Left Ventricular Sphericity Index is a reproducible bedside echocardiographic measure of geometric change between acute phase Takotsubo's syndrome and acute anterior myocardial infarction

Background: Left ventricular sphericity index (LVSI) is a simple, quick and reproducible measure to evaluate LV geometric changes. The aim of our study was to evaluate the utility of LVSI as a rapid discrimination tool in two disease processes; Takotsubo’s Syndrome (TS) and Anterior Myocardial Infarction (AMI), in the absence of significant left ventricular systolic dysfunction. Methods: Consecutive patients with acute phase TS admitted to our institution (Jan 2013 - Dec 2018) were evaluated (n=66). Patients with a comprehensive two-dimensional transthoracic echocardiogram were included in primary analysis (n=50) and age-matched with a cohort of patients with acute anterior AMI (n=50). Appraisal of demographic, clinical and echocardiographic parameters of patients was undertaken. Biplane LVSI was calculated as an average of the short- and long-axis length in the 4- and 2-chamber apical views. Results: A total of 50 TS patients (64.3±13.7 years, 18% men) were matched with 50 AMI (62.10±12.84 years, 74% men) patients. There was no significant difference in baseline cardiovascular risk factors other than diabetes mellitus (AMI 34% vs TS 17%, p = 0.034). There was also no difference in LV mass (p=0.10) or LVEF (p=0.52) between the two groups. Interestingly, there was a significant difference in mean LVSI between TS (0.60±0.06) vs AMI (0.52±0.07) (p<0.01) reflecting a more spherical shaped left ventricle in the acute TS group. Conclusions: LVSI is reflective of geometric changes in the left ventricle and may be helpful as a rapid and reproducible diagnostic tool in differentiating between TS and AMI in the acute phase

Left atrial reservoir strain by speckle tracking echocardiography : association with exercise capacity in chronic kidney disease

BACKGROUND: Left atrial (LA) function plays a pivotal role in modulating left ventricular performance. The aim of our study was to evaluate the relationship between resting LA function by strain analysis and exercise capacity in patients with chronic kidney disease (CKD) and evaluate its utility compared with exercise E/e’. METHODS AND RESULTS: Consecutive patients with stage 3 and 4 CKD without prior cardiac history were prospectively recruited from outpatient nephrology clinics and underwent clinical evaluation and resting and exercise stress echocardiography. Resting echocardiographic parameters including E/e’ and phasic LA strain (LA reservoir [LASr], conduit, and contractile strain) were measured and compared with exercise E/e’. A total of 218 (63.9±11.7 years, 64% men) patients with CKD were recruited. Independent clinical parameters associated with exercise capacity were age, estimated glomerular filtration rate, body mass index, and sex (P<0.01 for all), while independent resting echocardiographic parameters included E/e’, LASr, and LA contractile strain (P<0.01 for all). Among resting echocardiographic parameters, LASr demonstrated the strongest positive correlation to metabolic equivalents achieved (r=0.70; P<0.01). Receiver operating characteristic curves demonstrated that LASr (area under the curve, 0.83) had similar diagnostic performance as exercise E/e’ (area under the curve, 0.79; P=0.20 on DeLong test). A model combining LASr and clinical metrics showed robust association with metabolic equivalents achieved in patients with CKD. CONCLUSIONS: LASr, a marker of decreased LA compliance is an independent correlate of exercise capacity in patients with stage 3 and 4 CKD, with similar diagnostic value to exercise E/e’. Thus, LASr may serve as a resting biomarker of functional capacity in this population

Myocardial viability : from proof of concept to clinical practice

Ischaemic left ventricular (LV) dysfunction can arise from myocardial stunning, hibernation, or necrosis. Imaging modalities have become front-line methods in the assessment of viable myocardial tissue, with the aim to stratify patients into optimal treatment pathways. Initial studies, although favorable, lacked sufficient power and sample size to provide conclusive outcomes of viability assessment. Recent trials, including the STICH and HEART studies, have failed to confer prognostic benefits of revascularisation therapy over standard medical management in ischaemic cardiomyopathy. In lieu of these recent findings, assessment of myocardial viability therefore should not be the sole factor for therapy choice. Optimization of medical therapy is paramount, and physicians should feel comfortable in deferring coronary revascularisation in patients with coronary artery disease with reduced LV systolic function. Newer trials are currently underway and will hopefully provide a more complete understanding of the pathos and management of ischaemic cardiomyopathy

The impact of body mass index on cardiac structure and function in a cohort of obese patients without traditional cardiovascular risk factors

Background: Obesity has been linked with alterations in hemodynamic, autonomic, and hormonal pathways in the body, leading to a spectrum of cardiovascular changes. We sought to evaluate the effects of obesity on structural and functional changes of the heart in the absence of cardiac disease and associated risk factors.Methods: We identified healthy outpatients without any cardiovascular disease or risk factors from our institution's echocardiography database (2017-2020). Patients were stratified by body mass index (BMI; normal: 18.5-25 kg/m(2); overweight: 25-30 kg/m(2); class 1 obesity: 30-35 kg/m(2); class 2 obesity: 35-40 kg/m(2); class 3 obesity: >40 kg/m(2)). Traditional and advanced echocardiographic parameters of cardiac chamber size and function including left ventricular global longitudinal strain (LV-GLS), left atrial reservoir strain (LASr), and right ventricular free wall strain (RV-FWS) were examined. The optimal cut-off BMI for discriminating LV-GLS (>-17.5%), LASr (-23%) impairment was calculated using ROC curves.Results: 307 patients were assessed (41.5 +/- 13.3yrs; 36.5%male; LVEF 61.3 +/- 4.8%). No significant differences in indexed chamber volumes or LVEF were appreciated across BMI groups (p > 0.05 for all). LV-GLS, LASr, and RV-FWS were all significant on one-way ANOVA for differences from the group mean (all p < 0.01). Jonckheere-Terpstra test confirmed a significant trend of lower absolute LV-GLS, LASr and RV-FWS values across the rising BMI groups. On ROC curve analysis, a BMI value of 29.9 kg/m(2), 35.1 kg/m(2), and 37.3 kg/m(2) were associated with LASr (AUC: 0.75), RV-FWS (AUC: 0.72), and LV-GLS (AUC: 0.75) impairment respectively.Conclusion: Obesity is linked with subclinical reduction of cardiac function in otherwise healthy subjects without cardiovascular risk factors, with reduction of left atrial function occurring at lower BMI, followed by the right and left ventricular function

Embolic stroke of undetermined source : approaches in risk stratification for cardioembolism

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Embolic stroke of undetermined source has been recently proposed to categorize nonlacunar ischemic strokes without confirmed etiology after adequate investigation with a likely embolic stroke mechanism. A strategy of empirical anticoagulation for embolic stroke of undetermined source patients is attractive but may only be beneficial in a select subset of patients. Strategies which would help identify the subset of embolic stroke of undetermined source patients most likely to have cardioembolic origin of stroke, and hence benefit from anticoagulation, are needed. This article will review current evidence which may be useful in the development of a risk stratification approach based on arrhythmia monitoring, cardiac imaging, and clinical risk stratification. This approach may be beneficial in clinical practice in improving patient outcomes and reducing stroke recurrence in this population; however, further work is required with active trials underway

Determinants of LA reservoir strain : independent effects of LA volume and LV global longitudinal strain

Background: Left atrial (LA) deformation during the reservoir phase (LASr) has demonstrated strong prognostic value in different clinical settings. Although determinants of left atrial reservoir strain including left atrial relaxation, left atrial compliance, and left ventricular longitudinal systolic function are fairly well defined, there is incomplete information regarding the effect of left atrial volume on this relationship which is the focus of our study. Method: Consecutive patients without prior cardiac disease referred for transthoracic echocardiography were prospectively recruited. All participants underwent clinical assessment, transthoracic echocardiography (TTE), and screening exercise stress test. Only patients with normal left ventricular ejection fraction (LVEF) without left ventricular hypertrophy (LVH) or myocardial ischemia on stress testing were included. Results: A total of 260 patients (57% male, mean age 59 ± 14 years) were included. 70% had hypertension, 33% had diabetes mellitus, and 31% had both HTN and DM. On multivariate analysis, age, e’, LAVI, and LV GLS (P < .01 for all) showed an independent association with LASr. Of interest, at lower tertiles of LAVI, a linear decrease in LASr was observed parallel to worsening LV GLS, whilst at higher tertiles of LAVI, the reduction in LASr was non-linear implying that LA enlargement, consequent to LA remodeling, had an incremental effect on LASr. Conclusion: Age, e’, LV GLS, and LAVI were independently associated with LASr. LA remodeling reflected by larger LAVI had an incremental negative association with LASr independent of LV GLS

Left atrial strain is the best predictor of adverse cardiovascular outcomes in patients with chronic kidney disease

Background: Patients with chronic kidney disease (CKD) are at increased risk of adverse cardiovascular events, which is underestimated by traditional risk stratification algorithms. We sought to determine clinical and echocardiographic predictors of adverse outcomes in CKD patients. Methods: Two hundred forty-three prospectively recruited stage 3/4 CKD patients (male, 63%; mean age, 59.2 +/- 14.4 years) without previous cardiac disease made up the study cohort. All participants underwent a transthoracic echocardiogram, with left ventricular (LV) and left atrial (LA) strain analysis. Participants were followed for 3.9 ± 2.7 years for the primary end point of cardiovascular death and major adverse cardiovascular event (MACE). The secondary end point was the composite of all-cause death and MACE. Results: Fifty-four patients met the primary end point, and 65 the secondary end point. On log-rank tests, older age, diabetes mellitus, anemia, greater LV mass, reduced LV global longitudinal strain, larger indexed LA volume, higher E/e′ ratio, and reduced LA reservoir strain (LASr; P < .01 for all) were independent predictors of cardiovascular death and MACE. On multivariable regression analysis of univariate predictors, LASr (P < .01) was the only independent predictor for the primary end point as well as for the secondary end point. Receiver operating characteristic curve analysis showed LASr was a stronger predictor of adverse events (area under the curve [AUC] = 0.84) compared to the Framingham (AUC = 0.58) and Atherosclerotic Cardiovascular Disease (AUC = 0.59) risk scores. Conclusions: LASr is an independent predictor of cardiovascular death and MACE in CKD patients, superior to clinical risk scores, LV parameters, and LA volume

Association of left atrial metrics with atrial fibrillation rehospitalization and adverse cardiovascular outcomes in patients with nonvalvular atrial fibrillation following index hospitalization

Background: Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice, with significant clinical and economic burdens, largely driven by adverse cardiovascular outcomes and AF-related hospitalization. Left atrial (LA) parameters have been shown to have prognostic value in cardiovascular disease states. We sought to evaluate the prognostic value of measures of LA size and function, as measured through LA volume index and LA emptying fraction (LAEF), respectively, for AF rehospitalization and long-term adverse outcomes in patients with nonvalvular AF following index hospitalization. Methods: In this retrospective study, 594 consecutive patients (mean age, 67.8 ± 13.6 years, 53% men) admitted to a tertiary referral center with nonvalvular AF were assessed. Patients who underwent transthoracic echocardiography during their index admission and had complete follow-up data were included and followed for a mean period of 33.18 ± 21.27 months for the primary outcome of AF rehospitalization. The secondary outcome was a composite of all-cause death and major adverse cardiovascular events. Results: The primary outcome occurred in 250 (42%) patients, and the secondary outcome occurred in 219 (37%) patients. On multivariable regression analysis, LAEF had an independent association with AF rehospitalization (hazard ratio [HR] = 0.967; 95% CI, 0.953-0.982; P <.01), and time-dependent receiver operating characteristic curves demonstrated LAEF to have strong diagnostic accuracy in predicting early and intermediate AF rehospitalization. Both LA volume index (HR = 1.014; 95% CI, 1.003-1.026; P =.01) and LAEF (HR = 0.982; 95% CI, 0.970-0.993; P <.01) were associated with all-cause death and major adverse cardiovascular events. Conclusions: Adverse LA remodeling, as reflected through LA enlargement and reduced LA mechanical function, is associated with AF rehospitalization and long-term adverse cardiovascular outcomes in hospitalized patients with nonvalvular AF

Usefulness of left atrial strain to predict end stage renal failure in patients with chronic kidney disease

Left atrial (LA) enlargement predicts adverse cardiovascular events in patients with chronic kidney disease (CKD). The aim of our study was to evaluate the value of LA reservoir strain, a novel measure of LA function, as a prognostic marker for adverse renal outcomes. A total of 280 patients (65.8 ± 12.2years, 63% male) with stable Stage 3 and 4 CKD without prior cardiac history were evaluated with transthoracic echocardiography and prospectively followed for up to 5 years. The primary end point was progressive renal failure, which was the composite of death from renal cause, end-stage renal failure and/or doubling of serum creatinine. Over a mean follow up of 3.9 ± 2.7years, 56 patients reached the composite endpoint. By log rank test, older age, lower baseline eGFR, anemia, diabetes mellitus, higher urinary albumin/creatinine ratio, number of antihypertensive medications, higher indexed left ventricular mass, larger LA volumes, and impaired LA reservoir strain were significant predictors of the composite outcome (p <0.01 for all). Multi-variable Cox regression analysis found LA reservoir strain, eGFR, number of antihypertensive medications and urinary albumin/creatinine ratio were independent predictors for progressive renal failure (p <0.01 for all). Impaired LA reservoir strain was associated with a 2.5-fold higher risk of the composite outcome (HR 2.51, 95% CI 1.19 to 5.30, p = 0.02) and was the only echocardiographic parameter that predicted progressive renal failure independent of established clinical risk factors for end-stage renal failure. Its utility requires validation in high risk CKD patients with cardiac disease