Long-term prognostic significance of left atrial volume in acute myocardial infarction

Shortness of breath in clinical practice: A case for left atrial function and exercise stress testing for a comprehensive diastolic heart failure workup

The symptom cluster of shortness of breath (SOB) contributes significantly to the outpatient workload of cardiology services. The workup of these patients includes blood chemistry and biomarkers, imaging and functional testing of the heart and lungs. A diagnosis of diastolic heart failure is inferred through the exclusion of systolic abnormalities, a normal pulmonary function test and normal hemoglobin, coupled with diastolic abnormalities on echocardiography. Differentiating confounders such as obesity or deconditioning in a patient with diastolic abnormalities is difficult. While the most recent guidelines provide more avenues for diagnosis, such as incorporating the left atrial size, little emphasis is given to understanding left atrial function, which contributes to at least 25% of diastolic left ventricular filling; additionally, exercise stress testing to elicit symptoms and test the dynamics of diastolic parameters, especially when access to the "gold standard" invasive tests is lacking, presents clinical translational gaps. It is thus important in diastolic heart failure work up to understand left atrial mechanics and the role of exercise testing to build a comprehensive argument for the diagnosis of diastolic heart failure in a patient presenting with SOB.

Atrial Infarction and Ischemic Mitral Regurgitation Contribute to Post-MI Remodeling of the Left Atrium

BACKGROUND

Left atrial (LA) remodeling after an acute myocardial infarction (MI) is poorly characterized regarding its determinants or its effect on ischemic mitral regurgitation (MR) development.

OBJECTIVES

The purpose of this study was: 1) to compare LA structural remodeling in experimental MI swine models recapitulating the effects of left ventricular (LV) dysfunction, ischemic MR, and left atrial infarction (LAI); and 2) to analyze how LA remodeling influences ischemic MR development.

METHODS

Three models of MI were generated: 1) proximal left circumflex (LCx) coronary artery occlusion involving the LA branch (LAI group); 2) proximal LCx occlusion not involving the LA branch (LCx group); and 3) left anterior descending (LAD) occlusion (LAD group). Serial cardiac magnetic resonance scans were performed to define LA and LV remodeling and ischemic MR, and were correlated with histology.

RESULTS

Occlusion of the LA branch (LAI group) induced a greater degree of LA dilation at 1 and 8 weeks post-MI than the LCx and LAD groups, along with early and severe impairment of LA function. In the LCx and LAD groups, LA dysfunction was less pronounced and not consistent. Development of ischemic MR was more pronounced in the LAI group than in the LCx group. Histology confirmed atrial infarction with extensive fibrosis in the LAI group and interstitial fibrosis in the LCx group. In the LAD group, LA remodeling was not observed by cardiac magnetic resonance or histology.

CONCLUSIONS

We provide the first experimental evidence of the deleterious effect of acute LAI on atrial structural remodeling, characterized by early LA dilation, dysfunction, and fibrosis, and early occurrence of ischemic MR.

Nonalcoholic Steatohepatitis is Associated with Cardiac Remodeling and Dysfunction

OBJECTIVE

Preliminary data suggest that nonalcoholic fatty liver disease is associated with early heart failure (HF). However, whether nonalcoholic steatohepatitis (NASH) is directly associated with echocardiographic changes in cardiac structure or function remains unknown.

METHODS

A retrospective cohort was identified of individuals (N = 65) without known heart disease, undergoing elective bariatric surgery with perioperative liver biopsy, and available recent transthoracic echocardiography (TTE). TTE measures were evaluated by NASH status using correlation coefficients, ANOVA, and linear regression, accounting for cardiometabolic factors.

RESULTS

Median age was 47 years; 22% (n = 14) had NASH. NASH patients had increased median left atrial (LA) volume (28.6 mL/m2 vs. 24.8 mL/m2 ; P < 0.0001) and left ventricular (LV) mass (82.6 g/m2 vs. 78.6 g/m2 ; P < 0.0001), indexed for height. NASH was inversely correlated with indices of diastolic function, including septal E' (r = -0.90 [95% CI: -1.21 to -0.42]; P = 0.020) and E:A (r = -0.31 [95% CI: -0.51 to -0.09]; P = 0.037). In adjusted analyses, NASH remained associated with increased LV mass index (ß1  = 7.16 [SE: 4.95]; P = 0.001) and LA volume index (ß1  = 0.19 [SE: 0.08]; P = 0.001) and reduced lateral and septal E' (ß1  = -0.91, P = 0.015; ß1  = -0.89, P = 0.047, respectively).

CONCLUSIONS

In this bariatric cohort, NASH was associated with changes in myocardial structure and in load-dependent indices of LV diastolic function, suggestive of subclinical HF.

Atrial function, atrial volume and cardiovascular clinical outcomes in patients with end-stage renal disease - A study of cardiac computed tomography

BACKGROUND

Patients with chronic kidney disease (CKD) have an increased risk of cardiovascular events. Previous studies using 2-dimensional echocardiography show that left atrial end-diastolic volume (LAEDV) predicts cardiovascular outcomes and mortality in patients with CKD. However, contrast-enhanced cardiac CT may offers a more precise measure of atrial dimensions and function than 2-dimensional echocardiography and may provide improved predictionof patient outcome.

AIM

The aim of the present study was to examine the association of LAEDV and left atrial ejection fraction (LAEF) assessed by CT with left ventricle end-diastolic volume (LVEDV), left ventricular mass, left ventricular ejection fraction and N-terminal plasma-pro-brain natriuretic peptide (NT-PRO-BNP). Furthermore, we examined LAEDV and LAEF as predictors of major adverse cardiac events (MACE) and mortality.

METHODS

Kidney transplant candidates (n = 117) underwent contrast-enhanced CT screening for coronary artery disease as part of the work-up prior to kidney transplantation before being accepted on the transplantation waiting list. Left atrial (LA) and left ventricular (LV) volume and function were determined by cardiac CT. MACE and mortality data were extracted from the Western Denmark Heart Registry, a review of patient records and patient interviews.

RESULTS

Baseline patient characteristics did not differ between LAEDV tertiles. LAEDV was positively associated with measures of LV function - both LVEDV (β = 0.36, p < 0.05) and LV mass (β = 0.30, p < 0.05). LAEF was not associated with measures of LV function. LAEDV was positively and LAEF negatively associated with NT-PRO-BNP (LAEDV: β = 10.28, p < 0.05. LAEF: β = -0.06, p < 0.05). During a median follow-up of 3.7-years, 19 (16.2%) patients died and 19 (16.2%) patients suffered MACE. MACE and survival analysis showed no relation to LAEDV or LAEF.

CONCLUSIONS

Using contrast-enhanced CT, we demonstrated a correlation between atrial and ventricular functional parameters. However, we found no association with either LAEF or LAEDV or MACE and mortality in this cohort of kidney transplant candidates.

Left atrial remodeling, hypertrophy, and fibrosis in mouse models of heart failure

Left ventricular dysfunction increases left atrial pressures and causes atrial remodeling. In human subjects, increased left atrial size is a powerful predictor of mortality and adverse events in a broad range of cardiac pathologic conditions. Moreover, structural remodeling of the atrium plays an important role in the pathogenesis of atrial tachyarrhythmias. Despite the potential value of the atrium in assessment of functional endpoints in myocardial disease, atrial pathologic alterations in mouse models of left ventricular disease have not been systematically investigated. Our study describes the geometric, morphologic, and structural changes in experimental mouse models of cardiac pressure overload (induced through transverse aortic constriction), myocardial infarction, and diabetes. Morphometric and histological analysis showed that pressure overload was associated with left atrial dilation, increased left atrial mass, loss of myofibrillar content in a subset of atrial cardiomyocytes, atrial cardiomyocyte hypertrophy, and atrial fibrosis. In mice undergoing nonreperfused myocardial infarction protocols, marked left ventricular systolic dysfunction was associated with left atrial enlargement, atrial cardiomyocyte hypertrophy, and atrial fibrosis. Both infarcted animals and pressure overloaded mice exhibited attenuation and perturbed localization of atrial connexin-43 immunoreactivity, suggesting gap junctional remodeling. In the absence of injury, obese diabetic db/db mice had diastolic dysfunction associated with atrial dilation, atrial cardiomyocyte hypertrophy, and mild atrial fibrosis. Considering the challenges in assessment of clinically relevant functional endpoints in mouse models of heart disease, study of atrial geometry and morphology may serve as an important new tool for evaluation of ventricular function.

Quantifying left atrial structure and function using single-plane tissue-tracking cardiac magnetic resonance

PURPOSE

Left atrial (LA) structure and function are important markers of adverse cardiovascular outcomes. Tissue-tracking cardiovascular magnetic resonance (CMR) accurately quantifies LA volume, strain, and strain rate based on biplane long-axis imaging. We aimed to assess the accuracy of the LA indices quantification from single-plane tissue-tracking CMR.

METHODS

We included 388 subjects (mean age 57±13, male 70%) whose cine CMR images in sinus rhythm were available in both four-chamber and two-chamber views: 162 patients from the Prospective Observational Study of Implantable Cardioverter-Defibrillators (PROSE-ICD) Study, 208 patients from atrial fibrillation cohort, and 18 healthy volunteers. The group was divided into the training set (n=291) and the test set (n=97). In the training set, we compared the LA indices derived from biplane imaging and single-plane imaging (a four-chamber view), and developed regression equations. In the test set, we used the regression equations to estimate the LA indices from the single-plane imaging, and quantified the accuracy of the estimation against the LA indices from the biplane.

RESULTS

In the training set, all the LA indices from the single-plane imaging tended to be systematically underestimated compared with those from the biplane imaging, however, the correlation coefficient was high (r²=0.73-0.90, p<0.001). In the test set, LA volumetric indices showed excellent reproducibility (intra-class correlation coefficient (ICC): 0.91-0.92) with relatively low variability (16.3-22.3%); For LA strain and strain rate indices, reproducibility was excellent (ICC: 0.81-0.93), however, the variability was slightly higher than that of volumetric indices (21.7-25.4%).

CONCLUSIONS

LA volumetric indices measured from single-plane tissue-tracking CMR are highly accurate and reproducible with reference to those derived from the standard biplane imaging. The reproducibility of LA strain and strain rate indices from single-plane tissue-tracking CMR is excellent but the variability is higher than that of the volumetric indices.

Cardiac magnetic resonance assessment of diastolic dysfunction in acute coronary syndrome

Chest pain is an important presenting symptom. However, few cases of chest pain are diagnosed as acute coronary syndrome (ACS) in the acute setting. This results in frequent inappropriate discharge and major delay in treatment for patients with underlying ACS. The conventional methods of assessing ACS, which include electrocardiography and serological markers of infarct, can take time to manifest. Recent studies have investigated more sensitive and specific imaging modalities that can be used. Diastolic dysfunction occurs early following coronary artery occlusion and its detection is useful in confirming the diagnosis, risk stratification, and prognosis post-ACS. Cardiac magnetic resonance provides a single imaging modality for comprehensive evaluation of chest pain in the acute setting. In particular, cardiac magnetic resonance has many imaging techniques that assess diastolic dysfunction post-coronary artery occlusion. Techniques such as measurement of left atrial size, mitral inflow, and mitral annular and pulmonary vein flow velocities with phase-contrast imaging enable general assessment of ventricular diastolic function. More novel imaging techniques, such as T2-weighted imaging for oedema, T1 mapping, and myocardial tagging, allow early determination of regional diastolic dysfunction and oedema. These findings may correspond to specific infarcted arteries that may be used to tailor eventual percutaneous coronary artery intervention.

Left Atrial Structure in Relationship to Age, Sex, Ethnicity, and Cardiovascular Risk Factors: MESA (Multi-Ethnic Study of Atherosclerosis)

BACKGROUND

Left atrial (LA) size is a marker of diastolic function and is associated with atrial fibrillation and cardiovascular outcomes. However, there are no large population studies measuring LA structure. The relationship of demographics and cardiovascular risk factors to LA size is largely unknown. This study aimed to determine associations of LA size with demographic factors, cardiac structure and function, and cardiovascular risk factors.

METHODS AND RESULTS

LA volume indexed to body surface area was measured by cardiovascular magnetic resonance steady-state free precession and fast gradient echo cine long- and short-axis images in 2576 asymptomatic participants of MESA ([Multi-Ethnic Study of Atherosclerosis] 68.7 years, 53.0% women, white 42.2%, Chinese American 12.0%, black 24.5%, and Hispanic 21.2%) using biplane and short-axis images. The mean LA volume index was 36.5±11.4 mL/m2 in the entire cohort and 35.5±10.1 mL/m2 in subjects free of cardiovascular risk factors (n=283). Multivariable analysis included adjustment for demographics, ethnicity, cardiovascular risk factors, serological studies, socioeconomic status, left ventricular structure, and medications. In the adjusted analysis, age (β=0.2 mL/m2 per year, P<0.0001), male sex (β=-4.2 mL/m2, P<0.0001), obesity (β=1.3 mL/m2, P<0.01), end-diastolic volume index (β=0.4 mL/m2, P<0.0001), Chinese American (β=-2.6 mL/m2, P<0.0001), and Hispanic (β=1.1 mL/m2, P<0.05) ethnicities were associated with LA volume index. Diabetes mellitus and smoking were not associated with LA volume index. LA volumes measured by steady-state free precession were 3% larger than by fast gradient echo cine cardiovascular magnetic resonance (P<0.001).

CONCLUSIONS

Age, sex, ethnicity and left ventricular structural parameters were associated with LA size. Importantly, the study provides reference values of normal LA volume index.

The Effect of Metformin on Diastolic Function in Patients Presenting with ST-Elevation Myocardial Infarction

Introduction

Diastolic dysfunction is an important predictor of poor outcome after myocardial infarction. Metformin treatment improved diastolic function in animal models and patients with diabetes. Whether metformin improves diastolic function in patients presenting with ST-segment elevation myocardial infarction (STEMI) is unknown.

Methods

The GIPS-III trial randomized STEMI patients, without known diabetes, to metformin or placebo initiated directly after PCI. The previously reported primary endpoint was left ventricular ejection fraction at 4 months, which was unaffected by metformin treatment. This is a predefined substudy to determine an effect of metformin on diastolic function. For this substudy trans-thoracic echocardiography was performed during hospitalization and after 4 months. Diastolic dysfunction was defined as having the combination of a functional alteration (i.e. decreased tissue velocity: mean of septal e’ and lateral e’) and a structural alteration (i.e. increased left atrial volume index (LAVI)). In addition, left ventricular mass index and transmitral flow velocity (E) to mean e' ratio (E/e’) were measured to determine an effect of metformin on individual echocardiographic markers of diastolic function.

Results

In 237 (63%) patients included in the GIPS-III trial diastolic function was measured during hospitalization as well as at 4 months. Diastolic dysfunction was present in 11 (9%) of patients on metformin and 11 (9%) patients on placebo treatment (P = 0.98) during hospitalization. After 4 months 22 (19%) of patients with metformin and 18 (15%) patients with placebo (P = 0.47) had diastolic dysfunction. In addition, metformin did not improve any of the individual echocardiographic markers of diastolic function.

Conclusions

In contrast to experimental and observational data, our randomized placebo controlled trial did not suggest a beneficial effect of short-term metformin treatment on diastolic function in STEMI patients.

Global longitudinal strain predicts incident atrial fibrillation and stroke occurrence after acute myocardial infarction

Patients with acute myocardial infarction are at increased risk of developing atrial fibrillation. We aimed to evaluate whether speckle tracking echocardiography improves risk stratification for atrial fibrillation in these patients.The study comprised of 373 patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention. Patients had an echocardiogram performed at a median of 2 days after their STEMI. The echocardiograms consisted of conventional measurements and myocardial strain analysis by speckle tracking from 3 apical projections. The endpoint was a composite of new-onset atrial fibrillation and ischemic stroke. At a median follow-up time of 5.5 years (interquartile range 4.9, 6.1 years), 44 patients developed the endpoint (atrial fibrillation: n = 24, ischemic stroke: n = 24, both: n = 4). Patients who reached the endpoint had significantly reduced systolic function by the left ventricular ejection fraction (LVEF) (43% vs 46%; P = 0.042) and global longitudinal strain (10.9% vs 12.6%; P = 0.004), both being univariable predictors. However, only global longitudinal strain remained a significantly independent predictor (hazard ratio 1.12, 95% confidence interval 1.00; 1.25, P = 0.042, per 1% decrease) after multivariable adjustment for baseline predictors (age, sex, diabetes, hypertension, diastolic dysfunction, and LVEF) using Cox regression. Furthermore, global longitudinal strain resulted in significantly higher c-statistics for prediction of outcome compared with LVEF <45% (0.63 vs 0.52; P = 0.026). When stratified into tertiles of global longitudinal strain, it became evident that patients in the lowest tertile mediated this signal with a 2-fold increased risk compared with the highest tertile (hazard ratio 2.10, 95% confidence interval 1.04; 4.25).Global longitudinal strain predicts atrial fibrillation after STEMI and may add valuable information which can help facilitate arrhythmia detection in these patients.

Left atrial area index predicts adverse cardiovascular events in patients with unstable angina pectoris

Background

The left atrial size has been considered as a useful marker of adverse cardiovascular outcomes. However, it is not well known whether left atrial area index (LAAI) has predictive value for prognosis in patients with unstable angina pectoris (UAP). This study was aimed to assess the association between LAAI and outcomes in UAP patients.

Methods

We enrolled a total of 391 in-hospital patients diagnosed as UAP. Clinical and echocardiographic data at baseline were collected. The patients were followed for the development of adverse cardiovascular (CV) events, including hospital readmission for angina pectoris, acute myocardial infarction (AMI), congestive heart failure (CHF), stroke and all-cause mortality.

Results

During a mean follow-up time of 26.3 ± 8.6 months, 98 adverse CV events occurred (84 hospital readmission for angina pectoris, four AMI, four CHF, one stroke and five all-cause mortality). In a multivariate Cox model, LAAI [OR: 1.140, 95% CI: 1.016–1.279, P = 0.026], diastolic blood pressure (OR: 0.976, 95% CI: 0.956–0.996, P = 0.020) and pulse pressure (OR: 1.020, 95% CI: 1.007–1.034, P = 0.004) were independent predictors for adverse CV events in UAP patients.

Conclusions

LAAI is a predictor of adverse CV events independent of clinical and other echocardiographic parameters in UAP patients.

Association Between Left Atrial Dilatation and Invasive Hemodynamics at Rest and During Exercise in Asymptomatic Aortic Stenosis

Background—

Transition from an asymptomatic to symptomatic state in severe aortic stenosis is often difficult to assess. Identification of a morphological sign of increased hemodynamic load may be important in asymptomatic aortic stenosis to identify patients at risk.

Methods and Results—

Thirty-nine patients with asymptomatic severe aortic stenosis (aortic valve area <1 cm 2 , peak jet velocity >3.5 m/s) underwent exercise testing with simultaneous invasive hemodynamic monitoring and Doppler echocardiography. Cardiac index, pulmonary artery pressure, and pulmonary capillary wedge pressure (PCWP) were recorded. Patients were followed up for the composite end point of death, unplanned hospitalization, or aortic valve replacement. Patients were stratified into 2 groups according to left atrial (LA) volume index ≥35 mL/m 2 . In 25 patients (64%) LA volume index was ≥35 mL/m 2 . Aortic valve area was similar between groups (0.81±0.15 versus 0.84±0.18 cm 2 ; P =0.58). PCWP was higher at rest and during exercise in patients with LA volume index ≥35 mL/m 2 ( P <0.01), despite similar cardiac index. At rest, PCWP was <12 mm Hg in 11 patients (44%) with LA dilatation, whereas PCWP was <25 mm Hg in 1 patient (4%) with exercise. LA volume index and E/e′ predicted exercise PCWP>30 mm Hg with areas under the receiver operating curve of 0.75 and 0.84, respectively. During follow-up, 14 cardiac events were recorded. LA volume was associated with a hazard ratio of 1.90 (95% confidence interval, 0.92–4.15).

Conclusions—

LA size reflects hemodynamic burden in patients with asymptomatic severe aortic stenosis. Quantitative measurements of LA and diastolic function are associated with left ventricular filling pressures with exercise and could be used to identify asymptomatic patients with increased hemodynamic burden.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT02395107.

Prognostic value of new left atrial volume index severity partition cutoffs after cardiac rehabilitation program in patients undergoing cardiac surgery

BACKGROUND

Previous studies showed that left atrial enlargement is an independent marker of adverse outcomes in both primary and secondary cardiovascular prevention. However, no data are available on long-term outcomes in patients undergoing valve surgery and/or coronary artery by-pass graft (CABG) surgery. Aim of the study was to evaluate long-term prognostic role of left atrial volume index (LAVi) after cardiac surgery, using the cutoff values recently proposed by the European Association of Cardiovascular Imaging and American Society of Echocardiography.

METHODS

We created a retrospective registry of 1703 consecutive patients who underwent cardiovascular rehabilitation program after cardiac surgery, including CABG, valve surgery and valve + CABG surgery. LAVi was calculated as ratio of left atrium volume to body surface area, in ml/m(2) at discharge; 563 patients with available LAVi data were included in the study.

RESULTS

In the whole population LAVi was 36 ± 14 ml/m(2) (mean ± SD) and the follow-up time was 5 ± 1.5 years. Increased LAVi (>34 ml/m(2)) predicted major adverse cardiovascular and cerebrovascular events (MACCEs) (HR = 2.1; CI95 %: 1.4-3.1; p < 0.001) and cardiovascular mortality (HR = 2.2; CI95 %: 1.0-4.5; p = 0.032). An increased LAVi remained MACCEs predictor after adjustement for age, gender, diabetes, atrial fibrillation at discharge, echocardiographic E/A ratio and left ventricular ejection fraction (HR = 1.8; CI95 %: 1.0-3.0; p = 0.036). When the study population was split according to increasing LAVi values, left atrium enlargement resulted a predictor of progressively worse adverse outcome.

CONCLUSIONS

LAVi is a predictor of long-term adverse cardiovascular outcome after cardiac surgery, even after correction for main clinical and echocardiographic variables. The recently recommended LAVi severity cutoffs appear adequate to effectively stratify outcome in patients undergoing rehabilitation after cardiac surgery.

Early changes in left atrial volume after acute myocardial infarction. Relation to invasive hemodynamics at rest and during exercise

BACKGROUND

Dilatation of left atrium (LA) reflects chronic LA pressure or volume overload that possesses considerable prognostic information. Little is known regarding the interaction between LA remodeling after acute myocardial infarction (MI) and left atrial pressure at rest and during exercise. The objective was to assess changes in LA volume early after MI in patients with diastolic dysfunction and the relation to invasive hemodynamics and natriuretic peptides.

METHODS

62 patients with left ventricle ejection fraction (LVEF)≥45%, diastolic E/e'>8 and LA volume index >34ml/m² within 48h of MI were enrolled. After 1 and 4months blood sampling, echocardiography and right heart catheterization were performed during exercise test.

RESULTS

LA remodeling was considered in patients with a change from mild (35-41ml/m²), to severe (>48ml/m²) dilatation after 4months (Found in 22 patients (35%)). Patients with LA remodeling were characterized by lower a' (1month 8.9±2.0 vs. 10.4±2.5cm/s, p=0.002; 4month 8.8±2.0 vs. 10.4±2.4cm/s, p=0.007) and higher MR-proANP (1month 162±64 vs. 120±44pg/l, p=0.005; 4months 175±48 vs. 129±56pg/l, p=0.002). With exercise, pulmonary artery pressure, right atrial pressure and pulmonary capillary wedge pressure increased markedly in all patients. There were however, no significant differences in filling pressure at rest or during exercise irrespective of whether LA remodeling occurred.

CONCLUSION

Contrary to our hypothesis early LA dilatation after MI was weakly associated with resting and exercise induced changes in LA pressure overload. The dilatation was however associated with lower e' and higher MR-proANP.

Left Atrial Volumes and Function by Three-Dimensional Echocardiography

Background—

Our study sought to (1) identify reference values for left atrial (LA) volumes and phasic function indices by 3-dimensional echocardiography (3DE) and compare them with those measured by 2-dimensional echocardiography (2DE) and (2) analyze their relationship with age, sex, body size, and left ventricular function. Accuracy and reproducibility of 3DE and 2DE have been also tested to evaluate the robustness of our data.

Methods and Results—

We obtained maximal, minimal, and preA LA volumes by 3DE and 2DE in 276 healthy volunteers (18–79 years; 57% women). Limits of normality for LA volumes and total LA emptying fraction were larger with 3DE than with 2DE (maximal LA volume: 43 versus 35 mL/m 2 ; preA LA volume: 31 versus 25 mL/m 2 ; minimal LA volume: 18 versus 14 mL/m 2 ; 53 versus 48%, respectively; P <0.001). 3DE LA volumes indexed by body surface area were similar in men and women and increased with age. On multivariable analysis, age, weight, and left ventricular systolic and diastolic function indices resulted as correlates of LA 3DE indices. LA volumes were tightly correlated with cardiac magnetic resonance measurements, yet more underestimated by 2DE versus 3DE (bias±SD: −17±16 versus −7±15 mL, respectively). Among all LA parameters, maximal LA volume and total emptying fraction were the most reproducible, including at test-retest and at expert versus trainee comparisons.

Conclusions—

This study provides reference values for LA 3DE volumes and function from a relatively large cohort of healthy subjects with a wide age range. Our data may help clinicians to identify LA remodeling and dysfunction.

Predictive value of CHADS2 score for cardiovascular events in patients with acute coronary syndrome and documented coronary artery disease

BACKGROUND/AIMS

The CHADS2 score, used to predict the risk of ischemic stroke in atrial fibrillation (AF) patients, has been reported recently to predict ischemic stroke in patients with coronary heart disease, regardless of the presence of AF. However, little data are available regarding the relationship between the CHADS2 score and cardiovascular outcomes.

METHODS

This was a retrospective study on 104 patients admitted for acute coronary syndrome (ACS) who underwent coronary angiography, carotid ultrasound, and transthoracic echocardiography.

RESULTS

The mean age of the subjects was 60.1 ± 12.6 years. The CHADS2 score was as follows: 0 in 46 patients (44.2%), 1 in 31 (29.8%), 2 in 18 (17.3%), and ≥ 3 in 9 patients (8.7%). The left atrial volume index (LAVi) showed a positive correlation with the CHADS2 score (20.8 ± 5.9 for 0; 23.2 ± 6.7 for 1; 26.6 ± 10.8 for 2; and 30.3 ± 8.3 mL/m(2) for ≥3; p = 0.001). The average carotid total plaque area was significantly increased with CHADS2 scores ≥ 2 (4.97 ± 7.17 mm(2) vs. 15.52 ± 14.61 mm(2); p = 0.002). Eight patients experienced cardiovascular or cerebrovascular (CCV) events during a mean evaluation period of 662 days. A CHADS2 score ≥ 3 was related to an increase in the risk of CCV events (hazard ratio, 14.31; 95% confidence interval, 3.53 to 58.06). Furthermore, LAVi and the severity of coronary artery obstructive disease were also associated with an increased risk of CCV events.

CONCLUSIONS

The CHADS2 score may be a useful prognostic tool for predicting CCV events in ACS patients with documented coronary artery disease.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

New insights into symptomatic or silent atrial fibrillation complicating acute myocardial infarction

Atrial fibrillation (AF) is the most frequent heart rhythm disorder in the general population and contributes not only to a major deterioration in quality of life but also to an increase in cardiovascular morbimortality. The onset of AF in the acute phase of myocardial infarction (MI) is a major event that can jeopardize the prognosis of patients in the short-, medium- and long-term, and is a powerful predictor of a poor prognosis after MI. The suspected mechanism underlying the excess mortality is the drop in coronary flow linked to the acceleration and arrhythmic nature of the left ventricular contractions, which reduce the left ventricular ejection fraction. The principal causes of AF-associated death after MI are linked to heart failure. Moreover, the excess risk of death in these heart failure patients has also been associated with the onset of sudden death. Whatever its form, AF has a major negative effect on patient prognosis. In recent studies, symptomatic AF was associated with inhospital mortality of 17.8%, to which can be added mortality at 1year of 18.8%. Surprisingly, silent AF also has a negative effect on the prognosis, as it is associated with an inhospital mortality rate of 10.4%, which remains high at 5.7% at 1year. Moreover, both forms of AF are independent predictors of mortality beyond traditional risk factors. The frequency and seriousness of silent AF in the short- and long-term, which were until recently rarely studied, raises the question of systematically screening for it in the acute phase of MI. Consequently, the use of continuous ECG monitoring could be a simple, effective and inexpensive solution to improve screening for AF, even though studies are still necessary to validate this strategy. Finally, complementary studies also effect of oxidative stress and endothelial dysfunction, which seem to play a major role in triggering this rhythm disorder.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Association of nonalcoholic fatty liver disease with subclinical myocardial remodeling and dysfunction: A population-based study

Nonalcoholic fatty liver disease (NAFLD) and heart failure (HF) are obesity-related conditions with high cardiovascular mortality. Whether NAFLD is independently associated with subclinical myocardial remodeling or dysfunction among the general population is unknown. We performed a cross-sectional analysis of 2,713 participants from the multicenter, community-based Coronary Artery Risk Development in Young Adults (CARDIA) study who underwent concurrent computed tomography (CT) quantification of liver fat and comprehensive echocardiography with myocardial strain measured by speckle tracking during the Year-25 examination (age, 43-55 years; 58.8% female and 48.0% black). NAFLD was defined as liver attenuation ≤40 Hounsfield units after excluding other causes of liver fat. Subclinical left ventricular (LV) systolic dysfunction was defined using values of absolute peak global longitudinal strain (GLS). Diastolic dysfunction was defined using Doppler and tissue Doppler imaging markers. Prevalence of NAFLD was 10.0%. Participants with NAFLD had lower early diastolic relaxation (e') velocity (10.8 ± 2.6 vs. 11.9 ± 2.8 cm/s), higher LV filling pressure (E/e' ratio: 7.7 ± 2.6 vs. 7.0 ± 2.3), and worse absolute GLS (14.2 ± 2.4% vs. 15.2 ± 2.4%) than non-NAFLD (P < 0.0001 for all). When adjusted for HF risk factors or body mass index, NAFLD remained associated with subclinical myocardial remodeling and dysfunction (P < 0.01). The association of NAFLD with e' velocity (β = -0.36 [standard error = 0.15] cm/s; P = 0.02), E/e' ratio (β = 0.35 [0.16]; P = 0.03), and GLS (β = -0.42 [0.18]%; P = 0.02) was attenuated after controlling for visceral adipose tissue. Effect modification by race and sex was not observed.

CONCLUSIONS

NAFLD is independently associated with subclinical myocardial remodeling and dysfunction and provides further insight into a possible link between NAFLD and HF.

Clinical significance of left atrial volume in clinical outcomes of heart transplant recipients

Background

Left atrial volume (LAV) is surgically kept enlarged in heart transplant (HT) recipients. On the other hand, LAV has been known an independent predictor of various cardiovascular diseases and is associated with exercise capacity of HT recipients. Thus, we evaluated the hypothesis that LAV is still associated with clinical outcomes in HT recipients whose left atria are artificially enlarged.

Methods

Clinical outcomes over 5 years after HT were retrospectively evaluated in 35 HT recipients who had a LAV measurement with echocardiography at 1 year after HT at the University of Cincinnati Medical Center. The LAV was derived from a stacked disc method using apical 4 and 2 chamber views.

Results

The average LAV normalized to body surface area was 38.3 ± 9.9 ml/m² (mean ± SD) at 1 year after HT. Two deaths and one drop-out occurred during 5-year follow up. A total of 552 cardiac symptom-related hospitalizations occurred in the recipients. The average time to first hospitalization was 166 ± 279 days and average number of hospitalizations of each recipient was 15 ± 16. The indexed LAV failed to correlate with the time to first hospitalization and number of hospitalizations of each recipient (Spearman’s p-value; 0.141 and 0.519 respectively). When the patients were divided to groups of large LAV (n = 17) and small LAV (n = 18) using the cut off value of the mean LAV, no significant difference was noted in mortality, hospitalization, and new onset of atrial fibrillation between the groups.

Conclusions

Although our study is limited by a retrospective study design and relatively small number of patients, our results implicate that LAV is not significantly associated with clinical outcomes in HT recipients over 5 years after HT.

Usefulness of traditional echocardiographic parameters in assessment of left ventricular function in patients with normal ejection fraction early after acute myocardial infarction: results from a large consecutive cohort

AIMS

The aim of this study was to assess the frequency of left ventricular (LV) systolic function impairment using classical echocardiographic parameters and their relation to myocardial damage in patients hospitalized for acute myocardial infarction (MI) with normal LV ejection fraction (LVEF ≥52% in males or ≥54% in females).

METHODS AND RESULTS

All 421 consecutive patients with MI included in the REBUS (RElevance of Biomarkers for future risk of thromboembolic events in UnSelected post-myocardial infarction patients) study underwent two-dimensional and Doppler echocardiography within 72 h after admission. A normal LVEF was present in 262 (73.8%) of the 355 patients ultimately enrolled in the study. Patients with normal LVEF more often presented with non-ST-elevation myocardial infarction and had less comorbidities when compared with those with impaired LVEF. No differences in demographic factors or relevant medications were observed. Higher value of mean annular plane systolic excursion (MAPSE), lower wall motion score index (WMSI), lower LV as well as left atrial volumes characterized patients with normal LVEF. Impaired MAPSE was present in 64.4%, WMSI >1 in 72.1%, and dilated left atrium in 33.6% of those patients. Maximal cardiac troponin concentration reflecting infarct size showed the strongest association with WMSI (β = 0.35), followed by LVEF (β = -0.29), MAPSE (β = -0.25), and indexed LV end-systolic volume (β = 0.19; P < 0.001 for all the models).

CONCLUSION

In two-third of patients with MI and normal LVEF, at least one of the other markers of systolic function was outside of the normal range. WMSI reflected the size of MI better than global LV function parameters as LVEF or MAPSE.

Single breath-hold 3D measurement of left atrial volume using compressed sensing cardiovascular magnetic resonance and a non-model-based reconstruction approach

BACKGROUND

Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consuming and susceptible to misregistration.

AIM

To develop a time-efficient single breath-hold 3D CMR acquisition and reconstruction method to precisely measure LA volumes and function.

METHODS

A highly accelerated compressed-sensing multi-slice cine sequence (CS-cineCMR) was combined with a non-model-based 3D reconstruction method to measure LA volumes with high temporal and spatial resolution during a single breath-hold. This approach was validated in LA phantoms of different shapes and applied in 3 patients. In addition, the influence of slice orientations on accuracy was evaluated in the LA phantoms for the new approach in comparison with a conventional model-based biplane area-length reconstruction. As a reference in patients, a self-navigated high-resolution whole-heart 3D dataset (3D-HR-CMR) was acquired during mid-diastole to yield accurate LA volumes.

RESULTS

Phantom studies. LA volumes were accurately measured by CS-cineCMR with a mean difference of -4.73 ± 1.75 ml (-8.67 ± 3.54%, r2 = 0.94). For the new method the calculated volumes were not significantly different when different orientations of the CS-cineCMR slices were applied to cover the LA phantoms. Long-axis "aligned" vs "not aligned" with the phantom long-axis yielded similar differences vs the reference volume (-4.87 ± 1.73 ml vs. -4.45 ± 1.97 ml, p = 0.67) and short-axis "perpendicular" vs. "not-perpendicular" with the LA long-axis (-4.72 ± 1.66 ml vs. -4.75 ± 2.13 ml; p = 0.98). The conventional bi-plane area-length method was susceptible for slice orientations (p = 0.0085 for the interaction of "slice orientation" and "reconstruction technique", 2-way ANOVA for repeated measures). To use the 3D-HR-CMR as the reference for LA volumes in patients, it was validated in the LA phantoms (mean difference: -1.37 ± 1.35 ml, -2.38 ± 2.44%, r2 = 0.97). Patient study: The CS-cineCMR LA volumes of the mid-diastolic frame matched closely with the reference LA volume (measured by 3D-HR-CMR) with a difference of -2.66 ± 6.5 ml (3.0% underestimation; true LA volumes: 63 ml, 62 ml, and 395 ml). Finally, a high intra- and inter-observer agreement for maximal and minimal LA volume measurement is also shown.

CONCLUSIONS

The proposed method combines a highly accelerated single-breathhold compressed-sensing multi-slice CMR technique with a non-model-based 3D reconstruction to accurately and reproducibly measure LA volumes and function.

Predictors and prognostic value of left atrial remodelling after acute myocardial infarction

PURPOSE

Left atrial (LA) volume is a strong prognostic predictor in patients following ST-segment elevation myocardial infarction (STEMI). However, the change in LA volume over time (LA remodelling) following STEMI has been scarcely studied. We sought to identify predictors for LA remodelling and to evaluate the prognostic importance of LA remodelling.

METHODS

This is a subgroup analysis from a randomised clinical trial that evaluated the cardioprotective effect of exenatide treatment. A total of 160 patients with STEMI underwent a cardiovascular MR (CMR) 2 days after primary angioplasty and a second scan 3 months later. LA remodelling was defined as changes in LA volume or function from baseline to 3 months follow-up. Major adverse cardiac events were registered after a median of 5.2 years.

RESULTS

Adverse LA minimum volume (LAmin) remodelling was correlated to the presence of hypertension, larger infarct size by CMR, higher peak troponin T, larger area at risk and adverse left ventricular (LV) remodelling. LA maximum volume (LAmax) remodelling was correlated to larger infarct size by CMR, higher peak troponin T, larger area at risk, larger LV mass, impaired LV function and adverse LV remodelling. Kaplan-Meier and Log Rank analyses showed that patients in the highest tertiles of LAmin or LAmax remodelling are at higher risk (0.030 and p=0.018).

CONCLUSIONS

After a myocardial infarction, LA remodelling reflects a parallel ventricular-atrial remodelling. Infarct size is a major determinant of LA remodelling following STEMI and adverse LA remodelling is associated with an unfavourable prognosis.

Prognostic significance of NT-proBNP, 3D LA volume and LV dyssynchrony in patients with acute STEMI undergoing primary percutaneous intervention

OBJECTIVES

The aim of the present study was to assess the short term prognostic significance of N-terminal pro BNP (NT-proBNP), 3D left atrial volume (LAV) and left ventricular (LV) dyssynchrony in patients of acute ST-elevation myocardial infarction (STEMI) who underwent primary Percutaneous intervention (PCI).

BACKGROUND

NT-proBNP, LV dyssynchrony and LAV in patients with acute coronary syndrome have been associated with PCI outcomes and predict the short and long-term prognosis.

METHODS

This study consisted of 142 patients with a first STEMI who underwent primary PCI. Baseline echocardiographic data was collected at admission and at 6 months follow up. Left ventricular dyssynchrony was measured by tissue Doppler imaging and LAV by real time 3D-echocardiography, plasma NT-proBNP levels were estimated between 72 and 96 h of admission.

RESULTS

During study period 3 patients expired and 4 developed congestive heart failure (CHF). Baseline NT-proBNP and LV dyssynchrony correlated with LV size and LV ejection fraction (LVEF) at baseline and during follow up. Patients with higher NT-proBNP levels and higher LV dyssynchrony showed significant increase in LV size with decrease in LVEF during follow-up. Baseline Left atrial volume index (LAVI) showed significant correlation with LV size but no association with LVEF at baseline and during follow-up.

CONCLUSIONS

Higher levels of NT-proBNP and higher LV dyssynchrony can predict patients with increase in LV size, worsening of LV systolic and diastolic function during follow-up. Patients with higher NT-proBNP levels at baseline developed CHF during follow-up.

Left atrium function in patients with coronary artery disease

PURPOSE OF REVIEW

The left atrial cavity has recently been identified as a potential biomarker for cardiac and cerebrovascular accidents. This review examines the potential of left atrial size and function in predicting cardiovascular disease in the general population and outcomes in coronary artery disease (CAD) patients.

RECENT FINDINGS

The atrium is perfused primarily by branches of the proximal left circumflex coronary artery (LCx), and depression of the cavity mechanical performance has been demonstrated in experimental studies during LCx occlusion. Thus, left atrial volume and function assessment may have prognostic relevance, particularly in CAD patients. Such a line of thinking, however, is challenged by the widespread notion that the contribution by left atrial chamber morphology and functional quantitation to the risk stratification process after a first cardiovascular event is not adequately considered. However, a number of studies have shown that left atrial volume predicts survival and major adverse events after an acute myocardial infarction. Left atrial remodeling also provides an important overall prognostic information and correlates with brain natriuretic peptide after primary percutaneous coronary interventions.

SUMMARY

Evaluation of left atrial size and function is currently of great interest and it will be more so in the very near future, given its potential for insights into the pathophysiology of the ischemic heart, which makes it an important clinical risk identifier in CAD patients.

Relationship of ischemic times and left atrial volume and function in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Little is known about the impact of duration of ischemia on left atrial (LA) volumes and function during acute phase of myocardial infarction. We investigated the relationship of ischemic times, echocardiographic indices of diastolic function and LA volumes in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). A total of 433 consecutive STEMI patients underwent echocardiographic examination within 48 h of primary PCI, including the measurement of LA volumes and the ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity (E/e'). Time intervals from onset of chest pain to hospital admission and reperfusion were collected and magnitude of Troponin I release was used to assess infarct size. Patients with LA volume index (LAVI) ≥28 ml/m(2) had longer total ischemic time (410 ± 347 vs. 303 ± 314 min, p = 0.007) and higher E/e' ratio (15 ± 5 vs. 10 ± 3, p < 0.001) than those with LAVI <28 ml/m(2), while the indices of LA function were similar between the study groups (p > 0.05, for all). Significant correlation was found between E/e' and LA volumes at all stages of LA filling and contraction (r = 0.363-0.434; p < 0.001, for all) while total ischemic time along with E/e' and restrictive filling pattern remained independent predictor of LA enlargement. Increased LA volume is associated with longer ischemic times and may be a sensitive marker of increased left ventricular filling pressures in STEMI patients treated with primary PCI.

Relationship of left atrial global peak systolic strain with left ventricular diastolic dysfunction and brain natriuretic peptide level in patients presenting with non-ST elevation myocardial infarction

Background

In patients presenting with non-ST elevation myocardial infarction, we investigated the relationship of left atrial deformational parameters evaluated by 2-dimensional speckle tracking imaging (2D-STI) with conventional echocardiographic diastolic dysfunction parameters and brain natriuretic peptide level.

Material/Methods

We enrolled 74 non-ST segment elevation myocardial infarction patients who were treated with percutaneous coronary intervention and 58 healthy control subjects. Non-ST segment elevation myocardial infarction patients had echocardiographic examination 48 h after the percutaneous coronary intervention procedure and venous blood samples were drawn simultaneously. In addition to conventional echocardiographic parameters, left atrial strain curves were obtained for each patient. Average peak left atrial strain values during left ventricular systole were measured.

Results

BNP values were higher in non-ST segment elevation myocardial infarction patients compared to controls. Mean left atrium peak systolic global longitudinal strain in Group 2 (the control group) was higher than in the non-ST segment elevation myocardial infarction group. Left atrium peak systolic global longitudinal strain was significantly correlated with left ventricular ejection fraction. There was a significant inverse correlation between left atrium peak systolic global longitudinal strain and brain natriuretic peptide level, left atrium volume maximum, and left atrium volume minimum.

Conclusions

Our study shows that Left atrium peak systolic global longitudinal strain values decreased consistently with deteriorating systolic and diastolic function in non-ST segment elevation myocardial infarction patients treated with percutaneous coronary intervention. Left atrium peak systolic global longitudinal strain measurements may be helpful as a complimentary method to evaluate diastolic function in this patient population.

Relationships between biomarkers and left ventricular filling pressures at rest and during exercise in patients after myocardial infarction

BACKGROUND

Increased pulmonary capillary wedge pressure (PCWP) is an independent prognostic predictor after myocardial infarction (MI), but PCWP is difficult to assess noninvasively in subjects with preserved ejection fraction (EF). We hypothesized that biomarkers would provide information regarding PCWP at rest and during exercise in subjects with preserved EF after MI.

METHODS AND RESULTS

Seventy-four subjects with EF >45% and recent MI underwent right heart catheterization at rest and during a symptom-limited semisupine cycle exercise test with simultaneous echocardiography. Plasma samples were collected at rest for assessment of midregional pro-A-type natriuretic peptide (MR-proANP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), galectin-3 (Gal-3), copeptin, and midregional pro-adrenomedullin (MR-proADM). Plasma levels of MR-proANP and PCWP were associated at rest (r = 0.33; P = .002) and peak exercise (r = 0.35; P = .002) as well as with changes in PCWP (r = 0.26; P = .03). Plasma levels of NT-proBNP and PCWP were weakly associated at rest (r = 0.23; P = .03) and peak exercise (r = 0.28; P = .02) but not with changes in PCWP (r = 0.20; P = .09). In a multivariable analysis, plasma levels of MR-proANP remained associated with rest and exercise PCWP (P < .01), whereas NT-proBNP did not. Plasma levels of Gal-3, copeptin, and MR-proADM were not associated with PCWP at rest or peak exercise.

CONCLUSIONS

In subjects recovering from an acute MI with preserved EF, plasma levels of natriuretic peptides, particularly MR-proANP, are associated with filling pressures at rest and during exercise.

Association of left atrial booster-pump function with heart failure symptoms in patients with severe aortic stenosis and preserved left ventricular ejection fraction

BACKGROUND

Identification of heart failure (HF) symptoms in patients with severe aortic stenosis (AS) and preserved left ventricular (LV) ejection fraction (EF) is clinically important, but assessment of HF symptoms is challenging. It was recently reported that resting left atrium (LA) functions are related to exercise performance and are also important prognostic markers for patients with HF. The aim of this study was to assess the association of the HF symptoms with LA function in patients with severe AS and preserved LVEF.

METHODS

We retrospectively studied 40 patients with severe AS and preserved LVEF (all ≥50%) who were referred for aortic valve replacement (AVR). LA reservoir (SR-LAs), conduit (SR-LAe), and booster-pump (SR-LAa) functions were determined as the averaged global LA speckle tracking longitudinal strain rate from apical four- and two-chamber views. Twenty patients were symptomatic and 20 asymptomatic.

RESULTS

Aortic stenosis severity was similar for the 2 groups. Symptomatic status was associated with age, LV mass index, hemoglobin, B-type natriuretic peptide, LV end-systolic volume index, LVEF, LA volume index, SR-LAs, SR-LAe, and SR-LAa. Importantly, multivariate logistic regression analysis revealed that SR-LAa was the only independent determinant of symptomatic status (OR = 0.242, P = 0.002). Furthermore, significant improvement of SR-LAa was observed along with the reduction in LA volume index and LV mass index after AVR.

CONCLUSIONS

SR-LAa was found to be associated with the HF symptoms. Characterization of LA booster-pump function may be useful for the assessment of the symptomatic status in patients with severe AS patients and limited physical activity.

Imaging techniques in the evaluation of post-infarction function and scar

Imaging techniques are essential in the clinical evaluation of patients with a myocardial infarction. They are of value for both initial assessment of the ischemic injury and for detection of the subgroup of patients at higher risk of developing cardiovascular events during follow-up. Echocardiography remains the technique of choice for the initial evaluation, owing to its bedside capability to determine strong predictors, such as ventricular volumes, global and regional systolic function, and valvular regurgitation. New techniques for evaluating ventricular mechanics, mainly assessment of ventricular deformation, are revealing important aspects of post-infarction ventricular adaptation. The main alternative to echocardiography is cardiac magnetic resonance imaging. This technique is highly accurate for determining ventricular volumes and ventricular function and has the additional advantage of being able to characterize the myocardium and demonstrate changes associated with the ischemic insult such as necrosis/fibrosis, edema, microvascular obstruction, and intramyocardial hemorrhage. These features not only allow detection and quantification of the infarct size, but also reveal additional characteristics of the scar tissue with prognostic value.

Left atrial volume index and prediction of events in acute coronary syndrome: Solar Registry

Background

According to some international studies, patients with acute coronary syndrome (ACS) and increased left atrial volume index (LAVI) have worse long-term prognosis. However, national Brazilian studies confirming this prediction are still lacking.

Objective

To evaluate LAVI as a predictor of major cardiovascular events (MCE) in patients with ACS during a 365-day follow-up.

Methods

Prospective cohort of 171 patients diagnosed with ACS whose LAVI was calculated within 48 hours after hospital admission. According to LAVI, two groups were categorized: normal LAVI (≤ 32 mL/m²) and increased LAVI (> 32 mL/m²). Both groups were compared regarding clinical and echocardiographic characteristics, in- and out-of-hospital outcomes, and occurrence of ECM in up to 365 days.

Results

Increased LAVI was observed in 78 patients (45%), and was associated with older age, higher body mass index, hypertension, history of myocardial infarction and previous angioplasty, and lower creatinine clearance and ejection fraction. During hospitalization, acute pulmonary edema was more frequent in patients with increased LAVI (14.1% vs. 4.3%, p = 0.024). After discharge, the occurrence of combined outcome for MCE was higher (p = 0.001) in the group with increased LAVI (26%) as compared to the normal LAVI group (7%) [RR (95% CI) = 3.46 (1.54-7.73) vs. 0.80 (0.69-0.92)]. After Cox regression, increased LAVI increased the probability of MCE (HR = 3.08, 95% CI = 1.28-7.40, p = 0.012).

Conclusion

Increased LAVI is an important predictor of MCE in a one-year follow-up.

Association of left atrial reservoir function with left atrial structural remodeling related to left ventricular dysfunction in asymptomatic patients with hypertension: evaluation by two-dimensional speckle-tracking echocardiography

Left atrial (LA) structural and functional abnormalities are vital steps on the pathway toward heart failure with preserved ejection fraction in asymptomatic patients. The purpose of this study was to assess the relationship of LA function, particularly reservoir function, with LA structural remodeling related to the left ventricular (LV) dysfunction in asymptomatic patients with hypertension (HT) using conventional, tissue Doppler, and 2-D speckle-tracking echocardiography. Fifty age-matched healthy individuals and 140 patients with HT, including 75 with LA volume index (LAVI)<29 ml/m2 (normal LA group) and 65 with LAVI≥29 ml/m2 (large LA group), were enrolled. We defined peak early diastolic transmitral flow velocity/peak early diastolic mitral annular motion velocity (E/e')/peak systolic LA strain (S-LAs) as LA diastolic stiffness. The LV mass index, relative LV wall thickness, peak atrial systolic transmitral flow velocity, LA total, active, and passive emptying volume indexes, and E/e'/S-LAs were greatest, and S-LAs, peak early diastolic LA strain, peak systolic LV longitudinal strain and circumferential strain rate, and peak early diastolic LV radial strain rate were lower in the large LA group compared with control and/or normal LA group. Multivariate linear regression analysis revealed that aging, LA remodeling, and LV systolic and diastolic dysfunction are defined as strong predictors related to increased LA diastolic stiffness in the large LA group. HT alters LA dynamics significantly, with resultant increased LA volume and diastolic stiffness related to LV diastolic and systolic dysfunction, even in asymptomatic patients. Earlier treatment with renin–angiotensin system inhibitors may improve abnormal LA-LV interaction in this patient population.