Echocardiographic Detection of Regional Wall Motion Abnormalities Using Artificial Intelligence Compared to Human Readers

BACKGROUND

Although regional wall motion abnormality (RWMA) detection is foundational to transthoracic echocardiography, current methods are prone to interobserver variability. We aimed to develop a deep learning (DL) model for RWMA assessment and compare it to expert and novice readers.

METHODS

We used 15,746 transthoracic echocardiography studies-including 25,529 apical videos-which were split into training, validation, and test datasets. A convolutional neural network was trained and validated using apical 2-, 3-, and 4-chamber videos to predict the presence of RWMA in 7 regions defined by coronary perfusion territories, using the ground truth derived from clinical transthoracic echocardiography reports. Within the test cohort, DL model accuracy was compared to 6 expert and 3 novice readers using F1 score evaluation, with the ground truth of RWMA defined by expert readers. Significance between the DL model and novices was assessed using the permutation test.

RESULTS

Within the test cohort, the DL model accurately identified any RWMA with an area under the curve of 0.96 (0.92-0.98). The mean F1 scores of the experts and the DL model were numerically similar for 6 of 7 regions: anterior (86 vs 84), anterolateral (80 vs 74), inferolateral (83 vs 87), inferoseptal (86 vs 86), apical (88 vs 87), inferior (79 vs 81), and any RWMA (90 vs 94), respectively, while in the anteroseptal region, the F1 score of the DL model was lower than the experts (75 vs 89). Using F1 scores, the DL model outperformed both novices 1 (P = .002) and 2 (P = .02) for the detection of any RWMA.

CONCLUSIONS

Deep learning provides accurate detection of RWMA, which was comparable to experts and outperformed a majority of novices. Deep learning may improve the efficiency of RWMA assessment and serve as a teaching tool for novices.

Atrial secondary tricuspid regurgitation: pathophysiology, definition, diagnosis, and treatment

Atrial secondary tricuspid regurgitation (A-STR) is a distinct phenotype of secondary tricuspid regurgitation with predominant dilation of the right atrium and normal right and left ventricular function. Atrial secondary tricuspid regurgitation occurs most commonly in elderly women with atrial fibrillation and in heart failure with preserved ejection fraction in sinus rhythm. In A-STR, the main mechanism of leaflet malcoaptation is related to the presence of a significant dilation of the tricuspid annulus secondary to right atrial enlargement. In addition, there is an insufficient adaptive growth of tricuspid valve leaflets that become unable to cover the enlarged annular area. As opposed to the ventricular phenotype, in A-STR, the tricuspid valve leaflet tethering is typically trivial. The A-STR phenotype accounts for 10%-15% of clinically relevant tricuspid regurgitation and has better outcomes compared with the more prevalent ventricular phenotype. Recent data suggest that patients with A-STR may benefit from more aggressive rhythm control and timely valve interventions. However, little is mentioned in current guidelines on how to identify, evaluate, and manage these patients due to the lack of consistent evidence and variable definitions of this entity in recent investigations. This interdisciplinary expert opinion document focusing on A-STR is intended to help physicians understand this complex and rapidly evolving topic by reviewing its distinct pathophysiology, diagnosis, and multi-modality imaging characteristics. It first defines A-STR by proposing specific quantitative criteria for defining the atrial phenotype and for discriminating it from the ventricular phenotype, in order to facilitate standardization and consistency in research.

Doppler Echocardiographic Phenotypes in Suspected 'Severe' Aortic Stenosis: Matrix-Based Approach to Diagnosis and Management

BACKGROUND

Among patients with suspected severe aortic stenosis (AS), Doppler echocardiographic (DE) data are often discordant, and further analysis is required for accurate diagnosis and optimal management. In this study, an automated matrix-based approach was applied to an echocardiographic database of patients with AS that identified 5 discrete echocardiographic data patterns, 1 concordant and 4 discordant, each reflecting a particular pathophysiology/measurement error that guides further workup and management.

METHODS

A primary/discovery cohort of consecutive echocardiographic studies with at least 1 DE parameter of severe AS and analogous data from an independent secondary/validation cohort were retrospectively analyzed. Parameter thresholds for inclusion were aortic valve area (AVA) <1.0 cm2, transaortic mean gradient (MG) ≥ 40 mmHg, and/or transaortic peak velocity (PV) ≥ 4.0 m/sec. Doppler velocity index (DVI) was also determined. Logic provided by an in-line SQL query embedded within the database was used to assign each patient to 1 of 5 discrete matrix patterns, each reflecting 1 or more specific pathophysiologies. Feasibility of automated pattern-driven triage of discordant cases was also evaluated.

RESULTS

In both cohorts, data from each patient fitted only 1 data pattern. Of the 4,643 primary cohort patients, 39% had concordant parameters for severe AS and DVI <0.30 (pattern 1); 35% had AVA < 1.0 cm2, MG < 40 mm Hg, PV < 4 m/sec, DVI < 0.30 (pattern 2); 9% had MG ≥ 40 mmHg and/or PV ≥ 4 m/sec, DVI > 0.30 (pattern 3); 10% had AVA < 1.0 cm2, MG < 40 mmHg, PV < 4 m/sec, DVI >0.30 (pattern 4); and 7% had MG > 40 mmHg and/or PV ≥ 4 m/sec, AVA > 1.0 cm2, DVI < 0.30 (pattern 5). Findings were validated among the 387 secondary cohort patients in whom pattern distribution was remarkably similar.

CONCLUSIONS

Matrix-based pattern recognition permits automated in-line identification of specific pathophysiology and/or measurement error among patients with suspected severe AS and discordant DE data.

Multimodality Cardiac Imaging and the Imaging Workforce in the United States: Diversity, Disparities, and Future Directions

Innovations in cardiac imaging have fundamentally advanced the understanding and treatment of cardiovascular disease. These advances in noninvasive cardiac imaging have also expanded the role of the cardiac imager and dramatically increased the demand for imagers who are cross-trained in multiple modalities. However, we hypothesize that there is significant variation in the availability of cardiac imaging expertise and a disparity in the adoption of advanced imaging technologies across the United States. To evaluate this, we have brought together the leaders of cardiovascular imaging societies, imaging trainees, as well as collaborated with national imaging accreditation commissions and imaging certification boards to assess the state of cardiac imaging and the diversity of the imaging workforce in the United States. Aggregate data confirm the presence of critical gaps, such as limited access to imaging and imaging expertise in rural communities, as well as disparities in the imaging workforce, notably among women and underrepresented minorities. Based on these results, we have proposed solutions to promote and maintain a robust and diverse community of cardiac imagers and improve equity and accessibility for cardiac imaging technologies.

Three-dimensional echocardiographic evaluation of longitudinal and non-longitudinal components of right ventricular contraction: results from the World Alliance of Societies of Echocardiography study

AIMS

Right ventricular (RV) functional assessment is mainly limited to its longitudinal contraction. Dedicated three-dimensional echocardiography (3DE) software enabled the separate assessment of the non-longitudinal components of RV ejection fraction (EF). The aims of this study were (i) to establish normal values for RV 3D-derived longitudinal, radial, and anteroposterior EF (LEF, REF, and AEF, respectively) and their relative contributions to global RVEF, (ii) to calculate 3D RV strain normal values, and (iii) to determine sex-, age-, and race-related differences in these parameters in a large group of normal subjects (WASE study).

METHODS AND RESULTS

3DE RV wide-angle datasets from 1043 prospectively enrolled healthy adult subjects were analysed to generate a 3D mesh model of the RV cavity (TomTec). Dedicated software (ReVISION) was used to analyse RV motion along the three main anatomical planes. The EF values corresponding to each plane were identified as LEF, REF, and AEF. Relative contributions were determined by dividing each EF component by the global RVEF. RV strain analysis included longitudinal, circumferential, and global area strains (GLS, GCS, and GAS, respectively). Results were categorized by sex, age (18-40, 41-65, and >65 years), and race. Absolute REF, AEF, LEF, and global RVEF were higher in women than in men (P < 0.001). With aging, both sexes exhibited a decline in all components of longitudinal shortening (P < 0.001), which was partially compensated in elderly women by an increase in radial contraction. Black subjects showed lower RVEF and GAS values compared with white and Asian subjects of the same sex (P < 0.001), and black men showed significantly higher RV radial but lower longitudinal contributions to global RVEF compared with Asian and white men.

CONCLUSION

3DE evaluation of the non-longitudinal components of RV contraction provides additional information regarding RV physiology, including sex-, age-, and race-related differences in RV contraction patterns that may prove useful in disease states involving the right ventricle.

Limitations of Apical Sparing Pattern in Cardiac Amyloidosis: A Multicenter Echocardiographic Study

BACKGROUND

Although impaired left ventricular (LV) global longitudinal strain (GLS) with apical sparing is a feature of cardiac amyloidosis (CA), its diagnostic accuracy has varied across studies. We aimed to determine the ability of apical sparing ratio (ASR) and most common echocardiographic parameters to differentiate patients with confirmed CA from those with clinical and/or echocardiographic suspicion of CA, but with this diagnosis ruled out.

METHODS

We identified 544 patients with confirmed CA and 200 controls as defined above (CTRL Patients). Measurements from transthoracic echocardiograms (TTE) were performed using artificial intelligence software (Us2.AI, Singapore) and audited by an experienced echocardiographer. Receiver-operating characteristic curve analysis was used to evaluate the diagnostic performance and optimal cutoffs for the differentiation of CA patients from CTRL Patients. Additionally, a group of 174 healthy subjects (Healthy CTRL) was included to provide insight on how Patients and Healthy controls differed echocardiographically.

RESULTS

LV GLS was more impaired (-13.9 ± 4.6% vs -15.9 ± 2.7%, p < 0.0005) and ASR was higher (2.4 ± 1.2 vs 1.7 ± 0.9, p < 0.0005) in the CA group vs. CTRL Patients. Relative wall thickness and ASR were the most accurate parameters for differentiating CA from CTRL Patients (AUC: 0.77 and 0.74, respectively). However, even with the optimal cutoff of 1.67, ASR was only 72% sensitive and 66% specific for CA, indicating presence of apical sparing in 32% of CTRL Patients and even in 6% Healthy CTRLs.

CONCLUSIONS

Apical sparing did not prove to be a CA-specific biomarker for accurate identification of CA, when compared to clinically similar controls with no CA.

Right Ventricular Thrombus on Echocardiography

Right ventricular thrombi (RVTs) have been almost exclusively studied in patients with pulmonary embolism (PE). The implications of an isolated RVT, a finding typically encountered on transthoracic echocardiography (TTE), are lacking. In this study, we sought to identify the echocardiographic and clinical features associated with the presence of RVTs. Between 1998 and 2023, 138 patients with RVT documented on TTE were retrospectively identified. Demographic data, presence of intracardiac devices, hypercoagulable conditions, history of deep vein thrombosis (DVT), PE, and/or left ventricular thrombus were abstracted from electronic chart review. Measurements of right and left ventricular size, and function were performed on TTE. Of the total population of patients with RVT, <1/2 had intracardiac devices, 29% had a documented hypercoagulable state (e.g., cancer or a clotting disorder). Most patients had dilated (77%) and dysfunctional (72%) right ventricles. Approximately 50% of RVTs were discovered in nonstandard imaging planes, suggesting that the presence of RVT is likely underestimated in clinical practice. Of those evaluated for PE, 80% had PE. Of those evaluated for DVT, 53% had DVT. In conclusion, further investigations are warranted to better guide when to investigate the right ventricle for RVTs on TTE and the impact of RVTs on patient outcomes.

Reverse Remodeling Effects of Sacubitril-Valsartan: Structural and Functional Optimization in Stage C Heart Failure

Sacubitril-valsartan, an angiotensin receptor-neprilysin inhibitor, reduces all-cause mortality and the rate of heart failure hospitalizations in patients with heart failure with reduced ejection fraction. This study aimed to elucidate the benefits of initiating sacubitril-valsartan on ventricular remodeling in patients previously optimized on guideline-directed medical therapy. In this prospective, single-arm longitudinal study, 40 patients with heart failure with reduced ejection fraction who were optimized on guideline-directed medical therapy were transitioned to sacubitril-valsartan. The primary end point was the change in left ventricular (LV) volume at 1 year as assessed by 3-dimensional transthoracic echocardiography. Other echocardiographic end points included change in LV-function and change in right ventricular (RV) size and function. The mean age was 55 ± 12 years, and 63% were male. At 1 year, LV end-diastolic volume decreased from 242 ± 71 to 157 ± 57 ml (p <0.001) with a corresponding increase in LV ejection fraction from 32 ± 7% to 44 ± 9% (p <0.001). RV end-diastolic volume decreased from 151 ± 51 to 105 ±45 ml (p <0.001). Although RV ejection fraction did not change (51 ± 8 vs 51 ± 10; p = 0.35), RV global longitudinal strain improved from -14.9 ± 3.4 % to -19.3 ± 4.3% (p <0.001). When added to standard medical therapy for heart failure, sacubitril-valsartan induces significant remodeling of both the right and left ventricles as assessed by 3-dimensional echocardiography.

Added value of 3D echocardiography in the diagnosis and prognostication of patients with right ventricular dysfunction

Recent inroads into percutaneous-based options for the treatment of tricuspid valve disease has brought to light how little we know about the behavior of the right ventricle in both health and disease and how incomplete our assessment of right ventricular (RV) physiology and function is using current non-invasive technology, in particular echocardiography. The purpose of this review is to provide an overview of what three-dimensional echocardiography (3DE) can offer currently to enhance RV evaluation and what the future may hold if we continue to improve the 3D evaluation of the right heart.

Noninvasive assessment of left ventricular end-diastolic pressure using machine learning-derived phasic left atrial strain

AIMS

While transthoracic echocardiography (TTE) assessment of left ventricular end-diastolic pressure (LVEDP) is critically important, the current paradigm is subject to error and indeterminate classification. Recently, peak left atrial strain (LAS) was found to be associated with LVEDP. We aimed to test the hypothesis that integration of the entire LAS time curve into a single parameter could improve the accuracy of peak LAS in the noninvasive assessment of LVEDP with TTE.

METHODS AND RESULTS

We retrospectively identified 294 patients who underwent left heart catheterization and TTE within 24 h. LAS curves were trained using machine learning (100 patients) to detect LVEDP ≥ 15 mmHg, yielding the novel parameter LAS index (LASi). The accuracy of LASi was subsequently validated (194 patients), side by side with peak LAS and ASE/EACVI guidelines, against invasive filling pressures. Within the validation cohort, invasive LVEDP was elevated in 116 (59.8%) patients. The overall accuracy of LASi, peak LAS, and American Society of Echocardiography/European Association for Cardiovascular Imaging (ASE/EACVI) algorithm was 79, 75, and 76%, respectively (excluding 37 patients with indeterminate diastolic function by ASE/EACVI guidelines). When the number of LASi indeterminates (defined by near-zero LASi values) was matched to the ASE/EACVI guidelines (n = 37), the accuracy of LASi improved to 87%. Importantly, among the 37 patients with ASE/EACVI-indeterminate diastolic function, LASi had an accuracy of 81%, compared with 76% for peak LAS.

CONCLUSION

LASi allows the detection of elevated LVEDP using invasive measurements as a reference, at least as accurately as peak LAS and current diastolic function guideline algorithm, with the advantage of no indeterminate classifications in patients with measurable LAS.

Deep learning assisted measurement of echocardiographic left heart parameters: improvement in interobserver variability and workflow efficiency

Machine learning techniques designed to recognize views and perform measurements are increasingly used to address the need for automation of the interpretation of echocardiographic images. The current study was designed to determine whether a recently developed and validated deep learning (DL) algorithm for automated measurements of echocardiographic parameters of left heart chamber size and function can improve the reproducibility and shorten the analysis time, compared to the conventional methodology. The DL algorithm trained to identify standard views and provide automated measurements of 20 standard parameters, was applied to images obtained in 12 randomly selected echocardiographic studies. The resultant measurements were reviewed and revised as necessary by 10 independent expert readers. The same readers also performed conventional manual measurements, which were averaged and used as the reference standard for the DL-assisted approach with and without the manual revisions. Inter-reader variability was quantified using coefficients of variation, which together with analysis times, were compared between the conventional reads and the DL-assisted approach. The fully automated DL measurements showed good agreement with the reference technique: Bland-Altman biases 0-14% of the measured values. Manual revisions resulted in only minor improvement in accuracy: biases 0-11%. This DL-assisted approach resulted in a 43% decrease in analysis time and less inter-reader variability than the conventional methodology: 2-3 times smaller coefficients of variation. In conclusion, DL-assisted approach to analysis of echocardiographic images can provide accurate left heart measurements with the added benefits of improved reproducibility and time savings, compared to conventional methodology.

Preservation of Circumferential and Radial Left Ventricular Function as a Mitigating Mechanism for Impaired Longitudinal Strain in Early Cardiac Amyloidosis

BACKGROUND

In patients with cardiac amyloidosis (CA), left ventricular ejection fraction (LVEF) is frequently preserved, despite commonly reduced global longitudinal strain (GLS). We hypothesized that nonlongitudinal contraction may initially serve as a mitigating mechanism to maintain cardiac output and studied the relationship between global circumferential (GCS) and radial (GRS) strain with LVEF and extracellular volume (ECV), a marker of amyloid burden.

METHODS

Patients with CA who underwent cardiac magnetic resonance (CMR; n = 140, 70.7 ± 11.5 years, 66% male) or echocardiography (n = 67, 71 ± 13 years, 66% male) and normal controls (CMR, n = 20; echocardiography, n = 45) were retrospectively identified, and GCS, GLS, and GRS were quantified using feature-tracking CMR or speckle-tracking echocardiography and compared between CA patients with preserved and reduced LVEF (CAHFpEF, CAHFrEF) and controls. The prevalence of impaired strain (magnitudes <2.5th percentile of the controls) was compared between CAHFpEF and CAHFrEF and between ECV quartiles.

RESULTS

While echocardiography-derived GLS was impaired in both CAHFpEF (-13.4% ± 3.1%, P < .003) and CAHFrEF (-9.1% ± 3.2%, P < .003), compared with controls (-20.8% ± 2.4%), GCS was more impaired in CAHFrEF compared with both controls (-15.6% ± 5.0% vs -32.3% ± 3.3%, P < .003) and CAHFpEF (-30.4% ± 5.7%, P < .003) and did not differ between CAHFpEF and controls (P = .24). The prevalence of abnormal CMR-derived GCS (P < .0001) and GRS (P < .0001) but not GLS (P = .054) varied significantly across ECV quartiles.

CONCLUSIONS

Among CA patients with preserved LVEF, preserved GCS and GRS, despite near-universally impaired GLS, may be explained by an initial predominantly subendocardial involvement, where mostly longitudinal fibers are located. If confirmed in future studies, these findings may facilitate identification of patients with early stages of CA, when treatments may be most effective.

Imaging Methods for Evaluation of Chronic Aortic Regurgitation in Adults: JACC State-of-the-Art Review

A global multidisciplinary workshop was convened to discuss the multimodality diagnostic evaluation of aortic regurgitation (AR). Specifically, the focus was on assessment tools for AR severity and analyzing evolving data on the optimal timing of aortic valve intervention. The key concepts from this expert panel are summarized as: 1) echocardiography is the primary imaging modality for assessment of AR severity; however, when data is incongruent or incomplete, cardiac magnetic resonance may be helpful; 2) assessment of left ventricular size and function is crucial in determining the timing of intervention; 3) recent evidence suggests current cutpoints for intervention in asymptomatic severe AR patients requires further scrutiny; 4) left ventricular end-systolic volume index has emerged as an additional parameter that has promise in guiding timing of intervention; and 5) the role of additional factors (including global longitudinal strain, regurgitant fraction, and myocardial extracellular volume) is worthy of future investigation.

Normal Values of Echocardiographic Right Ventricular Size and Systolic Function Measurements in a Healthy Japanese Population - Subanalysis of the WASE Study

Background: Although accurate assessment of right ventricular (RV) morphology and function is clinically important, data regarding reference values for echocardiographic measurements of the right ventricle in the Japanese population are limited. Methods and Results: The World Alliance Society of Echocardiography (WASE) Normal Values Study was conducted to examine normal echocardiographic values in 15 countries. Using the WASE study database, we analyzed 2-dimensional echocardiographic parameters of RV size and systolic function in 192 healthy Japanese individuals and compared them with those obtained from 153 healthy American individuals. In the Japanese population, the absolute values of RV dimensions were smaller for women than men, although the difference disappeared after the data were adjusted for body surface area. RV dimensions, RV length and RV area were smaller in the elderly, but age did not affect RV systolic function. The absolute value, but not the adjusted value, of RV size tended to be smaller in Japanese than American individuals for both sexes. For men, RV systolic function parameters were lower in the Japanese population. This trend was not seen in women. Conclusions: The present study identified normal reference values for RV size and systolic function in a healthy Japanese population. Sex, age, and race had a significant impact on RV size; however, this trend was weak for RV systolic function.

Real-Time Artificial Intelligence-Based Guidance of Echocardiographic Imaging by Novices: Image Quality and Suitability for Diagnostic Interpretation and Quantitative Analysis

BACKGROUND

We aimed to assess in a prospective multicenter study the quality of echocardiographic exams performed by inexperienced users guided by a new artificial intelligence software and evaluate their suitability for diagnostic interpretation of basic cardiac pathology and quantitative analysis of cardiac chamber and function.

METHODS

The software (UltraSight, Ltd) was embedded into a handheld imaging device (Lumify; Philips). Six nurses and 3 medical residents, who underwent minimal training, scanned 240 patients (61±16 years; 63% with cardiac pathology) in 10 standard views. All patients were also scanned by expert sonographers using the same device without artificial intelligence guidance. Studies were reviewed by 5 certified echocardiographers blinded to the imager's identity, who evaluated the ability to assess left and right ventricular size and function, pericardial effusion, valve morphology, and left atrial and inferior vena cava sizes. Finally, apical 4-chamber images of adequate quality, acquired by novices and sonographers in 100 patients, were analyzed to measure left ventricular volumes, ejection fraction, and global longitudinal strain by an expert reader using conventional methodology. Measurements were compared between novices' and experts' images.

RESULTS

Of the 240 studies acquired by novices, 99.2%, 99.6%, 92.9%, and 100% had sufficient quality to assess left ventricular size and function, right ventricular size, and pericardial effusion, respectively. Valve morphology, right ventricular function, and left atrial and inferior vena cava size were visualized in 67% to 98% exams. Images obtained by novices and sonographers yielded concordant diagnostic interpretation in 83% to 96% studies. Quantitative analysis was feasible in 83% images acquired by novices and resulted in high correlations (r≥0.74) and small biases, compared with those obtained by sonographers.

CONCLUSIONS

After minimal training with the real-time guidance software, novice users can acquire images of diagnostic quality approaching that of expert sonographers in most patients. This technology may increase adoption and improve accuracy of point-of-care cardiac ultrasound.

Variations in indexation of left atrial volume across different races

Background

Left atrial volume (LAV) has prognostic value. Guidelines propose indexation to body surface area (BSA), however studies demonstrate this can overcorrect for body size. Limited studies investigate indexation across different ethnicities. We sought to evaluate the effect of ethnicity on indexation.

Methods

Using data from the World Alliance of Societies of Echocardiography (WASE) cohort, healthy subjects were classified by race as White, Black, Asian, or Other. Biplane LAV was indexed to traditional isometric measurements (BSA, height, weight, ideal body weight (IBW) and IBW derived BSA (IBSA)), as well as previously-derived allometric height exponents (2.7 and 1.72). Additionally, an allometric height exponent for our cohort was derived (linear regression of the logarithmic transformation of LAV = a(height)b) as 1.87. All indices were then assessed using Spearman correlation, with a good index retaining correlation of LAV/index to raw LAV (r∼1), while avoiding overcorrection by the index (r∼0).

Results

There were 1366 subjects (White: 524, Black: 149, Asian: 523, Other: 170; median age 44 years, 653 females (47.8%)). In the entire group, BSA, IBSA, height1.87 and height1.72 performed well with retaining correlation to raw LAV (r > 0.9 for all), and minimising overcorrection to body size (r < 0.1 for all). On race-specific analysis, BSA overcorrected for body size in the White population (r = 0.128). Height1.72 minimised overcorrection for body size in all populations (r ≤ 0.1 for all races).

Conclusion

Despite a cohort with normal BMI, there was still disparity in LAV indexation with BSA across races. Allometric height indexation, particularly using height1.72, is a possible solution, although further validation studies in BMI extremes are required.

Anomalous right coronary artery from the main pulmonary artery (ARCAPA): Incidental finding in an asymptomatic septuagenarian

Anomalous right coronary artery (RCA) from the main pulmonary artery (ARCAPA) is a rare finding. Clinical presentations range from asymptomatic to sudden death. We present the case of ARCAPA in a septuagenarian initially suspected on a screening chest computed tomography (CT) and later confirmed on cardiac CT. A summary of important points related to this entity is also discussed.

How Often Does Apical Sparing of Longitudinal Strain Indicate the Presence of Cardiac Amyloidosis?

Echocardiographic diagnosis of cardiac amyloidosis (CA) is frequently suggested by the presence of a left ventricular (LV) apical sparing pattern (ASP) on longitudinal strain (LS) assessment, the so-called "cherry on top" pattern, defined by strain magnitude preserved exclusively at the apex. However, it is unclear how frequently this strain pattern truly represents CA. This study aimed to evaluate the predictive value of ASP in the diagnosis of CA. We retrospectively identified consecutive adult patients who had the following studies performed within an 18-month period: (1) transthoracic echocardiogram and (2) either (a) cardiac magnetic resonance imaging, (b) Technetium-Pyrophosphate (PYP) imaging, or (c) endomyocardial biopsy. LS was retrospectively measured in the apical 4-, 3-, and 2-chamber views in patients who had adequate noncontrast images (n = 466). An apical sparing ratio (ASR) was calculated as (average apical strain)/[(average basal strain) + (average midventricular strain)]. Patients with ASR ≥1 were evaluated for the presence/absence of CA, using established criteria. Basic LV parameters were also measured. A total of 33 patients (7.1%) had ASP. Nine of these patients (27%) had "confirmed" CA, 2 (6.1%) "highly probable" CA, 1 (3.0%) "possible" CA, and 21 (64%) no evidence of CA. When comparing patients with and without confirmed CA, there were no significant differences in ASR, average global LS, ejection fraction, or LV mass. Patients with confirmed CA were older (76 ± 9 vs 59 ± 18 years, p = 0.01) and had thicker posterior wall (15 ± 3 vs 11 ± 3 mm, p = 0.004) with a trend toward thicker septal wall (15 ± 2 vs 12 ± 4 mm, p = 0.05). In conclusion, the presence of ASP on LS represents confirmed or highly probable CA in only 1/3 of patients and is more likely to indicate true CA in older patients with increased LV wall thickness. Although a larger, prospective study is needed to confirm these findings, 1/3 should be considered as a large diagnostic yield that justifies further testing, given the poor outcomes associated with CA diagnosis.

Normal Values of 3D Right Ventricular Size and Function Measurements: Results of the World Alliance of Societies of Echocardiography Study

BACKGROUND

Normal values for 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 of Societies of Echocardiography (WASE) study was designed to generate reference ranges for normal subjects around the world. In this study, we sought to assess the world-wide 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, including 6 continents. 3D wide-angle RV datasets were obtained and analyzed using dedicated RV software (Tomtec) to measure end-diastolic and end-systolic volumes (EDV, ESV), stroke volume (SV) and ejection fraction (EF). Results were categorized by sex, age (18-40, 41-65 and >65 years) and ethnicity.

RESULTS

Of the 2007 subjects with attempted 3D RV acquisitions, 1051 had adequate image quality for confident measurements. Upper and lower limits for BSA-indexed EDV (mL/m²) and ESV (mL/m²) and EF (%) were [48, 95], [19, 43] and [44, 58] for men and [42, 81], [16, 36] and [46, 61] for women. Men had significantly larger EDV, ESV and SV (even after BSA indexing) and lower EF than women (p<0.05). EDV and ESV did not show any meaningful differences between age groups. 3D RV volumes were smallest in Asians.

CONCLUSIONS

Reliability of 3D RV acquisition is low worldwide underscoring the importance for future improvements in imaging techniques. Sex and race must be taken into consideration in the assessment of both RV volumes and EF.

Predictive value of global longitudinal strain by left ventricular ejection fraction

BACKGROUND

The predictive value of left ventricular (LV) global longitudinal strain (GLS) to predict outcomes in different left ventricular ejection fraction (LVEF) cohorts is not well known. We aimed to assess the role of LV GLS predicting outcomes in HF patients by LVEF.

METHODS

In the Multicenter Automatic Defibrillator Implantation Trial Cardiac Resynchronization Therapy (MADIT-CRT), we studied 1077 patients (59%) with 2D speckle tracking data available, 437 patients with LVEF > 30% and 640 with LVEF ≤ 30%. Baseline LV GLS was stratified in tertiles in both LVEF subgroups. The primary endpoint was ventricular tachycardia/fibrillation (VT/VF) or death; the secondary endpoint was heart failure (HF) or death.

RESULTS

In patients with LVEF ≤ 30%, a higher tertile GLS (T3, less contractility) was associated with a higher rate of VT/VF/death (P < 0.001), with similar association in patients with LVEF > 30% (P = 0.057). In patients with LVEF ≤ 30%, a higher tertile GLS was also associated with a higher rate of HF/death. In multivariable models, LV GLS predicted VT/VF or death in the LVEF ≤ 30% subgroup [T1 vs. T2/3 HR = 1.67 (1.16-2.38), P = 0.005], but not in those with LVEF > 30% [T1 vs. T2.3 HR = 1.32 (0.86-2.04), P = 0.21]. LV GLS predicted HF/death in the LVEF ≤ 30% subgroup [T1 vs T2/3 HR = 2.00 (1.30-3.13), P = 0.002], but not in in those with LVEF > 30%.

CONCLUSIONS

In this MADIT-CRT sub-study, LV GLS identified patients at higher risk of VT/VF, HF/death risk independently of conventional clinical parameters in patients with LVEF ≤ 30%, but not in patients with LVEF > 30%.

Normative values of the aortic valve area and Doppler measurements using two-dimensional transthoracic echocardiography: results from the Multicentre World Alliance of Societies of Echocardiography Study

AIMS

Aortic valve area (AVA) used for echocardiographic assessment of aortic stenosis (AS) has been traditionally interpreted independently of sex, age and race. As differences in normal values might impact clinical decision-making, we aimed to establish sex-, age- and race-specific normative values for AVA and Doppler parameters using data from the World Alliance Societies of Echocardiography (WASE) Study.

METHODS AND RESULTS

Two-dimensional transthoracic echocardiographic studies were obtained from 1903 healthy adult subjects (48% women). Measurements of the left ventricular outflow tract (LVOT) diameter and Doppler parameters, including AV and LVOT velocity time integrals (VTIs), AV mean pressure gradient, peak velocity, were obtained according to ASE/EACVI guidelines. AVA was calculated using the continuity equation. Compared with men, women had smaller LVOT diameters and AVA values, and higher AV peak velocities and mean gradients (all P < 0.05). LVOT and AV VTI were significantly higher in women (P < 0.05), and both parameters increased with age in both sexes. AVA differences persisted after indexing to body surface area. According to the current diagnostic criteria, 13.5% of women would have been considered to have mild AS and 1.4% moderate AS. LVOT diameter and AVA were lower in older subjects, both men and women, and were lower in Asians, compared with whites and blacks.

CONCLUSION

WASE data provide clinically relevant information about significant differences in normal AVA and Doppler parameters according to sex, age, and race. The implementation of this information into clinical practice should involve development of specific normative values for each ethnic group using standardized methodology.

Artificial intelligence based left ventricular ejection fraction and global longitudinal strain in cardiac amyloidosis

BACKGROUND

Assessment of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) plays a key role in the diagnosis of cardiac amyloidosis (CA). However, manual measurements are time consuming and prone to variability. We aimed to assess whether fully automated artificial intelligence (AI) calculation of LVEF and GLS provide similar estimates and can identify abnormalities in agreement with conventional manual methods, in patients with pre-clinical and clinical CA.

METHODS

We identified 51 patients (age 80 ± 10 years, 53% male) with confirmed CA according to guidelines, who underwent echocardiography before and/or at the time of CA diagnosis (median (IQR) time between observations 3.87 (1.93, 5.44 years). LVEF and GLS were quantified from the apical 2- and 4-chamber views using both manual and fully automated methods (EchoGo Core 2.0, Ultromics). Inter-technique agreement was assessed using linear regression and Bland-Altman analyses and two-way ANOVA. The diagnostic accuracy and time for detecting abnormalities (defined as LVEF ≤ 50% and GLS ≥ -15.1%, respectively) using AI was assessed by comparisons to manual measurements as a reference.

RESULTS

There were no significant differences in manual and automated LVEF and GLS values in either pre-CA (p = .791 and p = .105, respectively) or at diagnosis (p = .463 and p = .722). The two methods showed strong correlation on both the pre-CA (r = .78 and r = .83) and CA echoes (r = .74 and r = .80) for LVEF and GLS, respectively. The sensitivity and specificity of AI-derived indices for detecting abnormal LVEF were 83% and 86%, respectively, in the pre-CA echo and 70% and 79% at CA diagnosis. The sensitivity and specificity of AI-derived indices for detecting abnormal GLS was 82% and 86% in the pre-CA echo and 100% and 67% at the time of CA diagnosis. There was no significant difference in the relationship between LVEF (p = .99) and GLS (p = .19) and time to abnormality between the two methods.

CONCLUSION

Fully automated AI-calculated LVEF and GLS are comparable to manual measurements in patients pre-CA and at the time of CA diagnosis. The widespread implementation of automated LVEF and GLS may allow for more rapid assessment in different disease states with comparable accuracy and reproducibility to manual methods.

Application of Allometric Methods for Indexation of Left Ventricular End-Diastolic Volume to Normal Echocardiographic Data and Assessing Gender and Racial Differences

BACKGROUND

Gender and racial differences in cardiac chamber size are vital to establish normal ranges of cardiac chamber size in healthy subjects. Many studies report either nonindexed raw measurements or measurements indexed to isometric body surface area (BSA) when establishing normal reference values. Other studies advocate allometric indexation for standardization of heart size. We compared several allometric methods on gender and racial differences in left ventricular end-diastolic volume (LVEDV) measured on three-dimensional echocardiography.

METHODS

Three-dimensional echocardiographic LVEDV data from the World Alliance Societies of Echocardiography normal values study were indexed to isometric BSA, BSA^1.5, BSA^1.8, isometric height, height^2.3, height^2.9, and estimated lean body mass. Gender, racial, national, and regional differences in indexed and nonindexed LVEDV were assessed using Cohen's d statistic or Cohen's f statistic, according to the number of groups being compared. Cohen's d < 0.20 and Cohen's f < 0.10 were regarded as very small relative magnitudes of difference.

RESULTS

Differences in LVEDV among White, Black, and Asian races were smallest when BSA^1.5 or BSA^1.8 was used for indexation, followed by estimated lean body mass. LVEDV/BSA^1.5 was nearly identical for men and women (very small, d = 0.05). However, both LVEDV/BSA^1.5 and LVEDV/BSA^1.8 still provided moderate relative magnitudes of difference (f = 0.22-0.37) among geographic regions. Specifically, among Asians, Indians had the smallest LVEDV/BSA^{1.5 (1.8)}. Brazilians had the smallest LVEDV/BSA^{1.5 (1.8)} among Whites.

CONCLUSIONS

Gender and racial differences in LVEDV became smaller when LVEDV was indexed to BSA^1.5 or BSA^1.8. However, differences in LVEDV among nations remain even after applying allometric scaling. This finding suggests that differences in body composition and/or hemodynamics are potentially more important determinants of heart size than race or gender.

Non-invasive diagnosis of transthyretin cardiac amyloidosis utilizing typical late gadolinium enhancement pattern on cardiac magnetic resonance and light chains

AIMS

While cardiac magnetic resonance (CMR) is often obtained early in the evaluation of suspected cardiac amyloidosis (CA), it currently cannot be utilized to differentiate immunoglobulin (AL) and transthyretin (ATTR) CA. We aimed to determine whether a novel CMR and light-chain biomarker-based algorithm could accurately diagnose ATTR-CA.

METHODS AND RESULTS

Patients with confirmed AL or ATTR-CA with typical late gadolinium enhancement (LGE) and Look-Locker pattern for CA on CMR were retrospectively identified at three academic medical centres. Comprehensive light-chain analysis including free light chains, serum, and urine electrophoresis/immunofixation was performed. The diagnostic accuracy of the typical CMR pattern for CA in combination with negative light chains for the diagnosis of ATTR-CA was determined both in the entire cohort and in the subset of patients with invasive tissue biopsy as the gold standard. A total of 147 patients (age 70 ± 11, 76% male, 51% black) were identified: 89 ATTR-CA and 58 AL-CA. Light-chain biomarkers were abnormal in 81 (55%) patients. Within the entire cohort, the sensitivity and specificity of a typical LGE and Look-Locker CMR pattern and negative light chains for ATTR-CA was 73 and 98%, respectively. Within the subset with biopsy-confirmed subtype, the CMR and light-chain algorithm were 69% sensitive and 98% specific.

CONCLUSION

The combination of a typical LGE and Look-Locker pattern on CMR with negative light chains is highly specific for ATTR-CA. The successful non-invasive diagnosis of ATTR-CA using CMR has the potential to reduce diagnostic and therapeutic delays and healthcare costs for many patients.

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.

Clinical Utility of Transillumination on Transthoracic Imaging

• TI is a 3D rendering tool that applies a movable virtual light. • TI may improve anatomic definition and diagnostic yield of transthoracic imaging. • TI is particularly useful for optimal valve anatomy visualization. • New 3D techniques may help achieve TTE images with similar diagnostic yield to TEE.

Three-Dimensional Echocardiographic Deconstruction: Feasibility of Clinical Evaluation from Two-Dimensional Views Derived from a Three-Dimensional Data Set

BACKGROUND

Three-dimensional echocardiography (3DE) makes it possible to capture the entire heart in a single data set that theoretically could be used to extract any two-dimensional (2D) views and potentially replace the standard practice of serial 2D acquisitions. The aim of this study was to test the hypothesis that the quality of 3DE-derived 2D images is sufficient to allow the visualization of the left ventricular (LV), right ventricular (RV), and left atrial (LA) endocardium, on par with images from conventional two-dimensional echocardiography (2DE), and potentially more accurate quantification of chamber size and function.

METHODS

First, the investigators prospectively studied 36 patients who underwent 2DE in 14 standard views, and full-volume data sets from 3DE, from which the same views were extracted offline. The ability to visualize the LV endocardium, RV free wall, and LA endocardium was scored. LV linear dimensions, LV volumes, and LV ejection fraction (LVEF), LA volume, and RV basal dimension were measured and compared between both types of images. Thereafter, 40 patients who underwent 2DE, 3DE, and cardiac magnetic resonance (CMR) imaging on the same day were retrospectively studied. LV volumes and LVEF derived from 2DE and 3DE were compared side by side against the CMR reference.

RESULTS

Intertechnique agreement in visualization scores was 87% for LV segments, 86% for the RV free wall, and 83% for the LA endocardium. The correlations between 2DE- and 3DE-derived measurements were 0.95, 0.97, and 0.97 for LV volumes and LVEF, respectively, and 0.88 for RV basal dimension. Three-dimensional echocardiography-derived measurements of LV volumes and LVEF were more similar to those on CMR than those obtained on conventional 2DE.

CONCLUSIONS

The feasibility of segmental assessment of cardiac chambers using 3DE-derived 2D views is similar to that using conventional 2DE. This approach provides similar quantitative information, including more accurate LV volumes and LVEF measurements compared with CMR, and thus promises to significantly shorten the duration of the echocardiographic examination.

Multiple Intracardiac Masses Involving 3 Chambers of the Heart

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A 42-year-old man presented with multiple cardiac masses.

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Metastatic disease is far more prevalent than primary cardiac tumors.

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Multimodality imaging aids in the diagnostic and management strategy.

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Optimal treatment of large, chronic intracardiac thrombi needs to be refined.

Value of 3D echocardiography in the diagnosis of arrhythmogenic right ventricular cardiomyopathy

Aims

The 2010 Task Force Criteria (TFC) require that both right ventricular (RV) regional wall-motion abnormalities (WMA) and specific RV size cut-offs be met in order to fulfil one of the major criterion for arrhythmogenic right ventricular cardiomyopathy (ARVC) diagnosis. Currently, 2D echocardiography (2DE) and cardiovascular magnetic resonance imaging (cMRI) are used to determine if these criteria are met. Little is known about the diagnostic value of 3D echocardiography (3DE) in ARVC. The aim of this study was to determine whether a combination of 2DE-3DE is non-inferior to the currently used 2DE-cMRI combination in the diagnosis of patients with ARVC.

Methods and results

Thirty-nine individuals (47±15 years) with suspected ARVC underwent evaluation of the RV with cMRI, 2DE, and 3DE. 3DE and cMRI were independently used to obtain RV volumes, ejection fraction (EF) and determine the presence of segmental RV WMA. Studies were blindly classified as meeting criteria for ARVC in accordance with the 2010 TFC. Kappa statistics were used to test the concordance between 2DE–cMRI and 2DE–3DE approaches. Using the 2DE–cMRI approach, 3/39 were not affected, 5/39 possible, 8/39 borderline, and 23/39 definite ARVC. The proposed 2DE–3DE approach yielded 5/39 not affected, 7/39 possible, 8/39 borderline, and 19/39 definite diagnoses. The two approaches were highly concordant (k = 0.71; 95% confidence interval: 0.44–0.84). Although 3DE underestimated RV volumes in comparison with cMRI, interfering, in some instances with the fulfilment of a major criterion, it was able to identify more RV WMA (28/39) than 2DE (11/39), with a detection-rate comparable to cMRI (33/39) highlighting a unique advantage.

Conclusion

The combination of 2DE–3DE for ARVC diagnosis is comparable to the conventional 2DE–cMRI approach. 3DE should be performed in all suspected ARVC patients to aide in the detection of WMA.

Tricuspid Regurgitation Related to Cardiac Implantable Electronic Devices: An Integrative Review

The use of cardiac implantable electronic devices, including permanent pacemakers, implantable cardiac defibrillators and cardiac resynchronization therapy, has dramatically increased in recent years. The interaction between the device lead and tricuspid valve leaflets is a potential cause of tricuspid regurgitation which in turn has an impact on morbidity and mortality. Echocardiography is necessary for grading of tricuspid regurgitation severity. The use of three-dimensional imaging helps determine whether the device lead is interfering with normal leaflet coaptation. Early identification of lead-related tricuspid regurgitation is critical to select the optimal treatment, which may include lead extraction or even tricuspid valve repair/replacement in severe cases. This review aims to provide a thorough assessment of the evidence about lead-associated tricuspid regurgitation, the benefits of using 3D echocardiography with some technical considerations, and finally, propose a treatment algorithm.

Three-Dimensional Transthoracic Static and Dynamic Normative Values of the Mitral Valve Apparatus: Results from the Multicenter World Alliance Societies of Echocardiography Study

BACKGROUND

Recent advances in mitral valve (MV) percutaneous interventions have escalated the need for a more quantitative and comprehensive assessment of the MV, which can be best achieved using three-dimensional echocardiography. Understanding normal valve size, structure, and function is essential for differentiation of healthy from disease states. The aims of this study were to establish normative values for MV apparatus size and morphology and to determine how they vary across age, sex, and race groups using data from the World Alliance Societies of Echocardiography Normal Values Study.

METHODS

Three-dimensional volumetric data sets obtained on transthoracic echocardiography in 748 normal subjects (51% men) were analyzed using commercial MV analysis software (TomTec Imaging Systems) to determine annular and leaflet dimensions and areas. The subjects were divided into groups by sex (378 men and 370 women) and age (18 to 40 years [n = 266], 41 to 65 years [n = 249], and >65 years [n = 233]) to identify sex- and age-related differences. In addition, differences among black, white, and Asian populations were studied. Inter- and intraobserver variability was assessed in a subset of 30 subjects and expressed as mean absolute difference between pairs of repeated measurements.

RESULTS

Compared with women, men had larger annular size measurements, larger tenting size parameters, and larger leaflet length and area. Compared with the black and white populations, the Asian population showed significantly smaller mitral annular size. Although many of the age, sex, and race differences in MV parameters were statistically significant, they were comparable with or smaller than the corresponding measurement variability. Indexing to body surface area and height did not eliminate these differences consistently, suggesting that parameters may need to be indexed according to their dimensionality.

CONCLUSIONS

This analysis of the World Alliance Societies of Echocardiography data provides normative values of mitral apparatus size and morphology. Although sex- and age-related differences were noted, they need to be interpreted with caution in view of the associated measurement variability.

Imaging assessment of the right atrium: anatomy and function

The right atrium (RA) is the cardiac chamber that has been least well studied. Due to recent advances in interventional cardiology, the need for greater understanding of the RA anatomy and physiology has garnered significant attention. In this article, we review how a comprehensive assessment of RA dimensions and function using either echocardiography, cardiac computed tomography, and magnetic resonance imaging may be used as a first step towards a better understanding of RA pathophysiology. The recently published normative data on RA size and function will likely shed light on RA atrial remodelling in atrial fibrillation (AF), which is a complex phenomenon that occurs in both atria but has only been studied in depth in the left atrium. Changes in RA structure and function have prognostic implications in pulmonary hypertension (PH), where the increased right ventricular (RV) afterload first induces RV remodelling, predominantly characterized by hypertrophy. As PH progresses, RV dysfunction and dilatation may begin and eventually lead to RV failure. Thereafter, RV overload and increased RV stiffness may lead to a proportional increase in RA pressure. This manuscript provides an in-depth review of RA anatomy, function, and haemodynamics with particular emphasis on the changes in structure and function that occur in AF, tricuspid regurgitation, and PH.

A Novel Approach for Semi Automated 3D Quantification of Mitral Regurgitant Volume Reflects a More Physiologic Approach to MR

BACKGROUND

Quantification of mitral regurgitation (MR) by echocardiography is an integral to assessing lesion severity, and entails integration of multiple Doppler-based parameters. These methods are primarily founded upon the principle of PISA (proximal isovelocity surface area), a 2D method known to employ several assumptions regarding MR jet characteristics. We analyzed the results of a semi-automated method of 3D-based RV estimation which accounts for jet behavior throughout the cardiac cycle, and compared it to conventional 2D PISA methods for MR.

METHODS

A total of 50 patients referred for transesophageal echocardiogram (TEE) for evaluation of primary (n= 25) and secondary MR (n=25) were included for analysis. 3D full volume color data sets were acquired, along with standard 2D methods for PISA calculation. 3D semi-automated MR flow quantification algorithm was applied offline to calculate 3D regurgitant volume (RVol), with simultaneous temporal curves generated from the 3D dataset. 3DRvol was compared to 2DRVol. 3D vena contracta area was also performed in all cases.

RESULTS

There was a modest correlation between 2DRVol and 3DRVol (r = 0.60). The semi-automated 3D approach resulted in significantly lower RV values compared to 2D PISA. Real-time and dynamic flow curve patterns were used for integral estimates of 3DRVol over the cardiac cycle, with a distinct bimodal pattern in functional MR, and brief and solitary peak in primary.

CONCLUSIONS

Using a semi-automated 3D software for quantification of mitral regurgitation allows for simultaneous calculation of 3D RVol with an automated generation of dynamic flow curves characteristic of the underlying MR mechanism. Our flow curve pattern results highlight well-known differences between MR flow dynamics in degenerative MR compared to functional MR.

Restoring Sinus Rhythm Reverses Cardiac Remodeling and Reduces Valvular Regurgitation in Patients With Atrial Fibrillation

BACKGROUND

Cardiac chamber remodeling in atrial fibrillation (AF) reflects the progression of cardiac rhythm and may affect functional regurgitation.

OBJECTIVES

The purpose of this study was to explore the 3-dimensional echocardiographic variables of cardiac cavity remodeling and the impact on functional regurgitation in patients with AF with/without sinus rhythm restoration at 12 months.

METHODS

A total of 117 consecutive patients hospitalized for AF were examined using serial 3-dimensional transthoracic echocardiography at admission, at 6 months, and at 12 months (337 examinations).

RESULTS

During follow-up, 47 patients with active restoration of sinus rhythm (SR) (through cardioversion and/or ablation) had a decrease in all atrial indexed volumes (Vi), end-systolic (ES) right ventricular (RV) Vi, an increase in end-diastolic (ED) left ventricular Vi, and an improvement in 4-chambers function (P < 0.05). Patients with absence/failure of restoration of SR (n = 39) had an increase in ED left atrial Vi and ED/ES RV Vi without modification of 4-chambers function, except for a decrease in left atrial emptying fraction (P < 0.05). Patients with spontaneous restoration of SR (n = 31) had no changes in Vi or function. The authors found an improvement vs baseline in severity of functional regurgitation in patients with active restoration of SR (tricuspid and mitral regurgitation) and in spontaneous restoration of SR (tricuspid regurgitation) (P < 0.05). In multivariable analysis, right atrial and/or left atrial reverse remodeling exclusively correlated with intervention (cardioversion and/or ablation) during 12-month follow-up.

CONCLUSIONS

Management of AF should focus on restoration of SR to induce anatomical (all atrial Vi, ES RV Vi) and/or functional (4 chambers) cardiac cavity reverse remodeling and reduce severity of functional regurgitation. (Thromboembolic and Bleeding Risk Stratification in Patients With Non-valvular Atrial Fibrillation [FASTRHAC]; NCT02741349).

AI Based CMR Assessment of Biventricular Function: Clinical Significance of Intervendor Variability and Measurement Errors

OBJECTIVES

The aim of this study was to determine whether left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) and left ventricular mass (LVM) measurements made using 3 fully automated deep learning (DL) algorithms are accurate and interchangeable and can be used to classify ventricular function and risk-stratify patients as accurately as an expert.

BACKGROUND

Artificial intelligence is increasingly used to assess cardiac function and LVM from cardiac magnetic resonance images.

METHODS

Two hundred patients were identified from a registry of individuals who underwent vasodilator stress cardiac magnetic resonance. LVEF, LVM, and RVEF were determined using 3 fully automated commercial DL algorithms and by a clinical expert (CLIN) using conventional methodology. Additionally, LVEF values were classified according to clinically important ranges: <35%, 35% to 50%, and ≥50%. Both ejection fraction values and classifications made by the DL ejection fraction approaches were compared against CLIN ejection fraction reference. Receiver-operating characteristic curve analysis was performed to evaluate the ability of CLIN and each of the DL classifications to predict major adverse cardiovascular events.

RESULTS

Excellent correlations were seen for each DL-LVEF compared with CLIN-LVEF (r = 0.83-0.93). Good correlations were present between DL-LVM and CLIN-LVM (r = 0.75-0.85). Modest correlations were observed between DL-RVEF and CLIN-RVEF (r = 0.59-0.68). A >10% error between CLIN and DL ejection fraction was present in 5% to 18% of cases for the left ventricle and 23% to 43% for the right ventricle. LVEF classification agreed with CLIN-LVEF classification in 86%, 80%, and 85% cases for the 3 DL-LVEF approaches. There were no differences among the 4 approaches in associations with major adverse cardiovascular events for LVEF, LVM, and RVEF.

CONCLUSIONS

This study revealed good agreement between automated and expert-derived LVEF and similarly strong associations with outcomes, compared with an expert. However, the ability of these automated measurements to accurately classify left ventricular function for treatment decision remains limited. DL-LVM showed good agreement with CLIN-LVM. DL-RVEF approaches need further refinements.

Routine use of automated strain analysis and 3D echocardiography provides a more comprehensive assessment of cardiac chambers than conventional 2D echocardiography and is time-saving

Funding Acknowledgements

Type of funding sources: None.

Background. In most laboratories three-dimensional echocardiography (3DE) and longitudinal strain (Lstrain) analysis are not part of the routine studies. Although these modalities have been shown to provide additional clinical information and prognostic value compared to conventional two-dimensional echocardiography (2DE), their acquisition and analysis are perceived as being time-consuming.  Recently, new automated tools have been developed to perform accurate, fast and reproducible analyses of heart chambers’ geometry and function. However, their cost-effectiveness when compared to conventional 2DE remains to be demonstrated.

Aim. We designed a prospective, multicenter, observational study aimed to compare the time required for the acquisition and analysis of conventional transthoracic 2DE vs advanced echocardiography (AEcho, i.e. 3DE+ Lstrain) for the assessment of cardiac chambers and myocardial mechanics.

Methods. According to current guidelines, 196 consecutive patients referred for clinically indicated echocardiography underwent complete 2DE and Doppler echocardiography. In addition, 3DE datasets of the left atrium (LA), left and right ventricle (LV, RV) were acquired using automated 3DE software package (Heart Model). Acquisition time for both 2DE and 3DE images were recorded. Conventional 2DE analyses of LA (biplane volume), LV (biplane volumes and mass) and RV (both linear dimensions, areas, and longitudinal function) were performed following current guidelines, and the time required for acquisition and analysis was recorded. The time spent for AEcho analysis (both 3DE volumetric analysis and Lstrain of LA, LV and RV) was also recorded.

Results. Feasibility of AEcho was 86% (169 patients). The additional time for 3D dataset acquisition over conventional 2DE was 38 ± 0.16 sec. Quantitative analysis of the cardiac chambers by 2DE required an average of 5.55 ± 1.51 min vs 4.25 ± 1.23 min using AEcho (p &lt; 0.001). Total time for both 3D dataset acquisition and AEcho assessment was 5.03 ± 1.28 min vs 5.55 ± 1.51 min of 2DE analysis alone (p &lt; 0.001). Globally, AEcho provided a more comprehensive assessment of heart chambers than 2DE (Table). Moreover, the time spent for 3DE dataset acquisition and AEcho analysis on top of standard 2DE acquisition was significantly shorter compared to the 2DE acquisition and analysis (18:50 ± 4.23 vs 19:42 ± 4.24 min, p &lt; 0.001) (Table).

Conclusions. Our data showed that the use of new AEcho automated tools are highly feasible resulting in significant time-savings compared to standard 2DE evaluation, while providing significant additional information. Abstract Table

Deep learning based classification of left ventricular function from two-dimensional echocardiographic images

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Philips Healthcare

Background. Echocardiographic quantification of left ventricular function (LVF) is mainly based on ejection fraction (EF) measurements, which relies on either manual or automated identification of endocardial boundaries followed by calculation of model-based end-systolic and end-diastolic LV volumes. Recent developments in artificial intelligence resulted in computer algorithms that allow fully automated detection of endocardial boundaries and measurement of LV volumes and EF. However, this methodology is prone to errors and inter-measurement variability. We hypothesized that a fully automated deep learning algorithm could be developed, which would accurately classify LVF while avoiding volume and EF measurements. This study was designed to test the accuracy of this approach.

Methods. Deep learning algorithm was developed (Philips Research) based on convolutional neural network (CNN) that uses as input dynamic sequences of apical 2- and 4-chamber echocardiographic views obtained without ultrasound enhancing agents. We used for CNN development a database of clinical DICOM studies: a training set of 14,427 studies with normal LV function and 6,135 abnormal, and a validation set of 2,898 normal and 1,081 abnormal studies, based on Philips IntelliSpace Cardiovascular (ISCV) codes found (defined by cardiologists) in the patients’ reports. The CNN was trained to automatically classify LVF into 3 categories: (1) normal, (2) mildly-to-moderately or moderately reduced, and (3) moderately-to-severely or severely reduced. In the validation set, the automated classifications were compared to those in the patients’ reports as a reference standard. Accuracy of the automated classification was tested using contingency tables, from which sensitivity, specificity, and negative and positive predictive values (NPV, PPV) and overall accuracy were calculated for each category of LVF. Additionally, the area under ROC curve (AUC) was calculated to assess the diagnostic accuracy of the automated classification for each LVF category.

Results.  Automated classification of LVF showed high levels of diagnostic accuracy in identifying cases with LVF in all 3 categories, reflected by high AUC values: (1) 0.94, (2) 0.87 and (3) 0.97 (Figure), and overall accuracy of 0.84 (Table). 

Conclusions. Deep learning algorithm based on CNN allowed accurate automated classification of LVF, when tested on ∼4,000 clinical studies and compared to ISCV codes found in the patients’ reports. This novel fully-automated methodology may become a useful aid in the interpretation of echocardiographic images by providing the reader with a preliminary assessment of LVF. Abstract Figure.

Intracardiac device associated interference with tricuspid valve apparatus on echocardiography: What can we learn from pathology?

Funding Acknowledgements

Type of funding sources: None.

Background

 New or worsening tricuspid regurgitation (TR) is associated with right-sided heart failure and worsened outcomes. Cardiac Implantable Electronic Devices (CIEDs), which are being implanted at growing rates worldwide, are increasingly being recognized as associated with TR occurrence related to interference with the tricuspid valve (TV) apparatus. Purpose: We sought to identify echocardiographic features in the right ventricle and TV that differentiate patients who have anatomically demonstrated interference with the TV on direct pathology inspection. 

Methods

 Explanted hearts from 44 consecutive patients undergoing orthotopic heart transplant (55 ±13 yrs, 68% men) with known implanted CIEDs were dissected to assess the presence (n = 18) or absence (n = 26) of CIED interference with the TV (Figure). Echocardiographic measurements performed prior to transplantation, including left and right ventricular (LV, RV) size and performance metrics as well as TR severity, were compared between both groups using non-parametric testing. 

Results

 Echocardiographic features of patients with and without anatomically demonstrated TV interference are shown in the Table. Although overall LV dimensions and volumes were not different between the two groups and LV ejection fraction was severely reduced in both groups, patients demonstrating CIED interference trended towards larger right atrial volumes (Table) and also larger RV and tricuspid annular sizes. Importantly, however, they were more than 4 times likely to have abnormal right ventricular function. Lastly, patients with tricuspid apparatus interference tended to have more significant TR, although these differences have not reached statistical significance (Table). 

Conclusion

 CIED interreference with tricuspid valve apparatus occurs frequently (41%) among patients with CIEDs, who undergo orthotopic heart transplantation. This may be associated with worsening TV function with subsequent changes in right atrial and ventricular geometry and function. In light of prior data showing poor outcomes with CIED associated TR, this study emphasizes the importance of non-invasive assessment of CIED interference with the tricuspid valve, in order to improve device placement and patient outcomes. Abstract Figure  Abstract Table

Performance of artificial intelligence system for prescriptive acquisition guidance of transthoracic echocardiography by novice users combined with automated quantification of ejection fraction

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Caption Health

Background

Artificial intelligence (AI) has the potential to expedite the acquisition of transthoracic echocardiograms (TTE) and provide automated quantitative data including left ventricular ejection fraction (LVEF).  Specifically, AI-based imaging systems may permit less experienced individuals to obtain quantitative measurements of LVEF, with important implications for clinical workflow. 

Purpose

We sought to evaluate the accuracy of an AI-based imaging system for the evaluation of LVEF in a spectrum of novice TTE imagers in a real-world clinical setting, and hypothesized that after appropriate training, it can perform as well as experienced sonographers. 

Methods

Consecutive exams (N = 102; BMI 29 ± 7; most common indications for TTE: heart failure, arrhythmia, valve assessment) were performed by a cohort of physician trainees (MD) and nurses (RN) with no prior TTE experience, using an AI-guided imaging system equipped with real-time prescriptive guidance software that automatically measures LVEF. Guided imaging included 3 views: parasternal long-axis (PLAX), apical 4-and apical 2-chamber (AP4, AP2), with the software recognizing when a satisfactory imaging window is obtained and then auto-capturing and automatically generating an AI based LVEF. AI-EF measurements were compared against the reference standard EF (Ref EF) measured by 2 expert sonographers according to ASE chamber quantification guidelines. Bland-Altman analysis was performed to determine inter-technique agreement.

Results

Feasibility was 80%. AI-EF and Ref EF demonstrated strong correlation when all 3 views were obtained, with a small bias (Table). In cases when &lt;3 views were available, the combination of PLAX and AP4 views achieved comparable results, with a slight increase in bias and limits of agreement. When results were stratified by cohort (MD vs RN), MD AI-EF attempts showed greater feasibility (100%, n = 51) with stronger correlation (r = 0.93) and smaller bias (-1.9%) compared to RN (feasibility of 61%; n = 31 and r= 0.85, bias -2.1%). 

Conclusions

Use of an AI-assisted imaging system for limited TTE imaging by novices is feasible in a real-world setting, with the AI based EF in good agreement with reference standard. Acquisition of all 3 views provided optimal results, but the combination of AP4/PLAX views performed reasonably well, without the AP2 view that is more difficult to acquire for less skilled users. Untrained MD were more successful when compared to RN, suggesting additional training may be needed for specific user groups. Abstract Figure.