Echocardiographic Imaging in Transcatheter Structural Intervention: An AAE Review Paper.

Transcatheter structural heart intervention (TSHI) has gained popularity over the past decade as a means of cardiac intervention in patients with prohibitive surgical risks. Following the exponential rise in cases and devices developed over the period, there has been increased focus on developing the role of "structural imagers" amongst cardiologists. This review, as part of a growing initiative to develop the field of interventional echocardiography, aims to highlight the role of echocardiography in myriad TSHIs available within Asia. We first discuss the various echocardiography-based imaging modalities, including 3-dimensional echocardiography, fusion imaging, and intracardiac echocardiography. We then highlight a selected list of structural interventions available in the region-a combination of established interventions alongside novel approaches-describing key anatomic and pathologic characteristics related to the relevant structural heart diseases, before delving into various aspects of echocardiography imaging for each TSHI.

Normal Values of Three-Dimensional Right Ventricular Size and Function Measurements: Results of the World Alliance Societies of Echocardiography Study.

BACKGROUND: Normal values for three-dimensional (3D) right ventricular (RV) size and function are not well established, as they originate from small studies that involved predominantly white North American and European populations, did not use RV-focused views, and relied on older 3D RV analysis software. The World Alliance Societies of Echocardiography study was designed to generate reference ranges for normal subjects around the world. The aim of this study was to assess the worldwide capability of 3D imaging of the right ventricle and report size and function measurements, including their dependency on age, sex, and ethnicity. METHODS: Healthy subjects free of cardiac, pulmonary, and renal disease were prospectively enrolled at 19 centers in 15 countries, representing six continents. Three-dimensional wide-angle RV data sets were obtained and analyzed using dedicated RV software (TomTec) to measure end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume, and ejection fraction (EF). Results were categorized by sex, age (18-40, 41-65, and >65 years) and ethnicity. RESULTS: Of the 2,007 subjects with attempted 3D RV acquisitions, 1,051 had adequate image quality for confident measurements. Upper and lower limits for body surface area-indexed EDV, ESV, and EF were 48 and 95 mL/m2, 19 and 43 mL/m2, and 44% and 58%, respectively, for men and 42 and 81 mL/m2, 16 and 36 mL/m2, and 46% and 61%, respectively, for women. Men had significantly larger EDVs, ESVs, and stroke volumes (even after body surface area indexing) and lower EFs than women (P < .05). EDV and ESV did not show any meaningful differences among age groups. Three-dimensional RV volumes were smallest in Asians. CONCLUSIONS: Reliability of 3D RV acquisition is low worldwide, underscoring the importance of future improvements in imaging techniques. Sex and race must be taken into consideration in the assessment of both RV volumes and EF.

Atrial functional mitral regurgitation: prevalence, characteristics and outcomes from the National Echo Database of Australia.

AIMS: Atrial functional mitral regurgitation (AFMR) is characterised by left atrial and consequent mitral annular dilatation causing mitral regurgitation. AFMR is likely to become more common with population ageing, alongside increases in atrial fibrillation and heart failure with preserved ejection fraction; conditions causing atrial dilatation. Here, we aim to define the prevalence and characterise the patient and survival characteristics of AFMR in the National Echocardiographic Database of Australia (NEDA). METHODS AND RESULTS: 14 004 adults with moderate or severe FMR were identified from NEDA. AFMR or ventricular FMR (VFMR) was classified by LA size, LV size and LVEF. AFMR was found in 40% (n=5562) and VFMR in 60% (n=8442). Compared with VFMR, the AFMR subgroup were significantly older (mean age 78±11 years), with a higher proportion of females and of AF. Participants were followed up for a median of 65 months (IQR 36-116 months). After adjustment for age, sex, AF, and pulmonary hypertension, the prognosis for VFMR was significantly worse than for AFMR (HR 1.57, 95% CI 1.47 to 1.68 for all-cause and 1.73, 95% CI 1.60 to 1.88, p<0.001 for both). After further adjustment for LVEF, mortality rates were similar in VFMR and AFMR patients (HR 0.93, p=NS), though advancing age and pulmonary hypertension remained independently associated with prognosis. CONCLUSIONS: AFMR is a common cause of significant functional MR that predominantly affects elderly female patients with AF. Advancing age and pulmonary hypertension independently associated with survival in FMR. Prognosis was better in AFMR compared with VFMR; however, this difference was accounted for by LV systolic impairment and not by MR severity.

Age-, Sex-, and Race-Based Normal Values for Left Ventricular Circumferential Strain from the World Alliance Societies of Echocardiography Study.

BACKGROUND: Left ventricular (LV) circumferential strain has received less attention than longitudinal deformation, which has recently become part of routine clinical practice. Among other reasons, this is because of the lack of established normal values. Accordingly, the aim of this study was to establish normative values for LV circumferential strain and determine sex-, age-, and race-related differences in a large cohort of healthy adults. METHODS: Complete two-dimensional transthoracic echocardiograms were obtained in 1,572 healthy subjects (51% men), enrolled in the World Alliance Societies of Echocardiography Normal Values Study. Subjects were divided into three age groups (<35, 35-55, and >55 years) and stratified by sex and by race. Vendor-independent semiautomated speckle-tracking software was used to determine LV regional circumferential strain and global circumferential strain (GCS) values. Limits of normal for each measurement were defined as 95% of the corresponding sex and age group falling between the 2.5th and 97.5th percentiles. Intergroup differences were analyzed using unpaired t tests. RESULTS: Circumferential strain showed a gradient, with lower magnitude at the mitral valve level, increasing progressively toward the apex. Compared with men, women had statistically higher magnitudes of regional and global strain. Older age was associated with a stepwise increase in GCS despite an unaffected ejection fraction, a decrease in LV volume, and relatively stable global longitudinal strain in men, with a small gradual decrease in women. Asian subjects demonstrated significantly higher GCS magnitudes than whites of both sexes and blacks among women only. In contrast, no significant differences in GCS were found between white and black subjects of either sex. Importantly, despite statistical significance of these differences across sex, age, and race, circumferential strain values were similar in all groups, with variations of the order of magnitude of 1% to 2%. Notably, no differences in GCS were found among brands of imaging equipment. CONCLUSION: This study established normal values of LV regional circumferential strain and GCS and identified sex-, age-, and race-related differences when present.

Pulmonary hypertension in remote and disadvantaged population: overcoming unique challenges for improved outcomes.

Pulmonary hypertension (PH) is a common and debilitating medical condition with high mortality. PH research has traditionally focused on pulmonary arterial hypertension and its management in expert PH centres. Other forms of PH such as PH associated with cardiac or respiratory disease are more common, less well-understood and associated with higher mortality. Epidemiology of PH in disadvantaged, remote and rural regions, remains largely undocumented. In this review, we discuss the unique challenges in identifying PH in rural and disadvantaged populations using the Top End region of the Northern Territory of Australia as an example. We propose a simple diagnostic approach, ideally suited to regions where resource allocation is scarce, using clinical skills, echocardiography, and an escalation algorithm. The brief history, epidemiology and current literature on PH are summarised to inform the busy clinicians. We highlight two case examples from the Top End to illustrate the challenges and potential solutions.

Normal Values of Left Ventricular Mass by Two-Dimensional and Three-Dimensional Echocardiography: Results from the World Alliance Societies of Echocardiography Normal Values Study.

BACKGROUND: Although increased left ventricular (LV) mass is associated with adverse outcomes, measured values vary widely depending on the specific technique used. Moreover, the impact of sex, age, and race on LV mass remains controversial, further limiting the clinical use of this parameter. Accordingly, the authors studied LV mass using a variety of two-dimensional and three-dimensional echocardiographic techniques in a large population of normal subjects encompassing a wide range of ages. METHODS: Transthoracic echocardiograms obtained from 1,854 healthy adult subjects (52% men) enrolled in the World Alliance Societies of Echocardiography (WASE) Normal Values Study, were divided into three age groups (young, 18-35 years; middle aged, 36-55 years; and old, >55 years). LV mass was obtained using five conventional techniques, including linear and two-dimensional methods, as well as direct three-dimensional measurement. All LV mass values were indexed to body surface area, and differences according to sex, age, and race were analyzed for each technique. RESULTS: LV mass values differed significantly among the five techniques. Three-dimensional measurements were considerably smaller than those obtained using the other techniques and were closer to magnetic resonance imaging normal values reported in the literature. For all techniques, LV mass in men was significantly larger than in women, with and without body surface area indexing. These technique- and sex-related differences were larger than measurement variability. In women, age differences in LV mass were more pronounced and depicted significantly larger values in older age groups for all techniques, except three-dimensional echocardiography, which showed essentially no differences. LV mass was overall larger in black subjects than in white or Asian subjects. CONCLUSIONS: Significant differences in LV mass values exist across echocardiographic techniques, which are therefore not interchangeable. Sex-, race-, and age-related differences underscore the need for separate population specific normal values.

Prognostic Value of Left and right ventricular deformation strain analysis on Acute Cellular rejection in Heart Transplant recipients: A 6-year outcome study.

PURPOSE: Two-dimensional (2D) strain analysis is a sensitive method for detecting myocardial dysfunction in acute cellular rejection (ACR) from post-transplant complications. This study aims to evaluate the utility of novel left (LV) and right ventricular (RV) strain parameters for prognostic risk stratification associated with ACR burden at 1-year post transplantation. METHODS: 128 Heart transplant patients, assessed between 2012 and 2018, underwent transthoracic echocardiography and endomyocardial biopsy. 2D strain analysis was performed and history of rejection burden was assessed and grouped according to ACR burden at 1-year post transplantation. The primary endpoint was all-cause mortality at 6-years follow up. RESULTS: 21 patients met primary the endpoint. Multivariate analysis of 6-year all-cause mortality showed LV global longitudinal strain (LV GLS) (Hazard Ratio [HR] = 1.21, CI = 1.06-1.49), LV early diastolic strain rate (LV ESr) (HR = 1.31, CI = 1.12-1.54), RV GLS (HR = 1.12, CI = 1.02-1.25) and RV ESr (HR = 1.26, CI = 1.12-1.47) were significant predictors of outcome. Univariate analysis also showed LV GLS, LV ESr, RV GLS and RV ESr were significant predictors of outcome. Optimal cut-off for predicting 6-year mortality for LV GLS by receive operator characteristic was 15.5% (sensitivity: 92%, specificity: 79%). Significant reductions (p < 0.05) in LV GLS, RV GLS and LV and RV ESr between rejection groups were seen. CONCLUSIONS: Non-invasive LV and RV strain parameters are predictors of mortality in post-transplant patient with ACR. LV GLS and LV ESr are superior to other strain and conventional echo parameters.

What are the prognostic implications and factors relating to exercise induced electrocardiographic ST segment changes in the setting of a non-ischemic stress echocardiogram?

BACKGROUND: Electrocardiographic (ECG) changes during stress testing are a common and perplexing finding during non-ischemic stress echocardiography (niSE). Research has provided conflicting results regarding the implications. METHODS: SE was performed after maximal Bruce protocol treadmill exercise. RESULTS: 3020 consecutive patients, mean age 58 ± 12 years, 36% female, were followed-up for up to 9 years (mean 36 ± 21 months) post niSE. Time to first cardiac event (composite of heart failure admission, worsening New York Heart Association class, worsening ejection fraction, acute coronary syndrome, revascularization, angina or cardiovascular death) was analysed and adjusted using Cox proportional hazards regression. Prognostic significance was found with 1.5 mm of downsloping or horizontal ST depression. Adjusting for baseline differences, increased risk of composite major adverse cardiac events was shown with at least 1.5 mm of exercise induced ST depression (Hazard ratio [HR] of 2.47, 95% Confidence ratio [CI] 1.67-3.72, p < 0.0001). Patients achieving high level exercise capacity (≥13 metabolic equivalents or METs) with ST depression lower risk of cardiac events during follow-up. CONCLUSION: Patients with ST segment depression but non-ischemic stress imaging have a poorer prognosis compared to patients with niSE with normal stress ECGs. ST depression of 1.5 mm or more was established as a prognostically significance value. High exercise capacity was associated with an improved prognosis, and ECG changes in that setting can be regarded as false positives. All niSE have low risk of a cardiac event in the very short term (<12 months). Overall, ST depression during non-ischaemic stress imaging is not a benign finding.

Impact of inter-vendor variability on evaluation of left ventricular mechanical dispersion.

PURPOSE: Left ventricular mechanical dispersion (LVMD) is a novel speckle tracking parameter for prognostic assessment of arrhythmic risk prediction. There is growing evidence to support its use in a variety of cardiomyopathic processes. There is paucity of data addressing any presence of inter-vendor discrepancies for LVMD. The aim of this study was to assess inter-vendor variability of LVMD in vendor specific software (VSS) and vendor independent software (VIS) in subjects with preserved and reduced left ventricular function. METHODS: Fifty-nine subjects (14 normal subjects and 45 subjects with cardiac disease) were recruited and 2D speckle tracking echocardiographic images were acquired on two different ultrasound machines (GE and Philips). LVMD was measured by two different VSS (EchoPac GE and QLAB Philips) and one VIS (TomTec Arena). RESULTS: There was significant bias and wide limits of agreement (LOA) in the overall cohort observed between two different VSS (17.6 ms; LOA: -29.6 to 64.8; r: .47). There was acceptable bias and narrower LOA with good agreement for LVMD between images obtained on different vendors when performed on VIS (-3.1 ms; LOA: -27.6 to 21.4; r: .75). QLAB LVMD was consistently higher than GE LVMD and TomTec LVMD in both preserved and reduced left ventricular function. LVMD measurements have high intra-vendor reproducibility with excellent inter and intra-observer agreement. CONCLUSIONS: There was acceptable bias and narrower LOA for LVMD assessment on a VIS. Inter-vendor variability exists for LVMD assessment between VSS. Serial measurements of LVMD should be performed using a single vendor for consistent and reliable results.

Normal Values of Aortic Root Size According to Age, Sex, and Race: Results of the World Alliance of Societies of Echocardiography Study.

BACKGROUND: Accurate measurements of the aortic annulus and root are important for guiding therapeutic decisions regarding the need for aortic surgery. Current echocardiographic guidelines for identification of aortic root dilatation are limited because current normative values were derived predominantly from white individuals in narrow age ranges, and based partially on M-mode measurements. Using data from the World Alliance Societies of Echocardiography study, the authors sought to establish normal ranges of aortic dimensions across sexes, races, and a wide range of ages. METHODS: Adult individuals free of heart, lung, and kidney disease were prospectively enrolled from 15 countries, with even distributions among sexes and age groups: young (18-40 years), middle aged (41-65 years) and old (>65 years). Transthoracic two-dimensional echocardiograms of 1,585 subjects (mean age, 47 ± 17 years; 50.4% men; mean body surface area [BSA], 1.77 ± 0.22 m2) were analyzed in a core laboratory following American Society of Echocardiography guidelines. Measurements, indexed separately by BSA and by height, included the aortic annulus, sinuses of Valsalva, and sinotubular junction. Differences among age, sex, and racial groups were evaluated using unpaired two-tailed Student's t tests. RESULTS: All aortic root dimensions were larger in men compared with women. After indexing to BSA, all measured dimensions were significantly larger in women, whereas men continued to show larger dimensions after indexing to height. Of note, the upper limits of normal for all aortic dimensions were lower across all age groups, compared with the guidelines. Aortic dimensions were larger in older age groups in both sexes, a trend that persisted regardless of BSA or height adjustment. Last, differences in aortic dimensions were also observed according to race: Asians had the smallest nonindexed aortic dimensions at all levels. CONCLUSIONS: There are significant differences in aortic dimensions according to sex, age, and race. Thus, current guideline-recommended normal ranges may need to be adjusted to account for these differences.

Sex-, Age-, and Race-Related Normal Values of Right Ventricular Diastolic Function Parameters: Data from the World Alliance Societies of Echocardiography Study.

BACKGROUND: Although the assessment of right ventricular (RV) diastolic function is feasible, it has garnered far less momentum for use compared with its left ventricular counterpart. The scarcity of data defining normative RV diastolic function and the fact that implications of RV diastolic dysfunction in different disease states on outcomes are less well known both hinder integration into routine clinical assessment. The aim of this study was to establish normal values of RV diastolic parameters stratified by sex, age, and race using data from the World Alliance Societies of Echocardiography study. METHODS: A subset of 888 normal subjects from the World Alliance Societies of Echocardiography database were analyzed, including measurements of tricuspid valve (TV) inflow E- and A-wave velocities, E-wave deceleration time, and TV annular tissue Doppler e' and a' velocities. Additionally, right atrial (RA) maximal volume and RA peak reservoir strain were measured. Patients were grouped by age (<40, 41-65, and >65 years) and stratified by sex and race. Differences were analyzed using unpaired t tests. RESULTS: Compared with men, women had significantly higher TV e' and E-wave and A-wave velocities, though differences were modest. Increasing age was associated with stepwise lower TV E wave, e' velocity, and TV E/A ratio and higher a' velocity and E/e' ratio. RA peak reservoir strain was also lower, and RA end-systolic volume trended toward being smaller for older age groups. Asian subjects demonstrated significantly higher a' velocities, lower E wave, the smallest RA end-systolic volumes, and the lowest RA peak strain values compared with white subjects of both sexes. CONCLUSIONS: This study provides normal values for parameters used in the assessment of RV diastolic function stratified by race, sex, and age. The results demonstrate significant differences in RV diastolic parameters between age groups, which manifest in both individual parameters and composite ratios of TV inflow and annular velocities. Although limited sex- and race-related differences were also noted, age appears to have the most significant impact on RV diastolic parameters. These findings may aid in refining current normative values.

Normal Values of Left Atrial Size and Function and the Impact of Age: Results of the World Alliance Societies of Echocardiography Study.

BACKGROUND: Left atrial (LA) evaluation includes volumetric and functional parameters with an abundance of diagnostic and prognostic implications. Solid normal reference ranges are compulsory for accurate interpretation in individual patients, but previous studies have yielded mixed conclusions regarding the effects of age, sex, and/or race. The present report from the World Alliance Societies of Echocardiography study focuses on two-dimensional (2D) and three-dimensional (3D) measures of LA structure and function, with subgroup analysis by age, sex, and race. METHODS: Transthoracic 2D and 3D echocardiographic images were obtained in 1,765 healthy individuals (901 men, 864 women) evenly distributed among age subgroups: 18 to 40 years (n = 745), 41 to 65 years (n = 618), and >65 years (n = 402); the racial distribution was 38.4% white, 39.9% Asian, and 9.7% black. Images were analyzed using dedicated LA analysis software to measure LA volumes and phasic function from 3D volume and 2D strain curves. RESULTS: Three-dimensional maximum and minimum LA volumes adjusted for body surface area were nearly identical for men and women, but women demonstrated higher 3D total and passive emptying fractions (EFs). Two-dimensional reservoir strain was similar for both sexes. Age was associated with an incremental rise in LA volumes alongside characteristic shifts in functional indices. Total 2D EF and reservoir and conduit strain varied inversely with age, counteracted by higher booster strain, with a greater magnitude of effect in women. Active 3D EF was significantly higher, while total and passive EFs decreased with age. Interracial differences were noted in LA volumes, without substantial differences in functional indices. CONCLUSION: Although similar normal values for LA volumes and strain can be applied to both sexes, meaningful differences in LA size occur with aging. Indices of function also shift with age, with a compensatory rise in booster function, which may serve to counteract observed lower total and passive EFs. Defining age-associated normal values may help differentiate age-associated "healthy" LA aging from pathologic processes.

Normal Values of Left Ventricular Size and Function on Three-Dimensional Echocardiography: Results of the World Alliance Societies of Echocardiography Study.

BACKGROUND: Echocardiography remains the most widely used modality to assess left ventricular (LV) chamber size and function. Currently this assessment is most frequently performed using two-dimensional (2D) echocardiography. However, three-dimensional (3D) echocardiography has been shown to be more accurate and reproducible than 2D echocardiography. Current normative reference values for 3D LV analysis are based predominantly on data from North America and Europe. The World Alliance Societies of Echocardiography study was designed to sample normal subjects from around the world to provide more universal global reference ranges. The aim of this study was to assess the worldwide feasibility of LV 3D echocardiography and report on size and functional measurements. METHODS: A total of 2,262 healthy subjects were prospectively enrolled from 19 centers in 15 countries. Three-dimensional LV full-volume data sets were obtained and analyzed offline using vendor-neutral software. Measurements included LV end-diastolic and end-systolic volumes, LV ejection fraction (LVEF), global longitudinal strain (GLS), and global circumferential strain. Results were categorized by age (18-40, 41-65, and >65 years), sex, and race. RESULTS: A total of 1,589 subjects (feasibility 70%) had adequate LV data sets for analysis. Mean normal values for indexed end-diastolic volume, end-systolic volume, and LVEF in men and women were 70 ± 15 and 65 ± 12 mL/m2, 28 ± 7 and 25 ± 6 mL/m2, and 60 ± 5% and 62 ± 5%, respectively. Men had larger LV volumes and lower LVEFs than women. GLS and global circumferential strain were higher in magnitude in women. In both sexes, LV volumes were lower and LVEF tended to be higher with increasing age, especially considering the differences between the youngest and oldest age groups. Although GLS was similar across age groups in men, in women, the youngest and middle-age cohorts revealed higher magnitudes of GLS compared with the oldest age group. Global circumferential strain was higher in magnitude at older age in both men and women. Finally, Asians had smaller chamber sizes and higher LVEFs and absolute strain values than both blacks and whites. CONCLUSIONS: Age, sex, and race should be considered when defining normal reference values for LV dimension and functional parameters obtained by 3D echocardiography.

Novel left and right ventricular strain analysis to detect subclinical myocardial dysfunction in cardiac allograft rejection.

Early detection of acute cellular rejection (ACR) by echocardiography shows potential clinical benefit as ACR remains a significant contributor to morbidity and mortality. This retrospective, longitudinal study sought to investigate the use of novel left (LV) and right ventricular (RV) strain analysis to detect biopsy proven ACR. 46 heart transplant patients (Mean age 46 ± 16 years) with biopsy proven ACR were grouped according to biopsy results: 1R-ACR (n = 36) and 2R-ACR (n = 10). Serial two-dimensional transthoracic echocardiography with strain analysis was performed. Echocardiographic parameters were serially measured: (1) rejection free period (0R-ACR); (2) pre-ACR period (pre-ACR); (3) during ACR (1R-ACR or 2R-ACR) and (4) post-ACR (Post-ACR). Significant reductions for LV Global Longitudinal Strain (LV GLS) and LV Early diastolic Strain rate (LV ESr) were observed between 0R-ACR and pre-ACR (LV GLS 0R-ACR: 17.3% vs Pre-2R ACR: 15.4%, p = 0.016; LV ESr 0R-ACR: 1.00/s vs Pre-2R ACR: 0.74/s, p = 0.007) with LV ESr demonstrating the highest sensitivity (92%) and specificity (81%) to predict ACR. LV ESr and the E/LV ESr ratio were significantly different (p = 0.0001; p = 0.016) during pre-1R ACR period vs 0R whereas LV GLS showed no significant differences for grade 1R-ACR. Diastolic mechanical dispersion showed significant increases in dispersion during ACR for the 1R-ACR group and early significant increases pre-2R ACR. Systolic and diastolic RV strain parameters showed a similar trend for both ACR groups. Systolic and diastolic strain parameters can detect myocardial dysfunction before biopsy confirmed 2R-ACR. Early diastolic strain rate parameters are most sensitive detecting subclinical myocardial dysfunction pre-ACR. Novel strain parameters are potentially useful clinical tool for prediction of early ACR in heart transplant.

Advantage and validation of vendor-independent software for myocardial strain analysis compared to vendor-specific software.

INTRODUCTION: One of the main limitations incorporating strain imaging into widespread clinical practice is inter-vendor incompatibility. This poses a problem when serial strain measurements are required in a multi-vendor echocardiography laboratory. METHODS: This study sought to compare the variability of two-dimensional speckle-tracking global and regional longitudinal strain using vendor-specific software and vendor-independent software from images acquired by two different commercially available ultrasound systems. Forty subjects underwent two sequential echocardiographic acquisitions using different ultrasound systems (GE Vivid E9 and Philips iE33). Global longitudinal strain and regional peak longitudinal strain were derived using vendor-specific software (EchoPAC BT 13 v201 and QLAB version 10.3) and vendor-independent software (TomTec Image Arena version 4.6). Agreement and reproducibility of global and regional strain between vendor-specific and vendor-independent software were assessed by independent blinded observers. RESULTS: Global longitudinal strain derived from vendor-independent software was comparable to global longitudinal strain derived from vendor-specific software, whilst regional strain was lower in agreement compared to global longitudinal strain. There was good overall agreement and high inter- and intra-observer reproducibility using vendor-independent software for global longitudinal strain and regional strain. CONCLUSIONS: Vendor-independent software provides good agreement with vendor-specific software for global longitudinal strain. However, minor variability exists for regional strain measurements between vendor-independent and vendor-specific software. Good agreement of strain measurements derived by vendor-independent software suggests vendor-independent software could potentially be useful for serial follow-up of global longitudinal strain.

Myocardial work and left ventricular contractile reserve during stress echocardiography: An angiographic validation.

OBJECTIVE: This study sought to determine the contractile reserve (CR) response to exercise stress echocardiography (ESE) quantified by the novel parameter, non-invasive myocardial work (MW), in subjects with angiographically proven coronary artery disease (CAD). METHODS: CR was measured by the relative change in ejection fraction (EF), global longitudinal strain (GLS) and MW indices from rest to peak exercise in 304 patients referred for clinically indicated ESE. Positive ESE patients proceeded to coronary angiography and further risk stratified based on either percutaneous or surgical intervention. RESULTS: CRGLS and global work index (CRGWI ) significantly decreased with exercise induced ischemia and angiographically proven significant CAD (CRGLS -1.6±3.5%; CRGWI -8.6±511 mm Hg% decrement, p < 0.001) compared to non-ischemic patients (CRGLS 1.4±2.2%; CRGWI 398±404 mm Hg% improvement). Global constructive work (CRGCW ) was significantly higher (p < 0.0001) in non-ischemic (818±457 mm Hg%) and blunted in ischemic patients (208±550 mm Hg%). CRGCW (AUC .81; 95%CI:.75-.86) demonstrated the most association for inducible ischemia followed by CRGLS (AUC .75; 95%CI:.69-.80), CRGWI (AUC .73, 95%CI:.67-.79) and CREF (AUC .71; 95%CI:.65-.77, p < 0.001). Subgroup analysis showed patients requiring surgical revascularization demonstrated a significantly lower CRGWE (-11.5±7.6%, p < 0.05) as a result of reduced CRGCW (281±573 mm Hg%, p < 0.05) and increased global wasted work (CRGWW , 289±151 mm Hg%, p = 0.09). CONCLUSION: Multivessel disease requiring surgical revascularization have the greatest reduction in CR. MW may potentially improve detection of ischemia and further risk stratification during ESE to maximize the benefits of revascularization.