Automated function imaging: a new operator-independent strain method for assessing left ventricular function

Left Ventricular Global Longitudinal Strain (GLS) Is a Superior Predictor of All-Cause and Cardiovascular Mortality When Compared to Ejection Fraction in Advanced Chronic Kidney Disease

Background

Echocardiographic global longitudinal strain (GLS) is increasingly recognised as a more effective technique than conventional ejection fraction (EF) in detecting subtle changes in left ventricular (LV) function. This study investigated the prognostic value of GLS over EF in patients with advanced Chronic Kidney Disease (CKD).

Methods

The study included 183 patients (57% male, 63% on dialysis) with CKD stage 4, 5 and 5Dialysis (D). 112 (61%) of patients died in a follow up of 7.8 ± 4.4 years and 41% of deaths were due to cardiovascular (CV) disease. GLS was calculated using 2-dimensional speckle tracking and EF was measured using Simpson’s biplane method. Cox proportional hazard models were used to assess the association of measures of LV function and all- cause and CV mortality.

Results

The mean GLS at baseline was -13.6 ± 4.3% and EF was 45 ± 11%. GLS was a significant predictor of all-cause [Hazard Ratio (HR) 1.09 95%; Confidence Interval (CI) 1.02–1.16; p = 0.01] and CV mortality (HR 1.16 95%; CI 1.04–1.30; p = 0.008) following adjustment for relevant clinical variables including LV mass index (LVMI) and EF. GLS also had greater predictive power for both all- cause and CV mortality compared to EF. Impaired GLS (>-16%) was associated with a 5.6-fold increased unadjusted risk of CV mortality in patients with preserved EF.

Conclusions

In this cohort of patients with advanced CKD, GLS is a more sensitive predictor of overall and CV mortality compared to EF. Studies of larger populations in CKD are required to confirm that GLS provides additive prognostic value in patients with preserved EF.

Global longitudinal strain and global circumferential strain by speckle-tracking echocardiography and feature-tracking cardiac magnetic resonance imaging: comparison with left ventricular ejection fraction

BACKGROUND

Left ventricular (LV) ejection fraction (EF) is a routine clinical standard to assess cardiac function. Global longitudinal strain (GLS) and global circumferential strain (GCS) have emerged as important LV functional measures. The objective of this study was to determine the relationships of GLS and GCS by speckle-tracking echocardiography and featuring-tracking cardiac magnetic resonance (CMR) to CMR EF as a standard of reference in the same patients.

METHODS

A total of 73 consecutive patients aged 55 ± 15 years clinically referred for both CMR and echocardiography (EF range, 8%-78%) were studied. Routine steady-state free precession CMR images were prospectively analyzed offline using feature-tracking software for LV GLS, GCS, volumes, and EF. GLS was averaged from three standard longitudinal views and GCS from the mid-LV short-axis plane. Echocardiographic speckle-tracking was used from the similar imaging planes for GLS, GCS, LV volumes, and EF.

RESULTS

Feature-tracking CMR strain was closely correlated with speckle-tracking strain in the same patients: GLS, r = -0.87; GCS, r = -0.92 (P < .0001). End-diastolic and end-systolic volumes and EF by feature-tracking CMR were significantly correlated with standard manual tracing of multiple CMR short-axis images (r = 0.97, r = 0.98, and r = 0.97, P < .0001 for all). GLS and GCS by echocardiography and CMR feature-tracking were closely correlated with standard CMR EF: r = -0.85 and r = -0.95, respectively (P < .001). Global strain measures (in absolute values) were correlated with EF using the formula EF = 3(GLS) + 8% or EF = 2.5(GCS) + 8%.

CONCLUSIONS

GLS and GCS by feature-tracking CMR analysis was a rapid means to obtain myocardial strain similar to speckle-tracking echocardiography. GLS and GCS were closely correlated with CMR EF in this patient series and may play a role in the clinical assessment of LV function.

Cyclooxygenase inhibitors in preterm infants with patent ductus arteriosus: effects on cardiac and vascular indices

Existing data suggest subendocardial ischemia in preterm infants with patent ductus arteriosus (PDA) and alterations in cardiac function after indomethacin administration. This study aimed to explore the evolution of left ventricular function by conventional echocardiography and speckle-tracking echocardiography (STE) and to ascertain the interrelationship with coronary flow indices in response to indomethacin. A prospective observational study was performed with preterm infants receiving indomethacin for medical closure of PDA. Serial echocardiography was performed, and the results were analyzed using analysis of variance. Intra- and interobserver variability was assessed using the intraclass correlation coefficient. Indomethacin was administered to 18 infants born at a median gestational age of 25.8 weeks (interquartile range [IQR], 24.2-28.1 weeks) with a birth weight of 773 g (IQR, 704-1,002 g). The median age of the infants was 7.5 days (IQR, 4-17). Global longitudinal strain (GLS) values significantly decreased immediately after indomethacin infusion (preindomethacin GLS, -19.1 ± 2.4 % vs. -15.9 ± 1.7 %; p < 0.0001) but had improved at reassessment after 1 h (-17.4 ± 1.8 %). Conventional echocardiographic indices did not show significant alterations. A significant increase in arterial resistance in the coronary vasculature from 1.7 to 2.4 mmHg/cm/s was demonstrated. A significant correlation was noted between peak systolic GLS and flow resistance in the coronary vasculature. Significant changes in myocardial indices were observed immediately after indomethacin infusion. Compared with conventional methods, STE is a more sensitive tool to facilitate understanding of hemodynamics in preterm infants.

Value of two-dimensional strain imaging in prediction of myocardial function recovery after percutaneous revascularization of infarct-related artery

BACKGROUND

Speckle tracking is integrated into echocardiographic systems for evaluation of left ventricular (LV) function by means of automated function imaging (AFI). This study aimed at evaluating role of AFI-based strain in predicting postpercutaneous coronary intervention (PCI) LV function recovery.

METHODS

Fifty patients with anterior wall myocardial infarction and impaired LV ejection fraction (LVEF) were prospectively enrolled. All patients showed positive viability results concerning left anterior descending (LAD) artery territory using low-dose dobutamine stress echocardiography (LDSE). All patients underwent strain imaging using AFI (before and after PCI).

RESULT

Mean age of the study population was 56.2 ± 5.4 years, 34 (68%) being males. 24 (48%) patients showed post-PCI LV function recovery after 4 months. They showed higher pre-PCI LVEF and AFI-based strain values. Logistic regression analysis presented baseline LVEF as an independent predictor of LV function recovery (Odds ratio = 0.7026, 95% CI: 0.54-0.93). A pre-PCI AFI strain value of -4.5% (sensitivity: 84% and specificity: 75%) for LAD territory and -9.5% (sensitivity and specificity of 50%) for global LV predicted LV function recovery.

CONCLUSION

Assessment of global and territorial LV strains using AFI; is of added value upon viability assessment using LDSE. Higher baseline LVEF and strain values are associated with post-PCI LV function recovery.

Left ventricular long-axis performance during exercise is an important prognosticator in patients with heart failure and preserved ejection fraction

BACKGROUND

Although many prognostic variables have been reported, the risk stratification of patients with heart failure and preserved ejection fraction (HFPEF) has long been controversial due to considerable discordance. Ergometry stress echocardiography may provide a more clinical relevant evaluation in HFPEF. We aimed at evaluating the prognostic value of echocardiographic parameters during exercise in HFPEF patients.

METHODS

Comprehensive echocardiographic examination with symptom-limited exercise testing on a semi-recumbent and tilting bicycle Ergometer (Lode BV, Groningen, the Netherlands) was performed on 80 consecutive HFPEF patients (aged 66±8years; 64% male). The exercise images for two-dimensional (2D) speckle tracking analysis were acquired with heart rate of 90-100bpm, while exercise images for tissue Doppler imaging (TDI) and M-mode echocardiography were stored with attainment of >85% of maximal age-predicted heart rate. All patients were followed up for 3years after stress echocardiography for all-cause mortality and/or heart failure (HF) hospitalization.

RESULTS

During the follow-up, 43 (54%) patients reached the combined end point: 5 (6%) patients died, and another 38 (48%) patients experienced HF hospitalizations. Univariate predictors were: decreased resting left atrial ejection fraction (LAEF), lower peak heart rate, elevated E/e' ratio, reduced TDI myocardial velocities, and impaired 2D global longitudinal strain (GLS) during exercise. Only impaired GLS (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.67 to 0.91) remained independent after multivariate analysis (p=0.008).

CONCLUSIONS

More than half of the HFPEF patients died or were hospitalized for HF at 3-year follow-up and this was significantly related to impaired left ventricular long-axis function during exercise.

Subclinical left ventricular systolic dysfunction in diabetic patients and its association with retinopathy: A 2D speckle tracking echocardiography study

AIM

It is important to diagnose diabetic cardiomyopathy in the early stages to prevent development of evident heart failure in the future. The primary objective of this study was to evaluate the presence of subclinical left ventricular (LV) dysfunction with two-dimensional (2D) speckle tracking echocardiography (STE) and the secondary objective was to compare retinopathy-positive and -negative diabetic patients.

PATIENTS AND METHODS

A total of 82 patients with type II diabetes mellitus (DM) and 90 gender-matched healthy controls were included. Retinopathy was present in 55 patients in the study group. All study participants underwent conventional 2D echocardiography and STE.

RESULTS

All diabetic patients had preserved LV ejection fraction (LV-EF ≥ 50). Compared with the control group, diabetic patients had a larger left atrium (47.3 ± 19.9 mm vs. 36.9 ± 17.8 mm, p < 0.001) and a higher E/Em ratio (12.0 ± 2.9 vs. 10.5 ± 3.7, p = 0.004). The LV-EF, LV end diastolic and end systolic volumes, E/A ratios, deceleration times, and tissue Doppler parameters were compared between groups. The study group was observed to have statistically significant lower four-chamber (4C; 17.7 ± 3.0 % vs. 19.3 ± 3.5 %, p = 0.002), three-chamber (3C; 17.5 ± 3.0 % vs. 19.2 ± 3.4 %, p = 0.001), and two-chamber (2C; 18.5 ± 3.5 % vs. 20.1 ± 2.4 %, p = 0.001) peak longitudinal strain values compared with the control group. Moreover, LV global strain values were found to be significantly lower in the DM group than in the control group (17.9 ± 2.7 % vs. 21.1 ± 3.2 %, p < 0.001). By contrast, basal rotation (4.9 ± 3.3° vs.2.8 ± 4.5°, p = 0.001), apical rotation (15.3 ± 6.7° vs. 12.1 ± 5.3°, p = 0.001) and LV twist (20.2 ± 7.2° vs. 16.9 ± 6.5°, p = 0.002) in the DM group were significantly increased compared with those of controls.

CONCLUSION

The STE procedure can be a useful novel technique in the determination of subclinical LV dysfunction in diabetic patients. Diabetic patients have lower longitudinal myocardial mechanics, and circumferential and rotational mechanics are impaired. There was no significant association between diabetic retinopathy and LV function.

Cardiac function and its evolution with pulmonary vasodilator therapy: a myocardial deformation study

Speckle tracking echocardiography-derived myocardial strain has useful clinical applications in adults with pulmonary hypertension (PH) as well as preterm infants with chronic lung disease. It is considered more sensitive compared to conventional indices. This report presents a 3-month-old infant with PH and poor right ventricular function who was treated with inhaled nitric oxide. Myocardial strain was noted to be impaired with paradoxical segmental strain. Impairment in strain improved after inhaled nitric therapy. Strain analysis can help improve understanding of cardiac adaptation in critical clinical situations.

Feasibility and correlation of standard 2D speckle tracking echocardiography and automated function imaging derived parameters of left ventricular function during dobutamine stress test

Speckle tracking echocardiography (STE) is a method of quantitative assessment of myocardial function complementary to ejection fraction and visual evaluation. Standard STE analysis, demands manual tracing of the myocardium whereas automated function imaging (AFI) offers more convenient (based on selection of three points) assessment of longitudinal strain. Nevertheless, feasibility and correlation between both methods were not thoroughly examined, especially during tachycardia at peak stage of dobutamine stress echocardiography (DSE). We performed DSE in 238 patients (pts) with recording of apical views during baseline (0) and peak (1) DSE and analyzed them by STE and AFI. According to angiography, 127/238 pts had significant (≥70%) lesions in coronary arteries. We assessed correlations between STE and AFI derived peak systolic longitudinal strain values for global and regional parameters, feasibility, time of analysis and interobserver agreement. Global systolic longitudinal strain measured during baseline and peak stage of DSE by AFI showed very good correlation with standard STE parameters, with correlation coefficients r = 0.90 and r = 0.86 respectively (p < 0.0001). For regional parameters correlation coefficients ranged from 0.83 to 0.85 for baseline and from 0.70 to 0.79 for peak DSE. Both methods provided good and similar feasibility with only 1% segments excluded from analysis at peak stage of DSE with shorter time and lower coefficient of variance offered by AFI. Global and regional longitudinal strain achieved by faster and less operator-dependent AFI method correlate well with standard more time-consuming STE analysis during baseline and peak stage of DSE.

Cardiac function and arterial indices in infants born small for gestational age: analysis by speckle tracking

AIM

To compare strain indices between small for gestational age (SGA) infants and asymptomatic appropriate for gestational age (AGA) infants and to ascertain correlations with arterial biophysical properties.

METHODS

In this prospective observational echocardiographic study, 20 inborn term SGA infants weighing <3rd centile for gestational age were compared with 20 AGA infants. Demographic and echocardiographic data were analysed regarding cardiac strain and strain rate and arterial indices (stiffness, impedance and strain elastic modulus). Correlations between variables were assessed using Pearson's coefficient of correlation.

RESULTS

Ponderal index was significantly lower in SGA infants (24.6 ± 2.9 vs. 29.5 ± 2.5). Left ventricular global longitudinal strain (GLS) was noted to be significantly impaired in the SGA infants (-15.9% ± 2.1 vs. -21.3% ± 2.8, p < 0.001). A basal to apical gradient was noted in segmental strain. Arterial biophysical measurements were significantly altered in the SGA infants. Significant correlations were noted between GLS and arterial stiffness (r = -0.4, p = 0.03), weight-indexed stiffness (r = -0.45, p = 0.02) and pressure-strain elastic modulus (r = -0.49, p = 0.01).

CONCLUSION

Impairment in myocardial deformation was noted in the presence of altered arterial biophysical properties in the SGA infants.

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.

Speckle tracking derived strain in infants with severe perinatal asphyxia: a comparative case control study

BACKGROUND

Speckle tracking echocardiography is increasingly being used to assess cardiac function in neonates. The objective was to compare speckle tracking strain indices between asphyxiated infants and healthy controls and to ascertain correlations between strain and 2D Doppler derived indices and cardiac troponin (biochemical marker of myocardial injury).

METHODS

Clinical and echocardiographic data from severely asphyxiated infants undergoing therapeutic hypothermia was evaluated retrospectively. This was compared with prospective data from healthy infants. Correlations between variables were assessed using Pearson's coefficient of correlation.

RESULTS

Twenty four infants with severe perinatal asphyxia were admitted during the study period of which 3 were not cooled and were excluded. The gestational age and birth weights of cases and controls were comparable. The mean left ventricular global longitudinal strain (GLS) from apical 4 chamber view was noted to be significantly impaired in the asphyxiated infants (- 11.01% ± 2.48 vs - 21.45% ± 2.74, p <0.001). Cardiac output was significantly lower in the asphyxiated infants (97 ± 26 vs 230 ± 60 ml/kg/min). In asphyxiated infants, GLS correlated positively with cardiac output (r2 = 0.86, p< 0.001) and negatively with serum troponin levels (r2 = 0.64, p< 0.001). GLS was less impaired in infants on inotropes compared to those not on inotropic support, -12.55% (1.9) vs -10.2% (1.3), p= 0.018. Infants who died had a lower global strain value compared to survivors, - 9.7% (1.6) vs - 12.8% (2.6), p = 0.02.

CONCLUSIONS

2D Speckle derived strain was impaired in asphyxiated infants. Significant correlations between GLS and cardiac output and troponin were noted.

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.

Independent role of left ventricular global longitudinal strain in predicting prognosis of chronic heart failure patients

AIMS

To evaluate the independent prognostic role of two-dimensional (2D) strain measures reflecting global longitudinal left ventricular (LV) systolic function in outpatients affected by chronic heart failure (CHF).

METHODS AND RESULTS

Global longitudinal LV systolic strain (GLS) was assessed in 308 outpatients affected by CHF, by analyzing standard views with 2D speckle tracking technique. During a mean follow-up of 26 ± 13 months 37 patients died (29 due to cardiovascular causes), 10 patients underwent heart transplantation, and 75 patients experienced at least 1 episode of hospitalization due to acute decompensated heart failure (ADHF). Thirty-one patients without a history of major ventricular arrhythmic events experienced the occurrence of ventricular fibrillation and/or tachycardia or sudden death was observed. Multivariate Cox regression analysis showed that GLS was significantly associated with all-cause mortality (HR: 1.15; 95%CI: 1.02-1.30; P: 0.026), cardiovascular death (HR: 1.20; 95%CI: 1.04-1.39; P: 0.011), cardiovascular death or heart transplantation (HR: 1.24; 95%CI: 1.09-1.41; P: 0.001), ADHF-related hospitalizations (HR: 1.15; 95%CI: 1.05-1.25; P: 0.003), and arrhythmic events (HR: 1.17; 95%CI: 1.03-1.33; P: 0.018).

CONCLUSIONS

Quantifying LV longitudinal systolic function in CHF outpatients on the basis of 2D speckle tracking analysis provides a new parameter that independently predicts patient outcome, thus, strengthening its possible role in current clinical practice.

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.

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.

Efficiency of quantitative longitudinal peak systolic strain values using automated function imaging on transthoracic echocardiogram for evaluating left ventricular wall motion: new diagnostic criteria and agreement with naked eye evaluation by experienced cardiologist

PURPOSE

To evaluate the efficiency of automated function imaging (AFI) on transthoracic echocardiogram (TTE) for detecting left ventricular (LV) wall motion (LVWM) abnormalities, we compared longitudinal peak systolic strain (LPSS) measurements using AFI with naked eye TTE evaluations by experienced cardiologists and non-experienced residents.

MATERIALS AND METHODS

A total of 352 segments of LV myocardium from 22 consecutive subjects with LVWM abnormalities based on American Heart Association classifications (11 male, mean age 58 ± 14 years) on previous TTE (Vivid-7, GE) were evaluated. LPSS was measured using stored AFI data. Naked eye evaluation of LVWM was performed by 2 experienced cardiologists and 2 non-experienced residents.

RESULTS

AFI successfully tracked 342 (97%) of all segments (mean LPSS -14.8 ± 8.1%). A significant strong negative correlation was observed between LV ejection fraction using method of disks and global LPSS (R=-0.8974). Temporary AFI criteria of LPSS were normal <-12; hypokinesis -12-2; and akinesis >2. Of 342 segments, 239, 87, and 16 segments were diagnosed as normal, hypokinesis, and akinesis, respectively. Level of agreement and kappa coefficients between qualitative evaluation of LVWM by AFI temporary criteria and qualitative evaluation of LVWM by experienced cardiologist 2 (0.784 and 0.479, respectively) were inferior to those comparing experienced cardiologists (0.845 and 0.595) but superior comparing experienced cardiologist with non-experienced resident (0.696 and 0.323), and between the 2 non-experienced-residents (0.682 and 0.347).

CONCLUSION

Qualitative evaluation of LVWM using temporary AFI criteria had a 97% success rate and agreed well with findings of an experienced cardiologist. AFI can be a useful tool for training residents.

Assessing left ventricular systolic dysfunction after myocardial infarction: are ejection fraction and dP/dt(max) complementary or redundant?

Among the various cardiac contractility parameters, left ventricular (LV) ejection fraction (EF) and maximum dP/dt (dP/dt(max)) are the simplest and most used. However, these parameters are often reported together, and it is not clear if they are complementary or redundant. We sought to compare the discriminative value of EF and dP/dt(max) in assessing systolic dysfunction after myocardial infarction (MI) in swine. A total of 220 measurements were obtained. All measurements included LV volumes and EF analysis by left ventriculography, invasive ventricular pressure tracings, and echocardiography. Baseline measurements were performed in 132 pigs, and 88 measurements were obtained at different time points after MI creation. Receiver operator characteristic (ROC) curves to distinguish the presence or absence of an MI revealed a good predictive value for EF [area under the curve (AUC): 0.998] but not by dP/dt(max) (AUC: 0.69, P < 0.001 vs. EF). Dividing dP/dt(max) by LV end-diastolic pressure and heart rate (HR) significantly increased the AUC to 0.87 (P < 0.001 vs. dP/dt(max) and P < 0.001 vs. EF). In naïve pigs, the coefficient of variation of dP/dt(max) was twice than that of EF (22.5% vs. 9.5%, respectively). Furthermore, in n = 19 pigs, dP/dt(max) increased after MI. However, echocardiographic strain analysis of 23 pigs with EF ranging only from 36% to 40% after MI revealed significant correlations between dP/dt(max) and strain parameters in the noninfarcted area (circumferential strain: r = 0.42, P = 0.05; radial strain: r = 0.71, P < 0.001). In conclusion, EF is a more accurate measure of systolic dysfunction than dP/dt(max) in a swine model of MI. Despite the variability of dP/dt(max) both in naïve pigs and after MI, it may sensitively reflect the small changes of myocardial contractility.

Comparison of real-time three-dimensional speckle tracking to magnetic resonance imaging in patients with coronary heart disease

This study compared strain values from 2-dimensional (2D) and real-time 3-dimensional (3D) speckle tracking with hyperenhancement transmural extent by magnetic resonance imaging (MRI). The study included 18 control subjects (mean age 51 ± 10 years) and 25 patients (20 men, mean age 62 ± 16 years) with ischemic left ventricular (LV) dysfunction (mean LV ejection fraction 41 ± 9%) referred for viability assessment using MRI. Longitudinal, radial, and circumferential strain values were computed using 2D speckle tracking. From analysis of 3D speckle tracking, conventional strain markers (longitudinal, radial, and circumferential) and 2 new 3D strain indexes (area and 3D strains) were obtained from apical view 3D datasets. A hyperenhancement transmural extent segment (16-segment model) was defined as delayed contrast enhancement >50%. Overall, 661 of 688 segments (96%) were analyzable by MRI and 3D speckle tracking. All 3D strain components in hyperenhancement transmural extent segments (n = 154) were lower than in nontransmural necrosis (n = 219) and control (n = 288) segments. Longitudinal strain by 3D, but not by 2D, differentiated nontransmural segments with scar <25%. All 3D global strain indexes correlated with LV ejection fraction (r(2) = 0.67 to 0.26, p <0.05 for all comparisons), whereas only area, longitudinal, and circumferential 3D strains correlated with global scar extent. The best reproducibility was provided by 3D longitudinal (6%) and area (8%) strains. In conclusion, longitudinal and area strains by 3D speckle tracking provide an accurate and reproducible measurement of myocardial deformation that correlate with infarct size in patients with ischemic LV dysfunction.

Two-dimensional strain profiles in patients with physiological and pathological hypertrophy and preserved left ventricular systolic function: a comparative analyses

OBJECTIVE

This study was designed to examine the utility of two-dimensional strain (2DS) or speckle tracking imaging to typify functional adaptations of the left ventricle in variant forms of left ventricular hypertrophy (LVH).

DESIGN

Cross-sectional study.

SETTING

Urban tertiary care academic medical centres.

PARTICIPANTS

A total of 129 subjects, 56 with hypertrophic cardiomyopathy (HCM), 34 with hypertensive left ventricular hypertrophy (H-LVH), 27 professional athletes with LVH (AT-LVH) and 12 healthy controls in sinus rhythm with preserved left ventricular systolic function.

METHODS

Conventional echocardiographic and tissue Doppler examinations were performed in all study subjects. Bi-dimensional acquisitions were analysed to map longitudinal systolic strain (automated function imaging, AFI, GE Healthcare, Waukesha, Wisconsin, USA) from apical views.

RESULTS

Subjects with HCM had significantly lower regional and average global peak longitudinal systolic strain (GLS-avg) compared with controls and other forms of LVH. Strain dispersion index, a measure of regional contractile heterogeneity, was higher in HCM compared with the rest of the groups. On receiver operator characteristics analysis, GLS-avg had excellent discriminatory ability to distinguish HCM from H-LVH area under curve (AUC) (0.893, p<0.001) or AT-LVH AUC (0.920, p<0.001). Tissue Doppler and LV morphological parameters were better suited to differentiate the athlete heart from HCM.

CONCLUSIONS

2DS (AFI) allows rapid characterisation of regional and global systolic function and may have the potential to differentiate HCM from variant forms of LVH.

Prognostic value of serial global longitudinal strain measured by two-dimensional speckle tracking echocardiography in patients with ST-segment elevation myocardial infarction

The aim of this study was to determine whether assessment of global longitudinal strain (GLS) before revascularization could predict adverse cardiac events after ST-segment elevation myocardial infarction (STEMI). In addition, the relation between GLS and cardiac biomarkers was investigated. From July 2006 through December 2009, 98 patients with first STEMI underwent conventional and speckle tracking echocardiography at initial presentation and 3 days after primary coronary intervention. Patients were divided into 3 groups according to percent changes of GLS compared to baseline GLS values: group 1, improved GLS >10%; group 2, unchanged GLS from -10% to 10%; and group 3, decreased GLS <-10%. Subsequent complications including all-cause mortality and readmission because of congestive heart failure during a 6-month period of follow-up were prospectively evaluated. After coronary intervention, GLS was improved in 29 patients (30%, group 1), unchanged in 55 patients (56%, group 2), and worsened in 14 patients (14%, group 3). Complications developed in 7 patients (group 1, n = 0, 0%; group 2, n = 2, 28%; group 3, n = 5, 72%, p <0.01). Multivariate Cox analysis showed an independent association of GLS before and after coronary intervention with subsequent complications. Significant correlations were observed between GLS and cardiac biomarkers. In conclusion, GLS assessment before coronary intervention was a good predictor of complications in patients with STEMI comparable to predictions using GLS after intervention at 6-month follow-up.

Viability Assessment With Global Left Ventricular Longitudinal Strain Predicts Recovery of Left Ventricular Function After Acute Myocardial Infarction

Background— The extent of viable myocardial tissue is recognized as a major determinant of recovery of left ventricular (LV) function after myocardial infarction. In the current study, the role of global LV strain assessed with novel automated function imaging (AFI) to predict functional recovery after acute infarction was evaluated.

Methods and Results— A total of 147 patients (mean age, 61�11 years) admitted for acute myocardial infarction were included. All patients underwent 2D echocardiography within 48 hours of admission. Significant relations were observed between baseline AFI global LV strain and peak level of troponin T ( r =0.64), peak level of creatine phosphokinase ( r =0.62), wall motion score index ( r =0.52), and viability index assessed with single-photon emission computed tomography ( r =0.79). At 1-year follow-up, LV ejection fraction was reassessed. Patients with absolute improvement in LV ejection fraction ≥5% at 1-year follow-up (n=70; 48%) had a higher (more negative) baseline AFI global LV strain ( P <0.0001). Baseline AFI global LV strain was a predictor for change in LV ejection fraction at 1-year follow-up. A cutoff value for baseline AFI global LV strain of −13.7% yielded a sensitivity of 86% and a specificity of 74% to predict LV functional recovery at 1-year follow-up.

Conclusions— AFI global LV strain early after acute myocardial infarction reflects myocardial viability and predicts recovery of LV function at 1-year follow-up.

Prediction of all-cause mortality from global longitudinal speckle strain: comparison with ejection fraction and wall motion scoring

BACKGROUND

Although global left ventricular systolic function is an important determinant of mortality, standard measures such as ejection fraction (EF) and wall motion score index (WMSI) have important technical limitations. The aim of this study was to compare global longitudinal speckle strain (GLS), an automated technique for measurement of long-axis function, with EF and WMSI for the prediction of mortality.

METHODS AND RESULTS

Of 546 consecutive individuals undergoing echocardiography for assessment of resting left ventricular function, 91 died over a period of 5.2+/-1.5 years. In addition to Simpson biplane EF, WMSI was determined by 2 experienced readers and GLS was calculated from 3 standard apical views using 2D speckle tracking. The incremental value of EF, WMSI, and GLS to significant clinical variables was assessed in nested Cox models. Clinical factors associated with outcome (model chi(2)=20.2) were age (hazard ratio [HR], 1.46; P<0.01), diabetes (HR, 1.88; P=0.01), and hypertension (HR, 1.59; P<0.05). Although addition of EF (HR, 1.23; P=0.03) or WMSI (HR, 1.28; P<0.01) added to the predictive power of clinical variables, the addition of GLS (HR, 1.45; P<0.001) caused the greatest increment in model power (chi(2)=34.9, P<0.001). GLS also provided incremental value in subgroups with EF >35% and those with and without wall motion abnormalities. A GLS >or=-12% was found to be equivalent to an EF <or=35% for the prediction of prognosis. Intraobserver and interobserver variations for EF and GLS were similar.

CONCLUSIONS

GLS is a superior predictor of outcome to either EF or WMSI and may become the optimal method for assessment of global left ventricular systolic function.

Evidence of left ventricular systolic dysfunction detected by automated function imaging in patients with heart failure and preserved left ventricular ejection fraction

BACKGROUND

Left ventricular ejection fraction (LVEF) cannot reflect cardiac contractile function in patients with heart failure and preserved LVEF (HFPEF). LV systolic impairment is actually debated in HFPEF patients. Automated function imaging (AFI) is a novel algorithm of speckle-tracking echocardiography and efficiently to assess global LV peak systolic longitudinal strain (PSLS), an index for systolic function. The purpose of the study is to examine whether contractile function is impaired in HFPEF patients.

METHODS AND RESULTS

This study included 49 heart failure patients (23 with systolic dysfunction [SHF] and 26 with HFPEF), and 40 patients, matched for age, sex, as well as concomitant disease and without heart failure as controls. All patients underwent transthoracic echocardiography. LVEF was measured by Simpson's method. Two-dimensional speckle tracking imaging with AFI assessment was applied to measure longitudinal strain. LVEF was 66+/-5% in the controls, 63+/-8% in the HFPEF group (P=.14), and 34+/-10% in the SHF group (P < .001). The value of LV global PSLS (controls: -20%, HFPEF: -14%, SHF: -8%, P < .001) was significantly less negative in both heart failure groups.

CONCLUSIONS

Deteriorated LV systolic function is demonstrated by decreased global PSLS in HFPEF patients. AFI is an effective and facile method for assessing LV systolic abnormalities.