Left atrium

Functional Mitral Regurgitation and Heart Failure With Preserved Ejection Fraction: Clinical Implications and Management

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent and associated with worse cardiovascular outcomes. The pathophysiology of HFpEF mostly relies on the development of elevated left ventricle filling pressure, diastolic dysfunction, and atrial dilatation and impairment. This dynamic process may eventually lead to the development of functional mitral regurgitation (MR), characterized by mitral annular dilatation and consequent leaflet remodeling, in the context of preserved left ventricular ejection fraction. These observations highlight the possible common pathophysiology of MR and HFpEF. However, less is known about the prevalence and the clinical value of MR in the context of HFpEF. This review aims to provide an overview of the association and interplay between functional MR and HFpEF, discuss the underlying mechanisms that are common to these diseases, and summarize potential targeted pharmacological treatments.

Predictors of Higher Frequency of Atrial Fibrillation in Patients with Cardiac Resynchronization Therapy

Background and Objectives: Cardiac resynchronization therapy (CRT) is one of the effective therapeutic options in the treatment of systolic heart failure (HF) with persistent symptoms. This prospective study was designed to determine whether CRT with biventricular pacing would reduce the risk of development of atrial fibrillation (AF) and to identify predictors for AF occurrence. Materials and Methods: The study population consisted of 126 patients, with a mean age of 63.8 ± 9.1 years, who were eligible for CRT with biventricular pacing. Inclusion criteria were left ventricular ejection fraction (LVEF) ≤ 35%, QRS duration ≥ 130 msec, and persistent HF symptoms of New York Heart Association (NYHA) II or III, despite optimal drug therapy. Patients were followed for a period of 24 months and were evaluated through clinical, electrocardiographic, and echocardiographic examination at baseline (prior to CRT implantation), as well as at 6 and 24 months post-implantation. At the end of follow-up, patients were divided into clinical responders and non-responders based on the following criteria: decrease in NYHA class ≥ I, increase in LVEF ≥ 10%, and reduction in QRS duration ≥ 20 msec. Results: At follow-up, CRT was associated with a significant increase in LVEF (20.6 ± 6.9% pre-implantation, 32.9 ± 9.3% 24 months after implantation; p < 0.001), reduction in left ventricular end-diastolic and end-systolic diameters, and decrease in QRS duration (167.6 ± 14.3 msec pre-implantation, 131.7 ± 11.7 msec 24 months after implantation; p < 0.001), while left atrial (LA) diameter was slightly increased (p = 0.070). The frequency of AF occurrence increased after two years of follow-up (52.4% to 56.9%, p < 0.001). Significant predictors of AF occurrence in our study population were response to CRT-AF more frequent in non-responders (B = 8.134; p < 0.001), LA diameter-AF more frequent with larger LA diameter (B = 0.813; p < 0.001), and coronary sinus (CS) lead position-AF more frequent with posterolateral in comparison with lateral CS lead position (B = 5.159; p = 0.005). Conclusions: The results of our study provide new data on AF predictors in patients with HF subjected to CRT. There remains a permanent need for new predictors, which might help in patient selection and improvement in response rate.

Rationale and design of the Biventricular Evaluation of Gliflozins effects In chroNic Heart Failure: BEGIN-HF study

AIMS

Sodium-glucose cotransporter type 2 inhibitors (SGLT-2i) represent a unique class of anti-hyperglycaemic agents for type 2 diabetes mellitus that selectively inhibit renal glucose reabsorption, thereby increasing urinary excretion of glucose. Several studies have demonstrated the cardioprotective effects of SGLT-2i in patients with heart failure (HF), unrelated to its glucosuric effect. It is unclear whether the benefits of SGLT-2i therapy also rely on the improvement of left ventricular (LV) and/or right ventricular (RV) function in patients with HF. This study aimed to evaluate the effect of SGLT-2i on LV and RV function through conventional and advanced echocardiographic parameters with a special focus on RV function in patients with HF.

METHODS AND RESULTS

The Biventricular Evaluation of Gliflozins effects In chroNic Heart Failure (BEGIN-HF) study is an international multicentre, prospective study that will evaluate the effect of SGLT-2i on echocardiographic parameters of myocardial function in patients with chronic stable HF across the left ventricular ejection fraction (LVEF) spectrum. Patients with New York Heart Association Class II/III symptoms, estimated glomerular filtration rate > 25 mL/min/1.73 m² , age > 18 years, and those who were not previously treated with SGLT-2i will be included. All patients will undergo conventional, tissue-derived imaging (TDI), and strain echocardiography in an ambulatory setting, at time of enrolment and after 6 months of SGLT-2i therapy. The primary endpoint is the change in LV function as assessed by conventional, TDI, and myocardial deformation speckle tracking parameters. Secondary outcomes include changes in RV and left atrial function as assessed by conventional and deformation speckle tracking echocardiography. Univariate and multivariate analyses will be performed to identify predictors associated with primary and secondary endpoints.

CONCLUSIONS

The BEGIN-HF will determine whether SGLT-2i therapy improves LV and/or RV function by conventional and advanced echocardiography in patients with HF irrespective of LVEF.

Clinical implications of left atrial changes after optimization of medical therapy in patients with heart failure

AIMS

Limited data exist regarding the prognostic relevance of changes in left atrial (LA) dimensions in patients with heart failure (HF). We assessed changes in LA dimension and their relation with outcomes after optimization of guideline-directed medical therapy (GDMT) in patients with new-onset or worsening HF.

METHODS AND RESULTS

Left atrial diameter was assessed at baseline and 9 months after GDMT optimization in 632 patients (mean age 65.8 ± 12.1 years, 22.3% female) enrolled in BIOSTAT-CHF. LA adverse remodelling (LAAR) was defined as an increase in LA diameter on transthoracic echocardiography between baseline and 9 months. After the 9-month visit, patients were followed for a median of 13 further months. LAAR was observed in 247 patients (39%). Larger baseline LA diameter (odds ratio [OR] 0.90; 95% confidence interval [CI] 0.87-0.93; p < 0.001) and up-titration to higher doses of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEi/ARBs) (OR 0.56; 95% CI 0.34-0.92; p = 0.022) were independently associated with lower likelihood of LAAR. LAAR was associated with an increased risk of the composite of all-cause mortality or HF hospitalization (log-rank p = 0.007 and adjusted hazard ratio 1.73, 95% CI 1.22-2.45, p = 0.002). The association was more pronounced in patients without a history of atrial fibrillation (p for interaction = 0.009).

CONCLUSION

Among patients enrolled in BIOSTAT-CHF, LAAR was associated with an unfavourable outcome and was prevented by ACEi/ARB up-titration. Changes in LA dimension may be a useful marker of response to treatment and improve risk stratification in patients with HF.

Left Atrium Involvement in Lymphoma Patients: Single Center Observational Study

Aim. To assess the structure and performance of left atrium (LA) before and after 3 cycles of anticancer treatment in lymphoma patients, as well as the incidences of supraventricular arrhythmia (SVA) and the levels of biomarkers of inflammation.

Material and Methods. This is a prospective observational study of patients with confirmed diagnosis of lymphoma [n=23; 57% men; median age 52 (34;64) years], who had no prior polychemotherapy. The comparison group included persons without lymphoma [n=18; 50% men; median age 43 (37; 54) years] comparable with the main group in terms of sex, age and risk factors for cardiovascular diseases. Patients with lymphoma underwent 24h-ECG monitoring and advanced transthoracic echocardiography at baseline and after 3 cycles (within 3 months) of anticancer treatment. Biomarkers of inflammation were measured. The results were compared with the data of the comparison group.

Results. In lymphoma patients, LA reservoir, conduit, and booster function were found to be impaired at baseline but were comparable with these in matched controls. After 3 cycles of anticancer treatment, a trend to reduction of LA booster and conduit strain was found. The proportion of those with SVA was significantly higher in lymphoma patients before chemotherapy compared to those after anti-cancer treatment or controls: 57% vs 10% and 33% respectively (p<0.05). Lymphoma patients had a higher number of premature ventricular beats at baseline than after treatment or in control [183 (14;841) vs 38 (14;94) and 9 (4;38) respectively]. There were no associations found between the parameters of LA structure and function and SVA. Moderate positive correlation between ESR and supraventricular premature complexes was found (rS=0.44; p<0.05). A positive correlation between LA contractile function and inflammatory biomarkers were revealed: LA active ejection fraction (LA EFact) and ESR (rS=0.42, p<0.05); LA volume index and β-globulin (rS=0.43, p<0.05); LA EFact and neuregulin-1β (rS=0.42, p<0.05); LA expansion index and neuregulin-1β (rS=0.55, p<0.05).

Conclusions. In lymphoma patients, LA phasic strain parameters were impaired regardless of anticancer treatment. The associations between inflammatory biomarkers with SVA and parameters of LA performance were found.

Association of Left Atrial Structure and Function With Heart Failure in Older Adults

BACKGROUND

Limited data exist to characterize novel measures of left atrial (LA) structure and function in older adults without prevalent heart failure (HF).

OBJECTIVES

The aim was to assess reference range of LA measures, their associations with N-terminal pro-B-type natriuretic-peptide (NT-proBNP) and the related risk for incident HF or death.

METHODS

We analyzed LA structure (LA maximal [LAViMax] and minimal volume indexed by body surface area) and function (LA emptying fraction, LA reservoir, conduit, and contraction strain) in 4,901 participants from the ARIC (Atherosclerosis Risk In Communities) study (mean age 75 ± 5 years, 40% male, and 19% Black) without prevalent HF. We assessed sex-specific 10th and 90th percentile ARIC-based reference limits in 301 participants free of prevalent cardiovascular disease, and related LA measures to NT-proBNP and incident HF or death (median follow-up of 5.5 years) in the whole ARIC cohort.

RESULTS

Approximately 20% of the overall population had LA abnormalities according to the ARIC-based reference limit. Each LA measure was associated with NT-proBNP and, except for LAViMax, with incident HF or death after multivariable adjustment (including left ventricular function and NT-proBNP). Results were consistent in participants with normal LAViMax (P for interaction > 0.05). LA measures were prognostic for both incident HF with preserved ejection fraction or death and incident HF with reduced ejection fraction or death. When added to HF risk factors and NT-proBNP (baseline C-statistics = 0.74) all LA measures, except for LAViMax, significantly enhanced the prognostic accuracy.

CONCLUSIONS

Novel measures of LA structure and function, but not standard assessment by LAViMax, are associated with increased risk of incident HF or death regardless of measures of left ventricular function and NT-proBNP.

Frequent premature atrial contractions as a signalling marker of atrial cardiomyopathy, incident atrial fibrillation and stroke

Premature atrial contractions are a common cardiac phenomenon. Although previously considered a benign electrocardiographic finding, they have now been associated with a higher risk of incident atrial fibrillation and other adverse outcomes such as stroke and all-cause mortality. Since premature atrial contractions can be associated with these adverse clinical outcomes independently of atrial fibrillation occurrence, different explanations have being proposed. The concept of atrial cardiomyopathy, where atrial fibrillation would be an epiphenomenon outside the causal pathway between premature atrial contractions and stroke has received traction recently. This concept suggests that structural, functional and biochemical changes in the atria lead to arrhythmia occurrence and thromboembolic events. Some consensus about diagnosis and treatment of this condition have been published, but this is based on scarce evidence, highlighting the need for a clear definition of excessive premature atrial contractions and for prospective studies regarding antiarrhythmic therapies, anticoagulation or molecular targets in this group of patients.

Correlation between Volumes Determined by Echocardiography and Cardiac MRI in Controls and Atrial Fibrillation Patients

Aims: We aimed to compare cardiac volumes measured with echocardiography (echo) and cardiac magnetic resonance imaging (MRI) in a mixed cohort of healthy controls (controls) and patients with atrial fibrillation (AF). Materials and methods: In total, 123 subjects were included in our study; 99 full datasets were analyzed. All the participants underwent clinical evaluation, EKG, echo, and cardiac MRI acquisition. Participants with full clinical data were grouped into 63 AF patients and 36 controls for calculation of left atrial volume (LA Vol) and 51 AF patients and 30 controls for calculation of left ventricular end-diastolic volume (LV EDV), end-systolic volume (ESV), and LV ejection fraction (LV EF). Results: No significant differences in LA Vol were observed (p > 0.05) when measured by either echo or MRI. However, echo provided significantly lower values for left ventricular volume (p < 0.0001). The echo LA Vol of all the subjects correlated well with that measured by MRI (Spearmen correlation coefficient r = 0.83, p < 0.0001). When comparing the two methods, significant positive correlations of EDV (all subjects: r = 0.55; Controls: r = 0.71; and AF patients: r = 0.51) and ESV (all subjects: r = 0.62; Controls: r = 0.47; and AF patients: r = 0.66) were found, with a negative bias for values determined using echo. For a subgroup of participants with ventricular volumes smaller than 49.50 mL, this bias was missing, thus in this case echocardiography could be used as an alternative for MRI. Conclusion: Good correlation and reduced bias were observed for LA Vol and EF determined by echo as compared to cardiac MRI in a mixed cohort of patients with AF and healthy volunteers. For the determination of volume values below 49.50 mL, an excellent correlation was observed between values obtained using echo and MRI, with comparatively reduced bias for the volumes determined by echo. Therefore, in certain cases, echocardiography could be used as a less expensive, less time-consuming, and contraindication free alternative to MRI for cardiac volume determination.

Biatrial volume ratio predicts low voltage areas in atrial fibrillation

BACKGROUND

Left atrial volume (LAV) and low voltage areas (LVAs) are acknowledged markers for worse rhythm outcome after ablation of atrial fibrillation (AF). Some studies reported the importance of increased right atrial volume (RAV) as a predictor for arrhythmia recurrences in AF patients.

OBJECTIVE

To investigate association between the LAV/RAV ratio and LVAs presence.

METHODS

Patients undergoing first AF ablation were included. LVAs were assessed peri-procedurally using high-density 3D maps and defined as <0.5 mV. All patients underwent pre-procedural cardiovascular magnetic resonance imaging. LAV (biplane) and RAV (monoplane 4-chamber) were assessed prior to ablation, and the LAV/RAV ratio was calculated.

RESULTS

The study population included 189 patients (age mean 63 ± 10 years, 33% women, 57% persistent AF, 22% LVAs). There were 149 (79%) patients with LAV > RAV. In univariable analysis LAV > RAV was associated with LVAs (OR 6.803, 95%CI 1.395-26.514, p = .016). The association remained robust in multivariable model after adjustment for persistent AF, CHA₂ DS₂ -VASc score, and heart rate (OR 5.981, 95%CI 1.256-28.484, p = .025). Using receiver operator curve analysis, LAV > RAV (AUC 0.668, 95%CI 0.585-0.751, p = .001) was significant predictor for LVAs. In multivariable analysis, after adjustment for age, persistent AF, and renal function, RAV≥LAV was threefold higher in males (OR 3.040, 95%CI 1.050-8.802, p = .04).

CONCLUSIONS

LAV > RAV is useful for the prediction of electro-anatomical substrate in AF. LAV > RAV was associated with LVAs presence, while male sex remained associated with RAV≥LAV and less LVAs.

The Central Role of Left Atrium in Heart Failure

In past cardiovascular medicine, the attention to the left ventricle-identified as the only indicator and determinant of healthy or unhealthy cardiac conditions- has systematically hidden the role of the left atrium (LA). The recent advances in cardiovascular imaging have provided a better understanding of LA anatomy, physiology, and pathology, making us realize that this functional structure is far from being an innocent spectator. We now know that the LA's mechanical and neuro-hormonal properties play a relevant part in several cardiovascular diseases, including atrial fibrillation, ischemic heart disease, valvular heart disease, and heart failure. The present review aims to describe the role of LA in the specific setting of heart failure. We provide currently available information on LA structure and function and summarize its role as a determinant of symptoms, prognosis, and potential therapeutic target in heart failure patients.

Atrial fibrillation pattern and factors affecting the progression to permanent atrial fibrillation

Atrial fibrillation (AF) may progress from a non-permanent to a permanent form, and improvement in prediction may help in decision-making. In- and outpatients with non-permanent AF were enrolled in a prospective study and followed every 6 months. At baseline, 314 out of 523 patients (60%) had non-permanent AF (25.5% paroxysmal AF, 52.5% persistent, 2% first diagnosed AF). They were mostly males (188, 59.9%), median age 71 years [interquartile range (IQ) 62-77], median CHA₂DS₂VASc 3 (IQ 1-4), median HATCH score 1 (IQ 1-2). During a follow-up of 701 (IQ 437-902) days, 66 patients (21%) developed permanent AF. CHA₂DS₂VASc and HATCH scores were incrementally associated with AF progression (p for trend CHA₂DS₂VASc < 0.001, HATCH p = 0.001). Cox multivariable proportional hazard regression analysis showed that age [hazard ratio (HR) 1.042; 95%CI 1.005-1.080; p = 0.025], moderate-severe left atrial (LA) enlargement at echo (HR 2.072, 95%CI, 1.121-3.831; p = 0.020), antiarrhythmics drugs (HR 0.087, 95%CI 0.011-0.659, p = 0.018), EHRA score > 2 (HR 0.358, 95%CI 0.162-0.791, p = 0.011) and valvular disease (HR 2.196, 95%CI 1.072-4.499, p = 0.032) were significantly associated with AF progression. Adding "moderate-severe LA dilation" to clinical scores, eg. HATCH score (HATCH-LA) with 2 points (Cox multivariable regression analysis) improved prediction of AF progression vs. HATCH score (p = 0.0225). In patients without permanent AF, progression of AF was independently associated with age, LA dilation, AF symptoms severity, antiarrhythmic drugs and valvular disease. Adding LA dilation (moderate-severe volume increase) to clinical scores improved prediction of progression to permanent AF.

Optimizing indices of AF susceptibility and burden to evaluate AF severity, risk and outcomes

Atrial fibrillation (AF) has heterogeneous patterns of presentation concerning symptoms, duration of episodes, AF burden, and the tendency to progress towards the terminal step of permanent AF. AF is associated with a risk of stroke/thromboembolism traditionally considered dependent on patient-level risk factors rather than AF type, AF burden, or other characterizations. However, the time spent in AF appears related to an incremental risk of stroke, as suggested by the higher risk of stroke in patients with clinical AF vs. subclinical episodes and in patients with non-paroxysmal AF vs. paroxysmal AF. In patients with device-detected atrial tachyarrhythmias, AF burden is a dynamic process with potential transitions from a lower to a higher maximum daily arrhythmia burden, thus justifying monitoring its temporal evolution. In clinical terms, the appearance of the first episode of AF, the characterization of the arrhythmia in a specific AF type, the progression of AF, and the response to rhythm control therapies, as well as the clinical outcomes, are all conditioned by underlying heart disease, risk factors, and comorbidities. Improved understanding is needed on how to monitor and modulate the effect of factors that condition AF susceptibility and modulate AF-associated outcomes. The increasing use of wearables and apps in practice and clinical research may be useful to predict and quantify AF burden and assess AF susceptibility at the individual patient level. This may help us reveal why AF stops and starts again, or why AF episodes, or burden, cluster. Additionally, whether the distribution of burden is associated with variations in the propensity to thrombosis or other clinical adverse events. Combining the improved methods for data analysis, clinical and translational science could be the basis for the early identification of the subset of patients at risk of progressing to a longer duration/higher burden of AF and the associated adverse outcomes.

Biatrial enlargement as a predictor for reablation of atrial fibrillation

Purpose: We aimed to determine whether biatrial enlargement could predict reablation of atrial fibrillation after first ablation. Methods: 519 consecutive patients with drug resistant atrial fibrillation [paroxysmal AF (PAF) 361, non-PAF 158] who underwent catheter ablation in Capital Medical University Xuanwu hospital between 2009 and 2014 were enrolled. Biatrial enlargement (BAE) was diagnosed according to trans-thoracic echocardiography (TTE). Ablation strategies included complete pulmonary vein isolation (PVI) in all patients and additional linear ablation across mitral isthmus, left atrium roof, left atrium bottom and tricuspid isthmus, or electrical cardioversion on the cases that AF could not be terminated by PVI. Anti-arrhythmic drugs or cardioversion were used to control the recurred atrial arrhythmia in patients with recurrence of atrial fibrillation after ablation. Reablation was advised when the drugs were resistant or that patient could not tolerate. Risk factors for reablation were analyzed. Results: After 33.11±21.45months, 170 patients recurred atrial arrhythmia, and reablation were applied in 117 patients. Multivariate Cox regression analysis demonstrated that that biatrial enlargement (BAE, HR 1.755, 95%CI 1.153-2.670, P=0.009) was an independent predictor for reablation and was associated with reablation (Log rank P=0.007). Conclusion: Biatrial enlargement is an independent risk predictor for the reablation in atrial fibrillation patients after first ablation.