Subclinical left atrial dysfunction profiles for prediction of cardiac outcome in the general population

Prognostic Relevance and Lower Limit of the Reference Range of Left Ventricular Global Longitudinal Strain: A Clinical Validation Study

BACKGROUND

The lower limit of the reference normal range (LLN) of left ventricular global longitudinal strain (GLS) for each ultrasound software vendor and its prognostic relevance in the elderly and in asymptomatic patients at risk for heart failure (HF) remain uncertain.

OBJECTIVES

In this study, the authors sought to validate the LLN of GLS for each ultrasound software vendor and its prognostic relevance in the elderly and in asymptomatic patients at risk for HF.

METHODS

To identify the LLN of GLS with the use of 2-dimensional speckle-tracking transthoracic echocardiography, a meta-analysis of studies including healthy subjects was conducted, followed by a validation study in a large cohort of healthy subjects. To validate the prognostic relevance of the LLN of GLS, 2 validation cohort studies were carried out, including elderly subjects aged ≥80 years and asymptomatic ambulatory patients with preserved left ventricular ejection fraction at risk for HF.

RESULTS

The meta-analysis, which included 47 studies with a total of 23,208 healthy adult subjects, identified the LLN for GLS at 16% (absolute value) across various ultrasound software vendors, including EchoPac, TomTec, and QLab. In the validation cohort study, which included 2,217 healthy adult subjects, a GLS cutoff of 16% was also identified as the LLN. Concerning the prognostic relevance of the LLN of GLS, a value of GLS <16% was significantly associated with HF hospitalization in asymptomatic ambulatory patients at risk for HF (n = 667; OR within 6 years: 5.1 [95% CI: 1.5-17.0]) and in elderly subjects (n = 159; OR within 2 years: 3.1 [95% CI: 1.1-8.8]).

CONCLUSIONS

This clinical validation study provides important clinical data concerning the LLN of GLS (identified and validated at 16%) and its prognostic relevance in the elderly and in asymptomatic ambulatory patients at risk for HF.

Peak left atrial longitudinal strain and incident atrial fibrillation in the general population: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is the commonest supraventricular arrhythmia in adults. Timely AF diagnosis seems to ameliorate patients prognosis.

PURPOSE

To investigate the association between peak left atrial longitudinal strain (PALS) and new onset AF in the general population.

OBJECTIVES

We searched major electronic databases for articles assessing the relationship between PALS and incident AF.

RESULTS

Eight studies (11,145 patients) were analysed. Lower levels of PALS were significantly associated with higher risk of incident AF (HR: 0.95; 95%CI: 0.92-0.97, I2: 83%). According to the diagnostic accuracy meta-analysis, PALS <33.4% presents 64% (95%CI: 46-79%) sensitivity and 69% (95%CI: 63-75%) specificity.

CONCLUSIONS

In a relatively healthy population, lower levels of PALS were significantly associated with incident AF. The overall diagnostic accuracy was moderate. Lower levels of PALS seem to justify an opportunistic - rather than a systematic-screening approach. These findings could allow more efficient utilisation of healthcare resources.

Cardiac mechanics and the risk of atrial fibrillation in a community-based cohort of older adults

AIMS

Assessment of cardiac structure and function improves risk prediction of new-onset atrial fibrillation (AF) in different populations. We aimed to comprehensively compare standard and newer measures of cardiac structure and function in improving prediction of AF in a cohort of older adults without history of AF and stroke.

METHODS AND RESULTS

We included 5050 participants without prevalent AF and stroke (mean age 75 ± 5 years, 59% women, and 22% Black) from the Atherosclerosis Risk in Communities (ARIC) study who underwent complete two-dimensional echocardiography, including speckle-tracking analysis of the left ventricle (LV) and left atrium (LA). We assessed the association of cardiac measures with incident AF (including atrial flutter) and quantified the extent to which these measures improved model discrimination and risk classification of AF compared with the CHARGE-AF score. Over a median follow-up time of 7 years, 676 participants developed AF (incidence rate 2.13 per 100 person-years). LV mass index and wall thickness, E/e', and measures of LA structure and function, but not LV systolic function, were associated with incident AF, after accounting for confounders. Above all, LA reservoir strain, contraction strain, and LA minimal volume index (C-statistics [95% confidence interval]: 0.73 [0.70, 0.75], 0.72 [0.70, 0.75], and 0.72 [0.69, 0.75], respectively) significantly improved the risk discrimination of the CHARGE-AF score (baseline C-statistic: 0.68 [0.65, 0.70]) and achieved the highest category-based net reclassification improvement (29%, 24%, and 20%, respectively).

CONCLUSION

In a large cohort of older adults without prevalent AF and stroke, measures of LA function improved the prediction of AF more than other conventional cardiac measures.

Clinical and biochemical predictors of longitudinal changes in left atrial structure and function: A general population study

PURPOSE

There is a need for better understanding the factors that modulate left atrial (LA) dysfunction. Therefore, we determined associations of clinical and biochemical biomarkers with serial changes in echocardiographic indexes of LA function in the general population.

METHODS

We measured LA maximal and minimal volume indexes (LAVImax and LAVImin) by echocardiography and LA reservoir strain (LARS) by two-dimensional speckle-tracking in 627 participants (mean age 50.8 years, 51.2% women) at baseline and after 4.8 years.

RESULTS

During follow-up, LARS decreased significantly in men (-.90%, P = .033) but not in women (-.23%, P = .60). In stepwise regression analysis, stronger decrease in LARS over time was associated with male sex, a higher age, body mass index (BMI), mean arterial pressure (MAP) and serum insulin at baseline and with a greater increase in BMI and MAP over time (P ≤ .018). Similarly, an increased risk of developing or retaining abnormal LARS was observed in older participants, in subjects with a higher baseline BMI, MAP, heart rate (HR), troponin T and ΔMAP, and in those who used β-blockers at baseline. Both LAVImax and LAVImin increased significantly over time (P ≤ .0007). This increase was associated with a higher baseline age, pulse pressure and a lower HR at baseline and a greater increase in pulse pressure over time (P ≤ .029). Higher serum insulin and D-dimer were independently associated with a stronger increase in LAVImin (P ≤ .0034).

CONCLUSION

Subclinical worsening in LA dysfunction was associated with older age, hypertension, obesity, insulin resistance and troponin T levels. Cardiovascular risk management strategies may delay LA deterioration.

Left atrial remodeling in adolescents with obesity evaluated by speckle-tracking echocardiography

BACKGROUND AND AIMS

In adolescents with obesity, a left atrial (LA) enlargement has been reported. However, data regarding its function and its stiffness are missing. The aim of this study was to describe LA morphology and function, using speckle-tracking echocardiography (STE) and to explore their potential determinants in adolescents with obesity.

METHODS

Twenty-eight adolescent women with obesity (13.2 ± 1.4 yr) with an illness duration of 130 ± 27 months and 33 controls (14.1 ± 2.0 yr) underwent a resting echocardiography including an analysis of left ventricular (LV) and LA morphologies and strains. A fasting venous blood sample was performed to biochemical determinations including inflammation markers.

RESULTS

LA volume and stiffness index were increased in adolescents with obesity compared to controls. LA reservoir, conduit and booster pump functions were not different between groups. By stepwise forward multivariate regression analyses, systolic blood pressures, cardiac output and sedimentation rate were the independent determinants of LA volume (p < 0.0001, β-coefficient = 0.460) whereas only the body mass index was an independent determinant of LA stiffness (p = 0.003, β-coefficient = 0.413).

CONCLUSION

In adolescents with obesity, we observed a specific LA remodeling, including higher volume and lower stiffness, which could constitute early signs of an altered LV diastolic function.

Feature-based clustering of the left ventricular strain curve for cardiovascular risk stratification in the general population

Objective

Identifying individuals with subclinical cardiovascular (CV) disease could improve monitoring and risk stratification. While peak left ventricular (LV) systolic strain has emerged as a strong prognostic factor, few studies have analyzed the whole temporal profiles of the deformation curves during the complete cardiac cycle. Therefore, in this longitudinal study, we applied an unsupervised machine learning approach based on time-series-derived features from the LV strain curve to identify distinct strain phenogroups that might be related to the risk of adverse cardiovascular events in the general population.

Method

We prospectively studied 1,185 community-dwelling individuals (mean age, 53.2 years; 51.3% women), in whom we acquired clinical and echocardiographic data including LV strain traces at baseline and collected adverse events on average 9.1 years later. A Gaussian Mixture Model (GMM) was applied to features derived from LV strain curves, including the slopes during systole, early and late diastole, peak strain, and the duration and height of diastasis. We evaluated the performance of the model using the clinical characteristics of the participants and the incidence of adverse events in the training dataset. To ascertain the validity of the trained model, we used an additional community-based cohort (n = 545) as external validation cohort.

Results

The most appropriate number of clusters to separate the LV strain curves was four. In clusters 1 and 2, we observed differences in age and heart rate distributions, but they had similarly low prevalence of CV risk factors. Cluster 4 had the worst combination of CV risk factors, and a higher prevalence of LV hypertrophy and diastolic dysfunction than in other clusters. In cluster 3, the reported values were in between those of strain clusters 2 and 4. Adjusting for traditional covariables, we observed that clusters 3 and 4 had a significantly higher risk for CV (28% and 20%, P ≤ 0.038) and cardiac (57% and 43%, P ≤ 0.024) adverse events. Using SHAP values we observed that the features that incorporate temporal information, such as the slope during systole and early diastole, had a higher impact on the model's decision than peak LV systolic strain.

Conclusion

Employing a GMM on features derived from the raw LV strain curves, we extracted clinically significant phenogroups which could provide additive prognostic information over the peak LV strain.

Unsupervised Time-Series Clustering of Left Atrial Strain for Cardiovascular Risk Assessment

BACKGROUND

Early identification of individuals at high risk for developing cardiovascular (CV) events is of paramount importance for efficient risk management. Here, the authors investigated whether using unsupervised machine learning methods on time-series data of left atrial (LA) strain could distinguish clinically meaningful phenogroups associated with the risk for developing adverse events.

METHODS

In 929 community-dwelling individuals (mean age, 51.6 years; 52.9% women), clinical and echocardiographic data were acquired, including LA strain traces, at baseline, and cardiac events were collected on average 6.3 years later. Two unsupervised learning techniques were used: (1) an ensemble of a deep convolutional neural network autoencoder with k-medoids and (2) a self-organizing map to cluster spatiotemporal patterns within LA strain curves. Clinical characteristics and cardiac outcome were used to evaluate the validity of the k clusters using the original cohort, while an external population cohort (n = 378) was used to validate the trained models.

RESULTS

In both approaches, the optimal number of clusters was five. The first three clusters had differences in sex distribution and heart rate but had a similar low CV risk profile. On the other hand, cluster 5 had the worst CV profile and a higher prevalence of left ventricular remodeling and diastolic dysfunction compared with the other clusters. The respective indexes of cluster 4 were between those of clusters 1 to 3 and 5. After adjustment for traditional risk factors, cluster 5 had the highest risk for cardiac events compared with clusters 1, 2, and 3 (hazard ratio, 1.36; 95% CI, 1.09-1.70; P = .0063). Similar LA strain patterns were obtained when the models were applied to the external validation cohort, and clinical characteristics revealed similar CV risk profiles across all clusters.

CONCLUSION

Unsupervised machine learning algorithms used in time-series LA strain curves identified clinically meaningful clusters of LA deformation and provide incremental prognostic information over traditional risk factors.

Evaluation of the relationship between left atrial strain and exercise tolerance in patients with hypertrophic cardiomyopathy by treadmill stress echocardiography

Objective

The aim of this study is to evaluate the left atrial strain (LAS) in patients with hypertrophic cardiomyopathy (HCM) by treadmill exercise stress echocardiography, combined with three-dimensional speckle tracking technology, for predicting exercise tolerance.

Methods

A total of 97 patients with HCM who underwent treadmill exercise stress echocardiography were recruited in Sichuan Provincial People's Hospital between January 2018 and January 2021, and 30 control subjects were selected to be included in the normal group. HCM patients with their metabolic equivalents (METS) ≤ 6.0 were included in the HCM-1 group, while those with METS > 6.0 were included in the HCM-2 group. The LAS and exercise tolerance were analyzed. The ultrasound parameters that could predict a decrease in exercise tolerance were screened, and a predictive model was constructed.

Results

It was found that METS, Rest-LASr, Rest-LAScd, and Rest-LASct were significantly lower in HCM patients than those in normal controls. There was a significant difference in age, Target_HR, LVMI, LAVI, E/e'-Rest, E/e'-Peak, Rest-LASr, Rest-LAScd, and Rest-LASct between the HCM-1 and the HCM-2 groups. LASr is an independent resting echocardiographic predictor of METS ≤ 6.0. LASr remained significant for predicting different subtypes (AHCM, asymmetric HCM, and obstructive HCM). Rest-LASr (AUC 0.990) was better at predicting METS ≤ 6.0 than Peak-E/e' (AUC 0.753). A multivariate model (LASr + Age + Target_HR) was established for METS prediction.

Conclusion

Left atrial reservoir strain (LASr) has the strongest association with METS ≤ 6.0. The LASr is an independent resting predictor of METS ≤ 6.0 and has a good performance record in predicting different subtypes of HCM. Compared with the traditional parameters, Peak-E/e' and Rest-E/e', Rest-LASr is the best predictor. Rest-LASr can serve as a reliable method for HCM patients who are unable to undergo exercise testing but require an urgent evaluation of their METS, which provides a basis for clinical treatment decision-making and treatment effect evaluation.

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.

Left Atrial Strain and the Risk of Atrial Arrhythmias From Extended Ambulatory Cardiac Monitoring: MESA

Background Abnormalities in left atrial (LA) function often occur before LA structural changes and clinically identified atrial fibrillation (AF). Little is known about the relationship between LA strain and the risk of subclinical atrial arrhythmias detected from extended ambulatory cardiac monitoring. Methods and Results A total of 1441 participants of MESA (Multi-Ethnic Study of Atherosclerosis) completed speckle-tracking echocardiography and cardiac monitoring during 2016 to 2018 (mean age, 73 years); participants in AF during echocardiography or during the entire cardiac monitoring period were excluded. Absolute values of LA reservoir, booster pump, and conduit strains were measured. We evaluated associations of LA strain with monitor-detected AF, premature atrial contractions, and supraventricular tachycardia. Primary analyses adjusted for demographic variables, blood pressure, diabetes, smoking, and clinical cardiovascular disease. Cardiac monitoring (median, 14 days) detected AF in 3%. Each SD (4.0%) lower (worse) LA booster pump strain was associated with 84% higher risk of monitor-detected AF (95% CI, 30%-162%), 39% higher premature atrial contraction frequency (95% CI, 27%-53%), and 19% higher supraventricular tachycardia frequency (95% CI, 10%-29%). Additional adjustment for NT-proBNP (N-terminal pro-B-type natriuretic peptide), LA volume index, tissue Doppler a' peak velocity, left ventricular ejection fraction, and global longitudinal strain had little impact on associations. Findings were similar for LA reservoir strain and null for LA conduit strain. Conclusions In a multiethnic community-based cohort, impaired LA strain was an important correlate of subclinical atrial arrhythmias, even after adjustment for conventional measures of LA structure and function.

Left atrial phasic function remodeling during its enlargement: a two-dimensional speckle-tracking echocardiography study

BACKGROUND

Left atrial (LA) size is often used as a surrogate marker of LA function in clinical practice, with larger atrial thought to represent a "dysfunctioning" atrium, since there is no accepted 'gold' standard to evaluate LA function. The exact relationship between LA size and phasic function, and whether LA dysfunction occur before LA enlargement (LAE) may be of clinical interest while have not been fully studied. Two-dimensional speckle-tracking echocardiography (2D STE) was showed a promising method in measuring LA physical deformation.

MATERIALS AND METHODS

A community cohort of 715 subjects at cardiovascular disease high risk accepted comprehensive echocardiography. LA longitudinal phasic strain Sa (absolute peak strain during atrial contraction), Se (peak strain at early diastole) and Stot (total atrial strain = Sa + Se), representing contractile, conduit, and reservoir function respectively, were measured using off-line 2D STE software in apical 4 chamber view, and data were compared among groups at different LA size and between subgroups in normal LA size with and without hypertension (HT).

RESULTS

With LAE (from normal size, mild, moderate to severe LAE), the Stot (21.74 ± 5.97, 20.75 ± 4.99, 20.49 ± 5.27, 17.75 ± 4.71, respectively, ANOVA P = 0.003) and Sa (11.84 ± 3.92, 11.00 ± 3.29, 10.11 ± 2.57, 8.55 ± 2.88, respectively, ANOVA P < 0.001) reduced while Se had no change. Stot of Severe LAE group was significantly lower than that of Normal LA size group (P = 0.002). Sa of the three LAE groups were all significantly lower than that of Normal LA size group (P = 0.024, P = 0.002, P < 0.001, respectively). In normal sized LA subgroups, Stot (21.35 ± 5.91 vs. 23.01 ± 6.02, P = 0.008) and Se (9.51 ± 4.41 vs. 11.17 ± 4.89, P < 0.001) reduced in subjects with HT comparing with those without.

CONCLUSION

LA phasic function remodeling occurs before LAE and continues with LAE, with reservoir, conduit and contractile function being affected unparalleled.

The Added Value of Atrial Strain Assessment in Clinical Practice

Speckle tracking echocardiography has emerged as a sensitive tool to analyze myocardial function with improved diagnostic accuracy and prognostic value. Left atrial strain assessment has become a novel imaging method in cardiology with superior prognostic value compared to conventional left atrial volume indices. Left atrial function is divided into three phases, reservoir function being the most important. This review summarizes the added value of speckle tracking echocardiography derived left atrial strain assessment in clinical practice. Recently published data suggest the prognostic value of left atrial reservoir function in heart failure, atrial fibrillation, stroke and valvular heart disease. Furthermore, left atrial reservoir strain proved to be a predictor of cardiovascular morbidity and mortality in the general population. Thus, routine assessment of left atrial function can be an optimal strategy to improve cardiovascular risk prediction and supplement the current risk prediction models.

Normal values and reference ranges for left atrial strain by speckle-tracking echocardiography: the Copenhagen City Heart Study

AIMS 

Left atrial (LA) function assessed by two-dimensional speckle-tracking echocardiography has shown increasing clinical and prognostic significance. We sought to establish age- and sex-based normative values of LA strain in the general population and to assess the prognostic yield of lower limits of normality of LA strain in relation to future atrial fibrillation (AF).

METHODS AND RESULTS 

We determined normative values of peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase (LACS) in 1641 healthy participants included in the fifth Copenhagen City Heart Study. In a secondary analysis, a validation cohort of 2016 participants, regardless of health status, were included to assess the prognostic value of the established reference values. In the healthy cohort, median age was 46 years (interquartile range 32-57), 62% were female. Median PALS, PACS, and LACS and corresponding limits of normality in the healthy participants were 39.4% (23.0-67.6%), 15.5% (6.4-28.0%), and 23.7% (8.8-44.8%), respectively. There was a tendency of lower values of PALS and LACS in males and older participants, while PACS tended to increase with advancing age. The established lower limits of normality showed high specificity (range 93-94%) regarding future AF, implying a low risk of developing AF in participants with LA strain above the lower limits of normality in their respective sex and age group.

CONCLUSION 

We report normal values for LA strain stratified by sex and age. The lower limits of normality showed high specificity regarding future AF.

Left atrial structural and mechanical remodelling in heart failure with reduced ejection fraction

Aims

In patients with heart failure with reduced ejection fraction (HFrEF), an association between left atrial (LA) dilatation and dysfunction is expected, but the degree of coexistence of the two abnormalities and their relative prognostic role is not known.

Methods and results

A total of 626 HFrEF patients formed the study population. All of them underwent a comprehensive echocardiographic evaluation. LA maximal volume was indexed to body surface area (LAVi); LA function was assessed using strain analysis during the reservoir phase: peak atrial longitudinal strain (PALS) analysis. Study primary endpoint was overall mortality or hospitalization for worsening heart failure. Four groups of patients were included in this study according to LAVi (≤34 or >34 mL/m²) and PALS (≤23% or >23%); 61 (10%) patients had normal LA volume and function (Group 1), 58 (9%) had LA dilatation but normal function (Group 2), 100 (16%) had normal volume but abnormal function (Group 3), and 407 (65%) had enlarged left atrium and abnormal function (Group 4). PALS was associated with primary endpoint in patients with both normal‐size [Groups 1 and 3: hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.88–0.96; P = 0.0006] and dilated left atria (Groups 2 and 4: HR 0.93, 95% CI 0.91–0.96; P < 0.0001). In contrast, LAVi was associated with the primary endpoint in patients with abnormal LA function (Groups 3 and 4: HR 1.018, 95% CI 1.011–1.024; P < 0.00001) but not in those with normal PALS (Groups 1 and 2: HR 1.023, 95% CI 0.99–1.057; P = 0.1).

Conclusions

Left atrial dilatation and dysfunction frequently but not invariably coexist. PALS emerged as a significant prognostic parameter in HFrEF even in the absence of LA dilation.

Subclinical heart remodeling and dysfunction in relation to peripheral endothelial dysfunction: A general population study

AIMS

Epidemiological studies should substantiate the paradigm that endothelial dysfunction contributes to the development of heart failure with preserved ejection fraction (HFpEF). We investigated the association of cardiac remodeling and dysfunction with peripheral vasoreactivity in the general population.

METHODS

In 424 individuals, we echocardiographically assessed cardiac structure and function and determined digital vasomotor function by photoplethysmography (PPG) during reactive hyperemia (RH). We regressed echocardiographic indexes and abnormalities on RH ratios averaged for 30 s time intervals. We derived sex-specific peripheral vasoreactivity profiles from PPG time-series and compared their echocardiographic phenotypes.

RESULTS

Higher left ventricular (LV) mass index and lower E/A ratio and e' peak and left atrial reservoir strain were independently related to lower RH ratios. Participants with LV hypertrophy or diastolic dysfunction presented significantly lower RH ratios during the 30 to 240s intervals than normal counterparts. Low RH responders (n = 250) presented higher odds for LV hypertrophy (adjusted OR: 2.60; p = .0040) and LV diastolic dysfunction (adjusted OR: 2.66; p = .0037) than moderate-to-high responders (n = 174).

CONCLUSION

The association between subclinical heart maladaptation and decreased microvascular reactivity supports the involvement of endothelial dysfunction in HFpEF pathogenesis. Time-integrated profiling of microvascular vasoreactivity may enable early detection of HFpEF in the community.

Quantification of Myocardial Deformation in Patients with Takayasu Arteritis by Cardiovascular Magnetic Resonance Feature Tracking Imaging

BACKGROUND

Cardiac involvement is one of the main causes of morbidity and mortality in patients with Takayasu arteritis (TA). Early detection and intervention of cardiac damage may be helpful to reduce the mortality of TA. Magnetic resonance (MR) imaging (MRI)-derived feature tracking (FT) is an effective quantitative method to assess myocardial deformation which may reflect early changes of cardiac function.

PURPOSE

To explore the utility of MR-FT as a method to detect cardiac damage in TA patients.

STUDY TYPE

Retrospective.

POPULATION

Fifty-seven TA patients who had undergone clinically indicated MRI and 57 healthy controls.

FIELD STRENGTH/SEQUENCES

Balanced steady-state free precession rest cine and 2D phase-sensitive inversion recovery breath-hold segmented gradient echo late gadolinium enhancement (LGE) sequences at 3.0 T.

ASSESSMENT

Based on LGE images, TA patients were divided into two subgroups, LGE (+) subgroup (N = 12) and LGE (-) subgroup (N = 45). In addition, patients were further subdivided into impaired (N = 26) and preserved left ventricle ejection fraction (LVEF) subgroups (N = 31). FT-derived deformation indices, including left ventricular (LV) global longitudinal strain (GLS), were measured by commercial software.

STATISTICAL TESTS

Mann-Whitney U-test, Kruskal-Wallis test followed by Dunn-Bonferroni post hoc method, and receiver operating characteristic curve analysis were conducted. A P-value of <0.05 was considered statistically significant.

RESULTS

GLS was significantly worse in TA than in controls (median [interquartile range, IQR]: TA -10.0 [-7.5 to 12.4] vs. controls -12.7 [-11.8 to 14.7]). Moreover, TA patients with LGE (+) had significantly poorer GLS than those with LGE (-) (median [IQR]: LGE (+) -6.8 [-4.0 to 8.1] vs. LGE (-) -10.7 [-8.5 to 12.9]). The reduced LVEF subgroup had significantly greater cardiac dysfunction as measured by MR-FT than the preserved LVEF subgroup (GLS median [IQR]: reduced LVEF -7.9 [-6.2 to 11.4] vs. preserved LVEF -10.8 [-8.6 to 13.5]).

DATA CONCLUSION

Myocardial deformation impairment was found in the majority of TA patients. MR-FT imaging may be helpful in the early diagnosis and management of TA patients.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY STAGE: 5.

Echocardiographic phenogrouping by machine learning for risk stratification in the general population

Aims

There is a need for better phenotypic characterization of the asymptomatic stages of cardiac maladaptation. We tested the hypothesis that an unsupervised clustering analysis utilizing echocardiographic indexes reflecting left heart structure and function could identify phenotypically distinct groups of asymptomatic individuals in the general population.

Methods and results

We prospectively studied 1407 community-dwelling individuals (mean age, 51.2 years; 51.1% women), in whom we performed clinical and echocardiographic examination at baseline and collected cardiac events on average 8.8 years later. Cardiac phenotypes that were correlated at r > 0.8 were filtered, leaving 21 echocardiographic features, and systolic blood pressure for phenogrouping. We employed hierarchical and Gaussian mixture model-based clustering. Cox regression was used to demonstrate the clinical validity of constructed phenogroups. Unsupervised clustering analyses classified study participants into three distinct phenogroups that differed markedly in echocardiographic indexes. Indeed, cluster 3 had the worst left ventricular (LV) diastolic function (i.e. lowest e' velocity and left atrial (LA) reservoir strain, highest E/e', and LA volume index) and LV remodelling. The phenogroups were also different in cardiovascular risk factor profiles. We observed increase in the risk for incidence of adverse events across phenogroups. In the third phenogroup, the multivariable adjusted risk was significantly higher than the average population risk for major cardiovascular events (51%, P = 0.0028).

Conclusion

Unsupervised learning algorithms integrating routinely measured cardiac imaging and haemodynamic data can provide a clinically meaningful classification of cardiac health in asymptomatic individuals. This approach might facilitate early detection of cardiac maladaptation and improve risk stratification.

The usefulness of morphology-voltage-P wave duration ECG score for predicting early left atrial dysfunction in hypertensive patients

OBJECTIVE

Left atrial (LA) function is an important predictor of adverse cardiovascular outcomes in patients with hypertension (HT). Therefore, recognition of subtle LA dysfunction in the early stages of HT is essential for controlling modifiable variables. Several electrocardiographic and echocardiographic parameters have been studied to show early LA dysfunction. The goal of this study was to investigate the relationship between newly defined morphology-voltage-P wave duration electrocardiography (MVP ECG) score and early LA dysfunction in hypertensive patients.

MATERIALS AND METHODS

Eighty-nine hypertensive patients were included in this study. Based on speckle tracking echocardiography results, the patients were divided into two groups: 67 patients with normal LA function were included in Group 1, and 22 patients with abnormal LA function in Group 2.

RESULTS

Age, diabetes mellitus history, duration of HT history, left ventricular mass index, E/Em, and MVP ECG score values were statistically significant between the two groups. Based on the results of the multivariate logistic regression test, duration of HT history, E/Em, and MVP ECG score were determined as independent predictive parameters for early LA dysfunction in hypertensive patients.

CONCLUSION

In conclusion, MVP ECG score assessment could be a novel approach to detect early LA dysfunction in hypertensive patients.

Left atrial reservoir strain provides incremental value to left atrial volume index for evaluation of left ventricular filling pressure

BACKGROUND

Left atrial analysis is employed in diastolic assessment with left atrial volume index (LAVI) incorporated in the 2016 ASE/EACVI diastology guideline algorithm. LAVI has sub-optimal correlation with invasive left ventricular filling pressure (LVFP) and incorporation of left atrial reservoir strain (LASr) may improve diastolic assessment.

METHODS

A cross-sectional prospective study of 139 patients was undertaken with all patients undergoing transthoracic echocardiography immediately prior to cardiac catheterization with invasive evaluation of LVFP. LASr by speckle tracking echocardiography and conventional echocardiographic parameters were assessed in relation to invasive LVFP. Modification of the 2016 guideline algorithm was performed with incorporation of LASr in place of LAVI (LASr ≤23% indicating elevated LVFP). Accuracy of the modified and conventional algorithm were assessed for predicting invasive LVFP.

RESULTS

The mean age was 63±12 years with 27% female. LASr demonstrated superior correlation and receiver operator characteristic for predicting LVFP than LAVI (LASr: r -.46 (p < 0.01), AUC: .82 vs LAVI: r .19 (p 0.02), AUC: .66). LASr of ≤23% was the optimal cut-off for discriminating elevated LVFP (sensitivity 80%, specificity 77%). Modification of the 2016 algorithm with incorporation of LASr in place of LAVI reclassified 12% of the patient cohort and improved concordance of echocardiographic and invasive LVFP assessment (modified algorithm κ .47 vs 2016 algorithm κ: .33). No patients were incorrectly reclassified by modified algorithm assessment.

CONCLUSIONS

LASr better predicts invasive LVFP than LAVI. Modification of the 2016 guideline algorithm with incorporation of LASr in place of LAVI improves accuracy of echocardiographic assessment of LVFP.

Proteomic profiling for detection of early-stage heart failure in the community

Aims

Biomarkers may provide insights into molecular mechanisms underlying heart remodelling and dysfunction. Using a targeted proteomic approach, we aimed to identify circulating biomarkers associated with early stages of heart failure.

Methods and results

A total of 575 community‐based participants (mean age, 57 years; 51.7% women) underwent echocardiography and proteomic profiling (CVD II panel, Olink Proteomics). We applied partial least squares‐discriminant analysis (PLS‐DA) and a machine learning algorithm [eXtreme Gradient Boosting (XGBoost)] to identify key proteins associated with echocardiographic abnormalities. We used Gaussian mixture modelling for unbiased clustering to construct phenogroups based on influential proteins in PLS‐DA and XGBoost. Of 87 proteins, 13 were important in PLS‐DA and XGBoost modelling for detection of left ventricular remodelling, left ventricular diastolic dysfunction, and/or left atrial reservoir dysfunction: placental growth factor, kidney injury molecule‐1, prostasin, angiotensin‐converting enzyme‐2, galectin‐9, cathepsin L1, matrix metalloproteinase‐7, tumour necrosis factor receptor superfamily members 10A, 10B, and 11A, interleukins 6 and 16, and α1‐microglobulin/bikunin precursor. Based on these proteins, the clustering algorithm divided the cohort into two distinct phenogroups, with each cluster grouping individuals with a similar protein profile. Participants belonging to the second cluster (n = 118) were characterized by an unfavourable cardiovascular risk profile and adverse cardiac structure and function. The adjusted risk of presenting echocardiographic abnormalities was higher in this phenogroup than in the other (P < 0.0001).

Conclusions

We identified proteins related to renal function, extracellular matrix remodelling, angiogenesis, and inflammation to be associated with echocardiographic signs of early‐stage heart failure. Proteomic phenomapping discriminated individuals at high risk for cardiac remodelling and dysfunction.

Subclinical Heart Dysfunction in Relation to Metabolic and Inflammatory Markers: A Community-Based Study

BACKGROUND

Population studies investigating the contribution of immunometabolic disturbances to heart dysfunction remain scarce. We combined high-throughput biomarker profiling, multidimensional network analyses, and regression statistics to identify immunometabolic markers associated with subclinical heart dysfunction in the community.

METHODS

In 1,236 individuals (mean age, 51.0 years; 51.5% women), we measured 39 immunometabolic markers and assessed echocardiographic indexes of left ventricular diastolic dysfunction (LVDD) and left atrial (LA) reservoir dysfunction. We used partial least squares (PLS) to filter the most relevant biomarkers related to the echocardiographic characteristics. Subsequently, we assessed the associations between the echocardiographic features and biomarkers selected in PLS while accounting for clinical confounders.

RESULTS

Influential biomarkers in PLS of echocardiographic characteristics included blood sugar, γ-glutamyl transferase, d-dimer, ferritin, hemoglobin, interleukin (IL)-4, IL-6, and serum insulin and uric acid. In stepwise regression incorporating clinical confounders, higher d-dimer was independently associated with higher E/e' ratio and LA volume index (P ≤ 0.05 for all). In multivariable-adjusted analyses, the risk for LVDD increased with higher blood sugar and d-dimer (P ≤ 0.048). After full adjustment, higher serum insulin and serum uric acid were independently related to worse LA reservoir strain and higher risk for LA reservoir dysfunction (P ≤ 0.039 for all). The biomarker panels detected LVDD and LA reservoir dysfunction with 87% and 79% accuracy, respectively (P < 0.0001).

CONCLUSIONS

Biomarkers of insulin resistance, hyperuricemia, and chronic low-grade inflammation were associated with cardiac dysfunction. These biomarkers might help to unravel cardiac pathology and improve the detection and management of cardiac dysfunction in clinical practice.

Assessment of the ability of the CHA2DS2-VASc scoring system to grade left atrial function by 2D speckle-tracking echocardiography

Background

The CHA₂DS₂-VASc scoring system is correlated with left atrial (LA) reservoir function in patients with atrial fibrillation (AF) rhythm or paroxysmal AF. We assessed the ability of CHA₂DS₂-VASc to grade LA function in patients with sinus rhythm who were candidates for coronary artery bypass grafting (CABG).

Methods

This cross-sectional study recruited 340 consecutive candidates for CABG and categorized them according to their CHA₂DS₂-VASc scores as mild-, moderate-, and high-risk score groups with 34 (10%), 83 (24%), and 223 (66%) patients, respectively. LA function was evaluated via 2D speckle-tracking echocardiography in terms of global longitudinal strain and strain rate during the reservoir, conduit, and contraction phases. In-hospital mortality, postoperative AF, prolonged intensive care unit (ICU) stay, and prolonged mechanical ventilation were assessed.

Results

LA strain and strain rate during the reservoir phase was statistically significantly lower in the high-risk score group than the low- and moderate-risk score groups (27.8 ± 6.9% vs 31.0 ± 5.0% vs 29.8 ± 6.1%, respectively; P = 0.004 and 2.6 ± 0.7 s⁻¹ vs 2.9 ± 0.6 s⁻¹ vs 2.9 ± 0.6 s⁻¹, correspondingly; P = 0.009) and regarding LA strain and strain rate during the conduit phase (9.7 [7.1–12.5]% vs 12.9 [9.4–15.1]% vs 11.5 [9.1–13.8]%, correspondingly; P < 0.001 and 2.1 [1.6–2.7] s⁻¹ vs 2.8 [2.4–3.6] s⁻¹ vs 2.6 [2.2–3.0] s⁻¹, respectively; P < 0.001). In addition, LA strain rate during the conduit phase was lower in the moderate-risk score group than the low-risk score group. After adjustments for possible confounders, these differences remained statistically significant. The risk of postoperative AF and prolonged ICU stay was highest in the high-risk score group (relative risk = 9.67 (1.31–71.43) and 8.05 (1.08–60.16), respectively; P = 0.026 and P = 0.042, respectively).

Conclusions

LA reservoir and conduit functions decreased in the high-risk score group, which was accompanied by an increased risk of postoperative AF and prolonged ICU stay.