Prediction of adverse cardiovascular events in children using artificial intelligence-based electrocardiogram

BACKGROUND

Convolutional neural networks (CNNs) have emerged as a novel method for evaluating heart failure (HF) in adult electrocardiograms (ECGs). However, such CNNs are not applicable to pediatric HF, where abnormal anatomy of congenital heart defects plays an important role. ECG-based CNNs reflecting neurohormonal activation (NHA) may be a useful marker of pediatric HF. This study aimed to develop and validate an ECG-derived marker of pediatric HF that reflects the risk of future cardiovascular events.

METHODS

Based on 21,378 ECGs from 8324 children, a CNN was trained using B-type natriuretic peptide (BNP) and the occurrence of major adverse cardiovascular events (MACEs). The output of the model, or the electrical heart failure indicator (EHFI), was compared with the BNP regarding its ability to predict MACEs in 813 ECGs from 295 children.

RESULTS

EHFI achieved a better area under the curve than BNP in predicting MACEs within 180 days (0.826 versus 0.691, p = 0.03). On Cox univariable analyses, both EHFI and BNP were significantly associated with MACE (log10 EHFI: hazard ratio [HR] = 16.5, p < 0.005 and log10 BNP: HR = 4.4, p < 0.005). The time-dependent average precisions of EHFI in predicting MACEs were 32.4%-67.9% and 1.6-7.5-fold higher than those of BNP in the early period. Additionally, the MACE rate increased monotonically with EHFI, whereas the rate peaked at approximately 100 pg/mL of BNP and decreased in the higher range.

CONCLUSIONS

ECG-derived CNN is a novel marker of HF with different prognostic potential from BNP. CNN-based ECG analysis may provide a new guide for assessing pediatric HF.

Association of Atrial Fibrillation Progression With Left Atrial Functional Reserve and Its Reversibility

BACKGROUND

Atrial fibrillation (AF) progression is closely related to heart failure occurrence, and catheter ablation carries a beneficial effect for heart failure prevention. Recently, particular attention has been given to left atrial (LA) function and functional reserve in the pathogenesis linking AF and heart failure, although its significance and reversibility is not well studied.

METHODS AND RESULTS

We prospectively investigated 164 patients with AF with normal left ventricular systolic function and free from heart failure who underwent first catheter ablation and pre-/postprocedural echocardiography. Conventional and speckle-tracking echocardiography were performed at rest and during passive leg lifting to assess LA size, LA reservoir strain (LARS), and functional reserve calculated as passive leg lifting-LARS - rest-LARS. Patients were categorized into 3 AF subtypes: paroxysmal AF (N=95), persistent AF (PeAF; N=50), and long-standing persistent AF (LS-PeAF; N=19). The PeAF and LS-PeAF groups had larger LA size and reduced LARS compared with the paroxysmal AF group (all P<0.05). LA functional reserve was significantly impaired in the LS-PeAF group (P=0.003). In multivariable analysis, LS-PeAF and advanced age were significantly associated with impaired LA functional reserve. Among 149 patients with sinus rhythm 1 to 2 days after catheter ablation, LARS was significantly improved in both PeAF and LS-PeAF groups but was still lower than that in the paroxysmal AF group. Sinus rhythm restoration also led to amelioration of LA functional reserve in patients with LS-PeAF.

CONCLUSIONS

AF progression was related to impaired LARS and LA functional reserve, and restoration of sinus rhythm might contribute to early LA reverse remodeling.

Efficacy and Tolerability of Ivabradine for Cardiomyopathy in Patients with Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is an intractable X-linked myopathy caused by dystrophin gene mutations. Patients with DMD suffer from progressive muscle weakness, inevitable cardiomyopathy, increased heart rate (HR), and decreased blood pressure (BP). The aim of this study was to clarify the efficacy and tolerability of ivabradine treatment for DMD cardiomyopathy.A retrospective analysis was performed in 11 patients with DMD, who received ivabradine treatment for more than 1 year. Clinical results were analyzed before (baseline), 6 months after, and 12 months after the ivabradine administration.The initial ivabradine dose was 2.0 ± 1.2 mg/day and the final dose was 5.6 ± 4.0 mg/day. The baseline BP was 95/64 mmHg. A non-significant BP decrease to 90/57 mmHg was observed at 1 month but it recovered to 97/62 mmHg at 12 months after ivabradine administration. The baseline HR was 93 ± 6 bpm and it decreased to 74 ± 12 bpm at 6 months (P = 0.011), and to 77 ± 10 bpm at 12 months (P = 0.008). A linear correlation (y = 2.2x + 5.1) was also observed between the ivabradine dose (x mg/day) and HR decrease (y bpm). The baseline LVEF was 38 ± 12% and it significantly increased to 42 ± 9% at 6 months (P = 0.011) and to 41 ± 11% at 12 months (P = 0.038). Only 1 patient with the lowest BMI of 11.0 kg/m2 and BP of 79/58 mmHg discontinued ivabradine treatment at 6 months, while 1-year administration was well-tolerated in the other 10 patients.Ivabradine decreased HR and increased LVEF without lowering BP, suggesting it can be a treatment option for DMD cardiomyopathy.

Deep Learning Models for Predicting Left Heart Abnormalities From Single-Lead Electrocardiogram for the Development of Wearable Devices

BACKGROUND

Left heart abnormalities are risk factors for heart failure. However, echocardiography is not always available. Electrocardiograms (ECGs), which are now available from wearable devices, have the potential to detect these abnormalities. Nevertheless, whether a model can detect left heart abnormalities from single Lead I ECG data remains unclear.Methods and Results: We developed Lead I ECG models to detect low ejection fraction (EF), wall motion abnormality, left ventricular hypertrophy (LVH), left ventricular dilatation, and left atrial dilatation. We used a dataset comprising 229,439 paired sets of ECG and echocardiography data from 8 facilities, and validated the model using external verification with data from 2 facilities. The area under the receiver operating characteristic curves of our model was 0.913 for low EF, 0.832 for wall motion abnormality, 0.797 for LVH, 0.838 for left ventricular dilatation, and 0.802 for left atrial dilatation. In interpretation tests with 12 cardiologists, the accuracy of the model was 78.3% for low EF and 68.3% for LVH. Compared with cardiologists who read the 12-lead ECGs, the model's performance was superior for LVH and similar for low EF.

CONCLUSIONS

From a multicenter study dataset, we developed models to predict left heart abnormalities using Lead I on the ECG. The Lead I ECG models show superior or equivalent performance to cardiologists using 12-lead ECGs.

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.

Association between non-alcoholic fatty liver disease and subclinical left ventricular dysfunction in the general population

Aims

Emerging evidence suggests an association between non-alcoholic fatty liver disease (NAFLD) and heart failure (HF). We investigated the relationship between NAFLD and left ventricular (LV) functional remodelling in a general population sample without overt cardiac and liver disease.

Methods and results

We included 481 individuals without significant alcohol consumption who voluntarily underwent an extensive cardiovascular health check. The fatty liver index (FLI) was calculated for each participant, and NAFLD was defined as FLI ≥ 60. All participants underwent 2D transthoracic echocardiography; LV global longitudinal strain (LVGLS) was assessed with speckle-tracking analysis. Univariable and multivariable linear regression models were constructed to investigate the possible association between NAFLD and LVGLS. Seventy-one (14.8%) participants were diagnosed with NAFLD. Individuals with NAFLD exhibited larger LV size and LV mass index than those without NAFLD, although left atrial size and E/e' ratio did not differ between groups. Left ventricular global longitudinal strain was significantly reduced in participants with vs. without NAFLD (17.1% ± 2.4% vs. 19.5% ± 3.1%, respectively; P < 0.001). The NAFLD group had a significantly higher frequency of abnormal LVGLS (<16%) than the non-NAFLD group (31.0% vs. 10.7%, respectively; P < 0.001). Multivariable linear regression analysis demonstrated that higher FLI score was significantly associated with impaired LVGLS independent of age, sex, conventional cardiovascular risk factors, and echocardiographic parameters (standardized β -0.11, P = 0.031).

Conclusion

In the general population without overt cardiac and liver disease, the presence of NAFLD was significantly associated with subclinical LV dysfunction, which may partly explain the elevated risk of HF in individuals with NAFLD.

Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

Prevalence, Associated Factors, and Echocardiographic Estimation of Left Atrial Hypertension in Patients With Atrial Fibrillation

Background Elevated left atrial (LA) pressure predisposes individuals to the initiation and persistence of atrial fibrillation (AF), and LA hypertension is associated with AF recurrence after catheter ablation (CA). However, the exact frequency and factors associated with LA hypertension are unknown, and its noninvasive estimation is challenging. This study aimed to investigate the prevalence and determinants of LA hypertension in patients with AF who underwent first CA. Methods and Results We examined 183 patients with AF who underwent conventional and speckle-tracking echocardiography before CA to assess LA size, reservoir strain, and stiffness. Direct LA pressure was measured at the time of CA, and LA hypertension was defined as mean LA pressure >15 mm Hg. Thirty-three (18.0%) patients exhibited LA hypertension. Patients with LA hypertension had a significantly larger LA volume index (40.2 [28.4-52.1] versus 34.1 [26.9-42.4] mL/m2, P=0.025), reduced LA reservoir strain (15.1 [10.4-21.7] versus 22.7 [14.4-32.3] %, P=0.002) and increased LA stiffness (0.69 [0.34-0.99] versus 0.36 [0.24-0.54], P<0.001). Multivariable analyses showed that waist circumference, C-reactive protein level, LA reservoir strain, and LA stiffness were independently associated with LA hypertension (all P<0.05), while LA volume and E/e' ratio were not. Among echocardiographic parameters, receiver operating characteristic curve analysis identified LA stiffness as the best predictor of LA hypertension. Conclusions Approximately 20% of patients with AF who underwent CA had LA hypertension. Central obesity and inflammation might be involved in the pathophysiological mechanisms of LA hypertension, and echocardiography-derived LA stiffness may have clinical utility for the detection of LA hypertension before CA.

Prevalence of glucose metabolism disorders and its association with left atrial remodelling before and after catheter ablation in patients with atrial fibrillation

AIMS

To investigate the exact prevalence of glucose metabolism disorders, and their impact on left atrial (LA) remodelling and reversibility in patients with atrial fibrillation (AF).

METHODS AND RESULTS

We examined 204 consecutive patients with AF who underwent their first catheter ablation (CA). Oral glucose tolerance test was used to evaluate glucose metabolism disorders in 157 patients without known diabetes mellitus (DM). Echocardiography was performed before and 6 months after CA. Oral glucose tolerance test identified abnormal glucose metabolism in 86 patients [11 with newly diagnosed DM, 74 with impaired glucose tolerance (IGT) and 1 with impaired fasting glucose (IFG)]. Ultimately, 65.2% of patients had abnormal glucose metabolism. Diabetes mellitus group had the worst LA reservoir strain and LA stiffness (both P < 0.05), while there was no significant difference in baseline LA parameters between normal glucose tolerance (NGT) group and IGT/IFG group. The prevalence of LA reverse remodelling (≥15% decrease in the LA volume index at 6 months after CA) was significantly higher in NGT group compared with IGT/IFG and DM group (64.1 vs. 38.6 vs. 41.5%, P = 0.006). Both DM and IFG/IGT carry a significant risk of lack of LA reverse remodelling independent of baseline LA size and AF recurrence.

CONCLUSION

Approximately 65% of patients with AF who underwent their first CA had abnormal glucose metabolism. Patients with DM had significantly impaired LA function compared with non-DM patients. Impaired glucose tolerance/IFG as well as DM carries significant risk of unfavourable LA reverse remodelling. Our observations may provide valuable information regarding the mechanisms and therapeutic strategies of glucose metabolism-related AF.

An explainable artificial intelligence-enabled electrocardiogram analysis model for the classification of reduced left ventricular function

Aims

The black box nature of artificial intelligence (AI) hinders the development of interpretable AI models that are applicable in clinical practice. We aimed to develop an AI model for classifying patients of reduced left ventricular ejection fraction (LVEF) from 12-lead electrocardiograms (ECG) with the decision-interpretability.

Methods and results

We acquired paired ECG and echocardiography datasets from the central and co-operative institutions. For the central institution dataset, a random forest model was trained to identify patients with reduced LVEF among 29 907 ECGs. Shapley additive explanations were applied to 7196 ECGs. To extract the model's decision criteria, the calculated Shapley additive explanations values were clustered for 192 non-paced rhythm patients in which reduced LVEF was predicted. Although the extracted criteria were different for each cluster, these criteria generally comprised a combination of six ECG findings: negative T-wave inversion in I/V5-6 leads, low voltage in I/II/V4-6 leads, Q wave in V3-6 leads, ventricular activation time prolongation in I/V5-6 leads, S-wave prolongation in V2-3 leads, and corrected QT interval prolongation. Similarly, for the co-operative institution dataset, the extracted criteria comprised a combination of the same six ECG findings. Furthermore, the accuracy of seven cardiologists' ECG readings improved significantly after watching a video explaining the interpretation of these criteria (before, 62.9% ± 3.9% vs. after, 73.9% ± 2.4%; P = 0.02).

Conclusion

We visually interpreted the model's decision criteria to evaluate its validity, thereby developing a model that provided the decision-interpretability required for clinical application.

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.

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.

Real-time intelligent classification of COVID-19 and thrombosis via massive image-based analysis of platelet aggregates

Microvascular thrombosis is a typical symptom of COVID-19 and shows similarities to thrombosis. Using a microfluidic imaging flow cytometer, we measured the blood of 181 COVID-19 samples and 101 non-COVID-19 thrombosis samples, resulting in a total of 6.3 million bright-field images. We trained a convolutional neural network to distinguish single platelets, platelet aggregates, and white blood cells and performed classical image analysis for each subpopulation individually. Based on derived single-cell features for each population, we trained machine learning models for classification between COVID-19 and non-COVID-19 thrombosis, resulting in a patient testing accuracy of 75%. This result indicates that platelet formation differs between COVID-19 and non-COVID-19 thrombosis. All analysis steps were optimized for efficiency and implemented in an easy-to-use plugin for the image viewer napari, allowing the entire analysis to be performed within seconds on mid-range computers, which could be used for real-time diagnosis.

Prevalence, Determinants, and Prognostic Value of Left Atrial Dysfunction in Patients With Chronic Coronary Syndrome and Normal Left Ventricular Ejection Fraction

Patients with chronic coronary syndrome (CCS), even when they have complete revascularization and normal left ventricular (LV) systolic function, experience subsequent cardiovascular disease (CVD), highlighting the importance of surrogate markers to prevent adverse consequences. Speckle-tracking echocardiography-derived left atrial (LA) reservoir strain has emerged as a sensitive marker for CVD in various clinical settings. The present study investigated the prevalence, determinants, and prognostic value of LA dysfunction in CCS. We included 278 consecutive patients with CCS with completed percutaneous coronary intervention and preserved LV ejection fraction who underwent follow-up echocardiography. Speckle-tracking analysis was performed to assess LA reservoir strain, and LA dysfunction was defined as LA reservoir strain ≤24%. The primary outcome comprised new-onset atrial fibrillation, heart failure hospitalization, acute coronary syndrome, stroke, or all-cause death. At baseline, 28 patients (10.1%) had LA dysfunction. Multivariable analysis identified age, hypertension, LV ejection fraction, and multivessel disease as independent determinants of LA reservoir strain (all p <0.05). During a median follow-up of 4.8 years, the primary outcome occurred in 60 patients (21.6%). LA dysfunction carried a significant risk for primary outcome independent of traditional risk factors, LV parameters, and LA size (adjusted hazard ratio 3.10, p = 0.003); the risk increase remained significant even after excluding atrial fibrillation from the primary outcome (adjusted hazard ratio 2.27, p = 0.043). In conclusion, approximately 10% of patients with CCS with normal LV ejection fraction had LA dysfunction associated with adverse cardiovascular outcomes. Further studies are needed to explore whether therapeutic interventions affecting LA remodeling may help prevent CVD events.

Epicardial fat accumulation and left heart remodelling in patients with chronic coronary syndrome

AIMS

Patients with chronic coronary syndrome (CCS) suffer from subsequent cardiovascular events, even after complete revascularization; thus, elucidation of the underlying pathophysiological mechanisms is required. Epicardial adipose tissue (EAT) is increasingly recognized as a metabolically active organ with a key role in the pathogenesis of metabolic-related cardiac diseases. The present study investigated the association between EAT burden and left heart remodelling in patients with CCS.

METHODS AND RESULTS

We studied 267 CCS patients (210 men; 71 ± 9 years) with complete revascularization and normal left ventricular (LV) ejection fraction who underwent follow-up echocardiography. All patients underwent the measurement of EAT thickness and speckle-tracking analysis to evaluate LV global longitudinal strain (LVGLS) and left atrial (LA) phasic strain. The mean EAT thickness was 5.0 ± 1.8 mm. Age, sex, body mass index, and diabetes mellitus were independently associated with EAT thickness (all P < 0.05). Multivariable linear regression analysis demonstrated that EAT thickness was significantly associated with LV mass index, early diastolic mitral annular velocity, and LA conduit strain independent of age, sex, and cardiovascular risk factors (all P < 0.05). On the other hand, there was no relationship between EAT thickness and LV systolic parameters including LV ejection fraction and LVGLS.

CONCLUSION

CCS patients with increased EAT thickness had unfavourable left heart remodelling. The assessment of EAT thickness by echocardiography may have clinical utility as a simple surrogate to aid in risk stratification for impaired left heart function in CCS 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.

Incidence of atrial functional tricuspid regurgitation and its correlation with tricuspid valvular deformation in patients with persistent atrial fibrillation

Background

With the growing prevalence of atrial fibrillation (AF), concomitant atrial functional tricuspid regurgitation (FTR) is increasing. In this study, we aimed to elucidate the incidence of significant atrial FTR and its association with tricuspid valvular (TV) deformation in patients with persistent AF.

Methods

We retrospectively enrolled 344 patients (73.0 ± 9.3 years, 95 female) with persistent AF who underwent 2-dimensional echocardiography. We excluded patients with left-sided heart disease, pulmonary hypertension treated with pulmonary vasodilators, and congenital heart disease. We defined significant TR as having TR ≥ moderate; and tricuspid annulus (TA) diameter, tethering height, and area were measured in all patients.

Results

Among the study population, 80 (23.3%) patients had significant TR. TA diameter, tethering height, and area were significantly greater in the significant TR group (all p < 0.001). In multivariable analysis, TA diameter was independently associated with significant TR (odds ratio 1.1 per mm, p = 0.03), whereas TV tethering height was not. Receiver operating characteristic curve for significant TR exhibited the best predictive value of TA diameter indexed for body surface area [23 mm/m²; area under the curve (AUC) = 0.87] compared with absolute TA diameter (39 mm; AUC = 0.74) and TA diameter indexed for height (0.22 mm/cm; AUC = 0.80).

Conclusion

Approximately 25% of patients with persistent AF had significant TR. The BSA-corrected TA diameter was strongly associated with significant TR, which might be helpful for predicting the development of significant TR and considering its therapeutic strategy in patients with persistent AF.

Association of arterial properties with left ventricular morphology and function in the community

OBJECTIVES

Arterial structural and functional remodeling is recognized as a key determinant of incident heart failure, although the contribution of arterial properties on left ventricular (LV) remodeling is not fully studied. Aortic dilatation is an early manifestation of arterial remodeling and estimated pulse wave velocity (ePWV) is emerging as a simple measure of arterial stiffness. This study aimed to characterize the association of aortic size and ePWV with LV morphology and function.

METHODS

The study cohort consisted of 539 participants without overt cardiac disease who underwent extensive cardiovascular examination. Aortic root diameter was measured by two-dimensional echocardiography and ePWV was calculated from a regression equation using age and mean blood pressure. LV global longitudinal strain (LVGLS) was obtained by speckle-tracking echocardiography.

RESULTS

Aortic root diameter and ePWV were correlated with LV mass index and LVGLS, while only ePWV was related to E / e' ratio. In multivariable analysis, aortic root diameter and ePWV were significantly related to LV mass index and LVGLS (all P  < 0.05), and the association of aortic root size and ePWV with LVGLS was independent of LV mass index and E / e' ratio. Individuals with both aortic root enlargement and increased ePWV had significantly larger LV mass index and reduced LVGLS compared with those either or those with normal aortic size and ePWV (both P  < 0.05).

CONCLUSION

Aortic root size and ePWV were independently associated with unfavorable LV remodeling in individuals free of cardiac disease, which might provide useful information into the pathogenesis-linking arterial remodeling and heart failure.

Aortic valve sclerosis and subclinical LV dysfunction in the general population with normal LV geometry

AIMS

Aortic valve sclerosis (AVS) without hemodynamically significant obstruction is related to cardiovascular morbidity and mortality independent of left ventricular (LV) hypertrophy, although the underlying mechanisms remain unknown. This study investigated the prevalence of AVS and its association with subclinical LV systolic and diastolic dysfunction in individuals with normal LV geometry free of cardiovascular disease.

METHODS

We examined 962 participants with normal LV geometry and free from significant AV stenosis who underwent standard and speckle-tracking echocardiography. AVS was categorized into 4 groups as follows: no AVS, AV thickening, calcification on one leaflet and calcification on ≥2 leaflets.

RESULTS

Among the 962 participants, 767 (79.7%) individuals were classified as no AVS, 74 (7.7%) as AV thickening, 87 (9.0%) as calcification on one leaflet, and 34 (3.5%) as calcification on ≥2 leaflets. The prevalence of subclinical LV diastolic dysfunction (E/e' ratio ≥13) and systolic dysfunction (LV global longitudinal strain (GLS) > -17.0% for men and > -18.0% for women) were greater in AVS groups than those in no AVS group. Subclinical LV diastolic impairment was evident from AV thickening and systolic dysfunction was observed at AV calcification. Multivariable logistic regression analysis demonstrated that AV thickening as well as calcification were independently associated with subclinical LV diastolic impairment (all p < 0.05), while only AV calcification on ≥2 leaflets conferred significant increased risk of impaired LVGLS.

CONCLUSIONS

AVS was observed in approximately 20% individuals without cardiac disease and was associated with subclinical LV diastolic and systolic function even in the absence of LV morphological change.

Automatic Detection of Left Ventricular Dilatation and Hypertrophy from Electrocardiograms Using Deep Learning

Left ventricular dilatation (LVD) and left ventricular hypertrophy (LVH) are risk factors for heart failure, and their detection improves heart failure screening. This study aimed to investigate the ability of deep learning to detect LVD and LVH from a 12-lead electrocardiogram (ECG). Using ECG and echocardiographic data, we developed deep learning and machine learning models to detect LVD and LVH. We also examined conventional ECG criteria for the diagnosis of LVH. We calculated the area under the receiver operating characteristic (AUROC) curve, sensitivity, specificity, and accuracy of each model and compared the performance of the models. We analyzed data for 18,954 patients (mean age (standard deviation): 64.2 (16.5) years, men: 56.7%). For the detection of LVD, the value (95% confidence interval) of the AUROC was 0.810 (0.801-0.819) for the deep learning model, and this was significantly higher than that of the logistic regression and random forest methods (P < 0.001). The AUROCs for the logistic regression and random forest methods (machine learning models) were 0.770 (0.761-0.779) and 0.757 (0.747-0.767), respectively. For the detection of LVH, the AUROC was 0.784 (0.777-0.791) for the deep learning model, and this was significantly higher than that of the logistic regression and random forest methods and conventional ECG criteria (P < 0.001). The AUROCs for the logistic regression and random forest methods were 0.758 (0.751-0.765) and 0.716 (0.708-0.724), respectively. This study suggests that deep learning is a useful method to detect LVD and LVH from 12-lead ECGs.

The effect of immunosuppressive therapy on cardiac involvements in anti-mitochondrial antibody-positive myositis

AIMS

Anti-mitochondrial antibody (AMA)-positive myositis is frequently associated with various cardiac involvements, such as arrhythmia and left ventricular (LV) dysfunction. However, the efficacy of immunosuppressive therapy in these complications remains unknown. This study aimed to investigate the cardiac response to immunosuppressive therapy in patients with AMA-positive myositis.

METHODS AND RESULTS

The clinical data of 15 AMA-positive myositis patients with cardiac involvement were retrospectively collected at our centre. To evaluate the effects of immunosuppressive therapy, echocardiographic and laboratory data of patients who received glucocorticoid therapy with additional immunosuppressants (n = 6) and those who did not (n = 6) were compared. Also, the characteristics of patients with or without >5% LV ejection fraction (LVEF) decline during the follow-up period (n = 5 vs. n = 7) were compared. Thirteen patients (87%) had arrhythmias, and eight patients (53%) had LV wall motion abnormalities. Although arrhythmias decreased after treatment, reduced LVEF and LV wall motion abnormalities persisted. Further investigation revealed an increased LV end-systolic dimension and reduced LVEF in patients without additional immunosuppressive therapy, while those in patients with additional immunosuppressive therapy were maintained. Six of seven patients (86%) without LVEF decline received additional immunosuppressive therapy, whereas no patients with LVEF decline had additional immunosuppressive therapy.

CONCLUSIONS

Cardiac involvement in AMA-positive myositis may worsen even with glucocorticoid monotherapy, and there might be some associations between the change of LV function and additional immunosuppressive therapy.

Guideline from the Japanese society of echocardiography: guidance for the management and maintenance of echocardiography equipment: 2022 focused update

Echocardiography plays a pivotal role as an imaging modality in modern cardiology practice. Information derived from echocardiography is essential for patient care. The Japanese Society of Echocardiography has promoted echocardiography for routine clinical and research use. One of the missions of the Society is to provide information that is useful for high-quality examinations. To ensure this, we believe that maintaining equipment in good condition and providing a comfortable environment for the examination are important for both the patient and examiner. Thus, the Committee for Guideline Writing of the Japanese Society of Echocardiography originally published brief guidance for the routine use of echocardiography equipment in 2015. In 2018, the committee updated our guidance incorporating the importance of international standardization. In 2022, the committee has revised and updated our guidance in line with the increase in awareness of infection prevention due to the worldwide spread of coronavirus disease 2019 (COVID-19).

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.

Blood pressure categorization and subclinical left ventricular dysfunction in antihypertensive medication-naive subjects

Aims

The impact of blood pressure (BP) levels on subclinical left ventricular (LV) dysfunction and possible sex‐specific difference remains unclarified. This study investigated the relationship between BP categories given in the new 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline and subclinical LV dysfunction in subjects free of cardiac disease.

Methods and results

We examined antihypertensive medication‐naive 858 individuals who underwent extensive cardiovascular health check‐up. LV global longitudinal (LVGLS) and circumferential strain (LVGCS) were assessed by two‐dimensional speckle‐tracking echocardiography. Participants were categorized into four groups: normal BP, elevated BP, isolated diastolic hypertension (IDH), and systolic hypertension (SH). Among the 858 participants, 422 individuals had normal BP, 113 had elevated BP, 160 had IDH, and 163 had SH. Prevalence of abnormal LVGLS (>−18.6%) was greatest in SH (19.0%), followed by IDH (17.5%), elevated BP (14.2%), and normal BP (7.1%, P < 0.001); no significant differences were observed for LVGCS (P = 0.671). In the multivariable analyses, IDH and SH were associated with impaired LVGLS [adjusted odds ratio (OR) 2.69 and 2.66, P < 0.001], and borderline significance was observed for elevated BP (adjusted OR 1.90, P = 0.060); there was no significant association between any of the BP groups and LVGCS. In sex‐stratified analysis, IDH and SH carried the significant risk of abnormal LVGLS in both sexes, while elevated BP was associated with LVGLS only in women.

Conclusions

Isolated diastolic hypertension and SH redefined by ACC/AHA guideline carried significant risk for LVGLS, but not LVGCS. Elevated BP was associated with LVGLS only in women. Our findings provide information on cardiac correlates of the newly established BP categories.

Recovery of sinus rhythm by tafamidis in patients with wild-type transthyretin amyloid cardiomyopathy with atrial arrhythmias

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening infiltrative disease in elderly patients. Atrial arrhythmias (AAr) are common in patients with ATTR-CM. However, AAr treatment in these patients is challenging. In this case, a patient diagnosed with wild-type ATTR-CM suffered atrial fibrillation (AF) for ~1 year, according to the data of his self-monitoring and regular electrocardiogram. This AF reverted to normal sinus rhythm a few months after the initiation of tafamidis without administering an antiarrhythmic drug. Tafamidis may be beneficial as alternative antiarrhythmic therapy in patients with ATTR-CM.

Segmental Tissue Speckle Tracking Predicts the Stenosis Severity in Patients With Coronary Artery Disease

Objective

Two-dimensional speckle tracking echocardiography (2D-STE) has been used as a diagnostic tool for coronary artery disease (CAD). However, whether vessel supplied myocardial strain and strain rate (SR) predict the severity of coronary artery stenosis in patients with CAD is unknown. This study aimed to investigate correlation of cardiac mechanical parameters in tissue speckle tracking measurements with coronary artery stenosis diagnosed by cardiac catheterization in patients with clinically diagnosed CAD.

Methods and Results

Among 59 patients analyzed, 170 vessels were evaluated by coronary angiography and the corresponding echocardiography to quantify left ventricular myocardial strain and SR. The average longitudinal strain and SR of the segmental myocardium supplied by each coronary artery were calculated to achieve vessel myocardium strain (VMS) and strain rate (VMSR). The VMS and VMSR at each of four severity levels of stenosis showed significant differences among groups (p = 0.016, and p < 0.001, respectively). The strain and SR in vessels with very severe stenosis (≥75%, group IV; n = 29), 13.9 ± 4.3, and 0.9 ± 0.3, respectively, were significantly smaller than those of vessels with mild stenosis ≤ 25%, group I; n = 88, 16.9 ± 4.9, p = 0.023, and 1.2 ± 0.3, p = 0.001, respectively. The SR in vessels with moderate stenosis (26–49%, group II; n = 37), 1.0 ± 0.2, was significantly smaller than that in vessels with mild stenosis vessels (p = 0.021). The lower VMS and VMSR, the higher possibility of severe coronary stenosis is. The VMS and VMSR lower than 13.9 ± 4.3 and 0.9 ± 0.3, respectively predicted the severe coronary stenosis. The VMS and VMSR higher than 16.9 ± 4.9 and 1.2 ± 0.3, respectively predicted mild or no coronary artery stenosis.

Conclusions

The actual stenosis rate in catheterization demonstrates that this technique was able to assess coronary artery condition. Thus, the application of a non-invasive method of 2D-STE to evaluate and simplify diagnosis of CAD is feasible.

Normal Values of Left Ventricular Size and Function on 3D Echocardiography: Results of the World Alliance of 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 2D echocardiography (2DE). Yet, 3D echocardiography (3DE) has been shown to be more accurate and reproducible than 2DE. Current normative reference values for 3D LV analysis are predominantly based on data from North America and Europe. The World Alliance of Societies of Echocardiography (WASE) study was a designed to sample normal subjects from around the world to provide more universal global reference ranges. In this study we sought to assess the world-wide feasibility of LV 3DE and report on size and function measurements.

METHODS

2262 healthy subjects were prospectively enrolled from 19 centers in 15 countries. 3D LV full-volume datasets were obtained and analyzed offline with vendor-neutral software. Measurements included end-diastolic and end-systolic volumes (EDV, ESV), ejection fraction (EF), global longitudinal and circumferential strain (GLS and GCS). Results were categorized by age (18-40, 41-65 and >65 years), sex and race.

RESULTS

1589 subjects (feasibility 70%) had adequate LV datasets for analysis. Mean normal values for indexed EDV, ESV and EF in men and women were 70 ± 15 and 65 ± 12 mL, 28 ± 7 and 25 ± 6 mL and 60 ± 5, 62 ± 5% respectively. Men had larger LV volumes and lower EF than women. GLS and GCS were higher in magnitude in women. In both sexes, LV volumes were lower and EF tended to be higher with increasing age, especially considering the differences between the youngest and oldest age groups. While GLS was similar across age groups in men, in women, the youngest and middle-age cohorts revealed higher magnitudes of GLS when compared to the oldest age group. GCS was higher in magnitude at older age in both men and women. Finally, Asians had smaller chamber sizes and higher EF 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 function parameters obtained by 3DE.

Atrioventricular and Ventricular Functional Interdependence in Individuals Without Overt Cardiac Disease

Background

Left atrial (LA) and right ventricular (RV) performance play an integral role in the pathophysiology and prognosis of heart failure. We hypothesized that subclinical left ventricular dysfunction adversely affects LA/RV geometry and function even in a preclinical setting. This study aimed to investigate the atrioventricular and ventricular functional interdependence in a community‐based cohort without overt cardiovascular disease.

Methods and Results

Left ventricular global longitudinal strain (LVGLS), RV free‐wall longitudinal strain and LA phasic strain were assessed by speckle‐tracking echocardiography in 1080 participants (600 men; 62±12 years) between 2014 and 2018. One hundred and forty‐three participants (13.2%) had an abnormal LVGLS (>−18.6%). LA reservoir strain, conduit strain, and RV free‐wall longitudinal strain were significantly decreased in abnormal LVGLS group compared with normal LVGLS group (all P<0.001). LA and RV dysfunction (LA reservoir strain<31.4% and RVLS>−19.2%) were present in 18.9% and 19.6% of participants with abnormal LVGLS. Decreased LVGLS was associated with worse LA reservoir strain, conduit strain and RV free‐wall longitudinal strain (standardized β=−0.20, −0.19 and 0.11 respectively, all P<0.01) independent of cardiovascular risk factors. LA and/or RV dysfunction concomitant with abnormal LVGLS carried significantly increased risk of elevated B‐type natriuretic peptide levels (>28.6 pg/mL for men and >44.4 pg/mL for women) compared with normal LVGLS (odds ratio, 2.01; P=0.030).

Conclusions

LA/RV dysfunction was present in 20% individuals with abnormal LVGLS and multi‐chamber impairment was associated with elevated B‐type natriuretic peptide level, which may provide valuable insights for a better understanding of atrioventricular and ventricular interdependence and possibly heart failure preventive strategies.

The Effectiveness of a Deep Learning Model to Detect Left Ventricular Systolic Dysfunction from Electrocardiograms

Deep learning models can be applied to electrocardiograms (ECGs) to detect left ventricular (LV) dysfunction. We hypothesized that applying a deep learning model may improve the diagnostic accuracy of cardiologists in predicting LV dysfunction from ECGs. We acquired 37,103 paired ECG and echocardiography data records of patients who underwent echocardiography between January 2015 and December 2019. We trained a convolutional neural network to identify the data records of patients with LV dysfunction (ejection fraction < 40%) using a dataset of 23,801 ECGs. When tested on an independent set of 7,196 ECGs, we found the area under the receiver operating characteristic curve was 0.945 (95% confidence interval: 0.936-0.954). When 7 cardiologists interpreted 50 randomly selected ECGs from the test dataset of 7,196 ECGs, their accuracy for predicting LV dysfunction was 78.0% ± 6.0%. By referring to the model's output, the cardiologist accuracy improved to 88.0% ± 3.7%, which indicates that model support significantly improved the cardiologist diagnostic accuracy (P = 0.02). A sensitivity map demonstrated that the model focused on the QRS complex when detecting LV dysfunction on ECGs. We developed a deep learning model that can detect LV dysfunction on ECGs with high accuracy. Furthermore, we demonstrated that support from a deep learning model can help cardiologists to identify LV dysfunction on ECGs.

Longitudinal change in postoperative right ventricular systolic function in patients undergoing surgery for isolated tricuspid regurgitation

Right ventricular (RV) dysfunction is an indication for tricuspid valve (TV) surgery in patients with severe isolated tricuspid regurgitation (TR). Postoperative RV dysfunction is associated with poor outcome; however, the longitudinal changes in RV function before and after surgery have not been established. We retrospectively analyzed 24 patients who underwent TV surgery for isolated severe TR. For assessing RV systolic function, we measured the RV fractional area change (RVFAC) at baseline, and 1 (immediate) and 4-20 (late) months after surgery. We divided patients into 2 groups according to the RVFAC late after surgery (<35%, post-op. reduced; and ≥35%, post-op. preserved). The mean RVFAC was significantly decreased immediately after surgery compared to baseline (41.5 ± 10.1% vs. 32.2 ± 9.6%; p < 0.001). The RVFAC reduction was still observed late after surgery (35.5 ± 7.4%; p = 0.002). Of 24 patients, 12 patients (50%) had preserved RV systolic function late after surgery. Although there was no significant difference in the preoperative RVFAC between the 2 groups, the preoperative RV end-systolic area (RVESA) /body surface area (BSA) was significantly less in the post-op. preserved RV systolic function group (13.8 ± 4.3 cm2/m2 vs. 8.6 ± 2.6 cm2/m2; p = 0.001). The optimal cut-off value for the preoperative RVESA/BSA in detecting postoperative preserved RV systolic function was 10.8 cm2/m2 (AUC, 0.85; sensitivity, 91.7%; and specificity, 75.0%). In patients undergoing surgery for isolated severe TR, the RVFAC was significantly decreased immediately after surgery and the reduction continued late after surgery. The preoperative RVESA/BSA might be helpful to predict preserved RV function after surgery.

Independent effect of visceral fat on left atrial phasic function in the general population

BACKGROUND AND AIMS

Obesity increases the risk for atrial fibrillation (AF), although the impact of abdominal fat distribution on left atrial (LA) morphology and functional remodeling remains unclear. This study aimed to investigate whether increased abdominal adiposity is independently associated with impaired LA function and/or LA enlargement in a sample of the general population and to evaluate the role of adipokines in this association.

METHODS AND RESULTS

The study cohort consisted of 527 participants (362 men; 57 ± 10 years) without overt cardiac disease who underwent laboratory testing, abdominal computed tomographic examination and echocardiography. Abdominal adiposity was quantitatively assessed as visceral fat area (VFA) and subcutaneous fat area (SFA) at the level of the umbilicus. Speckle-tracking echocardiography was performed to assess LA phasic function including reservoir, conduit and pump strain. LA reservoir and conduit strain decreased with increasing VFA quartiles (both p < 0.05), whereas no significant differences were observed in LA volume index and pump strain. When stratified by SFA, there were no significant differences in LA size and function across the quartiles. In multivariable analysis, VFA was significantly associated with LA conduit strain independent of cardiovascular risk factors, and pertinent laboratory and echocardiographic parameters (standardized β = -0.136, p = 0.019). VFA was correlated with serum adiponectin level (r = -0.51, p < 0.001), but there was no association between adiponectin level and three LA phasic strains.

CONCLUSION

In a sample of the general population, VFA accumulation was independently associated with worse LA conduit strain, which may be involved in the pathophysiological mechanism of obesity-related AF.

Chronic kidney disease and subclinical abnormalities of left heart mechanics in the community

Aims

Cardiovascular disease is the leading cause of death in chronic kidney disease (CKD) patients, although the pathophysiological mechanisms are not fully studied. This study aimed to determine whether CKD could adversely affect subclinical left heart function in a sample of the general population without cardiac disease.

Methods and results

We examined 1158 participants who voluntarily underwent extensive cardiovascular examination including laboratory test and two-dimensional speckle-tracking echocardiography to assess left ventricular global longitudinal strain (LVGLS) and left atrial (LA) reservoir, conduit, and pump strain. According to the estimated glomerular filtration rate (eGFR), participants were classified into four groups; Stage 1 (n = 112; eGFR ≥90 mL/min/1.73 m²), Stage 2 (n = 818; 60–89 mL/min/1.73 m²), Stage 3a (n = 191; 45–59 mL/min/1.73 m²), and Stage 3b–5 (n = 37; eGFR <45 mL/min/1.73 m²). Progressive declines of LVGLS, LA reservoir, and conduit strain were observed according to the severity of CKD (P < 0.001), while LA pump strain did not differ between the groups. In multivariable analyses, eGFR was associated with LVGLS (standardized β = −0.068, P = 0.019) as well as LA reservoir (standardized β = 0.117, P < 0.001) and conduit strain (standardized β = 0.130, P < 0.001), independent of traditional cardiovascular risk factors, pertinent biomarkers, and LV geometry and diastolic function. The independent association between eGFR and LA strain persisted even after adjustment for LVGLS.

Conclusion

Worsening renal function was independently associated with impaired LV/LA strain in an unselected community-based cohort. The assessment of LV and LA strain may allow better risk stratification in CKD patients.

Deep learning model to detect significant aortic regurgitation using electrocardiography: Detection model for aortic regurgitation

BACKGROUND

Aortic regurgitation (AR) is a common heart disease, with a relatively high prevalence of 4.9% in the Framingham Heart Study. Because the prevalence increases with advancing age, an upward shift in the age distribution may increase the burden of AR. To provide an effective screening method for AR, we developed a deep learning-based artificial intelligence algorithm for the diagnosis of significant AR using electrocardiography (ECG).

METHODS

Our dataset comprised 29,859 paired data of ECG and echocardiography, including 412 AR cases, from January 2015 to December 2019. This dataset was divided into training, validation, and test datasets. We developed a multi-input neural network model, which comprised a two-dimensional convolutional neural network (2D-CNN) using raw ECG data and a fully connected deep neural network (FC-DNN) using ECG features, and compared its performance with the performances of a 2D-CNN model and other machine learning models. In addition, we used gradient-weighted class activation mapping (Grad-CAM) to identify which parts of ECG waveforms had the most effect on algorithm decision making.

RESULTS

The area under the receiver operating characteristic curve of the multi-input model (0.802; 95% CI, 0.762-0.837) was significantly greater than that of the 2D-CNN model alone (0.734; 95% CI, 0.679-0.783; p<0.001) and those of other machine learning models. Grad-CAM demonstrated that the multi-input model tended to focus on the QRS complex in leads I and aVL when detecting AR.

CONCLUSIONS

The multi-input deep learning model using 12-lead ECG data could detect significant AR with modest predictive value.

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.

Sex-specific difference in the association between arterial stiffness and subclinical left ventricular dysfunction

AIMS

Increased arterial stiffness is one of the key mechanisms of heart failure with preserved ejection fraction (HFpEF). However, the possible association between arterial stiffness and subclinical left ventricular (LV) dysfunction and its sex-specific difference remains unclarified. LV strain is emerging as a highly sensitive tool to unmask early LV abnormalities.

METHODS AND RESULTS

We examined 1155 participants free of overt cardiovascular disease who underwent extensive cardiovascular examination. Speckle-tracking echocardiography was employed to assess LV global longitudinal strain (LVGLS) and circumferential strain (GCS), and arterial stiffness was assessed by cardio-ankle vascular index (CAVI). Mean age was 62 ± 12 years, and 56% were men. CAVI as continuous variable was associated with abnormal LVGLS (>-18.6%) independent of cardiovascular risk factors and echocardiographic parameters [adjusted odds ratio (OR) 1.23, P = 0.027] but not with LVGCS. In sex-stratified analysis, more pronounced association between quartiles of CAVI and abnormal LVGLS was observed in women than in men (unadjusted OR = 6.43 in women and 2.46 in men for upper quartile vs. lower quartile; both P < 0.01). CAVI was significantly associated with abnormal LVGLS independent of cardiovascular risk factors in both sexes. However, after further adjustment for LV mass index and diastolic parameters, the independent association persisted only in women (adjusted OR 1.67, P = 0.007), but not in men (adjusted OR 1.14, P = 0.227).

CONCLUSION

Increased arterial stiffness was independently associated with decreased LVGLS even without overt cardiovascular disease; a sex-specific pattern exists in the alteration of vascular-ventricular coupling, which might partially explain the greater susceptibility to HFpEF in women.

Combined evaluation of right ventricular function using echocardiography in non-ischaemic dilated cardiomyopathy

Aims

Although comprehensive assessment of right ventricular (RV) function using multiple echocardiographic parameters is recommended for management of patients with non‐ischaemic dilated cardiomyopathy (DCM), it is unclear which RV parameters to combine. Additionally, normalization of RV parameters by estimated pulmonary artery systolic pressure (PASP), in consideration of RV–pulmonary artery coupling, may be clinically significant. The aim of our study was to elucidate the best combination of echocardiographic RV functional parameters, with or without indexing for PASP, to predict outcome in patients with heart failure with reduced ejection fraction secondary to DCM.

Methods and results

We retrospectively analysed 109 DCM patients with left ventricular ejection fraction <40%. RV size was assessed by RV end‐diastolic area (RVEDA) and RV end‐systolic area (RVESA) from RV‐focused apical four‐chamber view. RV function was assessed by fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) and by RV longitudinal strain (RVLS) using two‐dimensional speckle‐tracking echocardiography. All functional parameters were also indexed for estimated PASP. Cox analyses were used to evaluate the association of RV morphology and functional parameters with 1 year outcome (composite of left ventricular assist device implantation and all‐cause death). Area under the curve was used to compare prognostic values. Mean age was 44 ± 14 years, and 76 (69.7%) were men. Mean left ventricular ejection fraction was 21.9%, median RVEDA was 22.1 cm², FAC was 27.0%, TAPSE was 15.0 mm, and RVLS was −12.5%. Forty‐one (37.6%) patients experienced the primary outcome. Multivariate Cox analysis revealed that RVEDA, RVESA, FAC, TAPSE, RVLS, FAC/PASP, and RVLS/PASP were independent predictors for primary outcome (all P < 0.05). However, normalization with PASP did not improve area under the curve for any RV functional parameters. When we evaluate hazard ratios according to the combination of two echocardiographic parameters of RV function, patients with impairment of both FAC (<27%) and RVLS (>−8.6%) had significantly higher hazard ratio than those with either impairment alone (11.3 vs. 3.4, P < 0.001); the other combinations did not improve prognostic value.

Conclusions

Normalizing echocardiographic RV parameters for PASP did not improve the prognostic values for our population. Meanwhile, combined evaluation of FAC and RVLS improved risk stratification in patients with heart failure with reduced ejection fraction secondary to DCM.

Aging and myocardial strain

Advanced age is widely recognized as a key risk factor for incident cardiovascular disease. The age-associated changes in cardiac properties alter the substrate on which cardiovascular disease is superimposed in various ways, and thus affect the development and manifestations of cardiovascular disease (CVD) in the elderly. However, it is still unclear whether age-related cardiac alteration is attributed to aging itself or whether it is secondary to other acquired cardiovascular risk factors. Understanding the association between aging and cardiac functional remodeling might provide insight into the pathogenesis of cardiovascular aging and may help inform possible preventive strategies for CVD in older individuals. Speckle-tracking echocardiography enables the objective and quantitative assessment of subtle myocardial alterations that are undetectable with conventional echocardiography, and has excellent feasibility and reproducibility. Left ventricular (LV) global longitudinal strain, a sensitive measure of LV systolic dysfunction, was found to be an independent risk factor for cardiovascular morbidity and mortality. More recently, deformation imaging has been employed to assess right ventricular (RV) and atrial performance, and impaired RV and atrial strain predict unfavorable outcomes in various clinical settings. This article reviews the association between aging and changes in myocardial strain values and describes future perspectives.

Two-Dimensional Echocardiographic Right Ventricular Size and Systolic Function Measurements Stratified by Sex, Age, and Ethnicity: Results of the World Alliance of Societies of Echocardiography Study

BACKGROUND

Echocardiographic assessment of right ventricular (RV) systolic function is an important component of clinical decision making. Although professional societies have worked to define normal ranges of RV size and function, their guidelines have not included the impacts of age, sex, and ethnicity on these parameters, as they have for the left ventricle. The World Alliance of Societies of Echocardiography study was designed to investigate the effects of age, sex, and ethnicity on all cardiac chambers. The aim of this study was to explore whether these differences exist for RV systolic parameters.

METHODS

Adequate two-dimensional RV-focused views for the measurement of systolic parameters, including fractional area change and global and free wall longitudinal strain, were available in 1,913 subjects (mean age, 47 ± 17 years; 51% men). Basal and mid-RV dimensions, length, tricuspid annular peak systolic excursion, tissue Doppler S' velocity, and myocardial performance index were also measured. Subjects were grouped by age (<40, 41-65, and >65 years), with results also stratified by sex and ethnicity (Asian, black, or white) and analyzed using vendor-independent software. Differences among groups were evaluated using analysis of variance.

RESULTS

Women had smaller absolute and indexed RV areas and absolute RV dimensions and higher magnitudes of fractional area change, free wall strain, and global longitudinal strain compared to men. With respect to age, most of the statistically significant differences were noted between the <40- and >65-year age groups, with RV areas and lengths smaller in older age groups and RV functional parameters (S', fractional area change, tricuspid annular plane systolic excursion, global longitudinal strain, free wall strain, and myocardial performance index) showing minimal decreases or no changes with age. Although there were no meaningful differences in functional parameters among ethnic groups, RV size was smallest in Asians.

CONCLUSIONS

These findings suggest that although two-dimensional RV parameters are age and sex dependent, association with race is less apparent, excepting that the Asian population appears to have smaller chamber sizes compared with whites and blacks.

Deep Learning Algorithm to Detect Cardiac Sarcoidosis From Echocardiographic Movies

BACKGROUND

Because the early diagnosis of subclinical cardiac sarcoidosis (CS) remains difficult, we developed a deep learning algorithm to distinguish CS patients from healthy subjects using echocardiographic movies.Methods and Results:Among the patients who underwent echocardiography from January 2015 to December 2019, we chose 151 echocardiographic movies from 50 CS patients and 151 from 149 healthy subjects. We trained two 3D convolutional neural networks (3D-CNN) to identify CS patients using a dataset of 212 echocardiographic movies with and without a transfer learning method (Pretrained algorithm and Non-pretrained algorithm). On an independent set of 41 echocardiographic movies, the area under the receiver-operating characteristic curve (AUC) of the Pretrained algorithm was greater than that of Non-pretrained algorithm (0.842, 95% confidence interval (CI): 0.722-0.962 vs. 0.724, 95% CI: 0.566-0.882, P=0.253). The AUC from the interpretation of the same set of 41 echocardiographic movies by 5 cardiologists was not significantly different from that of the Pretrained algorithm (0.855, 95% CI: 0.735-0.975 vs. 0.842, 95% CI: 0.722-0.962, P=0.885). A sensitivity map demonstrated that the Pretrained algorithm focused on the area of the mitral valve.

CONCLUSIONS

A 3D-CNN with a transfer learning method may be a promising tool for detecting CS using an echocardiographic movie.

Normal Values of Cardiac Output and Stroke Volume According to Measurement Technique, Age, Sex, and Ethnicity: Results of the World Alliance of Societies of Echocardiography Study

BACKGROUND

Assessment of cardiac output (CO) and stroke volume (SV) is essential to understand cardiac function and hemodynamics. These parameters can be examined using three echocardiographic techniques (pulsed-wave Doppler, two-dimensional [2D], and three-dimensional [3D]). Whether these methods can be used interchangeably is unclear. The influence of age, sex, and ethnicity on CO and SV has also not been examined in depth. In this report from the World Alliance of Societies of Echocardiography Normal Values Study, the authors compare CO and SV in healthy adults according to age, sex, ethnicity, and measurement techniques.

METHODS

A total of 1,450 adult subjects (53% men) free of heart, lung, and kidney disease were prospectively enrolled in 15 countries, with even distributions among age groups and sex. Subjects were divided into three age groups (young, 18-40 years; middle aged, 41-65 years; and old, >65 years) and three main racial groups (whites, blacks, and Asians). CO and SV were indexed (cardiac index [CI] and SV index [SVI], respectively) to body surface area and height and measured using three echocardiographic methods: Doppler, 2D, and 3D. Images were analyzed at two core laboratories (one each for 2D and 3D).

RESULTS

CI and SVI were significantly lower by 2D compared with both Doppler and 3D methods in both sexes. SVI was significantly lower in women than men by all three methods, while CI differed only by 2D. SVI decreased with aging by all three techniques, whereas CI declined only with 2D and 3D. CO and SV were smallest in Asians and largest in whites, and the differences persisted after normalization for body surface area.

CONCLUSIONS

The present results provide normal reference values for CO and SV, which differ by age, sex, and race. Furthermore, CI and SVI measurements by the different echocardiographic techniques are not interchangeable. All these factors need to be taken into account when evaluating cardiac function and hemodynamics in individual patients.

Mitral Valvular Coaptation-Zone Area Is Associated with the Severity of Atherosclerosis Assessed by Cardio-Ankle Vascular Index

Preservation of the mitral valve (MV) size is essential for valve function, and a reduced MV coaptation-zone area increases the risk of developing functional mitral regurgitation (FMR). We aimed to determine if the MV leaflet and coaptation-zone areas were associated with the severity of atherosclerosis assessed by cardio-ankle vascular index (CAVI) in patients with normal left ventricle (LV) systolic function and size by real-time 3D echocardiography (RT3DE).We performed RT3DE analysis in 66 patients with normal LV size and ejection fraction who underwent 2D echocardiography and CAVI. MV coaptation-zone areas were measured by custom 3D software and indexed by body surface area (BSA). The associations of clinical factors and mean CAVI with MV leaflet and coaptation-zone areas were evaluated by univariable and multivariable linear regression analyses.On univariable analysis, MV leaflet area/BSA was significantly associated with age (r = -0.335, P = 0.0069) and mean CAVI (r = -0.464, P < 0.001), and MV coaptation-zone area was significantly associated with age (r = -0.626, P < 0.001), hypertension (r = -0.626, P < 0.001), dyslipidemia (r = -0.626, P < 0.001), E/e' (r = -0.626, P < 0.001), and CAVI (r = -0.740, P < 0.001). On multivariable analysis, mean CAVI was independently associated only with MV leaflet area/BSA (standardized coefficient = -0.611, P < 0.001) and MV coaptation-zone area/BSA (standardized coefficient = -0.74, P < 0.001).In patients with normal LV systolic function and size, MV leaflet and coaptation-zone areas might be reduced according to advancing atherosclerosis. Patients with atherosclerosis might be at increased risk of developing FMR.

Surgical treatment for infective endocarditis in the ageing society: a nationwide retrospective study in Japan

Objective

The current status of surgical treatment for infective endocarditis (IE) among very elderly people is unclear.

Methods

We extracted data on patients in Japan with community-acquired IE who were admitted and discharged between April 2010 and February 2018 using a nationwide inpatient, the Diagnosis Procedure Combination database. We divided patients into three groups: non-elderly (<65 years), elderly (65–79 years) and very elderly (≥80 years). A 1:1 propensity score matching was performed to compare proportions of surgical treatment and in-hospital mortality among the groups.

Results

We identified 20 667 eligible patients (median age 70 years, 61.0% men). The proportion of very elderly patients significantly increased (19.1% in 2010 to 29.7% in 2018). The proportion of surgical treatment was significantly lower, and in-hospital mortality was significantly higher in very elderly patients. This tendency was more pronounced among patients with in-hospital complications such as heart failure, stroke or embolism. Surgical treatment was significantly associated with lower in-hospital mortality even in very elderly patients, both in an unmatched (OR 0.61; 95% CI 0.47 to 0.78) and a propensity score matched cohort (OR 0.61; 95% CI 0.43 to 0.85).

Conclusions

The proportion of very elderly patients with IE was increasing, and very elderly patients had higher in-hospital mortality. The proportion of surgical treatment for IE among very elderly patients was low, but it was associated with lower in-hospital mortality. Further studies are needed to establish the optimal strategy for IE among very elderly patients.

Risk factors including preoperative echocardiographic parameters for post-induction hypotension in general anesthesia

BACKGROUND

Severe hypotension immediately after induction of general anesthesia (post-induction hypotension) is a common complication and is associated with a poor postoperative outcome. We hypothesized that post-induction hypotension results from cardiac dysfunction which can be assessed by preoperative echocardiography.

METHODS

We retrospectively enrolled 200 patients who had undergone elective surgery within 6 months after preoperative transthoracic echocardiography. The incidence of post-induction hypotension identified from anesthesia records was defined as a decrease in mean blood pressure to ≤50 mmHg after injection of induction anesthetics prior to surgery. Logistic regression analysis of patient characteristics and echocardiographic variables was used to identify the independent factors for post-induction hypotension.

RESULTS

Post-induction hypotension was found in 63 of the 200 cases (incidence 32%). Independent risk factors for post-induction hypotension were the presence of a regional wall motion abnormality (RWMA) [odds ratio (OR), 6.65.; 95% confidence interval (CI), 1.76 - 25.10], an elevated E/e' (OR, 1.13; 95% CI, 1.00 - 1.28), female gender (OR, 3.61; 95% CI, 1.37 - 9.56), and the use of an angiotensin II receptor blocker (OR, 3.17; 95% CI, 1.12 - 8.96).

CONCLUSIONS

Assessment of RWMA and E/e' with preoperative transthoracic echocardiography might be helpful for stratification of patients at a risk of post-induction hypotension in general anesthesia.