Left atrium: the last bulwark before overt heart failure

Mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF)

Exercise intolerance is a well-established symptom of heart failure with preserved ejection fraction (HFpEF) and is associated with impaired quality of life and worse clinical outcomes. Historically attributed to diastolic dysfunction of the left ventricle, exercise intolerance in HFpEF is now known to result not only from diastolic dysfunction, but also from impairments in left ventricular systolic function, left atrial pathology, right ventricular dysfunction, and valvular disease. Disorders of heart rate and rhythm such as chronotropic incompetence and atrial fibrillation have also been implicated in exercise intolerance in this population. Pathologic changes to extra-cardiac organ systems including the respiratory, vascular, hormonal, and skeletal muscle systems are also thought to play a role in exercise impairment. Finally, comorbidities such as obesity, inflammation, and anemia are common and likely contributory in many cases. The role of each of these factors is discussed in this review of exercise intolerance in patients with HFpEF.

Left Atrial Roof Enlargement Is a Distinct Feature of Heart Failure With Preserved Ejection Fraction

BACKGROUND

It remains unknown to what extent intrinsic atrial cardiomyopathy or left ventricular diastolic dysfunction drive atrial remodeling and functional failure in heart failure with preserved ejection fraction (HFpEF). Computational 3-dimensional (3D) models fitted to cardiovascular magnetic resonance allow state-of-the-art anatomic and functional assessment, and we hypothesized to identify a phenotype linked to HFpEF.

METHODS

Patients with exertional dyspnea and diastolic dysfunction on echocardiography (E/e', >8) were prospectively recruited and classified as HFpEF or noncardiac dyspnea based on right heart catheterization. All patients underwent rest and exercise-stress right heart catheterization and cardiovascular magnetic resonance. Computational 3D anatomic left atrial (LA) models were generated based on short-axis cine sequences. A fully automated pipeline was developed to segment cardiovascular magnetic resonance images and build 3D statistical models of LA shape and find the 3D patterns discriminant between HFpEF and noncardiac dyspnea. In addition, atrial morphology and function were quantified by conventional volumetric analyses and deformation imaging. A clinical follow-up was conducted after 24 months for the evaluation of cardiovascular hospitalization.

RESULTS

Beyond atrial size, the 3D LA models revealed roof dilation as the main feature found in masked HFpEF (diagnosed during exercise-stress only) preceding a pattern shift to overall atrial size in overt HFpEF (diagnosed at rest). Characteristics of the 3D model were integrated into the LA HFpEF shape score, a biomarker to characterize the gradual remodeling between noncardiac dyspnea and HFpEF. The LA HFpEF shape score was able to discriminate HFpEF (n=34) to noncardiac dyspnea (n=34; area under the curve, 0.81) and was associated with a risk for atrial fibrillation occurrence (hazard ratio, 1.02 [95% CI, 1.01-1.04]; P=0.003), as well as cardiovascular hospitalization (hazard ratio, 1.02 [95% CI, 1.00-1.04]; P=0.043).

CONCLUSIONS

LA roof dilation is an early remodeling pattern in masked HFpEF advancing to overall LA enlargement in overt HFpEF. These distinct features predict the occurrence of atrial fibrillation and cardiovascular hospitalization.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03260621.

New perspectives in the echocardiographic hemodynamics multiparametric assessment of patients with heart failure

International Guidelines consider left ventricular ejection fraction (LVEF) as an important parameter to categorize patients with heart failure (HF) and to define recommended treatments in clinical practice. However, LVEF has some technical and clinical limitations, being derived from geometric assumptions and is unable to evaluate intrinsic myocardial function and LV filling pressure (LVFP). Moreover, it has been shown to fail to predict clinical outcome in patients with end-stage HF. The analysis of LV antegrade flow derived from pulsed-wave Doppler (stroke volume index, stroke distance, cardiac output, and cardiac index) and non-invasive evaluation of LVFP have demonstrated some advantages and prognostic implications in HF patients. Speckle tracking echocardiography (STE) is able to unmask intrinsic myocardial systolic dysfunction in HF patients, particularly in those with LV preserved EF, hence allowing analysis of LV, right ventricular and left atrial (LA) intrinsic myocardial function (global peak atrial LS, (PALS)). Global PALS has been proven a reliable index of LVFP which could fill the gaps "gray zone" in the previous Guidelines algorithm for the assessment of LV diastolic dysfunction and LVFP, being added to the latest European Association of Cardiovascular Imaging Consensus document for the use of multimodality imaging in evaluating HFpEF. The aim of this review is to highlight the importance of the hemodynamics multiparametric approach of assessing myocardial function (from LVFP to stroke volume) in patients with HF, thus overcoming the limitations of LVEF.

Reference intervals for various measurements of canine left atrial size and function obtained using two-dimensional and three-dimensional echocardiography

BACKGROUND

Many canine cardiac diseases are associated with left atrial (LA) remodeling and decreased function. For accurate assessment of LA indices, large-scale and prospectively determined reference intervals are necessary.

OBJECTIVES

To generate reference intervals of LA size and function using two-dimensional and three-dimensional echocardiography.

ANIMALS

Two hundred and one healthy adult dogs.

METHODS

Left atrial volume was assessed in right parasternal long-axis, left apical 4-chamber and 2-chamber views using monoplane Simpson's method, two-dimensional and three-dimensional speckle tracking. Additionally, LA diameter was measured in right parasternal short-axis and long-axis views. Furthermore, LA function was determined by measuring strain and calculating LA fractional shortening and ejection fraction. All variables were tested for correlation to heart rate, age, and body weight. For LA diameter and volume, scaling exponents and prediction intervals were generated using allometric scaling. Reference intervals for LA function parameters were calculated using nonparametric methods.

RESULTS

Left atrial diameter and volume showed a strong correlation with body weight. The scaling exponent for LA diameter was approximately 1/3 (0.34-0.40) and approximately 1 for volume measurements (0.97-1.26). Parameters of LA function showed no clinically relevant correlation with body weight, except for two variables, which showed a mild negative correlation. No clinically relevant correlations with age or heart rate were found.

CONCLUSIONS

Reference intervals for linear, two-dimensional and three-dimensional measurements of LA size and function were established. The wide range of measurement methods offers the opportunity to select the appropriate reference values for LA evaluation depending on the available technical possibilities.

Novel Biomarkers and Advanced Cardiac Imaging in Aortic Stenosis: Old and New

Currently, the symptomatic status and left ventricular ejection fraction (LVEF) play a crucial role in aortic stenosis (AS) assessment. However, the symptoms are often subjective, and LVEF is not a sensitive marker of left ventricle (LV) decompensation. Over the past years, the cardiac structure and function research on AS has increased due to advanced imaging modalities and potential therapies. New imaging parameters emerged as predictors of disease progression in AS. LV global longitudinal strain has proved useful for risk stratification in asymptomatic severe AS patients with preserved LVEF. The assessment of myocardial fibrosis by cardiac magnetic resonance is the most studied application and offers prognostic information on AS. Moreover, the usage of biomarkers in AS as objective measures of LV decompensation has recently gained more interest. The present review focuses on the transition from compensatory LV hypertrophy (H) to LV dysfunction and the biomarkers associated with myocardial wall stress, fibrosis, and myocyte death. Moreover, we discuss the potential impact of non-invasive imaging parameters for optimizing the timing of aortic valve replacement and provide insight into novel biomarkers for possible prognostic use in AS. However, data from randomized clinical trials are necessary to define their utility in daily practice.

Echocardiographic evaluation of left atrial strain for predicting iron overload in pediatric patients with β-thalassemia with preserved ejection fraction

Pediatric patients with β-thalassemia (β-TM) with preserved ejection fraction may experience early myocardial damage. This prospective study aimed to investigate left atrial (LA) function restructure in pediatric patients with β-TM by two-dimensional speckle tracking echocardiography (2D-STE) and evaluate the value of LA strain for predicting myocardial iron overload (MIO). We recruited 50 β-TM pediatric patients and 30 healthy children aged 3-14 years. The patients were assigned to a normal left ventricular (LV) lesion group (n = 20) and an enlarged LV lesion group (n = 30). Subjects all underwent echocardiography to measure conventional cardiac function parameters and LA strain parameters. The results displayed that LA reservoir strain (LASr), conduit strain (LAScd), contractile strain (LASct) and strain rate were significantly reduced in pediatric patients with β-TM with preserved ejection fraction. LASr, LAScd, and LASct were negatively correlated with the E/e' ratio, of which LASr had the most significant correlation (r = - 0.69, P < 0.001). LASr and LASct correlated positively with T2* (r = 0.70 and 0.62, respectively, all P < 0.001). In the multiple regression, LASr and LASct were independent predictors for T2*. The areas under the curve for LASr and LASct were 0.87 (P < 0.001) and 0.78 (P = 0.004), respectively. Our results demonstrated that LA strains were dramatically impaired in pediatric patients with β-TM, and LASr is an efficient indicator for detecting LV early diastolic dysfunction in β-TM pediatric patients and reflects early myocardial damage. LASr and LASct were independently predictive of MIO, but LASr was a more sensitive predictor.

Decreased Left Atrial Reservoir Strain Is Associated with Adverse Outcomes in Restrictive Cardiomyopathy

Background: Restrictive cardiomyopathy (RCM) places patients at high risk for adverse events. In this study, we aim to evaluate the association between left atrial function and time to adverse events such as all-cause mortality and cardiovascular hospitalizations related to RCM. Material and Methods: In this single-center study, ninety-eight patients with a clinical diagnosis of RCM were recruited from our registry: 30 women (31%); age (mean ± standard deviation) 61 ± 13 years. These patients underwent cardiac magnetic resonance (CMR) imaging from May 2007 to September 2015. Left atrial (LA) function (reservoir, contractile, and conduit strain), LA diameter and area, and left ventricular function (global longitudinal strain, ejection fraction), and volume were quantified, and the presence of late gadolinium enhancement was visually assessed. The cutoff value of the LA reservoir strain was selected based on tertile. An adjusted Cox proportional regression analysis was used to assess time to adverse outcomes with a median follow up of 49 months. Results: In our cohort, all-cause mortality was 36% (35/98). Composite events (all-cause mortality and cardiovascular hospitalizations) occurred in 56% of patients (55/98). All-cause mortality and composite events were significantly associated with a decreased LA reservoir strain (adjusted hazard ratio (aHR) = 0.957, p = 0.002 and aHR = 0.969, p = 0.008) using a stepwise elimination of imaging variables, demographics, and comorbidities. All-cause mortality and composite events were six and almost four times higher, respectively, in patients with the LA reservoir strain <15% (aHR = 5.971, p = 0.005, and HR = 4.252, p = 0.001) compared to patients with the LA reservoir strain >34%. Survival was significantly reduced in patients with an LA reservoir strain <15% (p = 0.008). Conclusions: The decreased LA reservoir strain is independently associated with time to adverse events in patients with RCM.

Left atrial function in patients with heart failure

Improvement of the treatment and diagnosis of hypertension and heart failure (HF) contributes to an increase in life expectancy of the population and, accordingly, its aging. The problem of diagnosing and predicting HF with preserved ejection fraction (HFpEF) is currently one of the urgent problems. The role of left atrial function in the development and course prediction of HF are the subject of scientific study. This review provides an analysis of recent studies on left atrial function in HF patients.

Current and new imaging techniques in risk stratification of asymptomatic severe aortic stenosis

Aortic stenosis (AS) is one of the most common valvular diseases in clinical practice. The prevalence of calcified AS with moderate or severe stenosis exceeds 2% after 75 years. The optimal timing of intervention for asymptomatic severe AS is uncertain and controversial. Identification of high-risk patients is based on echocardiographic parameters (left ventricular dysfunction, AS severity and progression), hemodynamic response to exercise, pulmonary hypertension, and elevated brain natriuretic peptides. However, early surgical aortic valve replacement (AVR), when compared to the watchful waiting approach, was associated with survival advantage. Moreover, new insights into pathophysiology of AS and advances in imaging modalities were helpful in the management of asymptomatic AS. In this report, we detail the potential role of echocardiography to guide timing of surgery and we discussed the use of early risk features based on recent imaging modalities.

The Predictive Value of Left Atrial Strain Following Transcatheter Aortic Valve Implantation on Anatomical and Functional Reverse Remodeling in a Multi-Modality Study

Introduction

Transcatheter aortic valve implantation (TAVI) can improve left ventricular (LV) mechanics and survival. Data on the predictive value of left atrial (LA) strain following TAVI are scarce. We aimed to evaluate the association of LA strain measured shortly post-TAVI with functional and anatomical reverse remodeling of the LA and LV, and its association with mortality.

Methods

We prospectively investigated 90 patients who underwent TAVI. Transthoracic echocardiography including strain analysis was performed shortly after TAVI and repeated 6 months later. CT angiography (CTA) was performed for pre-TAVI planning and 6 months post-TAVI. Speckle tracking echocardiography was used to determine LA peak reservoir strain (LASr) and LV global longitudinal strain (LV-GL), LA volume index (LAVi) was measured by TTE. LV mass index (LVMi) was calculated using CTA images. LA reverse remodeling was based on LASr and LAVi changes, whereas LV reverse remodeling was defined as an improvement in LV-GLS or a reduction of LVMi. The association of severely reduced LASr (&lt;20%) at baseline with changes (Δ) in LASr, LAVi, LV-GLS and LVMi were analyzed using linear regression, and Cox proportional hazard model for mortality.

Results

Mean LASr and LV-GLS were 17.7 ± 8.4 and −15.3 ± 3.4% at baseline and 20.2 ± 10.2 and −16.6 ± 4.0% at follow-up (p = 0.024 and p &lt; 0.001, respectively). Severely reduced LASr at baseline was associated with more pronounced ΔLASr (β = 5.24, p = 0.025) and LVMi reduction on follow-up (β = 5.78, p = 0.036), however, the majority of the patients had &lt;20% LASr on follow-up (44.4%). Also, ΔLASr was associated with ΔLV-GLS (adjusted β = 2.10, p &lt; 0.001). No significant difference in survival was found between patients with baseline severely reduced LASr (&lt;20%) and higher LASr (≥20%) (p = 0.054).

Conclusion

LV reverse remodeling based on LVMi was present even in patients with severely reduced LASr following TAVI, although extensive LA damage based on LA strain was demonstrated by its limited improvement over time.

Clinical Trial Registration

(ClinicalTrials.gov number: NCT02826200).

The Added Value of Atrial Strain Assessment in Clinical Practice

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

Altered cardiac reserve is a determinant of exercise intolerance in sickle cell anaemia patients

BACKGROUND

The underlying mechanisms of exercise intolerance in sickle cell anaemia (SCA) patients are complex and not yet completely understood. While latent heart failure at rest could be unmasked upon exercise, most previous studies assessed cardiac function at rest. We aimed to investigate exercise cardiovascular reserve as a potential contributor to exercise intolerance in adult SCA patients.

METHODS

In this observational prospective study, we compared prospectively 60 SCA patients (median age 31 years, 60% women) to 20 matched controls. All subjects underwent symptom-limited combined exercise echocardiography and oxygen uptake (VO₂ ) measurements. Differences between arterial and venous oxygen content (C(a-v)O₂ ) were calculated. Cardiac reserve was defined as the absolute change in cardiac index (Ci) from baseline to peak exercise.

RESULTS

Compared to controls, SCA patients demonstrated severe exercise intolerance (median peakVO₂ , 34.3 vs. 19.7 ml/min/kg, respectively, p < .0001). SCA patients displayed heterogeneously increased Ci from rest to peak exercise (median +5.8, range 2.6 to 10.6 L/min/m²) which correlated with peakVO₂ (r = 0.71, p < .0001). In contrast, the C(a-v)O₂ exercise reserve was homogenously reduced and did not correlate with peakVO₂ (r = 0.18, p = .16). While haemoglobin level and C(a-v)O₂ were similar in SCA subgroups, SCA patients in the lower VO₂ tertile had chronotropic incompetence and left ventricular diastolic dysfunction (left atrial peak longitudinal strain was reduced, and both E/e' ratio and left atrial volume index were increased) and were characterized by a reduced cardiac reserve, +5.0[4.2-5.5] compared to +6.7[5.5-7.8] L/min/m² for the rest of the patient cohort, p < .0001.

CONCLUSIONS

Altered cardiac reserve due to chronotropic incompetence and left ventricular diastolic dysfunction seems to be an important determinant of exercise intolerance in adult SCA patients.

Cardiac magnetic resonance fingerprinting: Trends in technical development and potential clinical applications

Quantitative cardiac magnetic resonance has emerged in recent years as an approach for evaluating a range of cardiovascular conditions, with T1 and T2 mapping at the forefront of these developments. Cardiac Magnetic Resonance Fingerprinting (cMRF) provides a rapid and robust framework for simultaneous quantification of myocardial T1 and T2 in addition to other tissue properties. Since the advent of cMRF, a number of technical developments and clinical validation studies have been reported. This review provides an overview of cMRF, recent technical developments, healthy subject and patient studies, anticipated technical improvements, and potential clinical applications. Recent technical developments include slice profile and pulse efficiency corrections, improvements in image reconstruction, simultaneous multislice imaging, 3D whole-ventricle imaging, motion-resolved imaging, fat-water separation, and machine learning for rapid dictionary generation. Future technical developments in cMRF, such as B0 and B1 field mapping, acceleration of acquisition and reconstruction, imaging of patients with implanted devices, and quantification of additional tissue properties are also described. Potential clinical applications include characterization of infiltrative, inflammatory, and ischemic cardiomyopathies, tissue characterization in the left atrium and right ventricle, post-cardiac transplantation assessment, reduction of contrast material, pre-procedural planning for electrophysiology interventions, and imaging of patients with implanted devices.

Fully automated left atrium segmentation from anatomical cine long-axis MRI sequences using deep convolutional neural network with unscented Kalman filter

This study proposes a fully automated approach for the left atrial segmentation from routine cine long-axis cardiac magnetic resonance image sequences using deep convolutional neural networks and Bayesian filtering. The proposed approach consists of a classification network that automatically detects the type of long-axis sequence and three different convolutional neural network models followed by unscented Kalman filtering (UKF) that delineates the left atrium. Instead of training and predicting all long-axis sequence types together, the proposed approach first identifies the image sequence type as to 2, 3 and 4 chamber views, and then performs prediction based on neural nets trained for that particular sequence type. The datasets were acquired retrospectively and ground truth manual segmentation was provided by an expert radiologist. In addition to neural net based classification and segmentation, another neural net is trained and utilized to select image sequences for further processing using UKF to impose temporal consistency over cardiac cycle. A cyclic dynamic model with time-varying angular frequency is introduced in UKF to characterize the variations in cardiac motion during image scanning. The proposed approach was trained and evaluated separately with varying amount of training data with images acquired from 20, 40, 60 and 80 patients. Evaluations over 1515 images with equal number of images from each chamber group acquired from an additional 20 patients demonstrated that the proposed model outperformed state-of-the-art and yielded a mean Dice coefficient value of 94.1%, 93.7% and 90.1% for 2, 3 and 4-chamber sequences, respectively, when trained with datasets from 80 patients.

Left Ventricular Diastolic Dysfunction and Diastolic Heart Failure in Preterm Infants

Diastolic dysfunction is primarily an echocardiographic diagnosis. Its clinical counterpart is diastolic heart failure, where the heart has difficulty to fill at normal pressure and the patient develops signs of pulmonary edema. Although diastolic dysfunction is common in adults, limited information is available in preterm infants. The aim of this study is to explore left ventricular diastolic dysfunction and diastolic heart failure in preterm infants and describe clinical manifestations in this population. This is a retrospective observational study in preterm infants < 30 weeks' gestation who received an echocardiography in the first 4 weeks after birth. Diastolic dysfunction was graded using a population-specific adapted version of the adult recommendations for the evaluation of left ventricular diastolic function by echocardiography. Left ventricular diastolic dysfunction was absent, indeterminate, and definite in 82%, 14%, and 4% of the 168 echocardiograms analyzed, and is associated with increased respiratory signs and respiratory deterioration at 48 h before echocardiogram. In seven infants, diastolic heart failure was diagnosed with both ultrasound and clinical signs. The cumulative risk of diastolic dysfunction increased with the increasing postnatal age and a patent ductus arteriosus. Evidence of left ventricular diastolic dysfunction on echocardiography is relatively common in preterm infants, while the left ventricular diastolic heart failure is less frequent. Prolonged exposure to volume load was the most common cause.

Potential usefulness and clinical relevance of a novel left atrial filling index to estimate left ventricular filling pressures in patients with preserved left ventricular ejection fraction

Aims

The aim of this study was to examine the potential usefulness and clinical relevance of a novel left atrial (LA) filling index using 2D speckle-tracking transthoracic echocardiography to estimate left ventricular (LV) filling pressures in patients with preserved LV ejection fraction (LVEF).

Methods and results

The LA filling index was calculated as the ratio of the mitral early-diastolic inflow peak velocity (E) over LA reservoir strain (i.e. E/LA strain ratio). This index showed a good diagnostic performance to determine elevated LV filling pressures in a test-cohort (n = 31) using invasive measurements of LV end-diastolic pressure (area under the curve 0.82, cut-off &gt; 3.27 = sensitivity 83.3%, specificity 78.9%), which was confirmed in a validation-cohort (patients with cardiovascular risk factors; n = 486) using the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging criteria (cut-off &gt; 3.27 = sensitivity 88.1%, specificity 77.6%) and in a specificity-validation cohort (patients free of cardiovascular risk factors, n = 120; cut-off &gt; 3.27 = specificity 98.3%). Regarding the clinical relevance of the LA filling index, an elevated E/LA strain ratio (&gt;3.27) was significantly associated with the risk of heart failure hospitalization at 2 years (odds ratio 4.3, 95% confidence interval 1.8–10.5), even adjusting this analysis by age, sex, renal failure, LV hypertrophy, or abnormal LV global longitudinal systolic strain.

Conclusion

The findings from this study suggest that a novel LA filling index using 2D speckle-tracking echocardiography could be of potential usefulness and clinical relevance in estimating LV filling pressures in patients with preserved LVEF.

Left Atrial Phasic Function in Patients with Hypertension and Recurrent Atrial Fibrillation: Gender Differences of the Relationship with Diastolic Dysfunction and Central Aortic Pressure

Aim. To evaluate gender-related differences of left atrial (LA) phasic function and structural remodeling in conjunction with the parameters of left ventricular (LV) diastolic dysfunction and central aortic pressure in patients with hypertension and recurrent atrial fibrillation (AF).

Material and methods. The comparative study included 30 men and 37 women with non-valvular AF, hypertension and LV hypertrophy. Conventional echocardiographic measures were extended with LA measures, including its volume in three phases, LAemptying fraction (LAEF), passive and active ejection fraction. The parameters of central aortic pressure were estimated by applanation tonometry method.

Results. No difference was observed between LA and LV structural parameters in men and women. However, in women LAEF (39 [28;50] vs 50 [42;55]%; p=0.02) and E/E’(9.7 [7.8;12] vs 7.1 [5.6;8.6]; p=0.001) were worse than in men. Active LA ejection fraction was higher in women (31 [21;42] vs 24 [19;31]%; p=0.04), whereas passive one – in men (12 [10;14] vs 33 [23;38]%; p<0.001), respectively. Men and women had comparable heart rate (HR), central and peripheral systolic and diastolic pressure, pulse wave velocity (PWV), but women had higher augmentation index (AI) values [33 [28;39] vs 23 [21;28]%; p<0.001], even adjusted by HR (AI 75) (34 [27;39] vs 26 [20;29]%; p<0.001). Only in men PWV weakly correlated with AI 75 (r=0.44; p=0.02 versus r=-0.11; p=0.51, respectively for men and women; intergroup differences: z=2.26; p=0.012). In a multivariate regression analysis in men LAEF was significantly associated with height, weight, E’, E/E’ and glomerular filtration rate (GFR), whereas in women – with E’ and AI 75.

Conclusion. Patients of different genders with recurrent AF and hypertension have comparable LA structuralremodeling. However, women characterized by a more pronounced decrease in LAEF and impaired LV diastolic function than men. In women as distinct from men LV filling is predominantly due to LA systole. In a multivariate regression analysis in men LAEF was significantly associated with height, weight, E’, E/E’ and GFR, whereas in women – with E’ and AI 75. 

Right ventricular diameter predicts all-cause mortality in heart failure with preserved ejection fraction

Left ventricular ejection fraction (EF) is helpful to differentiate heart failure (HF) phenotype in clinical practice. The aim of the study was to identify simple echocardiographic predictors of post-discharge all-cause mortality in hospitalized HF patients. Patients with acute HF (75 ± 9.8 years), classified in preserved (≥ 50%) and reduced (< 50%) EF (HFpEF and HFrEF, respectively), were enrolled. The mean follow-up period was of 25.4 months. Patients definitively analyzed were 135. At multivariate Cox model, right ventricular diameter (RVd), inferior vena cava diameter (IVCd) and blood urea nitrogen (BUN) resulted to be significantly associated with all-cause mortality in HFpEF (HR 2.4, p = 0.04; HR 1.06, p = 0.02; HR 1.02, p = 0.01), whereas, left atrial volume (LAV) was significantly associated with mortality in HFrEF (HR 1.06, p = 0.006). Excluding LAV from the model, only COPD remained an independent predictor of all-cause mortality (HR 2.15, p = 0.04) in HFrEF. At Kaplan-Meier analysis, no differences of survival between HFrEF and HFpEF were found, however, significantly increased all-cause mortality for higher values of basal-RVd, BUN, and IVCd (log-rank p = 0.0065, 0.0063, 0.0005) in HFpEF, and for COPD and higher LAV (log-rank p = 0.0046, p = 0.033) in HFrEF. These data are indicative that in patients hospitalized with HF, EF is not a suitable predictor of long-term all-cause mortality, whereas, right ventricular volumetric remodeling and IVCd have a prognostic role in HFpEF as well as LAV in HFrEF. Our study suggests that besides EF, other echocardiographic parameters are helpful to optimize the phenotyping and prognostic stratification of HF.

Central and Obstructive Apneas in Heart Failure With Reduced, Mid-Range and Preserved Ejection Fraction

Background: Although central apneas (CA) and obstructive apneas (OA) are highly prevalent in heart failure (HF), a comparison of apnea prevalence, predictors and clinical correlates in the whole HF spectrum, including HF with reduced ejection fraction (HFrEF), mid-range EF (HFmrEF) and preserved EF (HFpEF) has never been carried out so far.

Materials and methods: 700 HF patients were prospectively enrolled and then divided according to left ventricular EF (408 HFrEF, 117 HFmrEF, 175 HFpEF). All patients underwent a thorough evaluation including: 2D echocardiography; 24-h Holter-ECG monitoring; cardiopulmonary exercise testing; neuro-hormonal assessment and 24-h cardiorespiratory monitoring.

Results: In the whole population, prevalence of normal breathing (NB), CA and OA at daytime was 40, 51, and 9%, respectively, while at nighttime 15, 55, and 30%, respectively. When stratified according to left ventricular EF, CA prevalence decreased (daytime: 57 vs. 43 vs. 42%, p = 0.001; nighttime: 66 vs. 48 vs. 34%, p < 0.0001) from HFrEF to HFmrEF and HFpEF, while OA prevalence increased (daytime: 5 vs. 8 vs. 18%, p < 0.0001; nighttime 20 vs. 29 vs. 53%, p < 0.0001).

In HFrEF, male gender and body mass index (BMI) were independent predictors of both CA and OA at nighttime, while age, New York Heart Association functional class and diastolic dysfunction of daytime CA. In HFmrEF and HFpEF male gender and systolic pulmonary artery pressure were independent predictors of CA at daytime, while hypertension predicted nighttime OA in HFpEF patients; no predictor of nighttime CA was identified. When compared to patients with NB, those with CA had higher neuro-hormonal activation in all HF subgroups. Moreover, in the HFrEF subgroup, patients with CA were older, more comorbid and with greater hemodynamic impairment while, in the HFmrEF and HFpEF subgroups, they had higher left atrial volumes and more severe diastolic dysfunction, respectively. When compared to patients with NB, those with OA were older and more comorbid independently from background EF.

Conclusions: Across the whole spectrum of HF, CA prevalence increases and OA decreases as left ventricular systolic dysfunction progresses. Different predictors and specific clinical characteristics might help to identify patients at risk of developing CA or OA in different HF phenotypes.

Exercise chronotropic incompetence phenotypes the level of cardiovascular risk and exercise gas exchange impairment in the general population. An analysis of the Euro-EX prevention trial

BACKGROUND

Chronotropic insufficiency (CI) is defined as the inability of the heart to increase its rate commensurate with increased demand. Exercise CI is an established predictor of major adverse cardiovascular events in patients with cardiovascular diseases.

AIM

The aim of this study was to evaluate how exercise CI phenotypes different levels of cardiovascular risk and how it may better perform in defining cardiovascular risk when analysed in the context of cardiopulmonary exercise test (CPET)-derived measures and standard echocardiography in a healthy population with variable cardiovascular risk profile.

METHODS

Apparently healthy individuals (N = 702, 53.8% females) with at least one major cardiovascular risk factor (MCVRF; hypertension, diabetes, tabagism, dyslipidaemia, body mass index > 25), enrolled in the Euro-EX prevention trial, underwent CPET. CI was defined as the inability to reach 80% of the chronotropic index, that is, the ratio of peak heart rate - rest heart rate/peak heart rate - age predicted maximal heart rate (AMPHR: 220 - age), they were divided into four groups according to the heart rate reserve (<80%>) and respiratory gas exchange ratio (RER; < 1.05>) as a marker of achieved maximal performance. Subjects with a RER < 1.05 (n = 103) were excluded and the final population (n = 599) was divided into CI group (n = 472) and no-CI group (n = 177).

RESULTS

Compared with no-CI, CI subjects were more frequently females with a history of hypertension in a high rate. CI subjects also exhibited a significantly lower peak oxygen uptake (VO₂) and circulatory power and an echocardiographic pattern indicative of higher left atrial volume index and left ventricular mass index. An inverse stepwise relationship between heart rate reserve and number of MCVRFs was observed (one MCVRF: 0.71 ± 0.23; two MCVRFs: 0.68 ± 0.24, three MCVRFs: 0.64 ± 0.20; four MCVRFs: 0.64 ± 0.23; five MCVRFs: 0.57 ± 18; p < 0.01). In multivariate analysis the only variable found predicting CI was peak VO₂ (p < 0.05; odds ratio 0.91; confidence interval 0.85-0.97).

CONCLUSIONS

In a population of apparently healthy subjects, exercise CI is common and phenotypes the progressive level of cardiovascular risk by a tight relationship with MCVRFs. CI patients exhibit some peculiar abnormal exercise gas exchange patterns (lower peak VO₂ and exercise oscillatory ventilation) and echo-derived measures (higher left atrium size and left ventricle mass) that may well anticipate evolution toward heart failure.

The analysis of left atrial function predicts the severity of functional impairment in chronic heart failure: The FLASH multicenter study

BACKGROUND

Heart failure (HF) patients present with a variety of symptoms at different stages of the disease, but the underlying pathophysiology still is unclear. Left atrial (LA) function might be tightly related to changes in patients' symptoms, more than morphological and anatomic heart features, measurable by ultrasound imaging technique. This study sought to investigate the correlation between LA function, assessed by Speckle Tracking Echocardiography (STE) and Quality of Life (QoL), assessed by the Minnesota Living with Heart Failure Questionnaire (MLHFQ), in patients with chronic HF.

METHODS

Clinically stable HF outpatients (n = 369) were enrolled from 7 different international centres and underwent echocardiographic studies. Patients >75 years old and with atrial fibrillation were excluded. LA strain during reservoir phase (LASr) by STE was measured in all subjects by averaging the 6 atrial segments. LA size was assessed using biplane volume and 4-chamber area acquisition.

RESULTS

LASr strongly correlated with both MLHFQ total score (r = -0.87; p < 0.0001). Less significant correlations between MLHFQ and either LA volume or left ventricular global longitudinal strain (LV-GLS) were found (r = 0.28; p = 0.05 and r = 0.30; p = 0.01, respectively). No significant correlation was found between MLHFQ score, LVEF (r = -0.15; p = ns), E/E' ratio (r = 0.19; p = ns), and E/A ratio (r = 0.20; p = ns). Among all echocardiographic parameters analyzed, LASr presented the highest diagnostic accuracy (AUC = 0.74) in predicting a poor QoL (>45), when compared with LV-GLS (AUC = 0.61), LA volume (AUC = 0.54) and E/e' ratio (AUC = 0.51).

CONCLUSIONS

In patients with HF, irrespective of etiology, LA function strongly correlates with patients' QoL.

Evaluation of hemodynamics in patients with hypertrophic cardiomyopathy by vector flow mapping: Comparison with healthy subjects

The present study investigated the role of energy loss assessed by vector flow mapping (VFM) in patients with hypertrophic cardiomyopathy (HCM). VFM analysis was performed in 42 patients with HCM and in 40 control subjects, which were matched for age, sex and left ventricular (LV) ejection fraction. The intra-LV and left atrial blood flow were obtained from the apical 3-chamber view, and the energy loss (EL) during the systolic and diastolic phases was calculated. The measurements were averaged over three cardiac cycles and indexed to body surface area. Compared with the controls, the left ventricular energy loss (LVEL)-total value was significantly decreased in patients with HCM during the diastolic phase (P1, P2 and P3; all P<0.05). A tendency for increased systolic LVEL-total values was observed in the patients with HCM compared with the controls (P>0.05). LVEL-base values were decreased in the patients with HCM during P1 and P2 (slow filling time). Compared with the controls, patients with HCM had lower LVEL-mid values during the diastolic phases (P0, P1, P2 and P3; all P<0.05). However, the LVEL-mid value of patients with HCM was higher compared with that of the controls during systolic P5 (P<0.05). LVEL-apex was decreased in patients with HCM during P0, P2 and P3. Compared with the controls, the left atrial energy loss (LAEL) of all three phases in patients with HCM were lower (each P<0.01). The diastolic LVEL values were significantly lower in patients with HCM compared with the controls; however, the systolic LVEL levels tended to be higher in HCM. The LAEL of the reservoir phase, conduit phase and atrial systolic phase were decreased in HCM compared with controls. The present study demonstrated that measurement of EL by VFM is a sensitive method of determining subclinical LV dysfunction in patients with HCM. The value of EL has been considered to be a quantitative parameter for the estimation of the efficiency of intraventricular blood flow.

Left atrium function and deformation in very preterm infants with and without volume load

BACKGROUND

Left atrium (LA) function can be assessed by volumetric measurements, conventional and tissue Doppler, and more recently, deformation imaging using two-dimensional speckle tracking echocardiography (2DSTE). 2DSTE allows for measurement of volume and deformation and can quantify the contribution of the reservoir, conduit, and contraction phase. A common cause for LA dysfunction in very preterm infants is volume overload with a patent ductus arteriosus (PDA). The aim of this study was to explore the feasibility and reliability of LA 2DSTE in preterm infants, and describe LA function with and without PDA volume load.

METHODS

We prospectively recruited preterm infants <30 weeks of gestation referred for assessment of a possible PDA. A cardiac ultrasound was performed at day 3 and in week 4 of life and analyzed using conventional techniques and 2DSTE.

RESULTS

Forty-eight infants (32 with PDA) were included. LA 2DSTE analysis was feasible in 96% of measurements with good reliability of strain and volume parameters. Strain rate was less reliable. Poorer LA contraction and reservoir function was associated with larger LA volume index, higher inflow over the mitral valve at early diastole, higher EA ratio, and higher Ee' ratio. Poorer conduit function was associated with higher Ee' ratio. A larger PDA diameter was found to be an independent contributor to deteriorating LA contraction and reservoir function.

CONCLUSION

LA 2DSTE analysis is feasible in preterm infants and provides detailed information on atrium mechanics. Further studies are needed to explore the clinical value of these new parameters in this population.

Arterial hypertension and atrial fibrillation: standard and advanced echocardiography from diagnosis to prognostication

: Structural changes in left and right cardiac chambers that occur in arterial hypertension (AH) may lead to an increased risk of atrial fibrillation. Considering that AH is currently the most common cardiovascular disease in the general population, it represents a major risk factor for atrial fibrillation development. This review explores the complex relationship between atrial fibrillation and AH, starting from its pathophysiological basis. It focuses on the role of echocardiography in the management of hypertensive and atrial fibrillation patients, with emphasis on what should be evaluated about left ventricular remodeling, diastolic and systolic function, left atrial (LA) size and function and right ventricular deformation in patients with AH.

Early detection of cardiac alterations by left atrial strain in patients with risk for cardiac abnormalities with preserved left ventricular systolic and diastolic function

This study sought to examine whether early cardiac alterations could be detected by left atrial (LA) strain in patients with risk for cardiac abnormalities. In this cross-sectional and retrospective study, we included patients with (n = 234) and without (n = 48) risk for cardiac abnormalities (i.e. those with arterial hypertension, diabetes mellitus and/or a history of coronary artery disease) of similar age and with preserved left ventricular (LV) systolic and diastolic function according to standard criteria. LA strain was significantly altered in patients with risk for cardiac abnormalities in comparison to those without risk (29.2 ± 8.6 vs. 38.5 ± 12.6%; rate of impaired LA strain: 18.8% vs. 0%; all p < 0.01) and was the most sensitive parameter to detect early LA alterations in comparison with other LA functional parameters (rate of impaired LA strain rate, LA total emptying fraction, and LA expansion index 3.8%, 7.3%, and 3.8%, respectively). Moreover, in patients with risk for cardiac abnormalities LA strain was altered even in the absence of subtle LV systolic and diastolic alterations (rates 13.9% and 6.8%), albeit to a lesser extent than in patients with an abnormal LV longitudinal systolic strain or abnormal mitral annular e' velocities (rates 48.5% and 24.4%). Regarding the clinical relevance of these findings, an impaired LA strain (i.e. < 23%) was significantly linked to exertional dyspnea (OR 3.5 [1.7-7.0]) even adjusting the analyses by age, gender and subtle LV abnormalities. In conclusion, the findings from this study suggest that LA strain measurements could be useful to detect early cardiac alterations in patients with risk for cardiac abnormalities with preserved LV systolic and diastolic function and that these early LA strain alterations could be linked to exertional dyspnea.