Effect of Obesity on Left Atrial Strain in Persons Aged 35-55 Years (The Asklepios Study)

Obesity: the perfect storm for heart failure

Obesity condition causes morphological and functional alterations involving the cardiovascular system. These can represent the substrates for different cardiovascular diseases, such as atrial fibrillation, coronary artery disease, sudden cardiac death, and heart failure (HF) with both preserved ejection fraction (EF) and reduced EF. Different pathogenetic mechanisms may help to explain the association between obesity and HF including left ventricular remodelling and epicardial fat accumulation, endothelial dysfunction, and coronary microvascular dysfunction. Multi-imaging modalities are required for appropriate recognition of subclinical systolic dysfunction typically associated with obesity, with echocardiography being the most cost-effective technique. Therapeutic approach in patients with obesity and HF is challenging, particularly regarding patients with preserved EF in which few strategies with high level of evidence are available. Weight loss is of extreme importance in patients with obesity and HF, being a primary therapeutic intervention. Sodium-glucose co-transporter-2 inhibitors have been recently introduced as a novel tool in the management of HF patients. The present review aims at analysing the most recent studies supporting pathogenesis, diagnosis, and management in patients with obesity and HF.

Adiposity influences on myocardial deformation: a cardiovascular magnetic resonance feature tracking study in people with overweight to obesity without established cardiovascular disease

The objective of this study was to assess whether dietary-induced weight loss improves myocardial deformation in people with overweight to obesity without established cardiovascular disease applying cardiovascular magnetic resonance (CMR) with feature tracking (FT) based strain analysis. Ninety people with overweight to obesity without established cardiovascular disease (age 44.6 ± 9.3 years, body mass index (BMI) 32.6 ± 4 kg/m2) underwent CMR. We retrospectively quantified FT based strain and LA size and function at baseline and after a 6-month hypocaloric diet, with either low-carbohydrate or low-fat intake. The study cohort was compared to thirty-four healthy normal-weight controls (age 40.8 ± 16.0 years, BMI 22.5 ± 1.4 kg/m2). At baseline, the study cohort with overweight to obesity without established cardiovascular disease displayed significantly increased global circumferential strain (GCS), global radial strain (GRS) and LA size (all p < 0.0001 versus controls) but normal global longitudinal strain (GLS) and normal LA ejection fraction (all p > 0.05 versus controls). Dietary-induced weight loss led to a significant reduction in GCS, GRS and LA size irrespective of macronutrient composition (all p < 0.01). In a population with overweight to obesity without established cardiovascular disease subclinical myocardial changes can be detected applying CMR. After dietary-induced weight loss improvement of myocardial deformation could be shown. A potential clinical impact needs further studies.

Multi-Ethnic Study of Atherosclerosis Early Heart Failure Study: Rationale, Design, and Baseline Characteristics

BACKGROUND

Current prevalence estimates of heart failure (HF) are primarily based on self-report or HF hospitalizations. There is an unmet need to define the prevalence and pathogenesis of early symptomatic HF, which may be undiagnosed and precedes HF hospitalization.

METHODS

The MESA (Multi-Ethnic Study of Atherosclerosis) Early HF study was conducted during MESA exam 6 to determine the prevalence of early HF and investigate the transition from risk factors to early HF in a diverse population-based cohort of older adults. Between 2016 and 2018, 3285 MESA participants from 6 field centers underwent comprehensive speckle-tracking echocardiography with passive leg raise maneuver, Kansas City Cardiomyopathy Questionnaire, 6-minute walk test, arterial stiffness assessment, and proteomics (including NT-proBNP [N-terminal pro-B-type natriuretic peptide]).

RESULTS

Median age was 73 (25th-75th percentile 67-81) years, 53.2% were female, 25.6% were Black, 12.8% were Chinese, and 40.0% were White. The prevalence of HF risk factors was high: hypertension, 61.9%; former or current smoking, 53.7%; obesity 34.8%; diabetes; 24.7%; and chronic kidney disease; 22%. Overt cardiovascular disease, which ranged from 2.1% (HF) to 13.6% (atrial fibrillation), was less common. Of the 3285 participants, 96% underwent proteomics, 94% Kansas City Cardiomyopathy Questionnaire, 93% speckle-tracking echocardiography with passive leg raise, 82% arterial stiffness exam, and 77% 6-minute walk test. Feasibility of resting speckle-tracking echocardiography (87%-99% across cardiac chambers) and passive leg raise Doppler/speckle-tracking echocardiography (>84%) measurements was high. A total of 120 unique echocardiographic indices were measured.

CONCLUSIONS

The MESA Early HF study is a key resource for cardiovascular researchers who are interested in improving the epidemiological and phenotypic characterization of early HF.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00005487.

The effect of body weight on left atrial function determined by longitudinal strain analysis in young adults

PURPOSE

Obesity is a risk factor for various cardiovascular disorders. Left atrial (LA) function is vital for predicting adverse outcomes in many diseases. LA strain was recently proposed as a noninvasive and valuable parameter for LA functional evaluation. We investigated the effect of body mass index (BMI) values on left atrial functions determined by longitudinal strain analysis in young adults without concomitant disease.

METHODS

We prospectively included 134 subjects in our study. Participants were categorized into three subgroups, obese, overweight, and control, according to their BMI. Conventional echocardiographic measurements and strain analysis were performed on all patients.

RESULTS

There were 41 patients (30.5%) in the obesity group, 46 patients (34.3%) in the overweight group, and 47 patients (35.0%) in the control group. Obese patients had significantly larger LA volume (46.9 ± 12.1 ml; p < 0.001) compared to overweight and control subjects; however, LA volume index (21.4 ± 6.1 ml/m2 vs. 22.4 ± 6.1 ml/m2 vs. 22.4 ± 5.0 ml/m2; p = 0.652) were similar between groups. In the LA strain analysis, obese patients were found to have lower left atrial reservoir longitudinal strain (LASr) compared to both the overweight and control group (44.2 ± 5.8% vs. 39.1 ± 3.7% vs. 36.5 ± 4.9%; p < 0.001); moreover obese patients had significantly worse left atrial contraction phase longitudinal strain (LASct) (-15.1 ± 3.1% vs. -13.1 ± 2.5%; p = 0.007) and left atrial conduit phase longitudinal strain (LAScd) (-29.0 ± 7.1% vs. -23.3 ± 5.4%; p < 0.001) values compared to the control group. However, LASct and LAScd values did not differ between overweight and obese patients.

CONCLUSION

LA function determined by LA strain analysis was impaired in obese and overweight individuals compared to the control group, even in the early stages of life. The prognostic significance of this finding should be investigated in prospective studies.

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.

Interaction effect of type 2 diabetes mellitus and hypertension on left atrial function: a three-dimensional echocardiography study

Background

Type 2 diabetes mellitus (T2DM) and hypertension (HT) often coexist and contribute to left atrial (LA) functional abnormalities. The aim of the present study was to explore whether there is a potential interaction effect between T2DM and HT on LA function.

Methods

A total of 135 patients (45 with T2DM only, 45 with HT only, and 45 with both T2DM and HT) were enrolled and compared to 45 age- and sex-matched controls. LA volume fraction, including LA ejection fraction (LAEF), LA expansion index (LAEI), LA passive emptying fraction (LAPEF), and LA active emptying fraction (LAAEF), and strain parameters, including LA reservoir longitudinal strain (LASr), LA conduit longitudinal strain (LAScd), and LA contraction longitudinal strain (LASct), were obtained using three-dimensional echocardiography (3DE).

Results

Patients with T2DM had significantly more impaired LA reservoir and conduit functions compared to those without T2DM (P<0.05), and patients with HT had a significantly more impaired LA reservoir function, conduit function, and booster pump function compared to those without HT (P<0.05). Two-way analysis of variance showed that there were significant additive interaction effects between T2DM and HT with respect to LASr (PT2DM + HT =0.002) and LAScd (PT2DM + HT =0.001). Generalized linear model demonstrated that T2DM + HT had a greater relative contribution than either T2DM or HT alone to the LA strain indexes, even after adjustment for other confounders (LASr, βT2DM + HT =-3.931, 95% CI: -6.237 to -1.624, P=0.001; LAScd, βT2DM + HT=-3.781, 95% CI: -5.653 to -1.908, P<0.001).

Conclusions

Both T2DM and HT had an adverse effect on LA function. The coexistence of both conditions further impaired LA performance in an additive interaction fashion.

Left atrial phasic function: physiology, clinical assessment and prognostic value

Left atrial (LA) phasic function provides significant insights into the pathophysiology of cardiovascular disease. LA function is described in three phases: reservoir (atrial filling, during systole), conduit (passive emptying, during early diastole) and contractile (active emptying, during late diastole). LA phasic function can be evaluated by different imaging modalities, and a variety of techniques including volumetric analysis, deformation (strain) and Doppler methods. LA phasic function (particularly LA reservoir strain) is more sensitive and provides earlier detection of LA dysfunction than alterations in LA volume. LA function parameters have also demonstrated significant diagnostic and prognostic value, particularly in heart failure, atrial fibrillation and stroke. However, there remain barriers to implementation of phasic function parameters in clinical practice and guidelines. This review outlines the physiology of LA phasic function, methods of assessment, and its diagnostic and prognostic utility in varying pathologies.

The effects of obesity on longitudinal ventricular and atrial strain in a rural population of Spanish children and adolescents, evaluated by a new strain software

BACKGROUND AND OBJECTIVES

Research on the relationship between body mass index (BMI) and strain values in children and adolescents is limited. Our aim was to analyse the relationship between BMI and strain values of both ventricles and left atrium in children and adolescents.

METHODS

Both ventricles and left atrial strain values were compared among different BMI categories in children and adolescents from a town in the South of Spain.

RESULTS

Of the 198 subjects, aged 6-17 years, 53% were of normal weight, 26% were overweight and 21% had obesity. Lower absolute values of left ventricular global longitudinal strain (25.9 ± 2.0% vs. 26.9 ± 2.2%, p = 0.002) and right ventricular free wall longitudinal strain (29.5 ± 4.2% vs. 30.8 ± 4.5%, p = 0.04) were found in subjects with obesity and overweight versus subjects with normal weight. A lower right ventricular four-chamber longitudinal strain was also observed in males with obesity and overweight (24.8 ± 3.3% vs. 26.4 ± 3.6%, p = 0.03). Statistically significant negative correlations of BMI were found for all ventricular, but not atrial, strain values in univariate analysis. This association turned non-significant for right ventricular four-chamber longitudinal strain in multivariate analysis.

CONCLUSIONS

Utilizing this new strain software, children and adolescents with high BMI were associated with significantly lower values for left and right ventricular free wall longitudinal strain, without impact in left atrial strain.

Impact of body mass index on worsening of diastolic function and impairment of left atrial strain in the general female urban population: a subanalysis of the Berlin female risk evaluation echocardiography follow-up study

Background

The association of body mass index (BMI) with diastolic dysfunction (DD) is well described in the literature. However, there is conflicting evidence and long-term follow-up data regarding effects of BMI on preclinical DD and left atrial (LA) function are scarce, highlighting the importance of early detection tools, such as myocardial strain.

Purpose

The aim of our study was to prospectively analyze the impact of clinical and demographic parameters, especially of BMI, on worsening of diastolic function and left atrial strain (LAS) in an urban population of women with a low prevalence of cardiovascular risk factors.

Methods and Results

An extensive clinical and echocardiographic assessment comprising the analysis of phasic LAS using two-dimensional speckle-tracking echocardiography (2D STE) was performed in 258 participants of the Berlin Female Risk Evaluation (BEFRI) trial between October 2019 and December 2020 after a mean follow-up period of 6.8 years. We compared clinical and echocardiographic parameters stratifying women by BMI < or ≥25 kg/m2, and we analyzed the impact of demographic characteristics on the worsening of DD and LA mechanics in the longer-term follow-up using univariate and multivariate regression analyses. 248 women were suitable for echocardiographic analysis of LAS using 2D STE. After a mean follow-up time of 6.8 years, LA reservoir strain (LASr) and LA conduit strain (LAScd) were significantly reduced in participants with a BMI ≥25 kg/m2 compared with women with a BMI <25 kg/m2 at baseline (30 ± 8% vs. 38 ± 9%, p < 0.0001; -14 ± 7% vs. -22 ± 8%, p < 0.0001). 28% of the overweighted women presented a deterioration of diastolic function at the time of follow-up in contrast with only 7% of the group with a BMI <25 kg/m2 (p < 0.0001). BMI remained significantly associated with LAS reductions after adjustment for other risk factors in multivariate regression analyses.

Conclusion

Overweight and obesity are related to impaired LAS and to a worsening of diastolic function after a long-term follow-up in a cohort of randomly selected women.

The role of obesity-related cardiovascular remodelling in mediating incident cardiovascular outcomes: a population-based observational study

AIMS

We examined associations of obesity with incident cardiovascular outcomes and cardiovascular magnetic resonance (CMR) phenotypes, integrating information from body mass index (BMI) and waist-to-hip ratio (WHR). Then, we used multiple mediation to define the role of obesity-related cardiac remodelling in driving obesity-outcome associations, independent of cardiometabolic diseases.

METHODS AND RESULTS

In 491 606 UK Biobank participants, using Cox proportional hazard models, greater obesity (higher WHR, higher BMI) was linked to significantly greater risk of incident ischaemic heart disease, atrial fibrillation (AF), heart failure (HF), all-cause mortality, and cardiovascular disease (CVD) mortality. In combined stratification by BMI and WHR thresholds, elevated WHR was associated with greater risk of adverse outcomes at any BMI level. Individuals with overweight BMI but normal WHR had weaker disease associations. In the subset of participants with CMR (n = 31 107), using linear regression, greater obesity was associated with higher left ventricular (LV) mass, greater LV concentricity, poorer LV systolic function, lower myocardial native T1, larger left atrial (LA) volumes, poorer LA function, and lower aortic distensibility. Of note, higher BMI was linked to higher, whilst greater WHR was linked to lower LV end-diastolic volume (LVEDV). In Cox models, greater LVEDV and LV mass (LVM) were linked to increased risk of CVD, most importantly HF and an increased LA maximal volume was the key predictive measure of new-onset AF. In multiple mediation analyses, hypertension and adverse LV remodelling (higher LVM, greater concentricity) were major independent mediators of the obesity-outcome associations. Atrial remodelling and native T1 were additional mediators in the associations of obesity with AF and HF, respectively.

CONCLUSIONS

We demonstrate associations of obesity with adverse cardiovascular phenotypes and their significant independent role in mediating obesity-outcome relationships. In addition, our findings support the integrated use of BMI and WHR to evaluate obesity-related cardiovascular risk.

Association of Childhood Blood Pressure with Left Atrial Size and Function: Study of High Blood Pressure in Pediatrics-Adult Hypertension in Youth (SHIP AHOY)

OBJECTIVE(S)

To evaluate the cross-sectional association of cardiovascular disease risk factors with left atrial (LA) size and function among healthy youth, aged 11-18 years, with a wide range of blood pressures (BPs).

STUDY DESIGN

Echocardiographic images of youth enrolled in the Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth study were analyzed for LA measurements. The association of casual BP, ambulatory BP, and other cardiovascular disease risk factors with LA size and function were determined using descriptive statistics and multivariable regression. Regression models adjusting for age, sex, race, and body mass index z score determined the independent association between ambulatory systolic BP indices (mean systolic BP/50th %ile systolic BP) and BP phenotypes with LA outcomes while exploratory analyses investigated for additional predictors of LA outcomes.

RESULTS

The study population consisted of 347 youth: median age 15.7 years, 60% male and 40% non-White. Greater-risk casual systolic BP groups had worse cardiometabolic profiles but no differences in LA size and function. Each 0.1 increase in ambulatory systolic BP day or night index was associated with a 9.9 mL/m2 increase in LA volume/body surface area (LAV/BSA; 95th% CI 2.8-17.0, P = .006) and a 6.8 mL/m2 increase in LAV/BSA (95th% CI 0.8-12.8, P = .03), respectively. Ambulatory hypertension was associated with greater odds of abnormal LAV/BSA, defined as >75th %ile (2014 ambulatory BP monitoring criteria: OR 3.2 [95th% CI 1.4-7.2; P = .002]; 2022 ambulatory BP monitoring criteria: OR 2.1 [95th% CI 1.0-4.1; P = .008]).

CONCLUSIONS

Increasing ambulatory systolic BP and ambulatory hypertension are independently associated with LAV/BSA.

Decreased left atrial function in obesity patients without known cardiovascular disease

Obesity is a risk factor for heart failure with preserved ejection fraction (HFpEF). We hypothesized that assessment of left atrial (LA) strain may be useful to reveal precursors of HFpEF in obesity patients. Echocardiograms of obesity patients without known cardiovascular disease who underwent bariatric surgery, and echocardiograms of age- and gender matched controls were analyzed. The echocardiogram was repeated 1 year after bariatric surgery. LA reservoir strain (LASr), LA conduit strain (LAScd), and LA contractile strain (LASct) were measured. 77 Obesity patients were compared with 46 non-obese controls. Obesity patients showed a significantly decreased LA function compared with non-obese individuals (LASr 32.2% ± 8.8% vs. 39.6% ± 10.8%, p < 0.001; LAScd 20.1% ± 7.5% vs. 24.9% ± 8.3%, p = 0.001; LASct 12.1% ± 3.6% vs. 14.5% ± 5.5%, p = 0.005). There was no difference in prevalence of diastolic dysfunction between the obesity group and controls (9.1% vs. 2.2%, p = 0.139). One year after bariatric surgery, LASr improved (32.1% ± 8.9% vs. 34.2% ± 8.7%, p = 0.048). In the multivariable linear regression analysis, BMI was associated with LASr, LAScd, and LASct (β =  - 0.34, CI - 0.54 to - 0.13; β =  - 0.22, CI - 0.38 to - 0.06; β =  - 0.10, CI - 0.20 to - 0.004). Obesity patients without known cardiovascular disease have impairment in all phases of LA function. LA dysfunction in obesity may be an early sign of cardiac disease and may be a predictor for developing HFpEF. LASr improved 1 year after bariatric surgery, indicating potential reversibility of LA function in obesity.

Effect of Weight Loss on Early Left Atrial Myopathy in People With Obesity But No Established Cardiovascular Disease

Background Obesity is associated with left atrial (LA) remodeling (ie, dilatation and dysfunction) which is an independent determinant of future cardiovascular events. We aimed to assess whether LA remodeling is present in obesity even in individuals without established cardiovascular disease and whether it can be improved by intentional weight loss. Methods and Results Forty-five individuals with severe obesity without established cardiovascular disease (age, 45±11 years; body mass index; 39.1±6.7 kg/m²; excess body weight, 51±18 kg) underwent cardiac magnetic resonance for quantification of LA and left ventricular size and function before and at a median of 373 days following either a low glycemic index diet (n=28) or bariatric surgery (n=17). Results were compared with those obtained in 27 normal-weight controls with similar age and sex. At baseline, individuals with obesity displayed reduced LA reservoir function (a marker of atrial distensibility), and a higher mass and LA maximum volume (all P<0.05 controls) but normal LA emptying fraction. On average, weight loss led to a significant reduction of LA maximum volume and left ventricular mass (both P<0.01); however, significant improvement of the LA reservoir function was only observed in those at the upper tertile of weight loss (≥47% excess body weight loss). Following weight loss, we found an average residual increase in left ventricular mass compared with controls but no residual significant differences in LA maximum volume and strain function (all P>0.05). Conclusions Obesity is linked to subtle LA myopathy in the absence of overt cardiovascular disease. Only larger volumes of weight loss can completely reverse the LA myopathic phenotype.

Cardiorespiratory fitness, obesity and left atrial function in patients with atrial fibrillation

Background

Low cardiorespiratory fitness (CRF) and obesity are related to the development and maintenance of atrial fibrillation (AF). The aim of this study was to determine the association between CRF, obesity and left atrial (LA) mechanical parameters in patients with AF.

Methods

A cohort of 154 consecutive paroxysmal and persistent AF patients (Age: 62 ± 10, 26% female) referred for exercise stress testing and transthoracic echocardiography were included. We included patients in sinus rhythm with preserved left ventricular ejection fraction who were able to complete a maximal exercise test. Left atrial strain in the reservoir (LASr), booster (LASb) and conduit (LASc) phases were assessed using dedicated software. LA stiffness, emptying fraction (LAEF) and LA to LV ratio were calculated using previously described formulas.

Results

CRF was positively associated with LAEF (β = 1.3, 95% CI 0.1–2.3, p = 0.02), reservoir (β = 1.5, 95% CI 0.9–2.1, p < 0.001), booster (β = 0.8, 95% CI 0.4–1.2, p < 0.001) and conduit strain (β = 0.7, 95% CI 0.3–1.1, p = 0.001). We observed an inverse association between CRF and both LA stiffness index (β = −0.02, 95% CI (−0.03)–(−0.01), p < 0.001) and LA to LV ratio (β = −0.03, 95% CI (−0.04)–(−0.01), p < 0.001). Obese patients had significantly higher indexed LA volumes compared to overweight and normal BMI patients. The association between obesity and measures of LA function and stiffness did not reach statistical significance.

Conclusion

Among AF patients, higher CRF was independently associated with greater LA function and compliance. Obesity was associated with higher LA volumes yet preserved mechanical function.

The impact of lifestyle intervention on left atrial function in type 2 diabetes: results from the DIASTOLIC study

Aerobic exercise training and low energy diets have been shown to improve left ventricular remodelling and diastolic function in adults with type 2 diabetes (T2D), albeit with differential effects. The impact of these lifestyle interventions on left atrial (LA) function, however, has not previously been reported. The DIASTOLIC study was a prospective, randomised, open-label, blind endpoint trial, in which 90 people with obesity and T2D and no prevalent cardiovascular disease were randomised to a 12-week intervention of: (i) routine care, (ii) aerobic exercise training, or (iii) low energy (≈ 810 kcal/day) meal replacement plan (MRP). Cardiac magnetic resonance (CMR) imaging was performed pre- and post-intervention. Image analysis included LA volumes (LAV), emptying fraction (LAEF), and LA strain (LAS) corresponding to LA reservoir (LAS-r), conduit (LAS-cd), and booster pump (LAS-bp) function. 73 participants with T2D (mean age 50 ± 6 years, 62% male, body mass index (BMI) 36.1 ± 5.3 kg/m2) completed the trial and had analysable LA images. There was no significant change in CMR measured LA volumetric function (LAV/LAEF) in any group. The routine care group showed no significant change in BMI or LAS. In the MRP group, there were significant reductions in BMI (4.5 kg/m2) and a significant increase in LAS-r and LAS-bp (29.9 ± 7.0 to 32.3 ± 7.0%, p = 0.036 and 14.6 ± 5.3 to 17.2 ± 3.7%, p = 0.034). The exercise group showed a small reduction in BMI (0.49 kg/m2), with no significant change in LAS. Compared to routine care, weight loss via a 12-week MRP, led to improvements in LA filling and contractile function in adults with T2D and obesity. However, these within-group changes were not statistically significant on between-group comparison. ClinicalTrials.gov Identifier: NCT02590822.

Effects of obesity on left atrial phasic functions in patients with chronic ischemic heart disease and preserved left ventricular ejection fraction without recent myocardial infarction: a two-dimensional speckle-tracking echocardiography study

PURPOSE

Left atrial (LA) phasic functions in various subgroups of subjects with obesity are differently impaired, suggesting that obesity may have diverse effects in dissimilar subgroups of subjects with obesity. We aimed to compare the effects of obesity on LA phasic functions in patients suffering from chronic ischemic heart disease with a preserved left ventricular ejection fraction and without a recent myocardial infarction.

METHODS

In our cross-sectional study, 145 consecutive candidates for isolated coronary artery bypass graft (CABG) surgery were divided according to the presence of obesity into 2 groups: obese (36 patients) and nonobese (103 patients), and LA phasic functions were evaluated by two-dimensional speckle-tracking echocardiography (2D STE).

RESULTS

The longitudinal strain rate during the reservoir phase (3.0 ± 0.7 s-1 vs 2.7 ± 0.6 s-1; P = 0.032), longitudinal strain during the contraction phase (19.2 ± 4.7% vs 17.2 ± 4.1%; P = 0.022), and the longitudinal strain rate during the contraction phase (4.4 ± 1.2 s-1 vs 3.9 ± 1.2 s-1; P = 0.036) decreased in the obese group compared with the nonobese group. The other longitudinal 2D STE-derived markers of the LA phasic functions were not different between the 2 groups.

CONCLUSIONS

Among patients suffering from chronic ischemic heart disease with a preserved left ventricular ejection fraction and without a recent myocardial infarction, LA reservoir and contraction functions as measured by 2D STE were impaired in patients with obesity compared with those without it.

Left atrial evaluation by cardiovascular magnetic resonance: sensitive and unique biomarkers

Left atrial (LA) imaging is still not routinely used for diagnosis and risk stratification, although recent studies have emphasized its importance as an imaging biomarker. Cardiovascular magnetic resonance is able to evaluate LA structure and function, metrics that serve as early indicators of disease, and provide prognostic information, e.g. regarding diastolic dysfunction, and atrial fibrillation (AF). MR angiography defines atrial anatomy, useful for planning ablation procedures, and also for characterizing atrial shapes and sizes that might predict cardiovascular events, e.g. stroke. Long-axis cine images can be evaluated to define minimum, maximum, and pre-atrial contraction LA volumes, and ejection fractions (EFs). More modern feature tracking of these cine images provides longitudinal LA strain through the cardiac cycle, and strain rates. Strain may be a more sensitive marker than EF and can predict post-operative AF, AF recurrence after ablation, outcomes in hypertrophic cardiomyopathy, stratification of diastolic dysfunction, and strain correlates with atrial fibrosis. Using high-resolution late gadolinium enhancement (LGE), the extent of fibrosis in the LA can be estimated and post-ablation scar can be evaluated. The LA LGE method is widely available, its reproducibility is good, and validations with voltage-mapping exist, although further scan-rescan studies are needed, and consensus regarding atrial segmentation is lacking. Using LGE, scar patterns after ablation in AF subjects can be reproducibly defined. Evaluation of 'pre-existent' atrial fibrosis may have roles in predicting AF recurrence after ablation, predicting new-onset AF and diastolic dysfunction in patients without AF. LA imaging biomarkers are ready to enter into diagnostic clinical practice.

Impact of BMI on Left Atrial Strain and Abnormal Atrioventricular Interaction in Patients With Type 2 Diabetes Mellitus: A Cardiac Magnetic Resonance Feature Tracking Study

BACKGROUND

Type 2 diabetes mellitus (T2DM) and obesity often coexist and together contribute to left atrial (LA) functional abnormalities. However, little is known about the impact of body mass index (BMI) on LA strains measured using cardiac magnetic resonance feature tracking (MR-FT).

PURPOSE

To investigate the additive effect of BMI on LA functional remodeling using MR-FT as well as to explore abnormal atrioventricular interaction in T2DM patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred and fifty-nine T2DM patients (53, 34, and 72 normal-weight, overweight, and obese individuals) and 105 non-diabetic controls (46, 32, and 27 normal-weight, overweight, and obese individuals).

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession.

ASSESSMENT

LA reservoir strain (ε_s ), conduit strain (ε_e ), and active strain (ε_a ) and their corresponding strain rates (SRs, SRe, SRa) were measured together with left ventricular (LV) radial, circumferential, and longitudinal peak strain, peak systolic strain rate, and peak diastolic strain rate.

STATISTICAL TESTS

Student's t-test or Mann-Whitney U test, one-way ANOVA, univariate and multivariate linear regression. A P value <0.05 was considered statistically significant.

RESULTS

Compared to controls in the same BMI category, T2DM patients had significantly decreased reservoir and conduit function, while pump function was not significantly different (ε_a and SRa: P = 0.757 and 0.583 for normal-weight, P = 0.171 and 0.426 for overweight, P = 0.067 and 0.330 for obese). LA strains were significantly correlated with BMI (r = -0.346 for ε_s , -0.345 for ε_e ) in T2DM patients. Multivariable linear regression analysis indicated that BMI was independently associated with LA ε_s and ε_e , LV global longitudinal strain was independently associated with LA ε_s and ε_a , and LV circumferential peak diastolic strain rate was independently associated with LA ε_e .

DATA CONCLUSION

These findings suggest that the coexistence of increased body weight and T2DM patients can exacerbate the impairment of LA strains and indicate abnormal atrioventricular interactions.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Associations of body size and composition with subclinical cardiac dysfunction in older individuals: the cardiovascular health study

BACKGROUND

Focused studies in younger to middle-aged populations have demonstrated a relationship between obesity and adverse cardiac mechanics. We examined whether measures of overall and central adiposity are associated with cardiac mechanics, assessed by speckle-tracking echocardiography, in an older population without prevalent coronary heart disease or heart failure.

METHODS

Body composition was measured by anthropometry, bioelectrical impedance, and dual-energy x-ray absorptiometry among participants in the Cardiovascular Health Study, a population-based cohort of adults aged 65 years or older. Systolic and diastolic cardiac mechanics were measured with speckle-tracking analysis of echocardiograms. Multi-variable adjusted linear regression models were used to investigate associations of body composition measures and cardiac mechanics.

RESULTS

Mean age for the 3525 included participants was 72.6 years, 39% were male, and 10% were black. Mean body-mass index (BMI) was 26.3 ± 4.4 kg/m², waist circumference (WC) was 93.2 ± 12.9 cm, and waist-to-hip ratio was 0.92 ± 0.09. In fully adjusted analyses, all adiposity measures were associated with worse LV longitudinal strain, LV early diastolic strain rate, and left atrial reservoir strain; however, associations were strongest for WC and BMI (p < 0.001). When both BMI and WC were included in the same model, only WC remained associated with each cardiac strain measure.

CONCLUSION

In this cross-sectional study of older adults, central obesity was most robustly associated with impaired left ventricular systolic and diastolic strain as well as left atrial strain. The adverse effects of central obesity appear to extend even into older age.

Multichamber Dysfunction in Children and Adolescents With Severe Obesity: A Cardiac Magnetic Resonance Imaging Myocardial Strain Study

BACKGROUND

In severe obesity, left ventricular (LV) and right ventricular (RV) remodeling and contractile dysfunction have been documented, but less is known regarding left atrial (LA) dysfunction and its association with LV/RV remodeling, especially in children.

PURPOSE

To assess the effects of severe childhood obesity on cardiac function by using multichamber strain analysis with MRI.

STUDY TYPE

Prospective.

SUBJECTS

Forty-five children aged 7-18 years (including 20 with severe obesity, defined as a body mass index values above the 99th percentile).

FIELD STRENGTH

5 T.

SEQUENCE

Steady-state-free-precession (SSFP) images in short-axis views and longitudinal two- and four-chamber views.

ASSESSMENT

Cardiac strain measurements were derived from standard SSFP cine images by using a dedicated MR imaging feature tracking software. Inter- and intra-rater reliability were evaluated.

STATISTICAL TESTS

Independent sample t test, Spearman's correlation coefficient, principal component analysis, Bland-Altman analysis, and intra-class correlation coefficients (ICC). A P value <0.05 was considered statistically significant.

RESULTS

As compared to children without obesity, those with obesity showed significantly reduced LA reservoir function (22.2% ± 6.4% vs. 33.8% ± 9.0%) and contractile function (5.4% ± 3.2% vs. 13.3% ± 8.0%) as well as significantly decreased absolute values for LA longitudinal strain in reservoir and contraction phases and LA radial motion fraction in reservoir and contraction phases. Children with severe obesity showed significantly reduced absolute RV radial motion fraction (-10.6% ± 2.9% vs. -18.2% ± 2.9%) and circumferential strain (-10.6% ± 2.9% vs. -16% ± 2.5%) as well as higher LV mass index (28.7% ± 5.1% vs. 21.7 ± 4.6 g/m² ) along with significantly reduced LV ejection fraction (56.4% ± 3.9% vs. 60% ± 4.1%), LV radial strain (56% ± 6% vs. 61.8% ± 11.3%), and longitudinal strain (-17.8% ± 1.8% vs. -20.3% ± 3.2%). Reliability was good to excellent, with ICC ranging from 79.1% to 97.7%.

DATA CONCLUSION

MR feature-tracking strain analysis revealed multichamber dysfunction in severely obese children with impaired LA reservoir and atrial contraction phases, which suggest an early loss in the compensatory ability of atrial contraction with severe obesity.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 3.

Cardiopulmonary Pathophysiological Aspects in the Context of COVID-19 and Obesity

Obesity is a significant public health concern associated with high morbidity. Obese patients are at risk of severe COVID-19 infection, and obesity is a high-risk factor for admission to the intensive care unit. We aimed to write a narrative review of cardiac and pulmonary pathophysiological aspects of obese patients in the context of COVID-19 infection. Obesity affects lung volume, with a decrease in expiratory reserve volume, which is associated with a decrease in lung and chest wall compliance, an increase in airway resistance, and an increase in work of breathing. Obesity affects cardiac structure and hemodynamics. Obesity is a risk factor for hypertension and cardiovascular disorders. Moreover, obesity is associated with a low-grade inflammatory state, endothelial dysfunction, hyperinsulinemia, and metabolic disorders. Obesity is associated with severe COVID-19 and invasive mechanical ventilation. These previous cardiopulmonary pathological aspects may explain the clinical severity in obese patients with COVID-19. Obese patients are at risk of severe COVID-19 infection. Understanding cardiorespiratory pathophysiological aspects may help physicians manage patients in hospitals.

Interaction effect of myocardial infarction and obesity on left atrial functions

PURPOSE

To determine whether myocardial infarction (MI) would lead to a greater decrease in left atrial (LA) functions in subjects with than without obesity.

METHODS

A total of 310 consecutive patients were divided into four groups according to the presence or absence of obesity and MI. The functions of the LA were evaluated in terms of longitudinal deformation of the LA myocardium via 2D speckle-tracking echocardiography.

RESULTS

The adjusted analysis showed a reduction in the strain and strain rate during the reservoir and contraction phases and in the strain rate during the conduit phase in patients with MI and in subjects with obesity (P < .05). In addition, there was a significant interaction effect of obesity and MI on the strain rate during the contraction phase (P = .048).

CONCLUSIONS

There is an independent and additional interaction effect of obesity and MI on the reservoir and conduit functions of the LA. MI was more deleterious to the contraction function in subjects without than with obesity, so that the contraction function was similar in MI patients without obesity and MI patients with obesity.

Contemporary narrative review on left atrial strain mechanics in echocardiography: cardiomyopathy, valvular heart disease and beyond

Left atrial (LA) strain mechanics refer to the measurement of LA myocardial deformation expressed as a percentage, and have been gathering interest over the last decade with expanding research supporting their utility in multiple cardiovascular disorders. Measured through advanced dynamic imaging techniques which include tissue Doppler imaging (TDI) and two-dimensional (2D) speckle tracking echocardiography (STE), LA strain mechanics are affected by left ventricular diastolic dysfunction prior to the onset of functional and structural changes in the left ventricle (LV). There is a need for practising cardiologists to become more familiar with the clinical utility of LA strain mechanics. In this article, we begin by reviewing the physiologic function of the LA, using this as a basis for understanding LA strain mechanics. The focus of this review article is to provide a contemporary update on the utility of LA strain mechanics in a range of cardiovascular disorders, including atrial fibrillation (AF), hypertrophic cardiomyopathy (HCM), valvular pathologies, coronary artery disease (CAD) as well as systemic diseases, such as hypertension (HTN), obesity and diabetes mellitus (DM). This article also highlights the current limitations in more widespread clinical applications of LA strain mechanics, as well as outlining the future perspectives on the clinical applications of LA strain mechanics.

Impaired left atrial stiffness in patients with corrected congenital left ventricular outflow obstructions

OBJECTIVE

We examined the left atrial stiffness index (LA Stiff) on echocardiography and its determinants in adults and adolescents with repaired congenital left ventricular outflow obstructions (c-LVOOs), including isolated subaortic stenosis (SAS), stenotic bicuspid aortic valve (BAV), and aortic coarctation (CoA).

METHODS

Seventy-two patients (43 males, age: 31 ± 15 years) with repaired c-LVOOs (SAS: n = 12; BAV: n = 27; CoA: n = 33) were compared to 72 age- and sex-matched controls. 2D strain imaging was performed to assess left ventricular (LV) and LA function, including peak positive longitudinal LA strain (LAS), late diastolic LA strain (LDS), and LV global longitudinal strain (GLS). The (E/Ea)/LAS ratio was used to calculate LA Stiff.

RESULTS

LA Stiff was significantly higher in the c-LVOO group than in the control group. Among the c-LVOO patients, the CoA group had the lowest GLS and the highest LA Stiff; no significant differences were found with respect to sex, hypertension history, smoking status, or repeated repair among c-LVOO subtypes. Multivariable regression analysis with the variables "BMI" and "c-LVOO subtype" revealed that BMI and c-LVOO subtypes were independently associated with LA Stiff (b = 0.290, P = .009 and b = 0.353, P = .002, respectively).

CONCLUSIONS

We documented abnormal LA Stiff values in adults and adolescents after c-LVOO repair. Patients with CoA demonstrated the most impaired LA Stiff values. Overweight may contribute to worse LA Stiff values. Further studies are required to determine the prognostic implications of LA Stiff in patients with repaired c-LVOOs.

Associations of region-specific visceral adiposity with subclinical atrial dysfunction and outcomes of heart failure

AIMS

Excessive visceral adiposity (VAT) plays an essential role in metabolic derangements with those close to heart further mediates myocardial homeostasis. The disparate biological links between region-specific VAT and cardiometabolic profiles as mediators influencing atrial kinetics remain unexplored.

METHODS AND RESULTS

Among 1326 asymptomatic individuals, region-specific VAT including peri-aortic root fat (PARF) and total pericardial fat (PCF) of cardiac region, together with thoracic peri-aortic adipose tissue (TAT), was assessed using multiple-detector computed tomography. VAT measures were related to functional left atrial (LA) metrics assessed by speckle-tracking algorithm and clinical outcomes of atrial fibrillation (AF) and heart failure (HF). Multivariate linear regression models incorporating body fat, metabolic syndrome, and E/TDI-e' consistently demonstrated independent associations of larger PARF/PCF with peak atrial longitudinal systolic strain (PALS) reduction, higher LA stiffness, and worsened strain rate components; instead, TAT was independently associated with cardiometabolic profiles. PARF rather than PCF or TAT conferred independent prognostic values for incident AF/HF by multivariate Cox regression (adjusted hazard ratio: 1.56, 95% confidence interval: 1.17-2.08, P = 0.002) during a median of 1790 days (interquartile range: 25th to 75th: 1440-1927 days) of follow-up, with subjects categorized into worst PALS and largest VAT tertiles demonstrating highest events (all log-rank P < 0.001). Mediation analysis showed that higher triglyceride and lower high-density lipoproteins may serve as intermediary factors for effects between VAT and LA functional metrics, with lesser role by glucose level.

CONCLUSIONS

Visceral adiposity surrounding atrial region was tightly associated with subclinical atrial dysfunction and incident AF or HF beyond metabolic factors. Instead, peri-aortic adiposity may mediate their toxic effects mainly through circulating cardiometabolic profiles.

Left atrial strain and diastolic function abnormalities in obese and type 2 diabetic adolescents and young adults

Background

Adults with obesity and type 2 diabetes mellitus (T2DM) related to obesity are at increased risk of heart failure with preserved ejection fraction (HFpEF). Whether left ventricular (LV) diastolic function abnormalities related to obesity and T2DM start in adolescence and early adulthood is unknown. We non-invasively evaluated the differences seen in LV diastolic and left atrial (LA) function in adolescents and young adults with obesity and T2DM.

Methods

We analyzed echocardiographic measures of LV diastolic function in patients with structurally normal hearts which were divided into 3 groups (normal weight, obese, and T2DM). Spectral and tissue Doppler and 2-D speckle tracking measurements of diastolic function were obtained. Logistic regression was performed to compare the prevalence of abnormalities in diastolic function based on the worst 25th percentile for each measure to determine the prevalence of diastolic and LA function abnormalities in obese and T2DM patients.

Results

331 teenagers and young adults (median age 22.1 years) were analyzed (101 normal weight, 114 obese, 116 T2DM). Obese and T2DM group had lower E/A and higher E/e′. Obese and T2DM patients had significantly lower atrial reservoir, conduit, and booster strain and worse reservoir and conduit strain rate compared to normal patients (p < 0.001 for all measures). All patients had normal LA volumes. On multivariable analysis, conduit strain and reservoir and conduit strain rate were independently associated with having below the 25th percentile e′. Conduit strain rate was independently associated with having below the 25th percentile for mitral E/A ratio on multivariable analysis.

Conclusions

Abnormal indices of LV diastolic function are detected in adolescents and young adults with obesity and T2DM. LA function and strain analysis were able to detect evidence of decreased reservoir, conduit, and booster strain in these patients although LA volume was normal. The use of LA function strain may increase our ability to detect early diastolic function abnormalities in this population.

Sex Differences in the Association of Cumulative Body Mass Index from Early Adulthood to Middle Age and Left Atrial Remodeling Evaluated by Three-Dimensional Echocardiography: The Coronary Artery Risk Development in Young Adults Study

Background:

The relationship between long-term obesity and left atrial (LA) structure and function is not entirely understood. We examined the association of cumulative body mass index (cBMI) with LA remodeling using three-dimensional (3D) speckle-tracking echocardiography (STE).

Methods:

The Coronary Artery Risk Development in Young Adults (CARDIA) study is a community-based cohort of black and white, men and women, ages 18–30 years at baseline in 1985–86 from four U.S. centers. This study included 2,144 participants who had satisfactory image quality and body mass index measurements during the entire follow-up period. The 3D STE-derived LA parameters were maximum, minimum, and pretrial contraction volumes; total, passive, and active emptying fraction; maximum systolic longitudinal strain; and early and late diastolic longitudinal strain rates. Multivariable linear regression analyses stratified by sex assessed the relationship between cBMI and 3D STE-derived LA parameters, adjusting for demographics and traditional cardiovascular.

Results:

The mean age of the cohort was 55 ± 3.6 years; 54.8% were women, and 46.5% were black. There were statistically significant additive sex interactions for the association between cBMI and LA minimum contraction value, maximum systolic longitudinal strain, and early and late diastolic longitudinal strain rates. In the fully adjusted model, greater cBMI was associated with lower magnitude LA longitudinal deformation (maximum systolic longitudinal strain and early and late diastolic longitudinal strain rates) in men and with higher LA emptying fraction in women. In addition, greater cBMI was associated with higher LA phasic volumes indices in both men and women.

Conclusions:

This study showed that while greater cBMI from early adulthood throughout middle age was associated with higher LA volumes in both genders, differences were found for LA function, with lower longitudinal deformation in men and higher reservoir and active LA function in women. (J Am Soc Echocardiogr 2020;33:878–87.)

Evaluation of the left atrial function by two-dimensional speckle-tracking echocardiography in diabetic patients with obesity

Obesity and diabetes are risk factors for atrial cardiomyopathy and are, thus, deemed public health concerns. However, the effects of obesity on the left atrial (LA) function in patients with diabetes have not been determined yet. We sought to evaluate the effects of obesity on the LA function in patients with type 2 diabetes. Ninety-six consecutive patients with type 2 diabetes without significant coronary artery stenosis in selective coronary angiography were included in this cross-sectional study. Two-dimensional speckle-tracking echocardiography (2DSTE)-derived longitudinal LA myocardial deformation markers were compared between 42 obese and 54 nonobese patients. The longitudinal strain and the longitudinal strain rate of the LA myocardium during the reservoir phase and the contraction phase were reduced in the obese patients with diabetes compared with the nonobese patients with diabetes in the unadjusted analysis. In the adjusted analysis, longitudinal strain and the longitudinal strain rate during the contraction phase and the longitudinal strain rate during the reservoir phase were decreased in the obese patients with diabetes. The reservoir and contraction functions of the LA as evaluated by 2DSTE were decreased in our obese patients with diabetes compared with our nonobese patients with diabetes.