Determinants of left atrial reservoir and pump strain and use of atrial strain for evaluation of left ventricular filling pressure

Left Atrial Strain as a Predictor of Diastolic Stress Test Results in Patients With Arterial Hypertension

Aim      To study a possibility of using the left atrial strain (LAS) for predicting results of the noninvasive diastolic stress test (DST) in patients with arterial hypertension (AH).

Material and methods  The study included 98 patients previously diagnosed with AH. As a part of evaluation for complaints of dyspnea, palpitation or pain in the area of the heart, DST and transthoracic echocardiography were performed. Echocardiography included measurements of LAS in the reservoir phase, left atrial volume index (LAVI), pulmonary artery systolic pressure (PASP), and ratio of early filling transmitral flow velocity to mitral annular velocity (Е / е’).

Results The DST was negative in 52 patients (group 1) and positive in 46 patients (group 2). Group 2 had greater values of mean Е / е’ (11.0 [9.4; 12.6] vs 9.0 [7.9; 11.1], р=0.0003); LAVI (33.8 [29.0; 40.0] ml /m2 vs 28.0 ml /m2 [25.0; 32.9], р=0.0001); and PASP (29.0 mm Hg [28.0; 30.0] vs 26.0 mm Hg [25.0; 28.0], р<0.0001 were greater, but LAS values were lower (19.0 % [18.0; 21.0] vs 24.0 % [22.0; 28.0], р<0.0001. The predictive capability of LAS with respect of heart failure was higher than of other echocardiographic parameters. The area under the ROC curve (AUC) for the reservoir strain was 0.922 (95 % confidence interval, CI, 0.851–0.967), which was significantly greater than for Е / е’: 0.713 (0.613–0.800); the LAVI was 0.724 (0.624–0.809); and the PASP was 0.764 (0.668–0.844). A LAS value in the reservoir phase less than 22 % predicts a positive result of DST with a probability of 88.9 % (76.5–95.2 %). Higher values of the strain allow expecting a negative DST result with a probability of 88.7 % (77.4–94.7 %).

Conclusion      If the DST cannot be performed for a noninvasive diagnosis of heart failure with preserved ejection fraction, a positive result of this test can be predicted by a decrease of LAS in the reservoir phase to 21 % or lower. The diagnostic accuracy of this criterion is 88.8 % (81.0–93.6 %).

Prognostic Significance of the Combination of Left Atrial Reservoir Strain and Global Longitudinal Strain Immediately After Onset of ST-Elevation Acute Myocardial Infarction

BACKGROUND

The role of left atrial (LA) function in the long-term prognosis of ST-elevation acute myocardial infarction (STEMI) is still unclear.

METHODS AND RESULTS

Percutaneous coronary intervention (PCI) was performed in 433 patients with the first episode of STEMI within 12 h of onset. The patients underwent echocardiography 24 h after admission. LA reservoir strain and other echocardiographic parameters were analyzed. Follow up was performed for up to 10 years (mean duration, 91 months). The primary endpoint was major adverse cardiovascular events (MACE): cardiac death or hospitalization due to heart failure (HF). MACE occurred in 90 patients (20%) during the follow-up period. Multivariate Cox hazard analyses showed LA reservoir strain, global longitudinal strain (GLS), age and maximum B-type natriuretic peptide (BNP) were the significant predictors of MACE. Kaplan-Meier curves demonstrated that LA reservoir strain <25.8% was a strong predictor (Log rank, χ2=76.7, P<0.0001). Net reclassification improvement (NRI) demonstrated that adding LA reservoir strain had significant incremental effect on the conventional parameters (NRI and 95% CI: 0.24 [0.11-0.44]) . When combined with GLS >-11.5%, the patients with LA reservoir strain <25.8% were found to be at extremely high risk for MACE (Log rank, χ2=126.3, P<0.0001).

CONCLUSIONS

LA reservoir strain immediately after STEMI onset was a significant predictor of poor prognosis in patients, especially when combined with GLS.

The Role of Left Atrial Longitudinal Strain in the Diagnosis of Acute Cellular Rejection in Heart Transplant Recipients

Our aim was to investigate the role of left atrial longitudinal strain (LALS) in the non-invasive diagnosis of acute cellular rejection (ACR) episodes in heart transplant (HTx) recipients. Methods: We performed successive echocardiographic exams in 18 consecutive adult HTx recipients in their first year after HTx within 3 h of the routine surveillance endomyocardial biopsies (EMB) in a single center. LALS parameters were analyzed with two different software. We investigated LALS association with ACR presence, as well as inter-vendor variability in comparable LALS values. Results: A total of 147 pairs of EMB and echo exams were carried out. Lower values of LALS were significantly associated with any grade of ACR presence. Peak atrial longitudinal strain (PALS) offered the best diagnostic value for any grade of ACR, with a C statistic of 0.77 using one software (95% CI 0.68−0.84, p < 0.0005) and 0.64 with the other (95% CI 0.54−0.73, p = 0.013) (p = 0.02 for comparison between both curves). Reproducibility between comparable LALS parameters was poor (intraclass correlation coefficients were 0.60 for PALS, 95% CI 0.42−0.73, p < 0.0005; and 0.42 for PALS rate, 95% CI −0.13−0.68, p < 0.0005). Conclusions: LALS variables might be a sensitive marker of ACR in HTx recipients, principally discriminating between those studies without rejection and those with any grade of ACR. Inter-vendor variability was significant.

Left atrial reservoir strain improves diagnostic accuracy of the 2016 ASE/EACVI diastolic algorithm in patients with preserved left ventricular ejection fraction: insights from the KARUM haemodynamic database

AIMS

This study aimed to investigate the incremental value offered by left atrial reservoir strain (LASr) to the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging (ASE/EACVI) diastolic algorithm to identify elevated left ventricular (LV) filling pressure in patients with preserved ejection fraction (EF).

METHODS AND RESULTS

Near-simultaneous echocardiography and right heart catheterization were performed in 210 patients with EF ≥50% in a large, dual-centre study. Elevated filling pressure was defined as invasive pulmonary capillary wedge pressure (PCWP) ≥15 mmHg. LASr was evaluated using speckle-tracking echocardiography. Diagnostic performance of the ASE/EACVI diastolic algorithm was validated against invasive reference and compared with modified algorithms incorporating LASr. Modest correlation was observed between E/e', E/A ratio, and LA volume index with PCWP (r = 0.46, 0.46, and 0.36, respectively; P < 0.001 for all). Mitral e' and TR peak velocity showed no association. The ASE/EACVI algorithm (89% feasibility, 71% sensitivity, 68% specificity) demonstrated reasonable ability (AUC = 0.69) and 68% accuracy to identify elevated LV filling pressure. LASr displayed strong ability to identify elevated PCWP (AUC = 0.76). Substituting TR peak velocity for LASr in the algorithm (69% sensitivity, 84% specificity) resulted in 91% feasibility, 81% accuracy, and stronger agreement with invasive measurements. Employing LASr as per expert consensus (71% sensitivity, 70% specificity) and adding LASr to conventional parameters (67% sensitivity, 84% specificity) also demonstrated greater feasibility (98% and 90%, respectively) and overall accuracy (70% and 80%, respectively) to estimate elevated PCWP.

CONCLUSIONS

LASr improves feasibility and overall accuracy of the ASE/EACVI algorithm to discern elevated filling pressures in patients with preserved EF.

Bedside assessment of left atrial pressure in critical care: a multifaceted gem

Evaluating left atrial pressure (LAP) solely from the left ventricular preload perspective is a restrained approach. Accurate assessment of LAP is particularly relevant when pulmonary congestion and/or right heart dysfunction are present since it is the pressure most closely related to pulmonary venous pressure and thus pulmonary haemodynamic load. Amalgamation of LAP measurement into assessment of the ‘transpulmonary circuit’ may have a particular role in differentiating cardiac failure phenotypes in critical care. Most of the literature in this area involves cardiology patients, and gaps of knowledge in application to the bedside of the critically ill patient remain significant. Explored in this review is an overview of left atrial physiology, invasive and non-invasive methods of LAP measurement and their potential clinical application.

Difference in left atrial myocardial dynamics during reservoir phase between hypertrophic cardiomyopathy and hypertensive heart determined using three-dimensional speckle tracking echocardiography

We aimed to investigate left atrial (LA) myocardial dynamics during reservoir phase using three-dimensional speckle-tracking echocardiography (3DSTE) focusing on its longitudinal-circumferential relationship in patients with left ventricular (LV) hypertrophy and clarifying the difference in LA myocardial reservoir dynamics between hypertrophic cardiomyopathy (HCM) and hypertension with LV hypertrophy (HT-LVH). We studied 4 age-matched groups consisting of 27 patients with HCM, 16 with HT-LVH, 22 hypertensive patients without LV hypertrophy (HT), and 18 normal controls. Using 3DSTE, we measured LA global longitudinal strain (LA-LSR), global circumferential strain (LA-CSR), and global area strain (LA-ASR) during the reservoir phase, as well as LV global longitudinal strain (LV-LS), global circumferential strain (LV-CS), and global area strain (LV-AS). LA-LSR was significantly lower in the HCM and HT-LVH groups than in the controls, but there was no significant difference between the HCM and HT-LVH groups. LA-CSR and LA-ASR were significantly lower in the HCM group than in the other three groups, among which no significant difference was detected. In all subjects, LA-LSR was significantly correlated with LV-LS but not with LV-CS. LA-CSR was correlated with neither LV-LS nor LV-CS. In conclusion, both longitudinal and circumferential LA myocardial expansion during reservoir phase were reduced in HCM, while only the longitudinal one was reduced in HT-LVH. Reduction of LA circumferential expansion may reflect a more serious and intrinsic impairment of LA myocardial distensibility in HCM. Measuring LA-CSR and LA-ASR using 3DSTE would contribute to a more accurate understanding of LA reservoir function abnormality in HCM.

Echocardiography in the Diagnosis of Cardiomyopathies: Current Status and Future Directions

Cardiomyopathies are a challenging pathology and echocardiography is essential for diagnosis and prognosis. The most frequent cardiomyopathies are the dilated cardiomyopathy (DCM) and the hypertrophic cardiomyopathy (HCM), followed by the less frequent restrictive (RCM) and arrhythmogenic right ventricle cardiomyopathies (ARVC). Echocardiography can identify diagnostic features, and guide further testing for a definitive diagnosis. Echographic parameters are involved in risk score computing and prognosis assessment. While the most prevalent hallmark of HCM is the asymmetric left ventricular hypertrophy and systolic anterior motion of the mitral valve with the obstructive phenotype, DCM shows dilated left ventricle with different degrees of systolic dysfunction, and RCM is usually characterized by undilated ventricles associated with atrial enlargement. The aim of this review is to display and compare the most frequent cardiomyopathies encountered in clinical practice and highlight their most characteristic features in a useful way for the practicing clinician.

Phenotyping the hypertensive heart

Arterial hypertension remains the most frequent cardiovascular (CV) risk factor, and is responsible for a huge global burden of disease. Echocardiography is the first-line imaging method for the evaluation of cardiac damage in hypertensive patients and novel techniques, such as 2D and D speckle tracking and myocardial work, provide insight in subclinical left ventricular (LV) impairment that would not be possible to detect with conventional echocardiography. The structural, functional, and mechanical cardiac remodelling that are detected with imaging are intermediate stages in the genesis of CV events, and initiation or intensification of antihypertensive therapy in response to these findings may prevent or delay progressive remodelling and CV events. However, LV remodelling—especially LV hypertrophy—is not specific to hypertensive heart disease (HHD) and there are circumstances when other causes of hypertrophy such as athlete heart, aortic stenosis, or different cardiomyopathies need exclusion. Tissue characterization obtained by LV strain, cardiac magnetic resonance, or computed tomography might significantly help in the distinction of different LV phenotypes, as well as being sensitive to subclinical disease. Selective use of multimodality imaging may therefore improve the detection of HHD and guide treatment to avoid disease progression. The current review summarizes the advanced imaging tests that provide morphological and functional data about the hypertensive cardiac injury.

Unsupervised Machine Learning for Assessment of Left Ventricular Diastolic Function and Risk Stratification

BACKGROUND

The 2016 American Society of Echocardiography (ASE) guidelines have been widely used to assess left ventricular diastolic function. However, limitations are present in the current classification system. We aimed to develop a data-driven, unsupervised machine learning approach for diastolic function classification and risk stratification using the left ventricular diastolic function parameters recommended by the 2016 ASE guidelines; the guideline grading was used as the reference standard.

METHODS

Baseline demographics, heart failure hospitalization and all-cause mortality data were obtained for all adult patients who underwent transthoracic echocardiography at Mayo Clinic Rochester in 2015. Patients with prior mitral valve intervention, congenital heart disease, cardiac transplant, or cardiac assist device were excluded. Nine left ventricular diastolic function variables (mitral E and A wave peak velocities, E/A, deceleration time, medial and lateral annulus e' and E/e', and tricuspid regurgitation peak velocity) were used for an unsupervised machine learning algorithm to identify different phenotype clusters. The cohort average of each variable was used for imputation. Patients were grouped according to the algorithm-determined clusters for Kaplan-Meier survival analysis.

RESULTS

Among 24,414 patients, age 63.6 ±16.2 years, all-cause mortality occurred in 4,612 (18.9%) patients during median follow-up 3.1 years. The algorithm determined 3 clusters with echocardiographic measurement characteristics corresponding to normal diastolic function (n= 8,312), impaired relaxation (n=11,779) and increased filling pressure (n =4,323), with 3-year cumulative mortality of 11.8%, 19.9% and 33.4%, respectively (p<0.0001). All 10,694 (43.8%) patients classified as indeterminate were reclassified into the 3 clusters (3,324, 5,353, and 2,017, respectively) with 3-year mortality of 16.6%, 22.9% and 34.4%, respectively. The clusters also outperformed guideline-based grade for prognostication (c-index: 0.607 vs. 0.582, p=0.013).

CONCLUSIONS

Unsupervised machine learning identified physiologically and prognostically distinct clusters based on 9 diastolic function Doppler variables. The clusters can be potentially applied in echocardiography laboratory practice and future clinical trials for simple, replicable diastolic function related risk stratification.

Left atrial strain determinants and clinical features according to the heart failure stages. New insight from EACVI MASCOT registry

Few studies analyzed left atrial (LA) peak atrial longitudinal strain (PALS) determinants, particularly across heart failure (HF) stages. We aimed to analyze the pathophysiological and clinical PALS correlates in a large multicentric prospective study. This is a multicenter prospective observational study enrolling 745 patients with HF stages. Data included PALS and left ventricular global longitudinal strain (LV-GLS). Exclusion criteria were: valvular prosthesis; atrial fibrillation; cardiac transplantation; poor acoustic window. Median global PALS was 17% [24–32]. 29% of patients were in HF-stage 0/A, 35% in stage-B, and 36% in stage-C. Together with age, the echocardiographic determinants of PALS were LA volume and LV-GLS (overall model R2 = 0.50, p < 0.0001). LV-GLS had the strongest association with PALS at multivariable analysis (beta: −3.60 ± 0.20, p < 0.0001). Among HF stages, LV-GLS remained the most important PALS predictor (p < 0.0001) whereas age was only associated with PALS in lower HF-stage 0/A or B (R = − 0.26 p < 0.0001, R = − 0.23 p = 0.0001). LA volume increased its association to PALS moving from stage 0/A (R = − 0.11; P = 0.1) to C (R = − 0.42; P < 0.0001). PALS was the single most potent echocardiographic parameter in predicting the HF stage (AUC for B vs. 0/A 0.81, and AUC vs. 0/A for C 0.76). PALS remained independently associated with HF stages after adjusting for ejection fraction, E/e′ ratio, and mitral regurgitation grade (p < 0.0001). Although influenced by LV-GLS and LA size across HF stages, PALS is incrementally and independently associated with clinical status. LA function may reflect a substantial part of the hemodynamic consequences of ventricular dysfunction.

Advanced Echocardiographic Analysis in Medium-Term Follow-Up of Children with Previous Multisystem Inflammatory Syndrome

Multisystem inflammatory syndrome in children (MIS-C) is a severe hyperinflammatory disease related to SARS-CoV2 infection, with frequent cardiovascular involvement in the acute setting. The aim of the study was to evaluate the cardiac function at 6 months. Thirty-two patients diagnosed with MIS-C were enrolled and underwent advanced echocardiogram at discharge and at 6 months. According to the left ventricular ejection fraction (LVEF) at admission, the patients were divided into group A (LVEF < 45%) and group B (LVEF ≥ 45%) and the follow-up results were compared. At discharge, all patients had normal LV and RV systolic function (LVEF 61 ± 4.4%, LV global longitudinal strain −22.1%, TAPSE 20.1mm, s’ wave 0.13m/s, RV free wall longitudinal strain −27.8%) with normal LV diastolic function (E/A 1.5, E/e’ 5.7, and left atrial strain 46.5%) and no significant differences at 6 months. Compared to group B, the group A patients showed a reduced, even if normal, LV global longitudinal strain at discharge (−21.1% vs. −22.6%, p-value 0.02), but the difference was no longer significant at the follow-up. Patients with MIS-C can present with depressed cardiac function, but if treated, the cardiac function recovered without late onset of cardiac disease. This favorable result was independent of the severity of acute LV dysfunction.

Non-Invasive Assessment of Congestion by Cardiovascular and Pulmonary Ultrasound and Biomarkers in Heart Failure

Worsening chronic heart failure (HF) is responsible for recurrent hospitalization and increased mortality risk after discharge, irrespective to the ejection fraction. Symptoms and signs of pulmonary and systemic congestion are the most common cause for hospitalization of acute decompensated HF, as a consequence of increased cardiac filling pressures. The elevated cardiac filling pressures, also called hemodynamic congestion, may precede the occurrence of clinical congestion by days or weeks. Since HF patients often have comorbidities, dyspnoea, the main symptom of HF, may be also caused by respiratory or other illnesses. Recent studies underline the importance of the diagnosis and treatment of hemodynamic congestion before HF symptoms worsen, reducing hospitalization and improving prognosis. In this paper we review the role of integrated evaluation of biomarkers and imaging technics, i.e., echocardiography and pulmonary ultrasound, for the diagnosis, prognosis and treatment of congestion in HF patients.

Left Atrial Reservoir Strain-Based Left Ventricular Diastolic Function Grading and Incident Heart Failure in Hypertrophic Cardiomyopathy

BACKGROUND

The echocardiographic assessment of left ventricular (LV) diastolic dysfunction (LVDD) in patients with hypertrophic cardiomyopathy is complex and not well-established. We investigated whether the left atrial reservoir strain (LARS) could be used to categorize LVDD and whether this grading is predictive of heart failure (HF) events in hypertrophic cardiomyopathy.

METHODS

A total of 414 patients with hypertrophic cardiomyopathy (aged 58.3±12.8 years; 65.7% male) were categorized using LARS-defined LVDD (LARS-DD) grades: ≥35% (grade 0), ≥24% to <35%, ≥19% to <24%, and <19% (grade 3). Patients were followed for a median of 6.9 years to assess hospitalization for HF or HF-related death.

RESULTS

An increase in LARS-DD grade was associated with worse conventional echocardiographic parameters of LVDD, such as lower e', higher E/e' ratio, greater maximum tricuspid regurgitation velocity, and restrictive mitral inflow pattern. Higher LARS-DD grade was also associated with parameters reflecting increased LV filling pressure, such as greater LV wall thickness, greater extent of fibrosis, obstructive physiology, and decreased LV longitudinal strain. Furthermore, higher LARS-DD grade was associated with worse HF-free survival (log-rank P<0.001). Patients with LARS-DD grades 0, 1, 2, and 3 showed 10-year HF-free survival of 100%, 91.6%, 84.1%, and 67.5%, respectively. LARS-DD grade was an independent predictor of HF events after adjusting for clinical and echocardiographic variables (hazard ratio, 1.53 [95% CI, 1.03-2.28], per 1-grade increase). The LARS-DD grade also had incremental prognostic value for incident HF events over the traditional echocardiographic LVDD parameters and grading system. The prognostic value of advanced LARS-DD grade was consistent in sensitivity analyses and various patient subgroups.

CONCLUSIONS

LARS can be used as a simple single or supplemental index to categorize LV diastolic function and predict HF events in hypertrophic cardiomyopathy.

Left atrial contraction strain and controlled preload alterations, a study in healthy individuals

Background

In order to assess left atrial contractile function in disturbed circulatory conditions, it is necessary to have a clear understanding of how it behaves in a normal resting state with changes in loading conditions. However, currently the understanding of this relationship is incomplete. We hypothesize that in healthy individuals, left atrial contraction strain and its peak strain rate are increased or decreased by increasing or decreasing preload, respectively.

Methods

Controlled maneuvers used to change preload included continuous positive airway pressure by mask (CPAP 20 cmH₂O) for preload decrease, and passive leg raise (15 degrees angle) for preload increase. Cardiac ultrasound 4-chamber views of the left atria and left ventricle were acquired at baseline and during maneuver. Acquired images were post processed and analyzed offline. Comparisons were made using paired t-test and means with 95% confidence interval.

Results

There were 38 participants, complete results were obtained from 23 in the CPAP maneuver and 27 in the passive leg raise maneuver. For the CPAP group, left atrial contraction strain was 11.6% (10.1 to 13.1) at baseline and 12.8% (11.0 to 14.6) during the maneuver (p = 0.16). Left atrial contraction peak strain rate was − 1.7 s^− 1 (− 1.8 to − 1.5) at baseline and − 1.8 s^− 1 (− 2.0 to − 1.6) during the maneuver (p = 0.29). For the passive leg raise-group, left atrial contraction strain was 10.1% (9.0 to 11.2) at baseline and 10.8% (9.4 to 12.3) during the maneuver (p = 0.28). Left atrial contraction peak strain rate was − 1.5 s^− 1 (− 1.6 to − 1.4) at baseline and − 1.6 s^− 1 (− 1.8 to − 1.5) during the maneuver (p = 0.29). Left atrial area, an indicator of preload, increased significantly during passive leg raise and decreased during CPAP.

Conclusion

In healthy individuals, left atrial contraction strain and its peak strain rate seem to be preload-independent.

Trial registration

The study was 2018-02-19 registered at clinicaltrials.gov (NCT03436030).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-022-00278-1.

Left atrial reservoir strain as a predictor of cardiac outcome in patients with heart failure: the HaFaC cohort study

BACKGROUND

The left atrium (LA) is a key player in the pathophysiology of systolic and diastolic heart failure (HF). Speckle tracking derived LA reservoir strain (LAS_r) can be used as a prognostic surrogate for elevated left ventricular filling pressure similar to NT-proBNP. The aim of the study is to investigate the correlation between LAS_r and NT-proBNP and its prognostic value with regards to the composite endpoint of HF hospitalization and all-cause mortality within 1 year.

METHODS

Outpatients, sent to the echocardiography core lab because of HF, were enrolled into this study. Patients underwent a transthoracic echocardiographic examination, commercially available software was used to measure LAS_r. Blood samples were collected directly after the echocardiographic examination to determine NT-proBNP.

RESULTS

We included 174 HF patients, 43% with reduced, 36% with mildly reduced, and 21% with preserved ejection fraction. The study population showed a strong inverse correlation between LAS_r and log-transformed NT-proBNP (r = - 0.75, p < 0.01). Compared to NT-proBNP, LAS_r predicts the endpoint with a comparable specificity (83% vs. 84%), however with a lower sensitivity (70% vs. 61%).

CONCLUSION

LAS_r is inversely correlated with NT-proBNP and a good echocardiographic predictor for the composite endpoint of hospitalization and all-cause mortality in patients with HF.

TRIAL REGISTRATION

https://www.trialregister.nl/trial/7268.

Echocardiographic Assessment of Atrial Function: From Basic Mechanics to Specific Cardiac Diseases

The left and right atria serve as buffer chambers to control the flow of venous blood for ventricular filling. If an atrium is absent, blood does not flow effectively into the ventricle, leading to venous blood retention and low cardiac output. The importance of atrial function has become increasingly recognized, because left atrial (LA) function contributes to cardiac performance, and loss of LA function is associated with heart failure. LA volume change has been used for LA function assessment in experimental and clinical studies. In conjunction with LA pressure, the LA pressure–volume relationship provides a better understanding of LA mechanics. LA strain measurement by speckle tracking echocardiography was introduced to evaluate three components of LA function as a (booster) pump, reservoir and conduit. Furthermore, increasing evidence supports the theory that LA reservoir strain has prognostic utility in various cardiac diseases. In this review, we summarize LA contribution to maintain cardiac performance by evaluating LA function with echocardiography according to our experiences and previous reports. Furthermore, we discuss LA dysfunction in challenging cardiac diseases of cardiac amyloidosis and adult congenital heart disease.

Strain Imaging for the Early Detection of Cardiac Remodeling and Dysfunction in Primary Aldosteronism

Speckle tracking echocardiography is a novel technique to quantify cardiac function and deformation. It has been applied in a series of cardiovascular diseases for the evaluation of early cardiac impairment. We recently used this technique to investigate cardiac structure and function in patients with primary aldosteronism. Cardiac damage usually occurs earlier in patients with primary aldosteronism than those with primary hypertension, probably because aldosterone hypersecretion is more commonly observed in the former than the latter patients. In this article, we will review the imaging studies, especially with speckle tracking echocardiography, for the detection of early cardiac dysfunction in primary aldosteronism as a disease model.

Feasibility, Reproducibility and Reference Ranges of Left Atrial Strain in Preterm and Term Neonates in the First 48 h of Life

Left atrial strain (LAS) is the most promising technique for assessment of diastolic dysfunction but few data are available in neonates. Our aim was to assess feasibility and reproducibility, and to provide reference ranges of LAS in healthy neonates in the first 48 h of life. We performed one echocardiography in 30 neonates to assess feasibility and develop a standard protocol for image acquisition and analysis. LAS reservoir (LASr), conduit (LAScd) and contraction (LASct) were measured. We performed echocardiography at 24 and 48 h of life in an unrelated cohort of 90 neonates. Median (range) gestational age and weight of the first cohort were 34.4 (26.4–40.2) weeks and 2075 (660–3680) g. LAS feasibility was 96.7%. Mean (SD) gestational age and weight of the second cohort were 34.2 (3.8) weeks and 2162 (833) g. Mean (SD) LASr significantly increased from 24 to 48 h: 32.9 (3.2) to 36.8 (4.6). Mean (SD) LAScd and LASct were stable: −20.6 (8.0) and −20.8 (9.9), −11.6 (4.9) and −13.5 (6.4). Intra and interobserver intraclass correlation coefficient for LASr, LAScd and LASct were 0.992, 0.993, 0.986 and 0.936, 0.938 and 0.871, respectively. We showed high feasibility and reproducibility of LAS in neonates and provided reference ranges.

Multimodality imaging in patients with heart failure and preserved ejection fraction: an expert consensus document of the European Association of Cardiovascular Imaging

Nearly half of all patients with heart failure (HF) have a normal left ventricular (LV) ejection fraction (EF) and the condition is termed heart failure with preserved ejection fraction (HFpEF). It is assumed that in these patients HF is due primarily to LV diastolic dysfunction. The prognosis in HFpEF is almost as severe as in HF with reduced EF (HFrEF). In contrast to HFrEF where drugs and devices are proven to reduce mortality, in HFpEF there has been limited therapy available with documented effects on prognosis. This may reflect that HFpEF encompasses a wide range of different pathological processes, which multimodality imaging is well placed to differentiate. Progress in developing therapies for HFpEF has been hampered by a lack of uniform diagnostic criteria. The present expert consensus document from the European Association of Cardiovascular Imaging (EACVI) provides recommendations regarding how to determine elevated LV filling pressure in the setting of suspected HFpEF and how to use multimodality imaging to determine specific aetiologies in patients with HFpEF.

Left Atrial Strain as a Predictor of Left Ventricular Diastolic Dysfunction in Patients with Arterial Hypertension

Background and Objectives: There is emerging evidence of the usefulness of left atrial strain (LAS) in the assessment of diastolic dysfunction (DD). In this study we assess the sensitivity and specificity of LAS, to determine cut-off values and their association to DD with increased left atrial pressure (LAP) in patients with well-treated arterial hypertension. Materials and Methods: We performed a cross-sectional study on 180 subjects with well-treated arterial hypertension. All patients underwent transthoracic echocardiography. Patients were divided into two groups: a group without increased LAP and/or DD and a group with increased LAP DD. Results: In multivariate logistic regression, LAS proved to be the strongest statistically significant predictor of DD with increased LAP (OR 0.834, p < 0.0005), with AUC 0.885 and a set cut-off value of 24.27% with high sensitivity of 78.9% and specificity of 84.6%. The set cut-off for LAS > 24.27% was significantly highly prevalent in the group of DD with increased LAP 78.9% when compared to the group without increased LAP 15.4%, p < 0.0001. Conclusion: The findings of this study suggest that LAS could be a useful and highly sensitive and specific marker in the evaluation of DD. There is the potential for using LAS in everyday practice as a standard parameter in diastolic function assessment.

Cardiac Imaging for the Assessment of Left Atrial Mechanics Across Heart Failure Stages

The left atrium (LA) is emerging as a key element in the pathophysiology of several cardiac diseases due to having an active role in contrasting heart failure (HF) progression. Its morphological and functional remodeling occurs progressively according to pressure or volume overload generated by the underlying disease, and its ability of adaptation contributes to avoid pulmonary circulation congestion and to postpone HF symptoms. Moreover, early signs of LA dysfunction can anticipate and predict the clinical course of HF diseases before the symptom onset which, particularly, also applies to patients with increased risk of HF with still normal cardiac structure (stage A HF). The study of LA mechanics (chamber morphology and function) is moving from a research interest to a clinical application thanks to a great clinical, prognostic, and pathophysiological significance. This process is promoted by the technological progress of cardiac imaging which increases the availability of easy-to-use tools for clinicians and HF specialists. Two-dimensional (2D) speckle tracking echocardiography and feature tracking cardiac magnetic resonance are becoming essential for daily practice. In this context, a deep understanding of LA mechanics, its prognostic significance, and the available approaches are essential to improve clinical practice. The present review will focus on LA mechanics, discussing atrial physiology and pathophysiology of main cardiac diseases across the HF stages with specific attention to the prognostic significance. Imaging techniques for LA mechanics assessment will be discussed with an overlook on the dynamic (under stress) evaluation of the chamber.

The Prognostic Value of Lung Ultrasound in Patients With Newly Diagnosed Heart Failure With Preserved Ejection Fraction in the Ambulatory Setting

Background: Heart failure with preserved ejection fraction (HFpEF) is a growing healthcare burden, and its prevalence is steadily increasing. Lung ultrasound (LUS) is a promising screening and prognostic tool in the heart failure population. However, more information on its value in predicting outcome is needed.

Aims: The aim of our study was to assess the prognostic performance of LUS B-lines compared to traditional and novel clinical and echocardiographic parameters and natriuretic peptide levels in patients with newly diagnosed HFpEF in an ambulatory setting.

Methods: In our prospective cohort study, all ambulatory patients with clinical suspicion of HFpEF underwent comprehensive echocardiography, lung ultrasound and NT-proBNP measurement during their first appointment at our cardiology outpatient clinic. Our endpoint was a composite of worsening heart failure symptoms requiring hospitalization or loop diuretic dose escalation and death.

Results: We prospectively enrolled 75 consecutive patients with HFpEF who matched our inclusion and exclusion criteria. We detected 11 events on a 26 ± 10-months follow-up. We found that the predictive value of B-lines is similar to the predictive value of NT-proBNP (AUC 0.863 vs. 0.859), with the best cut-off at >15 B-lines. Having more B-lines than 15 significantly increased the likelihood of adverse events with a hazard ratio of 20.956 (p = 0.004). The number of B-lines remained an independent predictor of events at multivariate modeling. Having more than 15 B-lines lines was associated with a significantly worse event-free survival (Log-rank: 16.804, p < 0.001).

Conclusion: The number of B-lines seems to be an independent prognostic factor for adverse outcomes in HFpEF. Since it is an easy-to-learn, feasible and radiation-free method, it may add substantial value to the commonly used diagnostic and risk stratification models.

Left atrial strain: A novel "biomarker" for chronic kidney disease patients?

Cardiovascular disease and chronic kidney disease are frequently inter-connected and this association leads to an exponential growth of cardiovascular risk. This risk is currently underestimated by the existing algorithms and there is a constant need for new markers to predict adverse outcomes in this special population. In general population left atrial strain has emerged as an important tool for both the diagnosis and prognostic stratification, but data regarding its role in chronic kidney disease patients is scarce. The purpose of this review is to summarize the current evidence regarding this matter. Left atrial size and function mirror the duration and severity of increased left ventricular filling pressures. Increased left atrial volume index and impaired left atrial strain parameters are independent predictors for adverse cardiovascular events. Left atrial strain is impaired before changes in volume appear, thus being able to predict both diastolic and systolic function in chronic kidney disease patients. Finally, left atrial strain can identify renal patients with impaired exercise capacity and this could have clinical applications in the rehabilitation of this patients.

Visual echocardiographic scoring system of the left ventricular filling pressure and outcomes of heart failure with preserved ejection fraction

Aims

Elevated left ventricular filling pressure (LVFP) is a powerful indicator of worsening clinical outcomes in heart failure with preserved ejection fraction (HFpEF); however, detection of elevated LVFP is often challenging. This study aimed to determine the association between the newly proposed echocardiographic LVFP parameter, visually assessed time difference between the mitral valve and tricuspid valve opening (VMT) score, and clinical outcomes of HFpEF.

Methods and results

We retrospectively investigated 310 well-differentiated HFpEF patients in stable conditions. VMT was scored from 0 to 3 using two-dimensional echocardiographic images, and VMT ≥2 was regarded as a sign of elevated LVFP. The primary endpoint was a composite of cardiac death or heart failure hospitalization during the 2 years after the echocardiographic examination. In all patients, Kaplan–Meier curves showed that VMT ≥2 (n = 54) was associated with worse outcomes than the VMT ≤1 group (n = 256) (P < 0.001). Furthermore, VMT ≥2 was associated with worse outcomes when tested in 100 HFpEF patients with atrial fibrillation (AF) (P = 0.026). In the adjusted model, VMT ≥2 was independently associated with the primary outcome (hazard ratio 2.60, 95% confidence interval 1.46–4.61; P = 0.001). Additionally, VMT scoring provided an incremental prognostic value over clinically relevant variables and diastolic function grading (χ² 10.8–16.3, P = 0.035).

Conclusions

In patients with HFpEF, the VMT score was independently and incrementally associated with adverse clinical outcomes. Moreover, it could also predict clinical outcomes in HFpEF patients with AF.

Comparative analysis of phasic left atrial strain and left ventricular posterolateral strain pattern to discriminate Fabry cardiomyopathy from other forms of left ventricular hypertrophy

BACKGROUND

"Classical" echocardiographic signs of Fabry cardiomyopathy (FC), such as left ventricular hypertrophy (LVH), posterolateral strain impairment (PLSI), and papillary muscle hypertrophy may be of limited diagnostic accuracy in clinical practice. Our aim was to evaluate the diagnostic value of left atrial (LA) strain impairment compared to "classical" echocardiographic findings to discriminate FC.

METHODS

In standard echocardiographic assessments, we retrospectively analyzed the diagnostic value of the "classical" red flags of FC as well as LA strain in 20 FC patients and in 20 subjects with other causes of LVH. Receiver operating characteristic (ROC) curve analysis was performed to assess the respective diagnostic accuracy.

RESULTS

FC was confirmed in 20 patients by genetic testing. In the LVH group, 12 patients were classified by biopsy to have hypertrophic cardiomyopathy, two had hypertensive heart disease, and six LVH combined with borderline myocarditis. Global and regional left ventricular (LV) strain was not significantly different between groups while LA strain was significantly impaired in FC (Left atrial reservoir strain (LASr) 19.1%±8.4 in FC and 25.6%±8.9 in LVH, p = 0.009; left atrial conduction strain (LAScd) -8.4%±4.9 in FC and -15.9%±8.4 in LVH, p < 0.01). LAScd, with an area under the curve (AUC) of .81 (95% confidence interval [CI] .66-.96) showed the highest diagnostic accuracy to discriminate FC. The PLSI pattern showed an AUC of .49, quantification of papillary muscle hypertrophy an AUC of .47.

CONCLUSION

Adding LA strain analysis to a comprehensive echocardiographic work-up of unclear LVH may be helpful to identify FC as a possible cause.

Left Atrial Strain Determinants During the Cardiac Phases

OBJECTIVES

The present study investigated the determinants of left atrial (LA) strain in all phases of the cardiac cycle.

BACKGROUND

LA strain by speckle-tracking echocardiography allows the assessment of LA function in each phase of the cardiac cycle. However, its determinants and its relation with left ventricular (LV) function have not yet been fully described.

METHODS

The authors performed a retrospective analysis in 127 patients with different cardiovascular pathologies. Using 2-dimensional speckle tracking in 4- and 2-chamber apical views we derived both LA and LV strain curves. Strain-strain loops were reconstructed using LV strain and the corresponding, synchronized LA strain data. Linear regressions were calculated for the entire strain-strain loop as well as for the 3 phases of the cardiac cycle (systole, and early and late diastole). The association between LA strain parameters and LV systolic and diastolic parameters was studied. The prediction of cardiovascular events was evaluated for both measured and predicted LA strain and other parameters.

RESULTS

LA and LV strain curves presented excellent correlations with an R² >0.9 for the cardiac cycle, and >0.97 for its phases. Moreover, the ratios of LV/LA maximal volumes and the slopes of the LA-LV strain-strain loops of the individual patients correlated well (R² = 0.75). In each phase of the cardiac cycle, LA strain parameters correlated well with the corresponding LV strain and the LV-LA volume ratio (R² >0.78). No significant difference in predictive ability of cardiovascular events or atrial fibrillation between the measured and predicted LA strain was observed (P > 0.05 for both).

CONCLUSIONS

In the absence of abnormal LA/LV volume exchange, LA strain is, to a large extent, determined by LV strain and further modulated by the ratio of LV and LA volumes. Nonetheless, measuring LA strain is of high clinical interest because it integrates several parameters into a single, robust, and reproducible measurement.

Imaging of the left atrium: pathophysiology insights and clinical utility

Left atrial imaging and detailed knowledge of its pathophysiology, especially in the context of heart failure, have become an increasingly important clinical and research focus. This development has been accelerated by the growth of non-invasive imaging modalities, advanced image processing techniques, such as strain imaging, and the parallel emergence of catheter-based left atrial interventions like pulmonary vein ablation, left atrial appendage occlusion, and others. In this review, we focus on novel imaging methods for the left atrium, their pathophysiological background, and their clinical relevance for various cardiac conditions and diseases.

Non-Invasive Estimation of Left Ventricular Filling Pressure Based on Left Atrial Area Strain Measured With Transthoracic 3-Dimensional Speckle Tracking Echocardiography in Patients With Coronary Artery Disease

Background: Chronic elevation of left ventricular (LV) diastolic pressure (DP) or chronic elevation of left atrial (LA) pressure, which is required to maintain LV filling, may determine LA wall deformation. We investigated this issue using transthoracic 3-dimensional speckle tracking echocardiography (3D-STE).

Methods and Results: We retrospectively enrolled 75 consecutive patients with sinus rhythm and suspected stable coronary artery disease who underwent diagnostic cardiac catheterization and 3D-STE on the same day. We computed the global LA wall area change ratio, termed the global LA area strain (GLAS), during both the reservoir phase (GLAS-r) and contraction phase (GLAS-ct). The LVDP at end-diastole (LVEDP) and mean LVDP (mLVDP) were measured with a catheter-tipped micromanometer in each patient. GLAS-r and GLAS-ct were significantly correlated with both mLVDP (r=−0.70 [P<0.001] and r=0.71 [P<0.001], respectively) and LVEDP (r=−0.63 [P<0.001] and r=0.65 [P<0.001], respectively). In receiver operating characteristic curve analysis, the optimal cut-off values for diagnosing elevated LVEDP (≥16 mmHg) were 75.7% (sensitivity 83.3%, specificity 77.8%) for GLAS-r and −43.1% (sensitivity 90.0%, specificity 80.0%) for GLAS-ct. Similarly, for diagnosing elevated mLVDP (≥12 mmHg), the cut-off values were 63.6% (sensitivity 88.9%, specificity 80.3%) for GLAS-r and −26.2% (sensitivity 66.7%, specificity 97.0%) for GLAS-ct.

Conclusions: We showed that 3D-STE-derived GLAS values could be used to non-invasively diagnose elevated LV filling pressure.

Left atrial reservoir strain provides incremental value to left atrial volume index for evaluation of left ventricular filling pressure

BACKGROUND

Left atrial analysis is employed in diastolic assessment with left atrial volume index (LAVI) incorporated in the 2016 ASE/EACVI diastology guideline algorithm. LAVI has sub-optimal correlation with invasive left ventricular filling pressure (LVFP) and incorporation of left atrial reservoir strain (LASr) may improve diastolic assessment.

METHODS

A cross-sectional prospective study of 139 patients was undertaken with all patients undergoing transthoracic echocardiography immediately prior to cardiac catheterization with invasive evaluation of LVFP. LASr by speckle tracking echocardiography and conventional echocardiographic parameters were assessed in relation to invasive LVFP. Modification of the 2016 guideline algorithm was performed with incorporation of LASr in place of LAVI (LASr ≤23% indicating elevated LVFP). Accuracy of the modified and conventional algorithm were assessed for predicting invasive LVFP.

RESULTS

The mean age was 63±12 years with 27% female. LASr demonstrated superior correlation and receiver operator characteristic for predicting LVFP than LAVI (LASr: r -.46 (p < 0.01), AUC: .82 vs LAVI: r .19 (p 0.02), AUC: .66). LASr of ≤23% was the optimal cut-off for discriminating elevated LVFP (sensitivity 80%, specificity 77%). Modification of the 2016 algorithm with incorporation of LASr in place of LAVI reclassified 12% of the patient cohort and improved concordance of echocardiographic and invasive LVFP assessment (modified algorithm κ .47 vs 2016 algorithm κ: .33). No patients were incorrectly reclassified by modified algorithm assessment.

CONCLUSIONS

LASr better predicts invasive LVFP than LAVI. Modification of the 2016 guideline algorithm with incorporation of LASr in place of LAVI improves accuracy of echocardiographic assessment of LVFP.

Left Atrial Expansion Index for Noninvasive Estimation of Pulmonary Capillary Wedge Pressure: A Cardiac Catheterization Validation Study

BACKGROUND

Pulmonary capillary wedge pressure (PCWP) plays a pivotal role in cardiac disease diagnosis and management. Right heart catheterization (RHC) invasively provides accurate PCWP measurement, but it is impractical for widespread use in all patients. The left atrial expansion index (LAEI), measured on transthoracic echocardiography, describes the relative left atrial volume increase during the left atrial reservoir phase. The aim of this study was to validate LAEI as a noninvasive parameter for PCWP estimation.

METHODS

A total of 649 chronic cardiac patients (mean age, 66 ± 14 years; mean PCWP, 14 ± 7.6 mm Hg; mean left ventricular ejection fraction, 50 ± 15%) who underwent both clinically indicated RHC and transthoracic echocardiography within 24 hours were retrospectively enrolled. Patients were randomly divided into derivation (n = 509) and validation (n = 140) cohorts. PCWP was measured during RHC and defined as elevated when >12 mm Hg. Transthoracic echocardiographic parameters and LAEI were measured offline, blinded to RHC results.

RESULTS

In the derivation cohort, LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) correlated linearly with PCWP (r = -0.73, P < .001). lnLAEI showed an independent and additive predictive role for PCWP estimation over clinical and diastolic dysfunction (DD) parameters. The diagnostic accuracy of lnLAEI for elevated PCWP identification (area under the curve = 0.875, P < .001; optimal lnLAEI cutoff < 4.02) was higher than either the single DD parameters or their combination. In the validation cohort, lnLAEI cutoff < 4.02 showed higher accuracy than the 2016 DD algorithm (88% vs 74%) for elevated PCWP identification. Finally, the equation PCWP = 38.3 - 6.2 × lnLAEI, obtained from the derivation cohort, predicted invasively measured PCWP in the validation cohort.

CONCLUSIONS

In a cohort of patients with various chronic cardiac diseases, lnLAEI performed better than DD parameters and the 2016 DD algorithm for PCWP estimation. lnLAEI might be a useful echocardiographic parameter for noninvasive PCWP estimation.

Left atrial strain by speckle tracking predicts atrial fibrosis in patients undergoing heart transplantation

AIMS

In patients with heart failure (HF), chronically raised left ventricular (LV) filling pressures lead to progressive left atrial (LA) dysfunction and fibrosis. We aimed to assess the correlation of LA reservoir strain (peak atrial longitudinal strain, PALS) by speckle tracking echocardiography (STE) and LA fibrosis assessed by myocardial biopsy in patients undergoing heart transplantation (HTx).

METHODS AND RESULTS

Forty-eight patients with advanced HF [mean age 51.2 ± 8.1 years, 29% females; LV ejection fraction ≤25% and New York Heart Association (NYHA) class III-IV] referred for HTx were enrolled and underwent pre-operative echocardiographic evaluation, right heart catheterization, and cardiopulmonary exercise testing. Exclusion criteria were non-sinus rhythm, mechanical ventilation, severe mitral/tricuspid regurgitation, or other valvular disease and poor acoustic window. After HTx, LA bioptic samples were collected and analysed to determine the extent of myocardial fibrosis (%). LA fibrosis showed correlation with PALS (R = -0.88, P < 0.0001), VO2max (R = -0.68, P < 0.0001), NYHA class (R = 0.66, P < 0.0001), LA stiffness (R = 0.58, P = 0.0002), and E/e' (R = 0.44, P = 0.005), while poorly correlated with E/A ratio (R = 0.23, P = 0.21). PALS had a good correlation with NYHA class (R = -0.64, P < 0.0001), PAoP (R = -0.61, P = 0.03) and VO2max (R = 0.57, P = 0.0001). Multivariate regression analysis identified PALS (beta = -0.91, P < 0.001) and LA Volume (beta = -0.19, P = 0.03) as predictors of LA Fibrosis, while E/e' was not a significant predictor (beta = 0.15, P = 0.08).

CONCLUSION

Emerging as a possible index of myocardial fibrosis in patients with advanced HF, PALS could help to optimize the management and the selection of those patients with irreversible LA structural damage for advanced therapeutic strategies.

Left atrial strain in the assessment of diastolic function: providing new insights into primary myocardial dysfunction in Marfan syndrome

Previous studies using conventional echocardiographic measurements have reported subclinical left ventricular (LV) diastolic abnormalities in patients with Marfan syndrome (MFS). Left atrial (LA) strain allows an accurate categorization of LV diastolic dysfunction. We aimed to characterize LV myocardial performance in a cohort of MFS patients using STE-derived measurements (LV and LA strain) along with conventional echocardiographic parameters. We studied 127 adult patients with MFS (no prior cardiac surgery or significant valvular regurgitation) and 38 healthy controls. We performed detailed echocardiograms and selected left atrial reservoir strain (LASr) as a surrogate of impaired relaxation. Additionally, we searched for possible determinants of LASr in patients with MFS, with a special focus on the elastic properties of the aorta. In spite of lower E-wave, septal and lateral e' velocities and average E/e' ratio in MFS patients, all participants had normal diastolic function according to current guidelines. MFS patients exhibited reduced LV global longitudinal strain (19.3 ± 2.6 vs 21.6 ± 2.1%, p < 0.001) and reduced LASr (32.9 ± 8.5 vs 43.3 ± 7.8%, p < 0.001) compared to controls. In the MFS cohort, we found weak significant (p < 0.05) correlations between LASr and certain parameters: E/A ratio (R = 0.258), E wave (R = 0.226), aortic distensibility (R = 0.222), stiffness index (R = - 0.216), LV ejection fraction (R = 0.214), lateral e' (R = 0.210), LV end-systolic volume index (R =  - 0.210), LV global longitudinal strain (R = 0.201), septal e' (R = 0.185). After multivariate analysis, only LV end-systolic volume index and E/A ratio maintained a weak independent association with LASr (R =  - 0.220; p = 0.017 and R = 0.199; p = 0.046, respectively). In conclusion, LASr is reduced in patients with MFS, which may represent an early stage of LV diastolic dysfunction. LASr is not determined by the elastic properties of the aorta, suggesting that impaired myocardial relaxation is a primary condition in MFS.