal strain (GLS) after ST-segment elevation myocardial infarction (STEMI) is moderately correlated with infarct size and reflects the residual LV systolic function. This correlation may be influenced by the presence of myocardial ischemia. The present study investigated how myocardial ischemia modulates the correlation between LV GLS and infarct size determined with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in patients with first STEMI treated with primary coronary intervention. A total of 1,128 patients (age 60 ± 11 years) who underwent SPECT MPI for the evaluation of infarct size and residual ischemia were evaluated. LV GLS was measured on transthoracic echocardiography. The time interval between echocardiography and SPECT MPI was 1 ± 1 month. A moderate correlation between echocardiographic LV GLS and infarct size on SPECT MPI was observed (r = 0.58, p <0.001). This correlation was weakened by the presence or extent of ischemia; in the group of patients without ischemia, the correlation between LV GLS and infarct size on SPECT MPI was r = 0.66 (p <0.001), whereas in patients with mild or moderate-to-severe ischemia, the correlations were r = 0.56 and 0.38, respectively (both p <0.001). Moderate-to-severe myocardial ischemia was independently associated with more impaired LV GLS after adjusting for infarct size, age, diabetes mellitus, and hypertension (β 0.60, 95% confidence interval 013 to 1.06). In conclusion, the presence of myocardial ischemia after STEMI impacts on the correlation between echocardiographic LV GLS and infarct size measured on SPECT MPI. Residual ischemia is independently associated with more impaired LV GLS.

Early Speckle-tracking Echocardiography Predicts Left Ventricle Remodeling after Acute ST-segment Elevation Myocardial Infarction

Background:

Prediction of the left ventricular remodeling (LVR) after ST-segment elevation myocardial infarction (STEMI) in patients treated with effective myocardial reperfusion is challenging.

Methods:

Forty-one consecutive patients (36 males, age 59 ± 10 years) with STEMI who underwent effective (TIMI III) primary coronary angioplasty were enrolled. All patients had an echocardiography and cardiac magnetic resonance (CMR) study within 72 h from revascularization. Three echocardiographic parameters including LV ejection fraction (EF), global longitudinal strain (GLS) and severe altered longitudinal strain (SAS) area by two-dimensional speckle-tracking echocardiography (2D-STE) and 3 CMR indices including LV global function index (LV-GFI), myocardial salvage index (MSI), and microvascular obstruction (MVO) were calculated. LVR was defined as an increase in CMR LV end-diastolic volume (EDV) >15% after 6 months.

Results:

Of 41 patients, 10 (24%) had LVR (LV-EDV from 145.1 ± 29.3 to 185.9 ± 49.8 ml, P < 0.001). A significant correlation with LV-EDV variation was found for baseline SAS area (r = 0.81), LV-GFI (r = −0.56), MVO (r = 0.55), EF (r = −0.42), GLS (r = 0.42), not for MSI (r = −0.25). At the multivariable analysis, a significant correlation remained only for the SAS area. The receiver-operating characteristic curve analysis showed that a baseline SAS area ≥15% predicts LVR with a sensitivity of 80.0% and a specificity of 90.3%.

Conclusions:

The SAS area evaluated by 2D-STE early in acute STEMI is a valuable predictor of LVR after 6 months. Further investigations are needed to verify its value in predicting patient survival.

Two-Dimensional Speckle Tracking Echocardiography Predict Left Ventricular Remodeling after Acute Myocardial Infarction in Patients with Preserved Ejection Fraction

Objectives

Left ventricular remodeling after acute myocardial infarction increases cardiovascular events and mortality. But few study was done in patients with preserved ejection fraction (EF > 40%). We investigate whether the strain and strain rate by 2D speckle tracking echocardiography could predict left ventricular remodeling after acute myocardial infarction in this cohort.

Methods

The 83 patients (average age 60.7 ± 12.3 y, 75 [90.4%] male) with new-onset acute myocardial infarction receiving echocardiography immediately, and 6 months after admission were grouped by the presence or absence of left ventricular remodeling. Strain and strain rate including longitudinal, circumferential, and radial direction were calculated. The average of strain and strain rate of which segmental longitudinal strains > – 15% were defined as the injury longitudinal strain (InjLS).

Results

Left ventricular remodeling occurred in 24 of 83 patients (28.9%). In univariate logistic regression analyses, gender, peak CK-MB, log BNP, use of statin before discharge, wall motion score index, and InjLS were significantly associated with left ventricular remodeling (p < 0.05). In multivariate analysis using the forward stepwise method, gender, CK-MB, and InjLS were independent predictors. The hazard ratio for InjLS was 1.48 (p = 0.04). Receiver operating characteristic curve (ROC) analyses showed the area under the curve (AUC) of InjLS was largest (AUC = 0.75, cut-off value = –11.7%, sensitivity = 81%, specificity = 71%, p < 0.01). In ST-segment elevation myocardial infarction subgroup, InjLS was the only predictor according to ROC analysis (AUC = 0.79, p < 0.01, cut-off value = –11.4%, sensitivity = 88%, specificity = 77%) and multivariate logistic regression analysis (hazard ratio = 1.88, 95% CI: 1.22–2.88, p < 0.01).

Conclusions

InjLS was an excellent predictor for left ventricular remodeling after acute myocardial infarction in patient with preserved ejection fraction.

Risk assessment in patients with an acute ST-elevation myocardial infarction

ST-elevation myocardial infarction (STEMI) is one of the leading causes of mortality and morbidity worldwide. While the survival after acute STEMI has considerably improved, mortality rate still remains high, especially in high-risk patients. Survival after acute STEMI is influenced by clinical characteristics such as age as well as the presence of comorbidities. However, during emergency care increasing access to tools such as the electrocardiogram, chest x-ray and echocardiography can provide additional information helping to further risk stratify patients. In the invasive setting, this can also include coronary angiography, invasive hemodynamic recordings and angiographic assessments of coronary flow and myocardial perfusion. We outline the common investigations used in STEMI and their role in risk assessment of patients with an acute STEMI.

Global myocardial strain assessment by different imaging modalities to predict outcomes after ST-elevation myocardial infarction: A systematic review

AIM: To conduct a systematic review relating myocardial strain assessed by different imaging modalities for prognostication following ST-elevation myocardial infarction (STEMI).

METHODS: An online literature search was performed in PubMed and OVID^® electronic databases to identify any studies that assessed global myocardial strain parameters using speckle-tracking echocardiography (STE) and/or cardiac magnetic resonance imaging (CMR) techniques [either myocardial tagging or feature tracking (FT) software] in an acute STEMI cohort (days 0-14 post-event) to predict prognosis [either development of major adverse cardiac events (MACE)] or adverse left ventricular (LV) remodelling at follow-up (≥ 6 mo for MACE, ≥ 3 mo for remodelling). Search was restricted to studies within the last 20 years. All studies that matched the pre-defined search criteria were reviewed and their results interpreted. Due to considerable heterogeneity between studies, meta-analysis was not performed.

RESULTS: A total of seven studies (n = 7) were identified that matched the search criteria. All studies used STE to evaluate strain parameters - five (n = 5) assessed global longitudinal strain (GLS) (n = 5), one assessed GLS rate (GLS-R) (n = 1) and one assessed both (n = 1). Three studies showed that GLS independently predicted the development of adverse LV remodelling by multivariate analysis - odds ratio between 1.19 (CI: 1.04-1.37, P < 0.05) and 10 (CI: 6.7-14, P < 0.001) depending on the study. Four studies showed that GLS predicted the development of MACE - hazard ratio (HR) between 1.1 (CI: 1-1.1, P = 0.006) and 2.34 (1.10-4.97, P < 0.05). One paper found that GLS-R could significantly predict MACE - HR 18 (10-35, P < 0.001) - whilst another showed it did not. GLS < -10.85% had sensitivity/specificity of 89.7%/91% respectively for predicting the development of remodelling whilst GLS < -13% could predict the development of MACE with sensitivity/specificity of 100%/89% respectively. No suitable studies were identified that assessed global strain by CMR tagging or FT techniques.

CONCLUSION: GLS measured acutely post-STEMI by STE is a predictor of poor prognosis. Further research is needed to show that this is true for CMR-based techniques.

Global and regional myocardial deformation mechanics of microvascular obstruction in acute myocardial infarction: a three dimensional speckle-tracking imaging study

Microvascular obstruction (MVO) and transmural infarct size are prognostic factors after acute myocardial infarction (AMI). We assessed the value of myocardial deformation patterns using 3D speckle tracking imaging (3DSTI) in detecting myocardial and microvascular damage after AMI. One hundred patients with first ST-segment elevation MI from the REMI Study were prospectively included. Transthoracic echocardiography with 3DSTI and CMR were performed within 72 h after revascularization therapy. Global (3DG) and segmental (3DS) values of LV longitudinal (LS), circumferential and radial area strain were obtained. Late gadolinium enhancement (LGE) and MVO was quantified as transmural (>50%) or non-transmural (<50%). Predictive performance was assessed by area under the receiver operating curve characteristic (AUC). Mean LVEFCMR was 45.8 ± 9.2 % with 22.2 ± 12.7% transmural LGE. MVO was present in 55 patients (MVO transmural extent 11.4 ± 11.8%). In global analysis, all 3DG strain values were correlated with LVEFCMR and infarct size, with the best correlation obtained for 3DGAS (r = -0.678; p < 0.0001). All 3DG strain values, with the exception of LS, were significantly different between patients with and without MVO. In segmental analysis, all 3DS strain values were significantly lower in transmurally infarcted segments than in non-infarcted segments, and all 3DS values except 3DSRS were significantly lower in non-transmural infarcted segments than in non-infarcted segments. The best 3DS strain for detecting non-viable segments with MVO (MVO > 75%) was 3DSAS [AUC 0.867 (0.849-0.884), 78.0% sensitivity and 81.1% specificity for 3DSAS = -16.1%]. Importantly, 3DSRS and 3DSAS were associated with an increase in diagnostic accuracy of both transmural LGE and MVO over 3DSLS (all increase in AUC > 0.04, all p < 0.01). The newly developed 3DSTI, especially 3DSAS, is a sensitive and reproducible tool to predict and quantify the transmural extent of scar. This new early imaging strategy improve the prediction of MVO while enabling to assess the success of reperfusion and the risk of late systolic remodeling in STEMI.

Strain Echocardiography and Myocardial Mechanics: From Basics to Clinical Applications

The aim of this review is to summarize the recent developments in strain imaging, an evolving technique – from tissue Doppler to 3D echocardiography – for resolving the complex left ventricular mechanics. Following a brief overview of the different used technique to extract myocardial deformation data, the authors summarize the role of the technique in the assessment of cardiac mechanics and its role in the clinical arena.

Value of two-dimensional longitudinal strains analysis to assess the impact of thrombus aspiration during primary percutaneous coronary intervention on left ventricular function: a speckle tracking imaging substudy of the EXPIRA trial

BACKGROUND

Thrombectomy during primary percutaneous coronary intervention (Th-PCI) improves myocardial reperfusion in the absence of significant changes, in the acute phase, in traditional two-dimensional (2D) echo indexes of left ventricular (LV) function. The aim of this study was to evaluate the potential of 2D speckle tracking echocardiography (2DSTE) analysis in assessing the efficacy of thrombectomy as compared to standard 2D echo and cardiac magnetic resonance (CMR) data.

METHODS

Two-dimensional speckle tracking echocardiography analysis was performed in 60 anterior ST-segment elevation myocardial infarction (STEMI) patients to assess global (GLS), segmental (SLS) and regional longitudinal strain (RLS). 2D echo and CMR were performed within 5 days after PCI. Patients were divided into 2 groups according to the different methods of reperfusion used: 28 pts Th-PCI and 32 pts standard PCI (S-PCI).

RESULTS

Baseline clinical and angiographic characteristics, 2D echo, and DE-CMR data before and after PCI were similar in the 2 groups, except for microvascular obstruction (MVO), significantly lower (P = 0.001) in Th-PCI group. Conversely, GLS was significantly higher in Th-PCI group (P < 0.001), and in particular in the subset of patients without MVO (P = 0.012). RLS was also significantly higher in Th-PCI group (P = 0.001). GLS significantly correlates with infarct size, (R = 0.47; P = 0.03) and MVO (R = 0.69, P = 0.001). Finally, SLS was significantly lower in the DE segments (P < 0.001).

CONCLUSIONS

Patients treated with Th-PCI had a more preserved microvascular integrity resulting in a better myocardial longitudinal deformation. 2DSTE analysis adds significant information on the efficacy of thrombus aspiration as compared to standard echocardiography and it is closely related to the extent of microvascular damage.

Accuracy of two-dimensional speckle tracking echocardiography for the detection of significant coronary stenosis

Background

Visual assessment of wall motion abnormalities (WMA) by 2-dimensional echocardiography (2DE) is the most semi-quantitative method used to detect coronary artery disease (CAD), but it carries many limitations. Speckle tracking echocardiography (STE) overcomes these limitations and allows an objective quantification of myocardial deformation. The aim of the study to examine the accuracy of global and segmental longitudinal strain (LS) for the detection of CAD compared with visual assessment of WMA using coronary angiography as a golden standard.

Methods

The study enrolled 25 patients (mean age 51.0 ± 8.7, 64% are male) referred to coronary angiography with clinical suspicion of CAD. 2DE assessment of WMA and evaluation of LS using STE were performed using left ventricular 17-segments models. Significant CAD was defined as ≥ 50% stenosis in one or more major coronary arteries by angiography.

Results

Patients were classified into 2 groups: group I included 15 patients with significant CAD and group II included 10 patients with insignificant and/or absence of CAD. WM score was strongly correlated with the global LS in group I and II (R = 0.80, p < 0.0001 and R = 0.88, p < 0.0001 respectively). In all patients, 425 segments were analyzed. WMA was detected in 163 segments of 425 (38.3%) while abnormal LS was detected in 214 segments (50.3%). Compared with coronary angiography, the total sensitivity, specificity and accuracy for visual analysis and STE were (56%, 88.2%, and 60% vs. 68.6%, 77%, and 81.8% respectively).

Conclusion

Segmental LS is more accurate for the detection of ischemic myocardial segment corresponding to functionally relevant coronary anatomy than visual assessment of WM.

The impact of the width of the tracking area on speckle tracking parameters-methodological aspects of deformation imaging

AIMS

The aim of this study was to analyze the impact of the tracking area width on myocardial wall motion and deformation parameters in 2D speckle tracking.

METHODS AND RESULTS

Standardized apical views were acquired in 30 healthy subjects and 15 patients with left ventricular systolic dysfunction using 2D echocardiography. Longitudinal peak systolic strain (PSS), longitudinal peak systolic strain rate (PSSR), postsystolic index (PSI), peak longitudinal (PLD), and peak transverse displacement (PTD) were determined by 2D speckle tracking to analyze the impact of the tracking area width on global and regional myocardial wall motion and deformation parameters. The dimension of the tracking area has a significant impact on all parameters. With increasing width of the tracking area higher values of PSS, PSSR, PSI, and lower values of PLD and PTD were determined. With increasing width of the tracking area a significant number of segments were not tracked. In summary, especially global PSS is significantly influenced by the width of the tracking area.

CONCLUSIONS

The strain values determined by 2D speckle tracking are significantly influenced by the tracking area width. The tracking of the subendocardial layers only results in lower global strain values than tracking the complete ventricular wall using the medium or wide tracking area widths. The tracking quality in the far field is worse if the tracking area is too wide. The present data show that standard and reference values of deformation imaging should include detailed information about the position and the width of the tracking area.

Association between left ventricular global longitudinal strain and adverse left ventricular dilatation after ST-segment-elevation myocardial infarction

BACKGROUND

Myocardial infarct size is a major determinant of left ventricular (LV) remodeling after ST-segment-elevation myocardial infarction. We evaluated whether LV global longitudinal strain (GLS), proposed as a novel marker of infarct size, is associated with 3- and 6-month LV dilatation after ST-segment-elevation myocardial infarction.

METHODS AND RESULTS

In the first ST-segment-elevation myocardial infarction patients treated with primary percutaneous coronary intervention, baseline LVGLS was measured with 2-dimensional speckle-tracking echocardiography. Patients were dichotomized according to median value. The independent relationship between GLS groups and LV end-diastolic volume at 3 and 6 months (adjusted for clinical and echocardiographic variables) was assessed. The final study population comprised 1041 patients (60±12 years; 76% men). Median LVGLS was -15.0%. Patients with baseline LVGLS>-15.0% exhibited greater LV dilatation at 3 and 6 months compared with patients with GLS≤-15.0% (LV end-diastolic volume 123±44 versus 106±36 mL and 121±43 versus 102±34 mL, respectively; global group-time interaction P<0.001). This association retained the same statistical significance after adjustment for various relevant demographic, clinical, and echocardiographic characteristics. Further, net reclassification improvement index demonstrated significant incremental value of LVGLS for prediction of LV end-diastolic volume increase (0.14 [95% confidence interval, 0.00034-0.29]; P=0.04).

CONCLUSIONS

LVGLS before discharge after ST-segment-elevation myocardial infarction is independently associated with LV dilatation at follow-up.

Quantification of left ventricular longitudinal strain by two-dimensional speckle tracking: a comparison between expert and non-expert readers

The study aimed to examine whether global and segmental longitudinal strain (LS) using speckle tracking echocardiography could improve the interpretation of wall motion (WM) asynergy for expert and non-expert readers compared to visual assessment by 2-dimensional echocardiography (2DE). Using the 17 left ventricular segments model, both segmental and global LS were assessed by automatic function imaging in 20 patients with ischemic heart disease (61.0 ± 9.9 years, 70 % are male) and 20 normal controls (57.7 ± 16.9 years, 75 % are male). Global and segmental WM score was calculated by 2DE visual analysis using the same model. Both modalities were analyzed by two expert and two non-expert readers. Inter- and intra-observer agreement was calculated between all readers. Complete WM analysis of 680 segments was performed in 94.1 and 81 % by expert and non-expert readers respectively. Analysis of LS was completed in 96.3 and 95 % by both readers respectively. WM score by expert readers was correlated well with global LS by both expert and non-expert readers (R = 0.81, P < 0.0001, R = 0.79, P < 0.0001) while by the non-expert readers it was correlated fairly (R = 0.58, P < 0.01, R = 0.57, P < 0.01 respectively). Inter and intra-observer agreements between the expert readings were excellent in both techniques while the non-expert readings showed better agreement for LS than WM score. The mean difference between expert and non-expert readers was higher for WM score than LS (2.4 ± 2.9, -1.5 ± 1.6). Assessment of LS using 2D speckle tracking echocardiography showed better inter and intra-observer agreement than the visual analysis of WM regardless of the experience level. This may help to improved the quantification of WM asynergy by non-expert readers.

Are measures of left ventricular systolic performance during low dose dobutamine stress echocardiograms repeatable over time?

To establish the test-retest reliability and the normal dose-response relationship of echocardiographic measures of Left Ventricular (LV) contractile function to low dose dobutamine stress in healthy individuals. Thirty healthy volunteers (23 males, 7 females) with an average age of 38 ± 13 years underwent dobutamine stress echocardiography (DSE) (at successive doses of 0, 5, 10, and 20 mcg/kg/min) on two occasions, separated by 14 days. Ejection fraction (EF) was determined from 2D echocardiographic measures of left ventricular (LV) end diastolic and end systolic volumes. Longitudinal strain (S) and strain rate (SR) were measured using 2D speckle tracking analysis from three consecutive cardiac cycles. The Intraclass Correlation Coefficient (ICC) and the Coefficient of Variation (CV) were calculated to assess reliability and variability of the study population's EF, S, and SR responses to increasing doses of dobutamine. Left ventricular S and EF gradually increased with low doses of dobutamine but reached a plateau between 10 and 20 mcg/kg/min. Strain rate, however, gradually increases with each increasing dose of dobutamine. These responses were replicated on Day 2 with a high degree of reliability as determined from the ICC and low variability as determined from the CV, which fell within acceptable limits (<10 %). Left ventricular EF, S and SR can be measured during DSE with a high degree of test-retest reliability, and may be of clinical value when serial follow up of DSE measures of LV performance is indicated over time.

Prediction of all-cause mortality and heart failure admissions from global left ventricular longitudinal strain in patients with acute myocardial infarction and preserved left ventricular ejection fraction

OBJECTIVES

This study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%.

BACKGROUND

LVEF is a key determinant in decision making after acute MI, yet it is relatively indiscriminant within the normal range. Novel echocardiographic deformation parameters may be of particular clinical relevance in patients with relatively preserved LVEFs.

METHODS

Patients with MIs and LVEFs >40% within 48 h of admission for coronary angiography were prospectively included. All patients underwent echocardiography with semiautomated measurement of GLS. The primary composite endpoint (all-cause mortality and hospitalization for heart failure) was analyzed using Cox regression analyses. The secondary endpoints were cardiac death and heart failure hospitalization.

RESULTS

A total of 849 patients (mean age 61.9 ± 12.0 years, 73% men) were included, and 57 (6.7%) reached the primary endpoint (median follow-up 30 months). Significant prognostic value was found for GLS (hazard ratio [HR]: 1.20; 95% confidence interval [CI]: 1.10 to 1.32; p < 0.001). GLS > -14% was associated with a 3-fold increase in risk for the combined endpoint (HR: 3.21; 95% CI: 1.82 to 5.67; p < 0.001). After adjustment for other variables, GLS remained independently related to the combined endpoint (HR: 1.14; 95% CI: 1.04 to 1.26; p = 0.007). For the secondary endpoints, GLS > -14% was significantly associated with cardiovascular death (HR: 12.7; 95% CI: 3.0 to 54.6; p < 0.001) and heart failure hospitalization (HR: 5.31; 95% CI: 1.50 to 18.82; p < 0.001).

CONCLUSIONS

Assessment of GLS using a semiautomated algorithm provides important prognostic information in patients with LVEFs >40% above and beyond traditional indexes of high-risk MI.

Global and segmental myocardial deformation by 2D speckle tracking compared to visual assessment

AIM

To examine the feasibility and reliability of measuring global and segmental longitudinal strain (LS) compared to visual assessment of wall motion (WM).

METHODS

Assessment of segmental (17 left ventricular segments) LS using automatic function imaging (AFI) in 55 patients (60.0 ± 8.7 years, 73% male) divided into 2 groups: group I included 35 patients with WM abnormalities and/or impaired ejection fraction and group II included 20 patients with normal WM and ejection fraction. Visual analysis of WM abnormalities was performed using 2-dimensional echocardiography (2DE) and WM score was calculated. Both modalities were analyzed by one expert reader at 2 different sessions.

RESULTS

Analysis of 935 left ventricular segments was completed in 94.1% and 96.3% by visual assessment and AFI, respectively. There was a strong positive linear relationship between the WM score and global LS in all patients. Intra-observer agreement for calculation of WM score was excellent for group I patients (kappa: 0.97) and very good for group II patients (kappa: 0.92). Intra-observer agreement for AFI showed excellent agreement with very small mean difference in both group I and II (-0.0 ± 2.3 and -0.0 ± 1.9, respectively).

CONCLUSION

The interpretation of global and segmental LS using AFI is a more feasible and reliable technique for the quantification of myocardial deformation than visual assessment of WM scores.

Global left ventricular longitudinal systolic strain for early risk assessment in patients with acute myocardial infarction treated with primary percutaneous intervention

BACKGROUND

Left ventricular systolic function is a key determinant of outcome after ST-segment elevation myocardial infarction (STEMI). The aim of this study was to study speckle-tracking global longitudinal strain (GLS) for early risk evaluation in STEMI and compare it with left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and end-systolic volume index (ESVI).

METHODS

Five-hundred seventy-six patients underwent echocardiography ≤24 hours after primary percutaneous coronary intervention for STEMI. The end point was the composite of death, hospitalization with reinfarction, congestive heart failure, or stroke. Associations with outcome were assessed by multivariate Cox regression with adjustment for clinical parameters. Hazard ratios (HRs) for events within the first year are reported per absolute percentage GLS increase.

RESULTS

During a median follow-up period of 24 months, 162 patients experienced at least one event. GLS was associated with the composite end point (adjusted HR, 1.20; 95% confidence interval [CI], 1.12-1.29) and also when controlling for LVEF (adjusted HR, 1.17; 95% CI, 1.07-1.29) and ESVI (adjusted HR, 1.18; 95% CI, 1.08-1.28). Although WMSI was significantly associated with outcome beyond any association accounted for by GLS, a borderline significant association was found after controlling for WMSI (adjusted HR for GLS, 1.10; 95% CI, 1.00-1.21). When GLS or WMSI was known, there was no significant association between LVEF or ESVI and outcome.

CONCLUSIONS

In a large population of patients with STEMI, GLS and WMSI were comparable and both superior for early risk assessment compared with volume-based left ventricular function indicators such as LVEF and ESVI. Compared with WMSI, the advantage of GLS is the provision of a semiautomated quantitative measure.