The Association of Serum Galectin-3 Levels with Atrial Electrical and Structural Remodeling

Understanding Galectin-3's Role in Diastolic Dysfunction: A Contemporary Perspective

Diastolic dysfunction, a prevalent condition characterized by impaired relaxation and filling of the left ventricle, significantly contributes to heart failure with preserved ejection fraction (HFpEF). Galectin-3, a β-galactoside-binding lectin, has garnered attention as a potential biomarker and mediator of fibrosis and inflammation in cardiovascular diseases. This comprehensive review investigates the impact of galectin-3 on diastolic dysfunction. We explore its molecular mechanisms, including its involvement in cellular signaling pathways and interaction with components of the extracellular matrix. Evidence from both animal models and clinical studies elucidates galectin-3's role in cardiac remodeling, inflammation, and fibrosis, shedding light on the underlying pathophysiology of diastolic dysfunction. Additionally, we examine the diagnostic and therapeutic implications of galectin-3 in diastolic dysfunction, emphasizing its potential as both a biomarker and a therapeutic target. This review underscores the significance of comprehending galectin-3's role in diastolic dysfunction and its promise in enhancing diagnosis and treatment approaches for HFpEF patients.

The Role of Galectin-3 Levels for Predicting Paroxysmal Atrial Fibrillation in Patients with Embolic Stroke of Undetermined Source

Background/Objectives: Paroxysmal atrial fibrillation (PAF) is an important cause that is thought main potential factor in Embolic stroke of undetermined source (ESUS). Extended Holter ECG is an expensive and time-consuming examination. It needs another tools for predicting PAF in ESUS patients. In this study, serum galectin-3 levels, ECG parameters (PR interval, P wave time and P wave peak time) LA volume index, LA global peak strain and atrial electromechanical conduction time values were investigated for predicting PAF. Methods: 150 patients with ESUS and 30 volunteers for the control group were recruited to study. 48-72 h Holter ECG monitoring was used for detecting PAF. Patients were divided into two groups (ESUS + PAF and ESUS-PAF) according to the development of PAF in Holter ECG monitoring. Results: 30 patients with ESUS whose Holter ECG monitoring showed PAF, were recruited to the ESUS + PAF group. Other 120 patients with ESUS were recruited to the ESUS-PAF group. PA lateral, PA septum, and PA tricuspid were higher in the ESUS + PAF group (p < 0.001 for all). Serum galectin-3 levels were significantly higher in ESUS + PAF than in ESUS-PAF and control groups (479.0 pg/mL ± 435.8 pg/mL, 297.8 pg/mL ± 280.3 pg/mL, and 125.4 ± 87.0 pg/mL, p < 0.001, respectively). Serum galectin-3 levels were significantly correlated with LAVI, PA lateral, and global peak LA strain (r = 0.246, p = 0.001, p = 0.158, p = 0.035, r = -0.176, p = 0.018, respectively). Conclusion: Serum galectin-3 levels is found higher in ESUS patients which developed PAF and Serum galectin-3 levels are associated LA adverse remodeling in patients with ESUS.

Cigarette smoke-induced galectin-3 as a diagnostic biomarker and therapeutic target in lung tissue remodeling

Galectin-3 (Gal-3), a multifunctional carbohydrate-binding lectin, has emerged as a key player in various biological processes including inflammation, cancer, cardiovascular diseases and fibrotic disorders, however it remains unclear if Gal-3 is a bystander or drives lung tissue remodeling (LTR). Persistent exposure to cigarette smoke (CS) is the leading cause of oxidative and inflammatory damage to the lung tissues. CS-induced pathological increase in Gal-3 expression has been implicated in the pathogenesis of various respiratory conditions, such as chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and lung cancer. We and others have reported that CS induces Gal-3 synthesis and secretion, which modulates the pathological signaling pathways in lung epithelial cells implicating Gal-3 as a novel diagnostic marker and a factor driving LTR in CS-exposed lungs. Therefore, pharmacological interventions targeting Gal-3 and its upstream and downstream signaling pathways can help combat CS-induced LTR. Excitingly, preclinical models have demonstrated the efficacy of interventions such as Gal-3 expression inhibition, Gal-3 receptor blockade, and signaling pathways modulation open up promising avenues for future therapeutic interventions. Furthermore, targeting extracellular vesicles-mediated Gal-3 release and the potential of microRNA-based therapy are emerging as novel therapeutic approaches in CS-induced LTR and have been discussed in this article.

Factors associated with patent foramen ovale-related stroke: SAFAS study

BACKGROUND

Persistent foramen ovale (PFO) contributes to cryptogenic stroke and is associated with stroke recurrence, although the exact mechanism of ischemic events is not fully understood. Several biomarkers have been developed for the prediction of atrial fibrillation after stroke, but there are currently only limited data on their potential value for the diagnosis of PFO-related stroke.

METHODS

This study was a prospective single-center study that included all patients hospitalized between March 31, 2018, and January 18, 2020, in the stroke department of the Dijon University Hospital for ischemic stroke without obvious cause and without a history of atrial fibrillation. PFO was systematically screened by transthoracic echocardiography and images were reviewed by an independent cardiologist blinded from clinical data. PFO was defined according to the CLOSE trial criteria: PFO associated with interatrial septal aneurysm or significant interatrial shunt (> 30 microbubbles in the left atrium within three cardiac cycles after right atrial opacification). The potential association of PFO-related stroke with biomarkers of cardiac fibrosis and inflammation such as galectin-3, GDF-15, ST-2, osteoprotegerin and NT-proBNP was tested using multivariate backward stepwise logistic regression.

RESULTS

Of the 240 patients included in the SAFAS study, 229 had complete echocardiographic data, and 23 (10%) had PFO-related stroke. Patients with PFO-related stroke were significantly younger (58±14 vs. 69±14, P<0.001), had less frequent previous arterial hypertension (30 vs. 60%, P=0.008), and more frequent cerebellar territory involvement (26 vs. 9%, P=0.014) compared to the other patients. In addition, they had less frequently left atrial dilatation (left atrial index volume>34mL/m2 [9 vs. 35%, P=0.009]). After ROC curve analysis for definition of thresholds, PFO-related stroke patients more often had galectin-3<9.5ng/mL (59 vs. 27%, P=0.002), ST2<13380pg/ml (23 vs. 50%, P=0.007), GDF-15<1200ng/mL (59 vs. 27%, P=0.002), osteoprotegerin<1133pg/mL (82 vs. 58%, P=0.033) and NT-proBNP<300pg/mL (88 vs. 55%, P=0.009). After multivariate analysis, only galectin-3<9.5ng/mL (OR [95% CI] 3.4 [1.18; 9.8], P=0.024) and osteoprotegerin<1133pg/L (OR [95% CI] 5.0 [1.1; 22.9], P=0.038) were independently associated with PFO-related stroke.

CONCLUSION

Patients in whom cryptogenic stroke is attributed to a significant PFO have a specific clinical and biological phenotype. Low levels of galectin-3 and osteoprotegerin may help identify patients with PFO-related strokes.

The role of galectin-3 in atrial fibrillation

Numerous risk factors for atrial fibrillation (AF) progression have been identified. However, the biomarkers mentioned in the guidelines do not have any clinically relevant predictive value. Some research groups investigated the potential utility of galectin-3 (gal-3) as a diagnostic, prognostic, and predictive biomarker in AF. In this review, we have thoroughly summarized the current data on the role of gal-3 in AF based on the original research in this field. Patients suffering from AF present with increased levels of gal-3. The concentration of gal-3 differs between patients with AF depending on the type of AF - it is higher in patients with persistent AF than in patients with paroxysmal AF. Multiple studies investigating the reappearance of AF in patients who underwent ablation have shown that gal-3 is a promising biomarker to predict the outcome of this therapy. Patients with increased levels of gal-3 are at higher risk of AF recurrence. Although the research considered in this work addressed many aspects of the role of gal-3 in AF, most of it has been conducted on a small group of patients. Therefore, further research and extensive clinical trials confirming described findings are highly warranted.

Insights into the Role of Galectin-3 as a Diagnostic and Prognostic Biomarker of Atrial Fibrillation

Atrial fibrillation (AF) is an irregular atrial activity and the most prevalent type of arrhythmia. Although AF is easily diagnosed with an electrocardiogram, there is a keen interest in identifying an easy-to-dose biomarker that can predict the prognosis of AF and its recurrence. Galectin-3 (Gal-3) is a beta-galactoside binding protein from the lectin family with pro-fibrotic and -inflammatory effects and a pivotal role in a variety of biological processes, cell proliferation, and differentiation; therefore, it is implicated in the pathogenesis of many cardiovascular (e.g., heart failure (HF)) and noncardiovascular diseases. However, its specificity and sensitivity as a potential marker in AF patients remain debated and controversial. This article comprehensively reviewed the evidence regarding the interplay between Gal-3 and patients with AF. Clinical implications of measuring Gal-3 in AF patients for diagnosis and prognosis are mentioned. Moreover, the role of Gal-3 as a potential biomarker for the management of AF recurrence is investigated. The association of Gal-3 and AF in special populations (coronary artery disease, HF, metabolic syndrome, chronic kidney disease, and diabetes mellitus) has been explored in this review. Overall, although further studies are needed to enlighten the role of Gal-3 in the diagnosis and treatment of AF, our study demonstrated the high potential of this molecule to be used and focused on by researchers and clinicians.

Role of Soluble ST2 Biomarker in Predicting Recurrence of Atrial Fibrillation after Electrical Cardioversion or Pulmonary Vein Isolation

This study aims to determine the predictive value of the soluble suppression of tumorigenicity 2 (sST2) biomarker in atrial fibrillation (AF) recurrence. This prospective, observational study included patients with AF referred for electrical cardioversion (ECV) or pulmonary vein isolation (PVI) procedures. Baseline characteristics were collected, and sST2 was determined at baseline and at 3 and 6 months of follow-up. sST2 was determined at baseline in a matched control group. Left atrial voltage mapping was performed in patients undergoing PVI. The sST2 maximal predictive capacity of AF recurrence was at the 3-month FU in the cohort of patients undergoing ECV with respect to 6-month AF recurrence with an AUC of 0.669, a cut-off point of 15,511 pg/mL, a sensitivity of 60.97%, and a specificity of 69.81%. The ROC curve of the sST2 biomarker at baseline and 3 months in the cohort of patients undergoing PVI showed AUCs of 0.539 and 0.490, respectively. The logistic regression model identified the rhythm (AF) and the sST2 biomarker at 3 months as independent factors for recurrence at 6 months in the ECV cohort. In the logistic regression model, sST2 was not an independent factor for recurrence at 6 months of follow-up in the PVI cohort. In patients who underwent ECV, sST2 values at 3 months may provide utility to predict AF recurrence at 6 months of follow-up. In patients who underwent PVI, sST2 had no value in predicting AF recurrence at 6 months of follow-up.

The Role of Galectin-3 in Heart Failure-The Diagnostic, Prognostic and Therapeutic Potential-Where Do We Stand?

Heart failure (HF) is a clinical syndrome with high morbidity and mortality, and its prevalence is rapidly increasing. Galectin-3 (Gal-3) is an important factor in the pathophysiology of HF, mainly due to its role in cardiac fibrosis, inflammation, and ventricular remodeling. Fibrosis is a hallmark of cardiac remodeling, HF, and atrial fibrillation development. This review aims to explore the involvement of Gal-3 in HF and its role in the pathogenesis and clinical diagnostic and prognostic significance. We report data on Gal-3 structure and molecular mechanisms of biological function crucial for HF development. Over the last decade, numerous studies have shown an association between echocardiographic and CMR biomarkers in HF and Gal-3 serum concentration. We discuss facts and concerns about Gal-3's utility in acute and chronic HF with preserved and reduced ejection fraction for diagnosis, prognosis, and risk stratification. Finally, we present attempts to use Gal-3 as a therapeutic target in HF.

Molecular mechanisms of postoperative atrial fibrillation in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) promotes atrial remodeling and fibrosis, providing a substrate for atrial fibrillation (AF). Herein, we investigate the pathophysiological mechanisms of AF in association with OSA in a cohort of cardiac surgery patients. A prospective study including patients undergoing cardiac surgery. Biomarkers reflective of AF pathophysiology (interleukin [IL-6], C-reactive protein [CRP], von Willebrand factor [vWF], N-terminal pro-brain natriuretic peptide [NT-proBNP], high-sensitivity Troponin T [hs-TnT], and Galectin-3 [Gal-3]) was assessed by functional or immunological assays. miRNAs involved in AF were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Using atrial tissue samples, fibrosis was assessed by Masson's trichrome. Connexin 40 and 43 (Cx40; Cx43) were evaluated by immunolabeling. Fifty-six patients (15 with OSA and 41 non-OSA) were included in this hypothesis-generating pilot study. OSA group had a higher incidence of postoperative AF (POAF) (46.7% vs. 19.5%; p = .042), presented an increased risk of POAF (OR 3.61, 95% CI 1.01-12.92), and had significantly higher baseline levels of NT-proBNP (p = .044), vWF (p = .049), Gal-3 (p = .009), IL-6 (p = .002), and CRP (p = .003). This group presented lower levels of miR-21 and miR-208 (both p < .05). Also, lower Cx40 levels in POAF and/or OSA patients (50.0% vs. 81.8%, p = .033) were found. The presence of interstitial fibrosis (according to myocardial collagen by Masson's trichrome) was raised in OSA patients (86.7% vs. 53.7%, p = .024). Several biomarkers and miRNAs involved in inflammation and fibrosis were dysregulated in OSA patients, which together with a higher degree of interstitial fibrosis, altered miRNA, and Cxs expression predisposes to the development of a substrate that increases the AF risk.

Biomarkers of Atrial Fibrillation Recurrence in Patients with Paroxysmal or Persistent Atrial Fibrillation Following External Direct Current Electrical Cardioversion

Atrial fibrillation (AF) is associated with atrial remodeling, cardiac dysfunction, and poor clinical outcomes. External direct current electrical cardioversion is a well-developed urgent treatment strategy for patients presenting with recent-onset AF. However, there is a lack of accurate predictive serum biomarkers to identify the risks of AF relapse after electrical cardioversion. We reviewed the currently available data and interpreted the findings of several studies revealing biomarkers for crucial elements in the pathogenesis of AF and affecting cardiac remodeling, fibrosis, inflammation, endothelial dysfunction, oxidative stress, adipose tissue dysfunction, myopathy, and mitochondrial dysfunction. Although there is ample strong evidence that elevated levels of numerous biomarkers (such as natriuretic peptides, C-reactive protein, galectin-3, soluble suppressor tumorigenicity-2, fibroblast growth factor-23, turn-over collagen biomarkers, growth differential factor-15) are associated with AF occurrence, the data obtained in clinical studies seem to be controversial in terms of their predictive ability for post-cardioversion outcomes. Novel circulating biomarkers are needed to elucidate the modality of this approach compared with conventional predictive tools. Conclusions: Biomarker-based strategies for predicting events after AF treatment require extensive investigation in the future, especially in the presence of different gender and variable comorbidity profiles. Perhaps, a multiple biomarker approach exerts more utilization for patients with different forms of AF than single biomarker use.

Galectin-3, Inflammation, and the Risk of Atrial High-Rate Episodes in Patients with Dual Chamber Pacemakers

Atrial high-rate episodes (AHREs) are atrial tachyarrhythmias that are exclusively detected by cardiac implantable electronic devices (CIEDs) with an atrial lead. The objective of this study was to investigate the incidence and predictive factors for AHREs, and to evaluate the ability of inflammation biomarkers to predict the occurrence of AHREs. 102 patients undergoing CIED procedure who received a dual chamber pacemaker were included. CIED interrogation was performed 1 year after the implantation procedure. Patients were divided into groups according to the occurrence of AHREs, which was the primary endpoint of the study. The mean age of the patients was of 73 ± 8.6 years and 48% were male. The incidence of AHREs was 67% at 1 year follow-up. Patients with AHREs were older, had higher left atrial indexed volume (LAVi), higher baseline galectin-3 levels (1007.5 ± 447.3 vs. 790 ± 411.7 pg/mL) and received betablockers more often, along with amiodarone and anticoagulants. Interestingly, the CHADSVASC score did not differ significantly between the two groups. A cut-off value of galectin > 990 pg/mL predicted AHREs with moderate accuracy (AUC of 0.63, 95% CI 0.52 to 0.73, p = 0.04), and this association was confirmed in the univariate regression analysis (OR 1.0012, 95% CI 1.0001 to 1.0023, p = 0.0328). However, based on the multivariate regression analysis, galectin lost its prognostic significance under the effect of LAVi, which remained the only independent predictor of AHREs (OR 1.0883, 95% CI 1.0351 to 1.1441, p = 0.0009). AHREs are common in CIEDs patients. Galectin-3 may bring additional data in the prediction of AHREs.

Consequences and Mechanisms of Left Atrium Remodeling in Aging Rabbits

To investigate the consequences and mechanisms of myocardium remodeling of aging left atrium, we analyzed the main cardiac electrophysiological parameters such as rest membrane potential, action potential amplitude, maximum rate of action potential increase (max dV/dt), action potential plateau, and 30, 50, and 90% action potential duration (APD₃₀, APD₅₀, and APD₉₀, respectively), as well as the inducibility and duration of atrial arrhythmias in adult and aging rabbits. L-type calcium current was also recorded. The collagen content in the myocardium and ultrastructure of left atrial cells were also studied. Significant changes were detected in the electrophysiological parameters and structure in aged left atrium, which can contribute to atrial susceptibility to arrhythmia in aged rabbits.

Galectin-3 is an independent predictor of postoperative atrial fibrillation and survival after elective cardiac surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is a frequent complication after heart surgery and is associated with thromboembolic events, prolonged hospital stay, and adverse outcomes. Inflammation and fibrosis are involved in the pathogenesis of atrial fibrillation.

OBJECTIVE

The purpose of this study was to assess whether galectin-3, which reflects preexisting atrial fibrosis, has the potential to predict POAF and mortality after cardiac surgery.

METHODS

Four hundred seventy-five consecutive patients (mean age 67.4 ± 11.8 years; 336 (70.7%) male) undergoing elective heart surgery at the Medical University of Vienna were included in this prospective single-center cohort study. Galectin-3 plasma levels were assessed on the day before surgery.

RESULTS

The 200 patients (42.1%) who developed POAF had significantly higher galectin-3 levels (9.60 ± 6.83 ng/mL vs 7.10 ± 3.54 ng/mL; P < .001). Galectin-3 significantly predicted POAF in multivariable logistic regression analysis (adjusted odds ratio per 1-SD increase 1.44; 95% confidence interval 1.15-1.81; P = .002). During a median follow-up of 4.3 years (interquartile range 3.4-5.4 years), 72 patients (15.2%) died. Galectin-3 predicted all-cause mortality in multivariable Cox regression analysis (adjusted hazard ratio per 1-SD increase 1.56; 95% confidence interval 1.16-2.09; P = .003). Patients with the highest-risk galectin-3 levels according to classification and regression tree analysis (>11.70 ng/mL) had a 3.3-fold higher risk of developing POAF and a 4.4-fold higher risk of dying than did patients with the lowest-risk levels (≤5.82 ng/mL).

CONCLUSION

The profibrotic biomarker galectin-3 is an independent predictor of POAF and mortality after cardiac surgery. This finding highlights the role of the underlying arrhythmogenic substrate in the genesis of POAF. Galectin-3 may help to identify patients at risk of POAF and adverse outcome after cardiac surgery.

Circulating plasma galectin-3 predicts new-onset atrial fibrillation in patients after acute myocardial infarction during hospitalization

Background

New-onset atrial fibrillation (NOAF) is a common complication in patients with acute myocardial infarction (AMI) during hospitalization. Galectin-3 (Gal-3) is a novel inflammation marker that is significantly associated with AF. The association between post-AMI NOAF and Gal-3 during hospitalization is yet unclear.

Objective

The present study aimed to investigate the predictive value of plasma Gal-3 for post-AMI NOAF.

Methods

A total of 217 consecutive patients admitted with AMI were included in this retrospective study. Peripheral venous blood samples were obtained within 24 h after admission and plasma Gal-3 concentrations were measured.

Results

Post-AMI NOAF occurred in 18 patients in this study. Patients with NOAF were older (p < 0.001) than those without. A higher level of the peak brain natriuretic peptide (BNP) (p < 0.001) and Gal-3 (p < 0.001) and a lower low-density lipoprotein cholesterol level (LDL-C) (p = 0.030), and an estimated glomerular filtration rate (e-GFR) (p = 0.030) were recorded in patients with post-AMI NOAF. Echocardiographic information revealed that patients with NOAF had a significantly decreased left ventricular eject fraction (LVEF) (p < 0.001) and an increased left atrial diameter (LAD) (p = 0.004) than those without NOAF. The receiver operating characteristic (ROC) curve analysis revealed a significantly higher value of plasma Gal-3 in the diagnosis of NOAF for patients with AMI during hospitalization (area under the curve (p < 0.001), with a sensitivity of 72.22% and a specificity of 72.22%, respectively. Multivariate logistic regression model analysis indicated that age (p = 0.045), plasma Gal-3 (p = 0.018), and LAD (p = 0.014) were independent predictors of post-MI NOAF.

Conclusions

Plasma Gal-3 concentration is an independent predictor of post-MI NOAF.

Circulating Galectin-3 and Aldosterone for Predicting Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation

Background

Circulating galectin-3 (Gal-3) and aldosterone (ALD) are involved in fibrosis and inflammation. However, their potential value as predictors of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) is unknown or controversial. Therefore, the aim of this study was to assess the relationship between baseline Gal-3, ALD levels, and AF recurrence in patients performing RFCA.

Methods

153 consecutive patients undergoing RFCA were included. Gal-3 and ALD were measured at baseline. Univariate and multivariate Cox regressions were performed to determine the predictors of AF recurrence. Receiver operating characteristic (ROC) curve and Kaplan-Meier (K-M) curve were used to assess the value of predictors.

Results

There were 35 (22.88%) cases of AF recurrence after RFCA. The recurrence group had significantly higher preoperative serum levels of Gal-3 and ALD than the nonrecurrence group. Univariate and multivariate analysis showed that Gal-3 (HR = 1.28, 95% CI: 1.04-1.56, p = 0.02) and ALD (OR = 1.02, 95% CI: 1.00-1.03, p < 0.03) were significantly associated with AF recurrence after RFCA. The area under the curve (AUC) of preoperative serum Gal-3, ALD, and 2 combined to predict the recurrence of AF patients after RFCA was 0.636, 0.798, and 0.893, respectively, while sensitivity was 65.32%, 71.69%, and 88.61%, respectively and specificity was 77.46%, 78.53%, and 86.0%, respectively. Patients with Gal-3 above the cutoff value of 14.57 pg/ml had higher frequent AF recurrence than the patients with Gal − 3 ≤ 14.57 pg/ml (35% vs. 12%, p < 0.001) during a follow-up. Meanwhile, patients with ALD above the cutoff value of 243.61 pg/ml also had a higher AF recurrence rate than those with ALD ≤ 243.61 pg/ml (37% vs. 11%, p < 0.001) during a follow-up. The recurrence rate in patients with Gal − 3 > 14.57 pg/ml + ALD > 243.61 pg/ml was higher than that in patients with baseline Gal − 3 > 14.57 pg/ml or ALD > 243.61 pg/ml and patients with Gal − 3 ≤ 14.57 pg/ml + ALD ≤ 243.61 pg/ml (57% vs. 14% vs. 9%, p < 0.01, respectively).

Conclusion

AF recurrence after RFCA had higher baseline Gal-3 and ALD levels, and higher preoperative circulating Gal-3 and ALD levels were independent predictors of AF recurrence for patients undergoing RFCA, while combination of preoperative Gal-3 and ALD levels has higher prediction accuracy.

Trend of Galectin-3 Levels in Patients with Non-ST-Elevation and ST-Elevation Myocardial Infarction

Background and Objectives: Given the fact that galectin-3 has a predictive significance on the development of myocardial dysfunction after acute myocardial infarction, the aim of our study was to examine potential factors that could be important for the dynamics of the concentration of this biomarker in the early postinfarction period. Materials and Methods: This study included 89 patients with a diagnosis of stable angina pectoris (SAP) or the first non-ST elevation (NSTEMI) or ST-elevation (STEMI) myocardial infarction, who underwent percutaneous coronary intervention (PCI). The study group included 23 patients with the first NSTEMI and 42 patients with STEMI, while the control group consisted of 24 patients with SAP hospitalized for elective PCI without a previous MI. All patients had preserved left ventricular ejection fraction. Galectin-3 levels were determined on days 1, 5, and 30 after PCI. The significance of various independent variables as predictors of galectin-3 concentration was analyzed after a series of univariate linear regression modeling in a multivariate linear regression model. Results: The average patients’ age was 63.99 ± 9.13 years. Statistically significantly higher values of C-reactive protein were established in STEMI compared to SAP (p < 0.01) or NSTEMI (p < 0.001), whereas WBC count was significantly lower in SAP than in STEMI (p < 0.001) and NSTEMI (p < 0.01) group. Although there were no statistically significant differences in measured galectin-3 concentrations between the examined groups on days 1, 5, and 30 after PCI, HTA, triglyceride level, LA size, treatment with trimetazidine and long-acting nitrates, as well as percentage of LM stenosis and E/A ratio were identified as independent predictors of galectin-3 concentration. Conclusions: In the post-MI period, very early values of galectin-3 correlate mostly with atherosclerosis factors, while on day 30 this biomarker correlates with diastolic dysfunction and “announces” left ventricular remodeling.

The Diagnostic and Therapeutic Potential of Galectin-3 in Cardiovascular Diseases

Galectin-3 plays a prominent role in chronic inflammation and has been implicated in the development of many disease conditions, including heart disease. Galectin-3, a regulatory protein, is elevated in both acute and chronic heart failure and is involved in the inflammatory pathway after injury leading to myocardial tissue remodelling. We discussed the potential utility of galectin-3 as a diagnostic and disease severity/prognostic biomarker in different cardio/cerebrovascular diseases, such as acute ischemic stroke, acute coronary syndromes, heart failure and arrhythmogenic cardiomyopathy. Over the last decade there has been a marked increase in the understanding the role of galectin-3 in myocardial fibrosis and inflammation and as a therapeutic target for the treatment of heart failure and myocardial infarction.

The Role of Galectin-3 and ST2 in Cardiology: A Short Review

Galectin-3 is a lectin that binds beta-galactosides. It is involved in cardiac remodeling and fibrosis through the activation of macrophages and fibroblasts. ST2 is secreted by myocardial cells due to cardiac overload. These two biomarkers have been traditionally studied in the field of heart failure to guide medical therapy and detect the progression of the disease. Nevertheless, there are novel evidences that connect galectin-3 and ST2 with coronary heart disease and, specifically, with atrial fibrillation. The aim of this article is to concisely review the diagnostic and prognostic role of galectin-3 and ST2 in different cardiac diseases.

Analysis of the Correlation of Galectin-3 Concentration with the Measurements of Echocardiographic Parameters Assessing Left Atrial Remodeling and Function in Patients with Persistent Atrial Fibrillation

Galectin-3 (gal-3) is a fibrosis marker and may play a role in fibrosis of the left atrium (LA). Left atrial wall fibrosis may influence the transition from paroxysmal to non-paroxysmal atrial fibrillation (AF). In this study, we assessed the correlation of gal-3 concentration with the main echocardio-graphic parameters evaluating dimensions, volume, compliance, and left atrial contractility during AF and after successful electrical cardioversion (DCCV). The study included 63 patients with left atrial enlargement who qualified for DCCV due to persistent AF. The procedure recovered sinus rhythm in 43 (68.3%) patients. The concentration of gal-3 was negatively correlated with the echocardiographic parameters of LA including dimensions (LA length pre, rho = −0.38; p = 0.003), volume (LAV pre, rho = −0.39; p = 0.003), compliance (LASr mean post, rho = −0.33) and contractility (pLASRct mean post, rho = −0.33; p = 0.038). Negative correlations of gal-3 concentration were also observed in relation to the volume and contractility of the left ventricle. The concentration of gal-3 significantly negatively correlates with the size, systolic function, and compliance of the LA wall in patients with persistent AF. Determining gal-3 concentration in patients with persistent AF may help in the assessment of remodeling of the LA wall.

Potential Biomarkers in Atrial Fibrillation: Insight into their Clinical Significance

ABSTRACT

In risk-stratifying patients with atrial fibrillation (AF), physicians rely heavily on clinical parameters that provide risk scores and determine treatment strategies. There has been increasing research on potential biomarkers in the blood that could more accurately determine both risk of complications in AF and risk of incidence of AF. This review highlights the clinical significance of five novel biomarkers that have been shown to be linked to AF. These biomarkers are carbohydrate antigen 125 (CA-125), galectin-3 (gal-3), growth differentiating factor-15 (GDF-15), a member of the interleukin 1 receptor family, IL1RL1 (ST2) and N-terminal pro B-type natriuretic peptide (NT-proBNP).

The prognostic value of soluble suppression of tumourigenicity 2 and galectin-3 for sinus rhythm maintenance after cardioversion due to persistent atrial fibrillation in patients with normal left ventricular systolic function

AIMS

Soluble suppression of tumourigenicity 2 (sST2) and galectin-3 are involved in cardiac fibrosis, inflammation, and remodelling. However, the place of sST2 and galectin-3 in predicting the outcomes of electrical cardioversion of atrial fibrillation (AF) is uncertain. We evaluated whether these biomarkers could predict sinus rhythm (SR) maintenance after cardioversion of persistent AF in patients with normal left ventricular systolic function.

METHODS AND RESULTS

The study included 80 patients with persistent AF, who underwent cardioversion from February 2016 to August 2018. The blood concentrations of sST-2 and galectin-3 were measured with ELISA and the ASPECT-PLUS assays. Clinical and electrocardiographic follow-up was performed at months 1, 6, and 12. Patients who maintained SR at 12 months had significantly lower concentrations of sST2, measured by ELISA and ASPECT-PLUS assays, than the remaining patients (16.9 ± 9.8 vs. 28 ± 22.9 ng/mL; P < 0.001; 28.7 ± 13.4 vs. 40 ± 25.1 ng/mL; P = 0.003); the concentration of galectin-3 did not differ between these patients. Multivariable logistic regression showed that log-transformed sST2 ELISA was a significant predictor of SR maintenance at 12 months [odds ratio 0.14; 95% confidence interval (CI) 0.03-0.58; P = 0.006]. On receiver-operating characteristic curve analysis, the areas under the curve for the concentration of sST2 was 0.752 (95% CI 0.634-0.870; P < 0.001). The concentrations of sST2 measured with the two assays were strongly correlated (rho = 0.8; CI 95% 0.7-0.87; P = 0.001).

CONCLUSION

Soluble suppression of tumourigenicity 2, but not galectin-3, can be used to predict SR maintenance after cardioversion of AF in patients with normal left ventricular systolic function. The measurements of sST2 concentrations with the rapid lateral flow and enzyme-linked immunoassays were consistent.

Atrial fibrosis and substrate based characterization in atrial fibrillation: Time to move forwards

Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. However, current therapeutic interventions for atrial fibrillation have limited clinical efficacy as a consequence of major knowledge gaps in the mechanisms sustaining atrial fibrillation. From a mechanistic perspective, there is increasing evidence that atrial fibrosis plays a central role in the maintenance and perpetuation of atrial fibrillation. Electrophysiologically, atrial fibrosis results in alterations in conduction velocity, cellular refractoriness, and produces conduction block promoting meandering, unstable wavelets and micro-reentrant circuits. Clinically, atrial fibrosis has also linked to poor clinical outcomes including AF-related thromboembolic complications and arrhythmia recurrences post catheter ablation. In this article, we review the pathophysiology behind the formation of fibrosis as AF progresses, the role of fibrosis in arrhythmogenesis, surrogate markers for detection of fibrosis using cardiac magnetic resonance imaging, echocardiography and electroanatomic mapping, along with their respective limitations. We then proceed to review the current evidence behind therapeutic interventions targeting atrial fibrosis, including drugs and substrate-based catheter ablation therapies followed by the potential future use of electro phenotyping for AF characterization to overcome the limitations of contemporary substrate-based methodologies.

Evaluation of Galectin-3 Plasma Concentration in Adolescents with Ventricular Arrhythmia

Galectin-3 (G3) is a biomarker known as an inflammatory state exponent. The aim of this paper was to analyze the G3 in adolescents with ventricular arrhythmia (VES) in order to evaluate its impact on myocardial tissue preservation. The study group (SG) consisted of 25 VES adolescents. The control group (CG) was 21 healthy children. G3 was assessed in the SG and CG. In the SG electrocardiography, Holter monitoring, echocardiography and CMR were performed. The G3 in SG was 13.45 ± 11.4 ng/mL and in CG 7.2 ± 2.0 ng/mL, p < 0.001. Moderate positive correlation between the G3 and z-score of the left ventricular diameter (r = 0.47, p = 0.041) and moderate negative correlation between the G3 and the left ventricular ejection fraction in cardiac magnetic resonance (CMR EF) (-0.49, p = 0.032) were found. According to the multiple linear regression analysis, CMR EF and VES were independent predictors for G3 elevation. Conclusion: Galectin-3 plasma concentration is elevated and correlates with the chosen left ventricular dysfunction parameters in adolescents suffering from ventricular arrhythmia. Further investigation is necessary to establish if elevated G3 is a useful biomarker for screening young individuals with ventricular arrhythmia who are at risk of structural cardiovascular pathology.

sST2 and Galectin-3 genotyping in patients with persistent atrial fibrillation

Genotyping of ST2 and galectin-3 in atrial fibrillation (AF) is not well analyzed. The aim of our study was to analyze the possible relationship between levels of sST2 and galectin-3 and three polymorphisms in patients with AF. We included 125 patients with persistent AF undergoing electric cardioversion. We analyzed sST2 and galectin-3 levels and three polymorphisms in peripheral blood samples. Rs2274273 was significantly related with levels of galectin-3. Rs1558648 was associated with levels of sST2 but rs13019803 were not. None of the polymorphisms were connected to the variation of biomarkers levels during the follow up. We found a relationship between rs2274273 and galectin-3 levels and rs1558648 and sST2 levels in patients with AF.

Galectin-3 levels and the prediction of atrial high-rate episodes in patients with cardiac resynchronization therapy

Galectin-3 is an inflammation biomarker associated with atrial remodeling which plays a role in the development of atrial fibrillation (AF). Atrial high-rate episode (AHRE) is related to development of clinically documented AF and stroke. The present study aimed to determine the relationship between the presence of AHRE and the coronary sinus (CS) serum sampling of galectin-3 levels in the long-term follow-up of cardiac resynchronization therapy (CRT) patients. A total of 108 consecutive CRT patients were included prospectively in the study. AHREs were defined as atrial tachyarrhythmia episodes lasting at least 6 min with atrial rate >190 beats/min detected by cardiac implantable electronic device. CS blood samples were drawn from the CS guiding catheter to perform galectin-3 measurements. Galectin-3 levels were measured via ELISA. During a mean follow-up 12.6±4.9 months, AHRE was observed in 31 (28.7%) patients and not observed in 77 (72.3%) patients. CS galectin-3 levels were significantly higher in patients with AHRE than those without AHRE (18.09±2.62 vs 13.17±3.17, respectively, p<0.001). Moreover, CS galectin-3 levels showed significant positive correlation with percent of time spent in total AHRE (r=0.436, p<0.001). Multivariate logistic regression analysis demonstrated that left atrium (LA) volume and CS galectin-3 levels were significant and independent predictors for AHRE (OR=1.127, 95% CI: 1.045 to 1.216; p=0.002, OR=1.799, 95% CI: 1.388 to 2.330; p<0.001, respectively). In this study, we determined that high CS galectin-3 levels were a predictor for the development of AHRE in CRT patients.

Galectin-3 Induces Atrial Fibrosis by Activating the TGF-β1/Smad Pathway in Patients with Atrial Fibrillation

BACKGROUND

Atrial fibrosis plays a critical role in the occurrence and maintenance of atrial fibrillation. The role of TGF-β1 in mediating atrial fibrosis is well documented. The β-galactoside-binding lectin galectin-3 (Gal-3) is mainly produced by macrophages in biological events such as inflammation and angiogenesis. Previous studies have shown that Gal-3 is associated with atrial fibrosis, but the relationship between TGF-β1 and Gal-3 in atrial fibrosis remains unclear.

OBJECTIVE

To determine whether Gal-3 induces atrial fibrosis and atrial fibrillation by activating the TGF-β1/Smad pathway and whether the expression of Gal-3 is mediated by TGF-β1, which can enable assessing the relationship between Gal-3 and TGF-β1 in atrial fibrosis.

METHODS

In this study, 30 patients' right atrial appendages were collected and divided into 3 groups: congenital heart disease sinus rhythm group (n = 10, as a control group), rheumatic heart disease sinus rhythm group (n = 10), and rheumatic heart disease atrial fibrillation group (n = 10). Rat atrial fibroblasts were cultured in vitro, and recombinant Gal-3 and recombinant TGF-β1 proteins were added to the cell culture. The expression of Gal-3, TGF-β1, Smad2, and collagen I was detected by Western blotting and quantitative real-time PCR. Atrial tissues were stained with Masson's trichrome stain to evaluate the extent of atrial fibrosis. The expression of Gal-3 and TGF-β1 was detected by immunohistochemical staining and immunofluorescence staining. Gal-3 and TGF-β1 interaction was demonstrated by immunoprecipitation.

RESULTS

The expression levels of Gal-3, TGF-β1, Smad2, and collagen I were elevated in the rheumatic heart disease atrial fibrillation group compared with the congenital heart disease sinus rhythm group and the rheumatic heart disease sinus rhythm group. In cultured atrial fibroblasts, there is a synergistic interaction between Gal-3 and TGF-β1. Gal-3 stimulated the TGF-β1/Smad pathway, and overexpression of TGF-β1 induced Gal-3 expression.

CONCLUSIONS

Gal-3 and TGF-β1 interact with each other and stimulate the downstream TGF-β1/Smad pathway. This finding suggests that Gal-3 could be an important factor in TGF-β1-induced fibrosis in atrial fibrillation.

Correlation between serum homocysteine, Galectin-3 concentration and atrial structural remodeling in atrial fibrillation patients

Objective To investigate the correlation between serum homocysteine (Hcy), Galectin-3 concentration and atrial structural remodeling in atrial fibrillation (AF) patients.

Methods Twenty-five patients with persistent atrial fibrillation (PeAF), 24 patients with paroxysmal atrial fibrillation (PaAF) and 23 healthy controls were included in the present work. All subjects received an echocardiography examination. Serum concentration of Hcy and Galectin-3 were also examined by Enzyme Linked Immunosorbent Assay (ELISA).

Results Echocardiography examination demonstrated that there were significant differences for LAD (p=0.002), LVEF (p=0.005) and LVAI (p=0.0001) between the control, PaAF and PeAF groups. However, LVSD and LVDD were not significantly different between the three groups (pall>0.05). There was a significant positive correlation between LAVI and serum Hcy level in both PaAF (rpearson=0.49, p=0.016) and PeAF (rpearson=0.51, p=0.009) groups. The correlation between LAVI and serum Galectin-3 concentration was also statistically significant for PaAF (rpearson=0.54, p=0.006) and PeAF (rpearson=0.60, p=0.001) groups. Using serum Hcy as reference, diagnostic sensitivity and specificity were calculated as 72.00 (95%CI: 50.61-87.93) and 62.50 (95%CI: 40.59-81.20), respectively, with an AUC of 0.68 for PaAF and PeAF. For serum Galectin-3, the sensitivity and specificity values were 64.00 (95%CI:42.52-82.03) and 66.67 (95%CI:44.68-84.37), respectively, with an AUC of 0.68.

Conclusion: Serum Hcy and Galectin-3 were elevated in AF patients and thus may be potential markers of atrial structural remodeling. However, the diagnostic efficacy of PeAF from PaAF was limited by low AUC values.

miR-21 and NT-proBNP Correlate with Echocardiographic Parameters of Atrial Dysfunction and Predict Atrial Fibrillation

This study aimed to investigate the association of circulating biomarkers with echocardiographic parameters of atrial remodelling and their potential for predicting atrial fibrillation (AF). In patients with and without AF (n = 21 and n = 60) the following serum biomarkers were determined: soluble ST2 (sST2), Galectin-3 (Gal-3), N-terminal pro-brain natriuretic peptide (NT-proBNP), microRNA (miR)-21, -29a, -133a, -146b and -328. Comprehensive transthoracic echocardiography was performed in all participants. Biomarkers were significantly altered in patients with AF. The echocardiographic parameter septal PA-TDI, indicating left atrial (LA) remodelling, correlated with concentrations of sST2 (r = 0.249, p = 0.048), miR-21 (r = -0.277, p = 0.012), miR-29a (r = -0.269, p = 0.015), miR-146b (r = -0.319, p = 0.004) and miR-328 (r = -0.296, p = 0.008). In particular, NT-proBNP showed a strong correlation with echocardiographic markers of LA remodelling and dysfunction (septal PA-TDI: r = 0.444, p < 0.001, LAVI/a': r = 0.457, p = 0.001, SRa: r = 0.581, p < 0.001). Multivariate Cox regressions analysis highlighted miR-21 and NT-proBNP as predictive markers for AF (miR-21: hazard ratio (HR) 0.16; 95% confidence interval (CI) 0.04-0.7, p = 0.009; NT-proBNP: HR 1.002 95%CI 1.001-1.004, p = 0.006). Combination of NT-proBNP and miR-21 had the best accuracy to discriminate patients with AF from those without AF (area under the curve (AUC)= 0.843). Our findings indicate that miR-21 and NT-proBNP correlate with echocardiographic parameters of atrial remodeling and predict AF, in particular if combined.

Serum Galectin-3 level and recurrence of atrial fibrillation post-ablation - Systematic review and meta-analysis

BACKGROUND

Serum galectin-3, a circulating biomarker of fibrosis, has been associated with atrial remodelling. Recent studies investigating serum galectin-3 and AF recurrence post-ablation have shown mixed results. We aimed to analyze the latest evidence on the association between serum galectin-3 and AF recurrence after catheter ablation.

METHODS

We performed a comprehensive search on topics that assesses serum galectin-3 and AF recurrence post-ablation up until August 2019.

RESULTS

There were 597 patients from seven studies. The mean difference of serum galectin-3 was similar in both AF recurrence and non AF recurrence group (mean difference 0.78 ng/mL [-0.56, 2.13]; p = 0.25; I2: 69%. Upon removal of a study in sensitivity analysis, the serum galectin-3 became higher in AF recurrence group (mean difference 1.41 ng/mL [0.47, 2.34], p = 0.003; I2: 17%). Serum galectin-3 was associated with a higher risk for AF recurrence (HR 1.25 [1.01, 1.55]; p = 0.04; I2: 76%). Upon removal of a study in sensitivity analysis, HR became 1.45 [1.07, 1.96], p = 0.02; I2: 47%. Meta-analysis of adjusted HR demonstrated that high serum galectin-3 independently predicts AF recurrence (HR 1.15 [1.02, 1.29], p < 0.02; I2: 57%, p = 0.10) CONCLUSION: Serum galectin-3 is associated with an increased risk of AF recurrence post-ablation. Further studies are required, especially emphasis on the cut-off point should be given, before integrating it in routine risk stratification for AF ablation.

Risk factors for recurrence of atrial fibrillation

OBJECTIVE

Atrial fibrillation (AF) is a progressive disease, associated with increased risk of mortality, stroke, heart failure, and worsens quality of life. There is a high incidence of AF recurrence despite the treatment. The aim of the study was to assess the time to recurrence of AF after sinus rhythm restoration with electrical or pharmacological cardioversion and to identify the risk factors.

METHODS

This study included 101 patients with AF (56% females) at a mean age of 68.02±7 years, after sinus rhythm restoration in a clinical observation of 1-year placebo-controlled treatment with spironolactone (1: 1). The patients were analyzed on the basis of AF recurrence, hospitalization, demographic parameters, comorbidities, embolic risk, and value of biomarker galectin-3 (Gal-3).

RESULTS

The average number of AF recurrences was1.62 per patient per year. The median time of occurrence of at least one new episode was 48 days, 95% confidence interval (CI) 14.24-81.76. Female patients experienced significantly more recurrences than male-53.3% vs. 28.6% hazard ration (HR) =1.76, 95% CI 1.02-3.03, p=0.036. The recurrences were more common with increased age, although not significantly. Patients with arterial hypertension had a threefold risk of recurrences than those without hypertension (p=0.025), independently of the treatment. CHA2DS2-VASc score was significantly associated with AF recurrent episodes. Patients with gout had a twofold increased risk, without statistical significance (p=0.15). There was no difference in the AF episodes according to treatment with spironolactone. The levels of Gal-3 did not affect the number of AF recurrences (p=0.9).

CONCLUSION

AF is associated with frequent recurrences after restoration of sinus rhythm in the majority of the patients. Most of them occurred within the first 3 months. Female sex, arterial hypertension, and CHA2DS2-VASc score were significant predictors of AF recurrence. Spironolactone did not reduce AF recurrences.

Effects of febuxostat on atrial remodeling in a rabbit model of atrial fibrillation induced by rapid atrial pacing

Background

Febuxostat, a novel nonpurine selective inhibitor of xanthine oxidase (XO), may be used in the prevention and management of atrial fibrillation (AF). The purpose of this study was to evaluate the effects of febuxostat on atrial remodeling in a rabbit model of AF induced by rapid atrial pacing (RAP) and the mechanisms by which it acts.

Methods

Twenty-four rabbits were randomly divided into four groups: sham-operated group (Group S), RAP group (Group P), RAP with 5 mg/kg per day febuxostat group (Group LFP), and RAP with 10 mg/kg per day febuxostat group (Group HFP). All rabbits except those in Group S were subjected to RAP at 600 beats/min for four weeks. The effects of febuxostat on atrial electrical and structural remodeling, markers of inflammation and oxidative stress, and signaling pathways involved in the left atrium were examined.

Results

Shortened atrial effective refractory period (AERP), increased AF inducibility, decreased mRNA levels of Cav1.2 and Kv4.3, and left atrial enlargement and dysfunction were observed in Group P, and these changes were suppressed in the groups treated with febuxostat. Prominent atrial fibrosis was observed in Group P, as were increased levels of TGF-β1, Collagen I, and α-SMA and decreased levels of Smad7 and eNOS. Treatment with febuxostat attenuated these differences. Changes in inflammatory and oxidative stress markers induced by RAP were consistent with the protective effects of febuxostat.

Conclusions

This study is the first to find that febuxostat can inhibit atrial electrical and structural remodeling of AF by suppressing XO and inhibiting the TGF-β1/Smad signaling pathway.

Biomarkers Associated with Atrial Fibrosis and Remodeling

Atrial fibrillation is the most common rhythm disturbance encountered in clinical practice. Although often considered as solely arrhythmic in nature, current evidence has established that atrial myopathy constitutes both the substrate and the outcome of atrial fibrillation, thus initiating a vicious, self-perpetuating cycle. This myopathy is triggered by stress-induced (including pressure/volume overload, inflammation, oxidative stress) responses of atrial tissue, which in the long term become maladaptive, and combine elements of both structural, especially fibrosis, and electrical remodeling, with contemporary approaches yielding potentially useful biomarkers of these processes. Biomarker value becomes greater given the fact that they can both predict atrial fibrillation occurrence and treatment outcome. This mini-review will focus on the biomarkers of atrial remodeling (both electrical and structural) and fibrosis that have been validated in human studies, including biochemical, histological and imaging approaches.

Circulating Galectin-3 and Atrial Fibrillation Recurrence after Catheter Ablation: A Meta-Analysis

BACKGROUND

Galectin-3 (Gal-3) is involved in fibrosis and heart failure. However, epidemiological studies evaluating the association between Gal-3 and atrial fibrillation (AF) recurrence after catheter ablation showed inconsistent results. We conducted a meta-analysis to comprehensively evaluate the relationship between baseline circulating Gal-3 levels and AF recurrence in patients undergoing catheter ablation.

METHODS

Relevant studies were identified by systematically searching the PubMed and Embase databases. A random-effect model was used to synthesize the results. Sensitivity analyses, performed by omitting one study at a time, were used to evaluate the robustness of the results.

RESULTS

Seven prospective cohort studies including 645 AF patients were included. Within a follow-up duration of up to 18 months, 244 patients developed AF recurrence. Pooled results showed that baseline circulating Gal-3 levels were significantly higher in patients with AF recurrence compared to those without (standardized mean difference: 0.74; 95% confidence interval (CI): 0.21 - 1.27; p = 0.007; I2 = 89%). Moreover, higher baseline Gal-3 levels were independently associated with a significantly higher risk of AF recurrence after catheter ablation (risk ratio: 1.17 per unit of Gal-3; 95% CI: 1.01 - 1.35; p = 0.03; I2 = 40%), which was independent of age, gender, and left atrial dimension. Sensitivity analyses did not significantly affect the results. However, there was a significant publication bias for predicting efficacy of associating preprocedural Gal-3 levels with AF recurrence.

CONCLUSIONS

Higher preprocedural Gal-3 levels may be associated with increased risk of AF recurrence in patients undergoing catheter ablation.

Clinical scores used for the prediction of negative events in patients undergoing catheter ablation for atrial fibrillation

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia in adults. Catheter ablation (CA) is one of the most important management strategies to reduce AF burden and AF-associated complications. In order to stratify the risk of adverse events and to predict treatment success in AF patients undergoing CA, several risk stratification scores had been developed during the last decade. The aim of this review is to provide an overview of the most important clinical risk scores predicting rhythm outcomes, electro-anatomical substrate and mortality in AF.

Circulating Galectin-3 is Associated With Left Atrial Appendage Remodelling and Thrombus Formation in Patients With Atrial Fibrillation

BACKGROUND

Left atrial appendage (LAA) is gaining increasing attention in patients with atrial fibrillation (AF) in the context of cardioembolic stroke. Galectin-3 (Gal-3) is a mediator of profibrotic pathways and is associated with an increased incidence of heart failure. However, the role of Gal-3 in LAA remodelling and thrombus formation in AF has not been evaluated.

METHODS

This prospective study included 153 consecutive patients with paroxysmal (n=58), persistent (n=55) or permanent (n=40) nonvalvular AF. The serum level of Gal-3 was measured by enzyme-linked immunosorbent assay. The morphology and function of LAA were determined by transoesophageal echocardiography.

RESULTS

Left atrial appendage thrombus was observed in 22 patients (2 in paroxysmal AF, 11 in persistent AF and 9 in permanent AF). Significant differences among patients with different types of AF were found in terms of LAA morphology (orifice diameter and depth) and function (flow velocity and tissue Doppler contracting velocity) as well as serum levels of Gal-3. Furthermore, patients with persistent or permanent AF had higher levels of Gal-3. High Gal-3 level was closely related to LAA flow velocity and occurrence of LAA thrombus. Multivariate logistic regression analysis revealed that Gal-3 was an independent determinant of LAA thrombus in patients with AF. Receiver operating characteristic (ROC) curves related to LAA thrombus formation established a cut-off point for Gal-3 >18.95ng/ml.

CONCLUSIONS

Cardiac rhythm disturbances caused by AF may lead to morphologic and functional remodelling of LAA. The serum level of Gal-3 was significantly correlated with LAA remodelling in patients with AF. High levels of Gal-3 were also a predicator for LAA thrombus formation.

Galectin-3 in Atrial Fibrillation: Mechanisms and Therapeutic Implications

Maintenance of atrial fibrillation is a complex mechanism, including extensive electrical and structural remodeling of the atria which involves progressive fibrogenesis. Galectin-3 is a biomarker of fibrosis, and, thus, may be involved in atrial remodeling in atrial fibrillation patients. We review the role of galectin-3 in AF mechanisms and its potential therapeutic implications.

Galectin-3 as a novel biomarker for disease diagnosis and a target for therapy (Review)

Galectin-3 is a member of the galectin family, which are β‑galactoside‑binding lectins with ≥1 evolutionary conserved carbohydrate‑recognition domain. It binds proteins in a carbohydrate‑dependent and ‑independent manner. Galectin‑3 is predominantly located in the cytoplasm; however, it shuttles into the nucleus and is secreted onto the cell surface and into biological fluids including serum and urine. It serves important functions in numerous biological activities including cell growth, apoptosis, pre‑mRNA splicing, differentiation, transformation, angiogenesis, inflammation, fibrosis and host defense. Numerous previous studies have indicated that galectin‑3 may be used as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease and cancer. With emerging evidence to support the function and application of galectin‑3, the current review aims to summarize the latest literature regarding the biomarker characteristics and potential therapeutic application of galectin‑3 in associated diseases.

The Association between Galectin-3 and hs-CRP and the Clinical Outcome after Non-ST-Elevation Myocardial Infarction with Preexisting Atrial Fibrillation

Increased galectin-3 plasma concentration has been linked to an unfavorable outcome in patients with heart failure or atrial fibrillation (AF). There are no published data about the prognostic utility of galectin-3 and high-sensitivity C-reactive protein (hs-CRP) for long-term clinical outcome in the Non-ST elevation acute myocardial infarction (NSTEMI) patients with preexisting AF. Thirty-two patients with the first acute NSTEMI and preexisting AF and 22 patients without preexisting AF, were prospectively followed for fifteen months. Patients with AF had significantly higher galectin-3 plasma levels (p < 0.05) and hs-CRP concentration (p < 0.01), compared with patients without AF. Galectin-3 plasma concentration was not a significant covariate of the composite outcomes (p = 0.913). Patients with high hs-CRP (above 4.55 mg/L) showed 2.5 times increased risk (p < 0.05) of the composite outcome occurrence (p < 0.05). Besides, three-vessel coronary artery disease, creatinine serum level, and creatinine clearance were significant covariates (p < 0.05; p < 0.05; p < 0.01) of the composite outcome, respectively. Creatinine clearance, solely, has been shown to be an independent predictor of unfavorable prognosis after a 15-month follow-up. Galectin-3 and hs-CRP plasma levels were elevated in NSTEMI patients with AF, but with differential predictive value for an unfavorable clinical outcome. Only hs-CRP was associated with increased risk of composite outcome occurrence.

Potential Biological Markers of Atrial Fibrillation: A Chance to Prevent Cryptogenic Stroke

Stroke affects millions of people all over the world, causing death and disability. The most frequent type of this disease is ischemic stroke, which can be caused by different factors. In approximately 25 percent of cases, no obvious cause can be found. Recent observations have shown that paroxysmal atrial fibrillation could be responsible for a significant number of cryptogenic stroke events. Short- or long-lasting ECG monitoring could help with the diagnosis of transient arrhythmias. Unfortunately, these techniques either are expensive or require good patient compliance. An alternative option is the identification of biological markers that are specific for atrial fibrillation and can be used to predict arrhythmia. In this review, we give a summary of the recent advances in the research of arrhythmia markers. Based on their structure and function, we differentiated four groups of biomarkers: markers of inflammation, markers of fibrosis, markers with hormonal activity, and other markers. In spite of intensive researches, the optimal biological marker is still not available, but there are some promising markers, like NT-proBNP/BNP.

Serum galectin-3 level as a marker of thrombogenicity in atrial fibrillation

BACKGROUND

Left atrial appendage flow velocity (LAAFV) and presence of spontaneous echo contrast (SEC) have been reported to be predictors of thromboembolism in atrial fibrillation (AF) patients. Galectin-3 is a biomarker reflecting pro-inflammatory status, whose role in AF has recently drawn attention, particularly in persistent AF population.

AIM

In this study we aimed to investigate the association between serum galectin-3 levels and echocardiographic predictors of thromboembolism in persistent AF patients.

METHODS

We included 65 persistent AF patients (55.50±10.67 years, 46.15% male). Transesophageal echocardiography (TEE) was performed to assess LAAFV and presence of left atrial (LA)/LA appendage (LAA)-located SEC and thrombus prior to direct current cardioversion or catheter ablation for AF.

RESULTS

Median galectin-3 level was 0.63 ng/mL. Serum galectin-3 levels were significantly correlated with LAAFV (r=-.440, P<.001). Serum galectin-3 levels were associated with presence of SEC (P<.001), and LA thrombus (P=.008). Receiver operating characteristic analysis revealed that a serum galectin-3 greater or equal to the cut-off value of 0.69 predicted presence of SEC with a sensitivity and specificity of 91.00% and 79.00%, respectively (P<.001).

CONCLUSION

In conclusion, in the setting of persistent AF, serum galectin-3 levels are associated with presence of SEC and LAAFV on TEE. Our findings suggest that serum galectin-3 level may have a place in thromboembolism risk stratification in persistent AF patients.

Galectin-3 as a marker of interstitial atrial remodelling involved in atrial fibrillation

Remodelling in the atria could appear as a result of hypertension, diabetes or ischaemic heart disease. Galectin-3 (Gal-3) is a mediator of profibrotic pathways and a potential biomarker of cardiac remodelling. We prospectively recruited consecutive patients undergoing elective cardiac surgery. Preoperative Gal-3 levels were determined from serum samples, and the presence of fibrosis was assessed from atrial appendage tissue samples obtained during cardiac surgery. We included 100 patients with aortic valve or ischaemic heart diseases and 15 controls with permanent AF. Gal-3 levels were associated with sex, left atrial volume, previous cardiac disease, diabetes mellitus, hypertension, NYHA and NT-proBNP. We observed differences in serum Gal-3 concentrations between patients and controls with permanent AF (p = 0.020). We performed ROC curves related to fibrosis and established a cutoff point for Gal-3 >13.65 ng/ml. Multivariate analyses showed previous cardiac disease, NYHA scale and high Gal-3 to be independent predictors of fibrosis. After adjustment for confounding factors, atrial fibrosis remained the only independent factor for the development of AF (p = 0.022). High Gal-3 serum levels predict fibrosis of the atrial appendage. NYHA scale and previous cardiac disease were also associated with tissue fibrosis in patients undergoing surgery. Atrial fibrosis was the only independent predictor for post-operative AF occurrence in our model after correcting for confounding factors.

Electrocardiographic and Echocardiographic predictors of paroxysmal atrial fibrillation detected after ischemic stroke

BACKGROUND

Detection of atrial fibrillation after ischemic stroke is challenging due to its paroxysmal nature. We aimed to assess predictors of paroxysmal atrial fibrillation using non-invasive surface ECG and transthoracic echocardiography to select candidates for atrial fibrillation screening.

METHODS

Ischemic stroke patients without documented atrial fibrillation (n = 110, 67 ± 10 years, 40 female) and a control group of age- and gender-matched patients with history of paroxysmal atrial fibrillation prior to stroke (n = 55, 67 ± 10 years, 19 female) comprised the study sample. Using non-invasive ECG monitoring for three weeks, short episodes of paroxysmal atrial fibrillation were detected in 24 of 110 patients (22 %). The standard 12-lead ECG with sinus rhythm at stroke onset was digitally processed and analyzed. Transthoracic echocardiography data were reviewed for these patients.

RESULTS

Atrial fibrillation history was independently associated with P terminal force in lead V 1 > 40 mm*ms (OR 4.04 95 % CI 1.34-12.14, p = 0.013) and left atrial volume index (OR 1.08 95 % CI 1.03-1.13, p = 0.002; for LAVI > 40 mL/m² OR 6.40 95 % CL 1.47-27.91, p = 0.013). Among patients without atrial fibrillation history, no ECG characteristics were predictive of atrial fibrillation detected after stroke. Left atrial volume index remained an independent predictor of atrial fibrillation detected after stroke (OR 1.09 95 % CI 1.02-1.16, p = 0.017). A cutoff of <40 mL/m² had an 84 % negative predictive value for ruling out atrial fibrillation on ambulatory monitoring with a sensitivity of 50 % and a specificity of 86 %.

CONCLUSION

In a post hoc analysis, left atrial dilatation assessed by left atrial volume index independently predicted atrial fibrillation after stroke in patients without prior atrial fibrillation history, while the other clinical or ECG markers were not predictive of atrial fibrillation detected early after ischemic stroke.

TRIAL REGISTRATION

This study is a post hoc analysis from the prospective case-control study registered in December 2011, ClinicalTrials.gov ID: NCT01325545 .