Left atrial volume: a powerful predictor of survival after acute myocardial infarction

Assessment of left atrial volume and mechanical functions using real-time three-dimensional echocardiography in patients with mitral annular calcification

Objective:

Mitral annular calcification (MAC) is degeneration of the fibrous annular ring of the mitral valve. Left atrial (LA) function and volume have been evaluated by many methods; however, none have used real-time three-dimensional echocardiography (RT3DE) in patients with MAC. Our study is the first to evaluate LA volume and mechanical function using RT3DE in patients with MAC.

Methods:

Our study was a prospective cross-sectional study. In total, 32 patients with echocardiographic evidence of MAC and 30 volunteers without MAC were enrolled in the study. Kolmogorov–Smirnov test, Student’s t-test, Mann-Whitney U test, chi-square test, Pearson’s correlation test, and multiple linear regression analyses were used in this study.

Results:

LA diameter was significantly higher in patients with MAC (38.5±3.8 vs. 31.1±2.9, p<0.001). Maximum LA volume (49.6±11.2 vs. 35.6±2.5, p<0.001), minimum LA volume (23.8±7.9 vs. 12.6±2.3, p<0.001), and LA volume index (LAVI) (26.9±6.1 vs. 20.5±2.4, p<0.001) were also higher in the MAC group. LAVI was correlated with age (p<0.001), blood urea nitrogen levels (p=0.089), total cholesterol levels (p=0.055), left ventricular systolic myocardial velocity (p=0.048), E/A ratio (p<0.001), and MAC (p<0.001). Multiple linear regression analyses revealed that age (β=0.390, p<0.001) and MAC (β=0.527, p<0.001) were independent predictors of LAVI.

Conclusion:

We found that LA mechanical function was impaired in patients with MAC. Furthermore, age and MAC were independent predictors of increased LAVI according to our RT3DE examination.

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.

Assessment of left atrial volume and function by real time three-dimensional echocardiography in obese patients

OBJECTIVE

To evaluate left atrial (LA) volume and functions in obese subjects using real time three-dimensional echocardiography (RT3DE) and also the relationship between LA mechanical functions and N-terminal pro-atrial natriuretic peptide (NT-proANP).

METHODS

This study included 40 obese (26 females and 14 males, mean age 51.9 years) and 40 normal weight subjects (23 females and 16 males, mean age 53.5 years) with normal coronary angiograms. All the study participants underwent RT3DE to assess LA volume and mechanical function. Plasma NT-proANP was determined by ELISA method.

RESULTS

There was no significant difference between groups in left ventricular (LV) diameters and ejection fraction, which reflect LV systolic function. However, transmitral deceleration time, isovolumetric relaxation time, and peak late diastolic tissue Doppler velocity values, which reflect LV diastolic function, were found to be significantly higher in obese subjects when compared with controls. LA maximum volume (LAVmax), LAVmax index (LAVI), LA minimal volume (LAVmin), before atrial contraction volume (LAVpreA), LA active emptying volume, LA total emptying volume, and LA active emptying fraction, which reflect LA reservoir and pump functions, were also higher in obese subjects when compared with controls. LA passive emptying fraction was significantly lower in obese subjects than in controls. NT-proANP levels were similar between groups. There were positive correlations between NT-proANP level and LAVI, LAVmax, LAVmin, LAVpreA, and LA total and active emptying volumes.

CONCLUSIONS

Left atrial mechanical functions and volumes are impaired in obese subjects. These findings may be regarded as early markers of subclinical cardiac failure in obese subjects who have not yet exhibited any clinical evidence of cardiovascular disease.

Should pre-operative left atrial volume receive more consideration in patients with degenerative mitral valve disease undergoing mitral valve surgery?

BACKGROUND

Severe primary mitral regurgitation (MR) carries a significant incidence of mortality and morbidity. Though a number of prognostic factors have been identified, the best timing for mitral valve repair is still debated. We assessed the role of Left Atrial Volume Indexed (LAVI) as predictor of adverse events after mitral valve surgery.

METHODS

134 patients with severe MR were studied with a follow-up of 42±16months. Endpoints were Post-Operative Atrial Fibrillation (POAF), atrial and ventricular remodeling (LARR/LVRR) and correlation with outcome. POAF was defined as AF occurring within 2weeks and late AF (LAF) more than 2weeks after surgery. LARR was defined as LAVI reduction ≥15% and LVRR as any reduction of ventricular mass after surgery.

RESULTS

Forty-one patients experienced POAF, 26 had LAF. Pre-operative LAVI was an independent risk factor for POAF (OR 1.03, CI [1.00-1.06], p=0.01), LAF (OR 1.03, CI [1.00-1.06], p=0.02), LARR and LVRR (OR 1.04, CI [1.01-1.07], p=0.002, respectively). LARR was found in 75 patients, while LVRR in 111. Patients with heart remodeling had less incidence of LAF and cardiac adverse events, better diastolic function and improved their NYHA class after surgery.

CONCLUSIONS

LAVI should be given more weight into decision making for patients with MR as it predicts POAF and LAF and reverse atrial and ventricular remodeling, both associated to long-term outcome.

Evidence of left atrial remodeling and left ventricular diastolic dysfunction in type 2 diabetes mellitus with preserved systolic function

BACKGROUND AND AIMS

Prognosis of type 2 diabetes is associated with the occurrence of cardiovascular diseases. Left atrial (LA) size is a predictor of outcome in several diseases, including diabetes. Long duration of diabetes is an established risk factor of poor prognosis. No data are available on the relationship between LA size and duration of diabetes. The present study was aimed to investigate the relationship between LA volume index (LAVI) and the duration of diabetes to test the hypothesis that LA volume will increase as a function of diabetes duration.

METHODS AND RESULTS

Forty-four male patients with newly diagnosed and 172 male patients with established type 2 diabetes were recruited for this cross-sectional study. All patients were evaluated with a transthoracic echocardiographic Doppler. About 28.2% of patients had increased LAVI. Indices of both diastolic and systolic function were significantly lower in patients with larger left atrium. The values of LAVI increased across classes of duration of diabetes. In multivariable analysis, longer duration was a predictor of LAVI ≥34 ml/m² (odds ratio 1.65, 95% CI 1.11-2.46, p = 0.014) after adjusting for age, hemoglobin A1c, hypertension, microvascular complication status, and relevant echocardiographic parameters of systolic and diastolic function.

CONCLUSIONS

These results indicate that duration of diabetes is strongly and positively associated with larger LAVI in type 2 diabetic men with preserved systolic function. Future studies are needed to better elucidate the biological mechanisms underlying linking type 2 diabetes with abnormally increased LAVI in subjects with type 2 diabetes.

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.

Methodological Gaps in Left Atrial Function Assessment by 2D Speckle Tracking Echocardiography

The assessment of left atrial (LA) function is used in various cardiovascular diseases. LA plays a complementary role in cardiac performance by modulating left ventricular (LV) function. Transthoracic two-dimensional (2D) phasic volumes and Doppler echocardiography can measure LA function non-invasively. However, evaluation of LA deformation derived from 2D speckle tracking echocardiography (STE) is a new feasible and promising approach for assessment of LA mechanics. These parameters are able to detect subclinical LA dysfunction in different pathological condition. Normal ranges for LA deformation and cut-off values to diagnose LA dysfunction with different diseases have been reported, but data are still conflicting, probably because of some methodological and technical issues. This review highlights the importance of an unique standardized technique to assess the LA phasic functions by STE, and discusses recent studies on the most important clinical applications of this technique.

Atrial-focused views improve the accuracy of two-dimensional echocardiographic measurements of the left and right atrial volumes: a contribution to the increase in normal values in the guidelines update

Current guidelines recommend that the atria be measured in 2D echocardiographic (2DE) apical views using the method-of-disks (MOD) or area-length (AL) technique as an alternative, although no definitive data exists that these are interchangeable. However, standard apical views maximize the long-axis of the left ventricle, rather than the dimensions of the atria, resulting in atrial foreshortening. We hypothesized that the increase in normal values of atrial volumes in the recent guidelines update was driven by data obtained using either the AL technique or dedicated atrial-focused views, which maximize the longitudinal dimension of the atria and thus provide larger volumes than the MOD measurements in standard apical views. We prospectively studied 30 patients (Philips iE33) to compare 2DE measurements of left and right atrial volumes (LAV, RAV) using the MOD and AL techniques in standard and atrial-focused views, against 3D echocardiography (3DE) derived volumes (QLab) as a reference. Compared to standard views, atrial-focused views provided significantly larger MOD volumes for both atria, which were in better agreement with 3DE, as reflected by higher correlation coefficients (LAV: r = 0.95 vs. 0.89; RAV: r = 0.89 vs. 0.84), smaller biases (LAV: -1 ml vs. 7 ml; RAV: 3 ml vs. 7 ml) and tighter limits of agreement. This was also the case for the AL measurements, which were minimally larger than the MOD values (NS) for both atria. In conclusion, atrial-focused views are a more accurate alternative to standard apical views, which provides larger volumes. This finding can explain the increase in the normal values in the recent guidelines update, which was mostly driven by the use of atrial-focused views, rather than by the differences between MOD and AL techniques. This understanding is essential in order to correctly integrate the revised normal values into clinical practice.

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.

Diastolic Heart Failure Predicted by Left Atrial Expansion Index in Patients with Severe Diastolic Dysfunction

BACKGROUND

Left atrial (LA) echocardiographic parameters are increasingly used to predict clinically relevant cardiovascular events. The study aims to evaluate the LA expansion index (LAEI) for predicting diastolic heart failure (HF) in patients with severe left ventricular (LV) diastolic dysfunction.

METHODS

This prospective study enrolled 162 patients (65% male) with preserved LV systolic function and severe diastolic dysfunction (132 grade 2 patients, 30 grade 3 patients). All patients had sinus rhythm at enrollment. The LAEI was calculated as (Volmax - Volmin) x 100% / Volmin, where Volmax was defined as maximal LA volume and Volmin was defined as minimal volume. The endpoint was hospitalization for HF withp reserved LV ejection fraction (HFpEF).

RESULTS

The median follow-up duration was 2.9 years. Fifty-four patients had cardiovascular events, including 41 diastolic and 8 systolic HF hospitalizations. In these 54 patients, 13 in-hospital deaths and 5 sudden out-of-hospital deaths occurred. Multivariate analyses revealed that HFpEF was associated with LAEI.and atrial fibrillation during follow-up. For predicting HFpEF, the LAEI had a hazard ratio of 1.197per 10% decrease. In patients who had HFpEF events, the LAEI significantly (P< 0.0001) decreased from 69±18% to 39±11% during hospitalization. Although the LAEI improved during follow-up (53±13%), it did not return to baseline.

CONCLUSIONS

The LAEI predicts HFpEF in patients with severe diastolic dysfunction; it worsens during HFpEF events and partially recovers during followup.

Abnormal echocardiography in patients with type 2 diabetes and relation to symptoms and clinical characteristics

OBJECTIVES

We aimed to determine the prevalence of echocardiographic abnormalities and their relation to clinical characteristics and cardiac symptoms in a large, contemporary cohort of patients with type 2 diabetes.

RESULTS

A total of 1030 patients with type 2 diabetes participated. Echocardiographic abnormalities were present in 513 (49.8%) patients, mainly driven by a high prevalence of diastolic dysfunction 178 (19.4%), left ventricular hypertrophy 213 (21.0%) and left atrial enlargement, 200 (19.6%). The prevalence increased markedly with age from 31.1% in the youngest group (<55 years) to 73.9% in the oldest group (>75 years) (p < 0.001) and was equally distributed among the sexes (p = 0.76). In univariate analyses, electrocardiographic abnormalities, age, body mass index, known coronary heart disease, hypertension, albuminuria, diabetes duration and creatinine were associated with abnormal echocardiography along with dyspnoea and characteristic chest pain (p < 0.05 for all). Neither of the cardiac symptoms nor clinical characteristics had sufficient sensitivity and specificity to accurately identify patients with abnormal echocardiography.

CONCLUSION

Echocardiographic abnormalities are very common in outpatients with type 2 diabetes, but neither cardiac symptoms nor clinical characteristics are effective to identify patients with echocardiographic abnormalities.

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.

Relation of Stature to Outcomes in Korean Patients Undergoing Primary Percutaneous Coronary Intervention for Acute ST-Elevation Myocardial Infarction (from the INTERSTELLAR Registry)

Although epidemiologic studies have shown the impact of height on occurrence and/or prognosis of cardiovascular diseases, the underlying mechanism is unclear. In addition, the relation in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) remains unknown. We sought to assess the influence of height on outcomes of patients with acute STEMI undergoing primary PCI and to provide a pathophysiological explanation. All 1,490 patients with STEMI undergoing primary PCI were analyzed. Major adverse cardiac and cerebrovascular events (MACCE) were defined as all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, and unplanned hospitalization for heart failure (HF). Patients were divided into (1) MACCE (+) versus MACCE (-) and (2) first- to third-tertile groups according to height. MACCE (+) group was shorter than MACCE (-) group (164 ± 8 vs 166 ± 8 cm, p = 0.012). Prognostic impact of short stature was significant in older (≥70 years) male patients even after adjusting for co-morbidities (hazard ratio 0.951, 95% confidence interval 0.912 to 0.991, p = 0.017). The first-tertile group showed the worst MACCE-free survival (p = 0.035), and most cases of MACCE were HF (n, 17 [3%] vs 6 [1%] vs 2 [0%], p = 0.004). On post-PCI echocardiography, left atrial volume and early diastolic mitral velocity to early diastolic mitral annulus velocity ratio showed an inverse relation with height (p <0.001 for all) despite similar left ventricular ejection fraction. In conclusion, short stature is associated with occurrence of HF after primary PCI for STEMI, and its influence is prominent in aged male patients presumably for its correlation with diastolic dysfunction.

Advances in Echocardiographic Imaging in Heart Failure With Reduced and Preserved Ejection Fraction

Echocardiography, given its safety, easy availability, and the ability to permit a comprehensive assessment of cardiac structure and function, is an indispensable tool in the evaluation and management of patients with heart failure (HF). From initial phenotyping and risk stratification to providing vital data for guiding therapeutic decision-making and monitoring, echocardiography plays a pivotal role in the care of HF patients. The recent advent of multiparametric approaches for myocardial deformation imaging has provided valuable insights in the pathogenesis of HF, elucidating distinct patterns of myocardial dysfunction and events that are associated with progression from subclinical stage to overt HF. At the same time, miniaturization of echocardiography has further expanded clinical application of echocardiography, with the use of pocket cardiac ultrasound as an adjunct to physical examination demonstrated to improve diagnostic accuracy and risk stratification. Furthermore, ongoing advances in the field of big data analytics promise to create an exciting opportunity to operationalize precision medicine as the new approach to healthcare delivery that aims to individualize patient care by integrating data extracted from clinical, laboratory, echocardiographic, and genetic assessments. The present review summarizes the recent advances in the field of echocardiography, with emphasis on their role in HF phenotyping, risk stratification, and optimizing clinical outcomes.

Cardiac Abnormalities in Youth with Obesity and Type 2 Diabetes

Childhood obesity has been linked to cardiovascular disease (CVD) risk in adulthood. Of great concern is the expected increase in the population's CVD burden in relation to childhood obesity. This is compounded by the risk related to chronic hyperglycemia exposure in youth with type 2 diabetes. We herein provide an overview of the spectrum of early cardiovascular disease manifestation in youth with obesity and type 2 diabetes, in particular abnormalities in cardiac structure and function. Cardiac remodeling and adverse target organ damage is already evident in the pediatric age group in children with obesity and type 2 diabetes. This supports the importance of intensifying obesity prevention efforts and early intervention to treat comorbidities of obesity in the pediatric age group to prevent cardiac events in early adulthood.

Cardiac Imaging to Evaluate Left Ventricular Diastolic Function

Left ventricular diastolic dysfunction in clinical practice is generally diagnosed by imaging. Recognition of heart failure with preserved ejection fraction has increased interest in the detection and evaluation of this condition and prompted an improved understanding of the strengths and weaknesses of different imaging modalities for evaluating diastolic dysfunction. This review briefly provides the pathophysiological background for current clinical and experimental imaging parameters of diastolic dysfunction, discusses the merits of echocardiography relative to other imaging modalities in diagnosing and grading diastolic dysfunction, summarizes lessons from clinical trials that used parameters of diastolic function as an inclusion criterion or endpoint, and indicates current areas of research.

Left atrial remodeling in patients undergoing percutaneous mitral valve repair with the MitraClip system: an advanced echocardiography study

BACKGROUND

The goal of this study was to determine changes in left atrial (LA) function with two-dimensional speckle tracking echocardiography (2DSTE) and real-time full-volume three-dimensional echocardiography (RT3DE) after percutaneous mitral valve repair with the MitraClip system. Furthermore, we investigated whether baseline and/or changes in LA function after MitraClip repair had any impact on prognosis.

METHODS

A total of 25 consecutive patients (age: 57±12 years, 76% male) with moderate-to-severe or severe mitral regurgitation (MR) were included. Patients underwent 2DSTE and RT3DE before the clip implantation and after the 12-month follow-up. Prognostic data were also recorded via the use of telephone calls and follow-up visits for 12 months after the procedure.

RESULTS

Compared with the baseline, the LA reservoir strain (LA-Res) (7.66±4.3% vs 11.15±7.5%, P<.001) and LA contraction strain (LA-Pump) (4.64±4.3% vs 7.63±5.8%, P=.001) improved significantly after MitraClip repair; significant improvements were also seen in three-dimensional (3D) minimum LA volume index (LAV min) and maximum LA volume index (LAV max). On the other hand, conventional LA indices did not change. In total, eleven major adverse cardiac events (MACE) were observed at the 1-year follow-up. In univariate analyses, the preprocedural echocardiographic parameters that were associated with the MACE within 1 year after MitraClip repair were 3D-LAV min and LA-Res. Furthermore, these indices significantly correlated with improved functional parameters and MR reduction.

CONCLUSION

In conclusion, a successful MitraClip procedure can reverse the process of LA remodeling within 12 months, and this can be detected by 2DSTE and RT3DE. Also, patients with preprocedural lower LA-Res and higher 3D-LAV min had the worst prognoses at the 1-year follow-up.

Left Atrial Structure and Function Across the Spectrum of Cardiovascular Risk in the Elderly: The Atherosclerosis Risk in Communities Study

BACKGROUND

Although left atrial (LA) enlargement is a recognized risk factor for adverse cardiovascular outcomes, emerging evidence supports the importance of LA function. We examined LA emptying fraction (LAEF) across the spectrum of cardiovascular disease burden in a large cohort of elderly adults living in the community.

METHODS AND RESULTS

We studied 1142 participants in the Atherosclerosis Risk in Communities (ARIC) study who were in sinus rhythm, free of valvular disease, and had acceptable quality 3-dimensional echocardiograms (mean age, 76±5 years; 59% women). We determined the cross-sectional correlates of LAEF and compared LAEF among elderly adults without cardiovascular disease or cardiovascular risk factors (n=201), those with hypertension (n=734), and those with overt heart failure (HF; n=207). In multivariable analysis, lower LAEF was associated with higher LA volumes and worse left ventricular systolic and diastolic functions. Elderly participants free of cardiovascular disease or risk factors had smaller LA volumes than those with hypertension (LA volume max/ body surface area 30.2±6.6 versus 33.0±9.0 mL/m(2); P=0.001), but similar LAEF (55.2±10.3% versus 53.8±11.5%, respectively; P=0.357). Participants with HF had higher LA volume (39.8±13.3 mL/m(2)) and worse LAEF (47.6±14.6%) than participants with hypertension or participants free of cardiovascular disease or risk factors (all P<0.001).

CONCLUSIONS

In a community-based cohort, LA function was impaired in participants with prevalent HF, but there were no significant differences in LA function between participants with hypertension and those with free of cardiovascular disease or risk factors, despite greater LA size in the former.

Assessment and impact of diastolic function by echocardiography in elderly patients

Doppler echocardiography is the gold standard for assessment of diastolic dysfunction, which is increasingly recognised as a cause of heart failure, especially in the elderly. Using a combination of Doppler echocardiography techniques, it is possible to identify grades of diastolic dysfunction, estimate left ventricular filling pressures and establish the chronicity of diastolic dysfunction. These physiologically-derived measures have been widely validated against invasive measurements of left heart pressures and have been shown to be prognostically valuable in a wide range of clinical settings. This review explores the mechanisms, and approaches to the assessment of diastolic dysfunction in the elderly. The challenge for clinicians is to identify pathophysiological changes from those associated with normal ageing. When used in combination, and taking age into account, Doppler echocardiographic parameters are helpful in the assessment of dyspnoea in older patients and provide prognostic insights.

Respiratory influence on left atrial volume calculation with 3D-echocardiography

Background

Left atrial volume (LAV) estimation with 3D echocardiography has been shown to be more accurate than 2D volume calculation. However, little is known about the possible effect of respiratory movements on the accuracy of the measurement.

Methods

100 consecutive patients admitted with chest pain were examined with 3D echocardiography and LAV was quantified during inspiratory breath hold, expiratory breath hold and during free breathing.

Results

Of the 100 patients, only 65 had an echocardiographic window that allowed for 3D echocardiography in the entire respiratory cycle. Mean atrial end diastolic volume was 45.4 ± 14.5 during inspiratory breath hold, 46.4 ± 14.8 during expiratory breath hold and 45.6 ± 14.3 during free respiration. Mean end systolic volume was 17.6 ± 7.8 during inspiratory breath hold, 18.8 ± 8.0 during expiratory breath hold and 18.3 ± 8.0 during free respiration. No significant differences were seen in any of the measured parameters.

Conclusions

The present study adds to the feasibility of 3D LAV quantitation. LAV estimation by 3D echocardiography may be performed during either end-expiratory or end-inspiratory breath-hold without any significant difference in the calculated volume. Also, the LAV estimation may be performed during free breathing.

Three dimensional left atrial volume index is correlated with P wave dispersion in elderly patients with sinus rhythm

BACKGROUND

P wave dispersion is a noninvasive electrocardiographic predictor for atrial fibrillation. The aim of the study was to explore relation between left atrial volume index assessed by 3-dimensional echocardiography and P wave dispersion in elderly patients.

METHODS

Seventy-three consecutive patients over the age of 65 (mean age: 75 ± 7 years, 17 men) were included. P wave dispersion is calculated as the difference between maximum and minimum P wave durations. Left atrial volume index was measured by both 2-dimensional and 3-dimensional echocardiography and categorized as normal (≤ 34 mL/m(2)) or increased (mild, 35-41 mL/m(2); moderate, 42-48 mL/m(2); severe, ≥ 49 mL/m(2)).

RESULTS

Thirty-one patients had normal left atrium while 24 patients had mildly enlarged, nine had moderately enlarged, and nine had severely enlarged left atrium. Prolongation of P wave dispersion was more prevalent in patients with dilated left atrium. P wave dispersion was significantly correlated with both 2-dimensional (r = 0.600, p < 0.001) and 3-dimensional left atrial volume index (r = 0.688, p < 0.001). Both left atrial volume indexes were associated with prolonged P wave dispersion when adjusted for age, sex, presence of hypertension, and left ventricular mass index. Receiver-operator characteristic (ROC) analysis revealed that a 3-dimensional left atrial volume index ≥ 25 mL/m(2) separated patients with prolonged P wave dispersion with a sensitivity of 82.2 %, specificity of 67.9 %, positive predictive value of 80.4 %, and negative predictive value of 70.4 %.

CONCLUSION

In elderly patients, 3-dimensional left atrial volume index showed a better correlation with P wave dispersion and might be helpful in discriminating patients with prolonged P wave dispersion, who might be prone to atrial fibrillation.

Left Atrial Expansion Index Predicts Left Ventricular Filling Pressure and Adverse Events in Acute Heart Failure With Severe Left Ventricular Dysfunction

BACKGROUND

The power of left atrial (LA) parameters for predicting left ventricular (LV) filling pressure and adverse events in acute heart failure (HF) with severe LV dysfunction, either sinus rhythm or atrial fibrillation (AF), is not fully understood.

METHODS AND RESULTS

Echocardiography was performed in 141 patients with acute decompensated congestive HF and LV ejection fraction <35%, including 42 with permanent AF. The LA expansion index was calculated as (Volmax - Volmin) × 100%/Volmin, where Volmax was defined as maximal and Volmin as minimal LA volume. Of 141 patients, invasive LV filling pressures within 12 hours of LA expansion index measurement were available in 109. The end points were 3-year frequencies of HF hospitalization and all-cause mortality. Over a median follow-up of 3.1 years, 74 participants (52.5%) reached the end points (sinus vs AF group: 48.5% vs 61.9%, respectively; P = .047). Multivariate analysis revealed that adverse events of both groups were only independently associated with age and LA expansion index. Rates of adverse events were proportional to LA expansion index. There was a good logarithmic relationship between LA expansion index and LV filling pressure, regardless of presence or absence of AF.

CONCLUSIONS

LV filling pressure can be estimated well by LA expansion index, with or without AF. The LA expansion index predicts adverse events in HF patients with severe systolic dysfunction. (ClinicalTrials.gov number: NCT01307722).

Left atrio-vertebral ratio: A new computed-tomography measurement to identify left atrial dilation

BACKGROUND

Left cardiac chambers dilation, interstitial lung changes and pleural effusions are the characteristics of cardiogenic pulmonary oedema on computed tomography (CT) of the chest but mensuration of the left atrial size is not routinely performed. Cardiac chambers normal dimensions are known to be proportional to the patient's build and anthropomorphic data but adjustment of chambers dimensions to available elements seen on the axial CT images has never been evaluated before.

OBJECTIVES

Our objective was to use data easily available on axial images to directly scale the left atrium. We chose to divide the left atrial diameter by the thoracic vertebral diameter, using the latter as a body-mass indicator. As a preliminary study, we aimed to evaluate the range of values of this left atrio-vertebral ratio (LAVR) by comparing patients suffering from cardiogenic pulmonary oedema with patients free of cardiac disease. We hypothesized that if the difference of values in these two populations of patients was significant enough, this ratio would be relevant and could be used as a quick criterion in different clinical situations.

METHOD

Two radiologists reviewed CT scans of 32 of patients free of cardiac disease and 40 patients in acute cardiac failure. The maximum diameter of the left atrium at the level of the right inferior pulmonary vein was divided by the vertebral transverse diameter to generate a left atrio-vertebral ratio. Receiver operating characteristic curves identified the threshold associated with pulmonary oedema.

MEASUREMENTS AND MAIN RESULTS

The mean LAVR was 1.85 ± 0.27 in asymptomatic patients and 2.48 ± 0.35 in patients with pulmonary oedema. A LAVR of 2.1 yielded 85% sensitivity and 88% specificity for the diagnosis of cardiogenic pulmonary oedema.

CONCLUSIONS

LAVR is a simple new measure directly scaling the left atrial diameter to the anthropomorphic characteristics of the patient. In our series, a ratio above 2.1 is strongly associated with cardiogenic pulmonary oedema indirectly suggesting left atrial dilation. The results were significantly different between the two populations of patients (no heart condition versus cardiogenic pulmonary oedema) suggesting a high potential for clinical application.

Serum D-dimer Levels Are Proportionally Associated with Left Atrial Enlargement in Patients with an Acute Ischemic Stroke due to Non-valvular Atrial Fibrillation

Objective Left atrial enlargement (LAE) may predispose individuals to blood stasis in atrial fibrillation (AF), and thus play a crucial role in thrombogenesis. The D-dimer level is one of the surrogate markers for a hypercoagulable state and reflects thrombus formation in AF. Since the D-dimer level reflects hypercoagulability as well as thrombus and fibrin burdens, LAE could be associated with a D-dimer elevation. However, no studies have explored this association or which factors contribute to increases in the D-dimer levels in patients with AF. Therefore, we assessed whether the serum D-dimer levels are related to the left atrial volume index (LAVI) or other vascular risk factors and also evaluated the association between the D-dimer levels and the initial stroke severity. Methods Ninety-eight consecutive patients with an acute ischemic stroke and non-valvular AF (NVAF) who were anticoagulation-naïve were enrolled, and all patients were stratified into moderate-to-severe and mild neurologic deficit groups using the National Institutes of Health Stroke Scale on admission. The association between the initial serum D-dimer levels and the LAVI was evaluated in all enrolled patients, and the serum D-dimer levels were compared between the two groups. Results The patients were classified into two groups according to the severity of the neurologic deficit. In a partial correlation coefficient analysis adjusted for confounding factors, an increase in the initial serum D-dimer levels was significantly associated with LAVI (r=0.286; p=0.027). A linear regression analysis showed that a history of peripheral artery disease was the factor most strongly associated with the serum D-dimer level (t=3.90, p<0.001), followed by LAVI (t=2.37, p=0.021) and a history of congestive heart failure (t=2.16, p=0.035). The D-dimer levels were higher in the moderate-to-severe neurologic deficit group than in the mild deficit group, but this difference was not statistically significant (4.5±7.1 vs. 1.6±2.6 mg/L, p=0.068). Conclusion The serum D-dimer levels were significantly associated with LAE in anticoagulation-naïve patients with an acute ischemic stroke and NVAF.

Left Atrial Volume as a Predictor of Left Ventricular Functional Recovery in Patients With Dilated Cardiomyopathy and Absence of Delayed Enhancement in Cardiac Magnetic Resonance

BACKGROUND

Improvement of left ventricular (LV) systolic dysfunction can occur in patients with dilated cardiomyopathy (DCM), and it is more frequently observed if patients have no delayed enhancement (DE) in cardiac magnetic resonance imaging (CMR). However, even in the absence of DE, not all patients have functional recovery. We retrospectively investigated the predictors of LV functional recovery in patients with DCM who had no DE in CMR.

METHODS

A total of 136 patients with DCM underwent CMR. Among them, 44 (29 male, age 55 ± 14 years) showed no DE and these patients composed the study population. The study patients were divided into 2 groups according to the occurrence of functional recovery defined as an increase in LV ejection fraction to a level of ≥50% and net increase in ejection fraction of 20% or more: group 1 (n = 14) with functional recovery and group 2 (n = 30) without functional recovery.

RESULTS

In patients who showed functional recovery, left atrial volume index (LAVI [26 ± 8 mL/m(2) vs 45 ± 18 mL/m(2)]) and LV end-diastolic dimension (62 ± 6 mm vs 67 ± 7 mm) were significantly smaller when compared with those without functional recovery (P <.05 for all). In Cox multiple regression analysis, LAVI was the only significant parameter associated with LV functional recovery (hazard ratio 0.932, 95% confidence interval 0.877-0.991, P = .024). LAVI < 38 mL/m(2) had 100% specificity in predicting the improvement of LV systolic dysfunction.

CONCLUSION

In DCM patients who had no DE in CMR, LAVI predicts LV functional recovery with high specificity.

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.

Independent prognostic value of left atrial function by two-dimensional speckle tracking imaging in patients with non -ST-segment-elevation acute myocardial infarction

Background

The objective of this study is to evaluate left atrial(LA) function and its prognostic value by two-dimensional speckle tracking echocardiography (STE) in patients with non-ST-segment-elevation acute myocardial infarction (NSTEAMI).

Methods

Global longitudinal LA S/SR data obtained by 2D speckle imaging with automated software (Echo PAC, GE Medical).

Results

Clinical variables and angiographic, echocardiographic, and STE parameters were studied in 65 patients with NSTEAMI (51 males and 14 females; mean age of 60.7 ± 9.8 years) who underwent elective PCI. The final study population consisted of 51 individuals (43 males and 8 females; mean age of 62.9 ± 11.1 years) and a 12 ± 3 months follow-up was performed. A total of 22 combined cardiovascular events(20 patients) occurred. With the use of Univariable Cox regression, all parameters were evaluated in the prediction of cardiac events, ischemic events, and/or cardiac death. According to ROC analysis, baseline mean global left atrial SRs (ROC area 0.82, p = 0.001) and baseline mean global left atrial SRe (ROC area 0.68, p = 0.036) were the only predictive variables.

Conclusions

In patients with NSTEAMI, we found that the novel global strain parameter of left atrial function is a valuable predictor of combined cardiovascular events over conventional echocardiography and may therefore be an important clinical tool for risk stratification in the acute phase of NSTEAMI.

Prediction of All-Cause Mortality by the Left Atrial Volume Index in Patients With Normal Left Ventricular Filling Pressure and Preserved Ejection Fraction

OBJECTIVE

To describe the prevalence of left atrial (LA) enlargement (LAE) and its association with all-cause mortality in 10,719 patients with an early diastolic transmitral flow velocity (E) to early diastolic mitral annular velocity (e') ratio-determined normal left ventricular (LV) filling pressure and preserved LV ejection fraction (LVEF).

METHODS

We evaluated 10,719 patients (deceased patients: n = 479; mean [SD] age, 65 [14] years; 60% male; surviving patients: n = 10,240; mean (SD) age, 54 (16) years; 48% male) with estimated normal LV filling pressure (E/e' ratio ≤ 8) and preserved LVEF (≥ 50%) to determine the impact of LA volume index (LAVi) on all-cause mortality during a mean (SD) follow-up of 2.2 (1.0) years.

RESULTS

In the univariate analysis, with every milliliter per square meter increase in LAVi, all-cause mortality risk increased by 3% (hazard ratio [HR], 1.03; 95% CI, 1.02-1.04; P < .001). After adjusting for covariates, LAVi (as a continuous variable) was an independent predictor of all-cause mortality (HR, 1.015; 95% CI, 1.005-1.026; P = .01). When LAVi was assessed as a categorical variable with normal LAVi (≤ 28 mL/m(2)) as the reference group, moderate LAVi (34-39 mL/m(2)) and severe LAVi (≥ 40 mL/m(2)) were independent predictors of all-cause mortality (HR, 1.34; 95% CI, 1.01-1.79; P = .04; and HR, 1.65; 95% CI, 1.18-2.29; P = .003, respectively).

CONCLUSION

LAE was independently associated with an increased risk of all-cause mortality in our large cohort of 10,719 patients with normal LV filling pressure and preserved LVEF.