Incremental Prognostic Value of Left Ventricular Longitudinal Strain Over Ejection Fraction in Coronary Artery Bypass Grafting

OBJECTIVES

To evaluate the incremental prognostic value of longitudinal strain over left ventricular ejection fraction (LVEF) after coronary artery bypass grafting (CABG).

DESIGN

Retrospective cohort study.

SETTING

Single tertiary-care center.

PARTICIPANTS

Patients underwent isolated CABG between January 2014 and December 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 999 patients (median age, 65 years, 23.5% female) categorized into 3 groups according to their left ventricular (LV) systolic function status: pEF/pS (preserved LVEF and preserved longitudinal strain, n = 490), pEF/iS (preserved LVEF and impaired longitudinal strain, n = 186), and rEF (reduced LVEF, n = 323). During a median follow-up of 2.7 years, 86 (8.6%) patients had died. The 5-year survival significantly differed in patients with preserved LVEF according to the strain status (pEF/pS v pEF/iS, 90.0% v 84.6%; p = 0.002). After adjusting for potential confounders, the pEF/iS group (adjusted hazard ratio [HR], 2.17; 95% CI, 1.10-4.28; p = 0.03) and the rEF group (adjusted HR, 2.96; 95% CI, 1.46-6.00; p = 0.003) had significantly higher risks for all-cause death compared with the pEF/pS group. The addition of longitudinal strain to LVEF in the prediction model significantly improved its performance (global chi-squared, 105.2 v 110.2; p = 0.03).

CONCLUSIONS

Left ventricular longitudinal strain could differentiate the prognosis after CABG in patients with preserved LVEF and provide significant incremental prognostic value to LVEF.

Comparison of effects of sevoflurane versus propofol on left ventricular longitudinal global and regional strain in patients undergoing on-pump coronary artery bypass grafting

Background:

Assessment of myocardial deformation by quantifying peak systolic longitudinal strain (PSLS) is a sensitive and robust index to detect subclinical myocardial dysfunction. We hypothesize that sevoflurane by virtue of anesthetic preconditioning preserves myocardial function better than propofol.

Aims:

The authors have assessed the effects of sevoflurane and propofol on global longitudinal strain (GLS) as a primary outcome in patients undergoing on-pump coronary artery bypass grafting. Our secondary aim was to assess the pattern of regional distribution of segmental PSLS between the groups.

Materials and Methods:

Fifty patients with normal left ventricular function undergoing coronary artery bypass grafting were analyzed in this prospective observational study. Consecutive patients received either propofol (P) or sevoflurane (S) anesthesia.

Measurements:

Trans-esophageal echocardiographic images (mid-esophageal four-chamber, two-chamber, and three-chamber (long-axis)) were recorded during the precardiopulmonary bypass (CPB) and post-CPB period. Strain analysis (GLS/segmental PSLS) was done offline by investigators blinded to the study. The inotropic score, duration of inotropic support, and mechanical ventilation required were recorded.

Results:

Following cardiopulmonary bypass and coronary revascularization, GLS reduced significantly in both the groups (P < 0.05). In the S-group, significant reduction in segmental strain was observed only in apical segments including apex, whereas in P-group significant reduction in segmental strain was seen in mid- and apical segments. The postoperative VIS, duration of inotropes/vasopressor required, and mechanical ventilation were similar in both the groups.

Conclusions:

There are no significant differences in global left ventricular function as assessed by GLS between patients anesthetized with sevoflurane or propofol. However, regional PSLS was better preserved in the S-group compared to P-group.

Association of baseline and change in global longitudinal strain by computed tomography with post-transcatheter aortic valve replacement outcomes

AIMS

Transcatheter aortic valve replacement (TAVR) procedural planning requires computed tomography angiography (CTA) which allows for the assessment of left ventricular global longitudinal strain (CTA-LVGLS). There is, however, limited data on the feasibility of CTA-LVGLS, and its prognostic value. This study sought to evaluate the incremental prognostic value of baseline CTA-LVGLS, change in CTA-LVGLS after TAVR, and their association with post-TAVR outcomes.

METHODS AND RESULTS

A total of 431 patients who underwent multiphasic gated CTA using dual-source system for TAVR planning at baseline and 1-month follow-up were included [median (interquartile range) age, 83 (77-87) years; 44% female, STS-PROM score: 3.3 (2.3-5.1)%, Echo-left ventricular ejection fraction (LVEF): 60 (55-65)%, CTA-LVGLS: -18.0 (-21.6 to -14.2)%, feasible in 97% of patients]. CTA-LVGLS was measured using dedicated feature-tracking software. Over a median follow-up of 19 (13-27) months, 99 endpoints of all-cause death or heart failure hospitalization occurred. The relative hazard of the endpoint increased as baseline CTA-LVGLS worsened with -18.2% as the threshold for higher events (P = 0.005). After adjustment for baseline characteristics, CTA-LVGLS remained associated with the endpoint [hazard ratio (HR) (95% confidence interval, CI), 1.08 (1.03-1.14); P = 0.005] and incrementally improved prognostication (C-index difference, 0.026). Although CTA-LVGLS improved after TAVR [-18.3 (-21.6 to -14.3)% vs. -18.7 (-21.9 to -15.4)%, P < 0.001], patients without CTA-LVGLS improvement had higher risk of the endpoint than those with improvement or preserved baseline global longitudinal strain [HR (95% CI), 1.92 (1.19-3.12); P = 0.008].

CONCLUSIONS

In this predominantly low-risk TAVR cohort of patients, mostly with normal LVEF, assessment of CTA-LVGLS is highly feasible improving risk stratification by providing independent and incremental prognostic value over clinical and echocardiographic characteristics.

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 (TMAD_4ch and TMAD_2ch, respectively), and a mean value (TMAD_av) was calculated. TMAD_4ch, TMAD_2ch, 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 TMAD_av 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). TMAD_av discriminated patients with higher all-cause mortality when patients were divided into 3 groups, namely upper 25%, middle range, and lower 25% of TMAD_av (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.

Utility of echocardiographic right ventricular subcostal strain in critical care

AIMS

Right ventricular (RV) strain is a known predictor of outcomes in various heart and lung pathologies but has been considered too technically challenging for routine use in critical care. We examined whether RV strain acquired from the subcostal view, frequently more accessible in the critically ill, is an alternative to conventionally derived RV strain in intensive care.

METHODS AND RESULTS

RV strain data were acquired from apical and subcostal views on transthoracic echocardiography (TTE) in 94 patients (35% female), mean age 50.5 ± 15.2 years, venovenous extracorporeal membrane oxygenation (VVECMO) (44%). RV strain values from the apical (mean ± standard deviation; -20.4 ± 6.7) and subcostal views (-21.1 ± 7) were highly correlated (Pearson's r -0.89, P < 0.001). RV subcostal strain correlated moderately well with other echocardiography parameters including tricuspid annular plane systolic excursion (r -0.44, P < 0.001), RV systolic velocity (rho = -0.51, P < 0.001), fractional area change (r -0.66, P < 0.01), and RV outflow tract velocity time integral (r -0.49, P < 0.001). VVECMO was associated with higher RV subcostal strain (non-VVECMO -19.6 ± 6.7 vs. VVECMO -23.2 ± 7, P = 0.01) but not apical RV strain. On univariate analysis, RV subcostal strain was weakly associated with survival at 30 days (R2 = 0.04, P = 0.05, odds ratio =1.08) while apical RV was not (P = 0.16).

CONCLUSION 

RV subcostal deformation imaging is a reliable surrogate for conventionally derived strain in critical care and may in time prove to be a useful diagnostic marker in this cohort.

Quantitative analysis of three-dimensional left ventricular global strain using coronary computed tomography angiography in patients with heart failure: Comparison with 3T cardiac MR

PURPOSE

The objective of this study was to investigate whether three dimentional (3D)- Coronary CT angiography (CCTA)- feature tracking (FT) can measure global myocardial strain of the left ventricle (LV) in patients with heart failure using cardiac MR (CMR) as reference.

METHODS

Consecutive patients (n = 44) with variable degrees of heart failure who underwent an ECG-gated CCTA and CMR within 24 h were included. Both modalities were compared for 2D/3D LV global radial strain (2D/3D-GRS), circumferential strain (2D/3D-GCS), longitudinal strain (2D/3D-GLS) and conventional functional parameters.

RESULTS

Compared to CMR, CCTA-derived 3D-GLS and LVEF showed no significant difference (p > 0.05). Bland-Altman plots showed a small bias (0.3 %) between CCTA-derived 3D-GLS and CMR 3D-GLS. Close correlations were observed between the two modalities regarding LV global strain (3D-GRS, r = 0.89; 3D-GCS, r = 0.86; 3D-GLS, r = 0.79, respectively, p < 0.001 for all). However, CCTA-derived 3D-GRS and 3D-GCS were statistically different compared with CMR. CCTA-derived 3D-GLS had an inverse correlation with CCTA-LVEF(r=-0.75, p < 0.05). Intraobserver agreements for CCTA-derived 3D-global strain were good (ICC = 0.856 for 3D-GLS, ICC = 0.741 for 3D-GCS and ICC = 0.762 for 3D-GRS). 2D global strain showed statistical differences between the two modalities (p＜0.05 for all), but close correlations were observed regarding 2D LV global strain (2D-GRS, r = 0.80; 2D-GCS, r = 0.81; 2D-GLS, r = 0.81, respectively, p < 0.001 for all). The average radiation dose-long-product (DLP) of CCTA was 387.86 ± 89.3 mGy*cm.

CONCLUSION

CCTA-derived 3D-GLS can provide both reliable and interchangeable results for quantitative assessment of myocardial mechanical changes in HF patients compared to CMR with good intra-observer agreement.

Contrast-enhanced echocardiographic measurement of longitudinal strain: accuracy and its relationship with image quality

The importance of left ventricular (LV) global longitudinal strain (GLS) is increasingly recognized in multiple clinical scenarios. However, in patients with poor image quality, strain is difficult or impossible to measure without contrast enhancement. The feasibility of contrast-enhanced GLS measurement was recently demonstrated. We sought to determine: (1) whether contrast enhancement improves the accuracy of GLS measurements against cardiac magnetic resonance (CMR) reference, (2) their reproducibility compared to non-enhanced GLS, and (3) the dependence of accuracy and reproducibility on image quality. We prospectively enrolled 25 patients undergoing clinically indicated CMR imaging who subsequently underwent transthoracic echocardiography (TTE) with and without low-dose contrast injection (1-2 mL Optison/3-5 mL saline IV, GE Healthcare). GLS was measured from both non-contrast and contrast-enhanced images using speckle tracking (EchoInsight, Epsilon Imaging). These measurements were compared to each other and to CMR reference values obtained using feature tracking (SuiteHEART, NeoSoft). Inter-technique comparisons included linear regression and Bland-Altman analyses. A random subgroup of 15 patients was used to assess inter- and intra-observer variability using intra-class correlation (ICC). Contrast-enhanced GLS was in close agreement with non-enhanced GLS (r = 0.95; bias: - 0.2 ± 1.5%). Both inter-observer (ICC = 0.88 vs. 0.82) and intra-observer variability (ICC = 0.91 vs. 0.88) were improved by contrast enhancement. The agreement with CMR was better for contrast-enhanced GLS (r = 0.87; bias: 1.1 ± 2.2%) than for non-enhanced GLS (r = 0.80; bias: 1.3 ± 2.7%). In 12/25 patients with suboptimal TTE images that rendered GLS difficult to measure, contrast-enhanced GLS showed better agreement with CMR than non-enhanced GLS (r = 0.88 vs. 0.83) and also improved inter-observer (ICC = 0.83 vs. 0.76) and intra-observer variability (ICC = 0.88 vs. 0.82). In conclusion, contrast enhancement of TTE images improves the accuracy and reproducibility of GLS measurements, resulting in better agreement with CMR, even in patients with suboptimal acoustic windows. This approach may aid in the assessment of LV function in this patient population.

Application of strain and other echocardiographic parameters in the evaluation of early and long-term clinical outcomes after cardiac surgery revascularization

Background

Coronary artery bypass graft (CABG) surgery is an effective therapeutic strategy for coronary heart disease (CHD). Myocardial longitudinal strain echocardiography with 2D speckle tracking could obtain ventricular function with better accuracy and reliability than the left ventricular ejection fraction.

The aim of the study was to assess changes in left ventricular function in patients before and after surgical revascularization for a 24-month period of observation, using echocardiography with speckle tracking strain imaging. We searched for echocardiographic predictors of poor early and long-term outcome after CABG.

Methods

We enrolled 69 patients scheduled for elective coronary bypass grafting. Patients were divided into groups based on pre-operative systolic and diastolic parameters, depending on the GLS value and the E’ Lat and E/E’ value. The correlation between these parameters and early and long-term outcomes was analyzed.

Results

Preoperative EF was preserved in 86, 95% (60) patients. Pre-operative reduced GLS was observed in 73.91% (51) of patients and severely reduced in 31.88% (22).

In the first post-operative 6-month period, we observed a significant decrease in the GLS. The GLS was a predictor of early postoperative outcome for intubation time, the inotropes use and length of ICU stay. Diastolic dysfunction was a predictor of the greater inotrope requirements.

Conclusions

Global longitudinal strain and diastolic dysfunction parameters are a good predictors of worse early outcome after CABG.

Variability of longitudinal strain measurements: levelling the playing field

Speckle tracking echocardiography offers a unique opportunity to evaluate myocardial function, and global longitudinal strain (GLS) is currently recommended as a measurement of global left ventricular function. To facilitate clinical applicability of the method, collective efforts have been made to standardise strain measurements and to raise awareness of the potential sources of variability. The purpose of this review is to familiarise the reader with the most common sources of variability of longitudinal strain measurements and detail the possible measures to increase the accuracy and reproducibility of strain parameters.

A Case of Myocardial Ischemia Detected by Global Longitudinal Strain Using Intraoperative Speckle-Tracking Echocardiography in a High-Risk Patient Undergoing Abdominal Aortic Aneurysm Repair

Patient: Male, 75

Final Diagnosis: Coronary artery disease

Symptoms: Chest pain

Medication: —

Clinical Procedure: Open abdominal aortic aneurysm repair

Specialty: Anesthesiology

Myocardial multilayer strain does not provide additional value for detection of myocardial viability assessed by SPECT imaging over and beyond standard strain

BACKGROUND

The aim of this study was to evaluate the value of multilayer strain analysis to the assessment of myocardial viability (MV) through the comparison of both speckle tracking echocardiography and single-photon emission computed tomography (SPECT) imaging. We also intended to determine which segmental longitudinal strain (LS) cutoff value would be optimal to discriminate viable myocardium.

METHODS

We included 47 patients (average age: 61 ± 11 years) referred to our cardiac imaging center for MV evaluation. All patients underwent transthoracic echocardiography with measures of LS, SPECT, and coronary angiography.

RESULTS

In all, 799 segments were analyzed. We correlated myocardial tracer uptake by SPECT with sub-endocardial, sub-epicardial, and mid-segmental LS values with r = .514 P < .0001, r = .501 P < .0001, and r = .520 P < .0001, respectively. The measurements of each layer strain (sub-endocardial, sub-epicardial, and mid) had the same performance to predict MV viability as defined by SPECT with areas under curve of 0.819 [0.778-0.861, P < .0001], 0.809 [0.764-0.854, P < .0001], and 0.817 [0.773-0.860, P < .0001], respectively. The receiver-operating characteristic analysis yielded a cutoff value of -6.5% for mid-segmental LS with a sensitivity of 76% and specificity of 76% to predict segmental MV as defined by SPECT.

CONCLUSIONS

Multilayer strain analysis does not evaluate MV with more accuracy than standard segmental LS analysis.

Longitudinal strain assessed by cardiac magnetic resonance correlates to hemodynamic findings in patients with severe aortic stenosis and predicts positive remodeling after transcatheter aortic valve replacement

AIMS

To assess left-ventricular strain parameters before and after transcatheter aortic valve replacement (TAVR) by feature tracking cardiac magnetic resonance imaging (FT CMR) and to correlate the findings to hemodynamic state and left-ventricular remodeling.

METHODS AND RESULTS

Patients with symptomatic AS underwent FT CMR before and after TAVR. Patients were carefully evaluated by a comprehensive work-up including CMR, echocardiography and left and right heart catheterization. Thirty patients formed the study population. High-flow/high-gradient (HF/HG) aortic stenosis was diagnosed in 11 patients (36.7%), 6 patients (20.0%) exhibited low-flow/low-gradient AS (LF/LG) and 13 patients (43.3%) were classified to have so-called paradoxical low-flow/low-gradient (PLF/LG) AS. The HF/HG patients had a significantly reduced longitudinal strain which recovered after TAVR (-12.67 ± 4.60 to -15.46 ± 5.61%, p = 0.048). In the LF/LG group, an even more pronounced reduction of longitudinal strain and also an impairment of longitudinal velocity could be observed. Both parameters improved after therapy (strain: -5.06 ± 4.25 to -8.02 ± 3.28%, p = 0.045; velocity: 25.33 ± 9.63 to 37.13 ± 11.64 mm/s, p = 0.042). Patients with PLF/LG showed preserved longitudinal strain but a reduction of longitudinal velocity similar to the LF/LG group. These patients did not show a significant improvement of strain parameters after TAVR. Longitudinal velocity exhibited the highest predictive power for the identification of a low-flow state (sensitivity 75%, specificity 80%).

CONCLUSION

Improvement of longitudinal strain parameters after TAVR is dependent on the initial hemodynamically defined AS subgroup.

Distribution pattern of left-ventricular myocardial strain analyzed by a cine MRI based deformation registration algorithm in healthy Chinese volunteers

The cine magnetic resonance imaging based technique feature tracking-cardiac magnetic resonance (FT-CMR) is emerging as a novel, simple and robust method to evaluate myocardial strain. We investigated the distribution characteristics of left-ventricular myocardial strain using a novel cine MRI based deformation registration algorithm (DRA) in a cohort of healthy Chinese subjects. A total of 130 healthy Chinese subjects were enrolled. Three components of orthogonal strain (radial, circumferential, longitudinal) of the left ventricle were analyzed using DRA on steady-state free precession cine sequence images. A distinct transmural circumferential strain gradient was observed in the left ventricle that showed universal increment from the epicardial to endocardial myocardial wall (epiwall: -15.4 ± 1.9%; midwall: -18.8 ± 2.0%; endowall: -22.3 ± 2.3%, P < 0.001). Longitudinal strain showed a similar trend from epicardial to endocardial layers (epiwall: -16.0 ± 2.9%; midwall: -15.6 ± 2.7%; endowall: -14.8 ± 2.4%, P < 0.001), but radial strain had a very heterogeneous distribution and variation. In the longitudinal direction from the base to the apex of the left ventricle, there was a trend of decreasing peak systolic longitudinal strain (basal: -23.3 ± 4.6%; mid: -13.7 ± 7.3%; apical: -13.2 ± 5.5%; P < 0.001). In conclusion, there are distinct distribution patterns of circumferential and longitudinal strain within the left ventricle in healthy Chinese subjects. These distribution patterns of strain may provide unique profiles for further study in different types of myocardial disease.

Reproducibility and experience dependence of echocardiographic indices of left ventricular function: Side-by-side comparison of global longitudinal strain and ejection fraction

BACKGROUND

Although left ventricular (LV) ejection fraction (EF) and global longitudinal strain (GLS) are recommended by the current echocardiographic chamber quantification guidelines, these measurements are not performed routinely. Because EF measurements rely on manual tracing of LV boundaries, and are subject to inter-reader variability and experience dependence, we hypothesized that semiautomated GLS measurements using speckle tracking would be more reproducible and less experience-dependent.

METHODS

Images from 30 patients were analyzed to obtain biplane EF using manual tracing. GLS was measured in three long-axis views using EchoInsight software (Epsilon Imaging) that automatically detects LV endocardial boundary, which is edited manually as necessary and is then automatically tracked throughout the cardiac cycle. All measurements were performed by an expert echocardiographer and three first-year cardiology fellows.

RESULTS

Semiautomated GLS analysis showed excellent correlation (r=.98) and small bias (-1.0±13% of measured value) between the experienced and less experienced readers, superior to EF (r=.91, bias 7.3±16%). Also, in repeated measurements, GLS showed higher intra-class correlation (ICC=.98) than EF (ICC=.89). Additionally, GLS analysis required ~1 minute per patient, while biplane EF measurements took twice as long.

CONCLUSIONS

Semiautomated GLS measurements are fast, less experience-dependent, and more reproducible than conventional EF measurements. This is probably because, irrespective of experience, the readers' choice of boundary position varies less when asked to refine the automated detection than to draw borders without initial clues. This technique may facilitate the workflow of a busy laboratory and make a step forward toward incorporating quantitative analysis into everyday echocardiography practice.

Cardiac function in vertically HIV-infected children and adolescents in the era of highly active antiretroviral therapy

BACKGROUND

Previous studies have demonstrated increased risk of adverse cardiac outcomes in adults with HIV infection. However, few studies have addressed this problem in vertically HIV-infected children and adolescents, and the long-term cardiac health of this unique population in the antiretroviral therapy era is still unknown.

METHODS

Ventricular function was evaluated cross-sectionally in a group of HIV-infected children and adolescents and healthy controls, using conventional echocardiography along with tissue Doppler imaging and strain analysis by speckle tracking. Simultaneously, measurements of carotid intima-media thickness were performed.

RESULTS

A total of 64 cases and 58 controls were included, mean age was 13.6 ± 5.4 years and 64% were females. All but 2 patients were on antiretroviral treatment, and 64% had undetectable viral load. HIV-infected patients showed higher intima-media thickness (0.425 ± 0.019 vs. 0.415 ± 0.019 mm, P = 0.003). Statistically significant differences were found between groups in ejection fraction and fractional shortening (66.1% and 36.2% in the HIV-infected group vs. 71.5% and 40.8% in the control group, respectively, P = 0.001), although individual values fell within or near normal ranges. There were no significant differences in diastolic function, tissue Doppler imaging or cardiac strain (longitudinal and rotational) between both groups. No associations were identified between echocardiographic parameters and current CD4+ T-lymphocyte counts, CD4+ T-lymphocyte nadir, HIV viral load, duration or type of antiretroviral treatment regimens.

CONCLUSIONS

In a context of highly effective antiretroviral treatment, no differences were found regarding cardiac abnormalities using conventional and advanced ultrasound imaging techniques in this cohort of vertically HIV-infected children and adolescents, when compared with healthy controls.

Diastolic function improves after resolution of takotsubo cardiomyopathy

BACKGROUND

Takotsubo cardiomyopathy (TTC) is a condition of reversible left ventricular (LV) systolic dysfunction. However, the diastolic function (DF) manifestations of TTC have not been widely investigated. We performed a bicentric study with retrospective analysis of DF in patients with TTC, during onset and at follow-up.

METHODS

Twenty-eight patients with TTC (64 ± 10 years, F 24) were included. All underwent echocardiograms acutely and at the recovery phase (average three months later). Diastolic and systolic function parameters were recorded, including E-wave velocity (E), A-wave velocity, E/A ratio, relaxation (e') and contractility (S') based on tissue Doppler velocities of the mitral annuli, ejection fraction (EF), left atrial (LA) size and DF stages.

RESULTS

Recovery, including the mean difference with 95% confidence interval, was associated with tending improvement (i.e. uncorrected significance) in E [13 cm s(-1) (-24, -2·3), P = 0·02] and in E/A ratio [0·2 (-0·41, -0·02), P = 0·04], as well as significant improvement (after multiple comparison correction) in mean e' [2·0 cm s(-1) (-3·3, -1·2), P<0·001] and in A-wave duration [29 ms (-46·7, -12·7), P = 0·002]. LA area tended to decrease during recovery [-2 cm² (0·33, 2·4), P = 0·01]. Improvement in DF stages was significant between the phases (21% versus 58% defined as normal DF, P = 0·016). Improvement in LVEF correlated with improvement in mean e' (r = 0·52, P = 0·02).

CONCLUSIONS

TTC is associated with an acute impairment of conventional DF variables, which improves during recovery. DF recovery seems to occur in parallel with systolic recovery in patients with TTC.

Speckle-tracking imaging to monitor myocardial function after coronary artery bypass graft surgery

OBJECTIVES

The purpose of this study was to investigate the changes in myocardial function in patients after coronary artery bypass graft (CABG) surgery using longitudinal and circumferential strain on speckle-tracking imaging.

METHODS

A total of 145 patients who successfully underwent CABG surgery with a left ventricular ejection fraction (LVEF) of 50% or greater were enrolled in this study. Patients were classified into 4 groups based on age: group 1 (33-59 years), group 2 (60-64 years), group 3 (65-69 years), and group 4 (70-79 years). Routine echocardiography and longitudinal and circumferential strain measurements on speckle-tracking imaging were performed 1 week before and 1, 3, and 6 months after the CABG.

RESULTS

In all groups, longitudinal strain increased significantly at 3 and 6 months after CABG therapy compared to baseline (P < .05). A significant increase in circumferential strain was found 1 month after the CABG in groups 1, 2, and 3, and a continuous increase in the parameter was observed in all groups 3 months after therapy (P < .05). However, the LVEF, left ventricular end-diastolic dimension, and stroke volume measured by routine echocardiography were not significantly changed after successful CABG treatment in all groups during 6 months of follow-up.

CONCLUSIONS

Based on the results of our study in all age groups, speckle-tracking imaging parameters are more effective than the LVEF, left ventricular end-diastolic dimension, and stroke volume for monitoring improvement in myocardial function after CABG surgery.

Myocardial deformation analysis in contrast echocardiography: first results using two-dimensional cardiac performance analysis

BACKGROUND

Contrast echocardiography (CE) provides closer agreement with magnetic resonance imaging (MRI) for left ventricular (LV) volumes and ejection fraction (EF) than noncontrast echocardiography. However, the feasibility and role of myocardial deformation analysis on contrast echocardiographic images have not been well established. The aim of this study was to assess the feasibility of deformation analysis on CE using a new software tool that provides simultaneous measurements for LV volumes and EF.

METHODS

Data from 52 patients who were recruited for the Alberta Heart Failure Etiology and Analysis Research Team Study (34 men; mean age, 64 ± 9 years) and underwent CE and MRI were considered. Contrast bolus injections were administered for optimal endocardial definition. Offline LV volume analysis was performed by standard manual tracing. A single frame was traced manually for two-dimensional (2D) cardiac performance analysis (CPA), which automatically calculated LV volumes, EF, and global longitudinal strain (GLS). Volumes obtained with 2D CPA were compared with those measured with standard CE and MRI. GLS from noncontrast echocardiographic recordings was also calculated with 2D CPA and compared with CE-derived and MRI-derived GLS.

RESULTS

Tracing of contrast echocardiographic images with 2D CPA was possible in 49 out of 52 patients, and measurements correlated well with standard CE and MRI (EF: r = 0.93, P < .001, and r = 0.85, P < .001, respectively). Mean GLS from noncontrast echocardiographic and contrast echocardiographic recordings was -13.4 ± 5.8 and -15.3 ± 4.64, respectively (P = .056), and the latter correlated well with MRI-derived GLS (r = 0.78 vs 0.81, respectively).

CONCLUSIONS

Simultaneous volumetric and deformation analysis on contrast echocardiographic recordings is feasible and reproducible. While volumes and EF obtained with the new software compare well with those obtained from standard CE and MRI, GLS from CE shows a good correlation with strain measured with MRI.

Incremental value of global longitudinal strain for predicting early outcome after cardiac surgery

AIMS

Global longitudinal strain (GLS) seems accurate for detecting subclinical myocardial dysfunction, and may therefore be used to improve risk stratification for cardiac surgery.

METHODS AND RESULTS

Longitudinal strain (by two-dimensional speckle tracking) was computed in 425 patients [mean age 67 ± 13 years, 69% male, left ventricular ejection fraction (LVEF) 51 ± 13%] referred for cardiac surgery [isolated coronary artery bypass graft (CABG) (n = 155), aortic valve surgery (n = 174), mitral surgery (n = 96)]. GLS (global-ε) was assessed for predicting early postoperative death. Despite a fair correlation between LVEF and global strain (r = -0.73, P < 0.0001), 40% of patients with preserved LVEF (defined as LVEF ≥50%) had abnormal global-ε (defined as global-ε >-16%): -12.8 ± 1.7%, range -15% to -8%. In patients with preserved LVEF, NT-proBNP level (983 vs. 541 pg/mL, P = 0.03), heart failure symptoms (NYHA class, 2.2 ± 0.9 vs. 1.9 ± 0.9, P = 0.02), and the need for prolonged (>48 h) inotropic support after surgery (33.3 vs. 21.2%, P = 0.03) were greater when global-ε was impaired. Importantly, despite similar EuroSCORE (9.7 ± 12 vs. 7.7 ± 9%, P = 0.2 for EuroSCORE I and 4.2 ± 6.2 vs. 3.4 ± 4.9%, P = 0.4 for EuroSCORE II), the rate of postoperative death was 2.4-fold (11.8 vs. 4.9%, P = 0.04) in patients with preserved LVEF when global-ε was impaired. Multivariate analysis showed that global-ε is an independent predictor for early postoperative mortality [odds ratio = 1.10 (1.01-1.21)] after adjustment to EuroSCORE.

CONCLUSION

GLS has an incremental value over LVEF for risk stratification in patients referred for cardiac surgery.