Association of dietary and gut microbiota-related metabolites with calcific aortic stenosis.

BACKGROUND: Histopathological changes in calcific aortic stenosis (CAS) resemble changes in coronary atherosclerosis. Concerning recent evidence on dietary and gut microbiota-related metabolites representing players in atherosclerosis, we aimed to investigate the link between dietary and gut microbiota-derived metabolites and CAS. METHODS: We consecutively recruited eligible subjects with moderate-severe CAS (n = 60), aortic sclerosis (ASc) (n = 49) and age and gender-matched control subjects (n = 48) in May 2016-December 2016. Plasma dietary and gut microbiota-related metabolite levels, namely choline, betaine, and trimethylamine N-oxide (TMAO), were measured using ultra-performance liquid chromatography-tandem mass spectroscopy method. Histopathological examinations were performed in patients that underwent aortic valve surgery. RESULTS: Prevalence of traditional cardiovascular risk factors or co-morbidities did not differ among groups (all p > 0.05). CAS patients had higher plasma choline levels compared to both control (p < 0.001) and ASc (p = 0.006). Plasma betaine and TMAO levels were similar (both p > 0.05). Compared to the lowest quartile choline levels (<11.15 µM), patients with the highest quartile choline levels (≥14.98 µM) had higher aortic valvular (p < 0.001) and mitral annular (p = 0.013) calcification scores. Plasma choline levels were independently associated with aortic peak flow velocity (B ± SE:0.165 ± 0.060, p = 0.009). Choline levels were elevated in subjects who had aortic valves with denser lymphocyte infiltration (p < 0.001), neovascularization (p = 0.011), osseous metaplasia (p = 0.004), more severe tissue remodelling (p = 0.002) and calcification (p = 0.002). CONCLUSION: We found a significant association between choline levels and CAS presence and severity depicted on imaging modalities and histopathological examinations. Our study may open new horizons for prevention of CAS.

Cholesterol efflux promoting function of high-density lipoproteins in calcific aortic valve stenosis.

Background and aims: Cholesterol efflux capacity is a functional property of high-density lipoproteins (HDL) reflecting the efficiency of the atheroprotective reverse cholesterol transport process in humans. Its relationship with calcific aortic valve stenosis (CAVS) has not been fully assessed yet. Methods: We evaluated HDL-CEC in a patient population with varying degrees of aortic valvular calcific disease, assessed using echocardiography and cardiac computed tomography. Measurement of biomarkers that reflect osteogenic and tissue remodeling, along with dietary and gut microbiota-derived metabolites were performed. Results: Patients with moderate-severe CAVS had significantly lower HDL-CEC compared to both control and aortic sclerosis subjects (mean: 6.09%, 7.32% and 7.26%, respectively). HDL-CEC displayed negative correlations with peak aortic jet velocity and aortic valve calcium score, indexes of CAVS severity (ρ = -0.298, p = 0.002 and ρ = -0.358, p = 0.005, respectively). In multivariable regression model, HDL-CEC had independent association with aortic valve calcium score (B: -0.053, SE: 0.014, p < 0.001), GFR (B: -0.034, SE: 0.012, p = 0.007), as well as with levels of total cholesterol (B: 0.018, SE: 0.005, p = 0.002). Conclusion: These results indicate an impairment of HDL-CEC in moderate-severe CAVS and may contribute to identify potential novel targets for CAVS management.

Serum galectin-3 level predicts early recurrence following successful direct-current cardioversion in persistent atrial fibrillation patients.

OBJECTIVE: Atrial structural remodeling has been suggested to contribute to atrial fibrillation (AF) recurrence following direct-current cardioversion (DCCV). The role of several inflammatory and extracellular matrix turnover markers in AF recurrence following DCCV has been investigated. However, data on the impact of galectin-3, which is known to play a role in various fibrotic conditions, including cardiac fibrosis are lacking. The aim of this study was to demonstrate the predictive role of serum galectin-3 levels in AF recurrence following successful DCCV. METHODS: A total of 90 persistent AF patients who were sche-duled for DCCV were prospectively enrolled. Serum samples were assayed to determine pre-DCCV galectin-3 levels using the enzyme-linked immunosorbent assay method. Patients were followed up for 3 months for AF recurrence. RESULTS: Of 90 persistent AF patients (mean age: 55.33±7.94 years; 53.33% male) who underwent successful DCCV, 28 (31.11%) experienced early AF recurrence within 3 months. Patients with AF recurrence had a greater left atrial volume index (LAVI) (33.35±2.45 mL/m2 vs. 29.21±3.08 mL/m2; p<0.001) and serum galectin-3 levels were higher (0.88 ng/mL [min-max: 0.52-1.32] vs. 0.60 ng/mL [min-max: 0.38-0.91]; p<0.001). In multivariate analysis, the number of DCCV attempts (hazard ratio [HR]: 1.879, 95% confidence interval [CI]: 1.052-3.355; p=0.033), LAVI (HR: 1.180, 95% CI: 1.028-1.354; p=0.018), and serum galectin-3 level (HR: 11.933, 95% CI: 1.220-116.701; p=0.033) were found to be independently associated with early AF recurrence following successful DCCV. CONCLUSION: Circulating levels of galectin-3 may have an association with early AF recurrence following DCCV.

The association between serum angiogenin and osteopontin levels and coronary collateral circulation in patients with chronic total occlusion.

OBJECTIVE: A well-developed coronary collateral circulation lowers both in-hospital and long-term morbidity and mortality limiting the infarct. Angiogenin (AGN) and osteopontin (OPN) are known to be potent inducers of angiogenesis. The aim of the present study was to investigate the relationship between serum ANG and OPN levels and collateral filling grade in subjects with stable coronary artery disease (SCAD). METHODS: A total of 122 age- and gender-matched consecutive patients who were found to have total occlusion (n=70) and no significant stenosis in epicardial coronary arteries (n=52) who underwent coronary angiography due to SCAD between January 2015 and July 2017 were included in the study. AGN and OPN levels were measured using enzyme linked immunosorbent assay. Coronary collateral circulation was graded using Rentrop's classification of collateral filling. RESULTS: A total of 52 patients (61.60±11.78 years, 61.5% male) without significant epicardial coronary artery stenosis and 70 patients (62.87±8.24 years, 65.7% male) with totally occluded coronary arteries were included in the study. Subjects with total occlusion had significantly higher levels of AGN [122.00 (79.00-623.00) pg/mL vs. 98.00 (18.00-160.00) pg/mL, p<0.001] and OPN [1863.50 (125.00-6500.00) pg/mL vs. 451.00 (112.00- 1850.00) pg/mL, p<0.001] than those without significant stenosis. In addition, AGN [127.00 (87.00-623.00) pg/mL vs. 110.00 (79.00-188.00) pg/mL, p=0.011] and OPN [2681.00 (126.00-6500.00) pg/mL vs. 649.00 (125.00-4255.00) pg/mL, p=0.001] levels were significantly higher in patients with better developed collaterals. Serum AGN and OPN levels were found to be significantly associated with coronary collateral development. CONCLUSION: AGN and OPN are associated with better developed coronary collateral circulation and may have therapeutic implications for the promotion of coronary collateral development.

Cancer associated fibroblasts sculpt tumour microenvironment by recruiting monocytes and inducing immunosuppressive PD-1+ TAMs.

Fibroblasts turn into cancer associated fibroblasts (CAFs) in the tumour microenvironment. CAFs have recently attracted attention for their function as a regulator of immune cell recruitment and function in addition to their tumour-promoting roles. In this study, we aimed to determine the role of CAFs on monocyte recruitment and macrophage polarization in breast cancer. CAFs, which were α-SMA expressing fibroblasts in contrast to normal fibroblasts (NFs), effectively recruited monocytes. Recruitment of monocytes by CAFs might be mediated by monocyte chemotactic protein-1 (MCP-1) as well as stromal cell-derived factor-1 (SDF-1) cytokines. CAFs differentiated the recruited monocytes into M2-like macrophages which are capable of exerting their immunosuppressive roles via the PD-1 axis. CAF-educated monocytes exhibited strong immune suppression unlike NF-educated monocytes and enhanced the motility/invasion of breast cancer cells in addition to increasing the expressions of epithelial-mesenchymal transition (EMT)-related genes and vimentin protein in cancer cells. CAF-educated M1 macrophages displayed increased expression of M2 markers and production of anti-inflammatory cytokine IL-10 in contrast to decreased production of pro-inflammatory cytokine IL-12 compared with control M1 macrophages; suggesting that CAFs were also able to induce the trans-differentiation of M1 macrophages to M2 macrophages. We then investigated the relationship between the infiltration of CAFs and tumour associated macrophages (TAMs) using tissue samples obtained from breast cancer patients. High grade of CAFs significantly correlated with the number of TAMs in human breast cancer tissue samples. It was also associated with higher Ki-67 proliferation index, and higher tumour volume. This result is in line with our finding of increased breast cancer cell proliferation due to the effects of CAF-educated monocytes in vitro. Our results concluded that CAFs play pivotal roles in sculpturing the tumour microenvironment in breast cancer, and therapeutic strategies to reverse the CAF-mediated immunosuppressive microenvironment should be taken into consideration.

Platelet Toll-like receptor and its ligand HMGB-1 expression is increased in the left atrium of atrial fibrillation patients.

BACKGROUND: Atrial fibrillation(AF) is the most common sustained arrhythmia. Its most feared sequelae are stroke and peripheral thromboembolism due to atrial thrombi formation. Mechanisms underlying the relationship between platelet activation and left atrial thrombi have not been clearly elucidated yet. We aimed to investigate whether immune-mediated platelet activation occurred in AF patients in this cross-sectional study. METHODS: Persistent and paroxysmal AF patients who underwent cryoballoon-based AF ablation between March 2015 and July 2016 were included as the patient group. Patients without AF in whom transseptal puncture was performed at the same period for purposes other than AF ablation were included as the control group. Peripheral and left atrial blood samples were obtained for determination of platelet Toll-like receptor(TLR)-2, TLR-4 and high mobility group box-1(HMGB-1) expression levels. RESULTS: A total of 75 subjects (53 patients with AF and 22 control subjects) [mean: 60.33 (SD: 6.14) years, 57.33% male] were included. Left atrial and peripheral TLR-2, 4 and HMGB-1 expression levels were significantly higher in the patient group when compared to the controls. Left atrial platelet TLR-2 and TLR-4 expression and serum HMGB-1 levels were higher in persistent AF patients compared to paroxysmal AF patients. In the patient group, left atrial expression of TLR-2, 4 and HMGB-1 were significantly higher than the peripheral expression levels. CONCLUSION: Findings of our study suggest evidence for immune-mediated platelet activation in the left atria of AF patients.

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.

Investigation of hemophagocytic lymphohistiocytosis in severe sepsis patients.

PURPOSE: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition characterized by uncontrolled inflammation and has common clinical and laboratory features with sepsis. The aim of this study was to investigate patients treated with severe sepsis who had bicytopenia for the presence of HLH. MATERIALS AND METHODS: Patients with severe sepsis who were non-responsive to treatment and developed at least bicytopenia were included. Peripheral blood samples were collected and stored for later evaluation for natural killer (NK) activity and soluble interleukin-2 receptor levels. Diagnostic criteria of HLH were retrospectively analyzed. RESULTS: Seventy-five of 382 patients (20%) were followed as severe sepsis and septic shock. Among them, 40 patients had bicytopenia. Twenty-six of 40 patients were excluded due to the presence of active solid or hematological malignancies. Three patients died before fulfillment of HLH criteria and one patient denied to give consent. All of the remaining 10 patients had at least five of the eight criteria according to criteria of the Histiocyte Society. Only one of 10 patients was diagnosed as HLH and received treatment during intensive care unit stay. None of the 10 patients survived. CONCLUSIONS: This study emphasizes to consider the possibility of HLH and the need of rapid assessment of patients with severe sepsis who had bicytopenia and were resistant to treatment in intensive care.

Monocyte Toll-Like Receptor Expression in Patients With Atrial Fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia. Inflammation has been suggested to play a vital role in the pathogenesis. Previous studies have investigated expression of inflammatory markers in AF. Several studies have focused on the effects of toll-like receptors (TLRs) on heart in terms of capability of modulating inflammation. In this study, we aimed to investigate whether peripheral monocyte TLR expression was associated with the AF presence, and recurrence of AF after cryoablation, as a reflection of inflammatory status. Patients with AF who were scheduled for cryoballoon-based ablation for AF and age- and gender-matched subjects in sinus rhythm were included. Peripheral monocyte TLR-2 and TLR-4 expressions were evaluated by flow cytometric analysis in peripheral venous blood samples obtained during evaluation in outpatient clinics: 172 patients (56.5 ± 6.6 years, 52.3% men) were included in the study. Peripheral monocyte TLR-2 and TLR-4 expression levels were significantly higher in patients with AF (p <0.05). Among patients with AF, 12 patients (14.0%) developed AF recurrence at a follow- up of 17 months. Multivariate Cox regression analysis showed that left atrial volume index (hazard ratio 2.040, 95% CI 1.197 to 3.477, p = 0.009) and monocyte TLR-4 expression (hazard ratio 1.226, 95% CI 1.042 to 1.443, p = 0.014) were independent predictors of AF recurrence after blanking period following second-generation cryoballoon-based pulmonary vein isolation for paroxysmal AF. In conclusion, our study highlights the role of TLR-mediated inflammation in the pathogenesis of AF. This link may also constitute a therapeutic target in patients with AF.

Elevated Serum Beta-Trace Protein Levels are Associated With the Presence of Atrial Fibrillation in Hypertension Patients.

Beta-trace protein (BTP) has emerged as a novel biomarker of cardiovascular risk. In this study, the authors aimed to assess the relationship between BTP levels and presence of atrial fibrillation in patients who had controlled hypertension (HTN) and normal renal function. A total of 80 controlled HTN patients with paroxysmal atrial fibrillation (PAF) and 80 age- and sex-matched controls with controlled HTN were enrolled. Serum BTP levels were measured by enzyme-linked immunosorbent assay. BTP levels were found to be significantly higher in patients with PAF (P<.001). Other parameters including mean systolic and diastolic blood pressure values, serum creatinine levels, and glomerular filtration rate were similar between the two groups. Along with left atrial diameter (odds ratio, 1.504; P<.001), BTP levels (odds ratio, 1.015; P<.001) were independently associated with the presence of PAF. BTP levels were increased in controlled HTN patients with PAF compared with controls, and this association was observed within normal renal functions as reflected by normal glomerular filtration rate.

Enhanced Platelet Toll-like Receptor 2 and 4 Expression in Acute Coronary Syndrome and Stable Angina Pectoris.

Evidence is accumulating that toll-like receptors (TLR) are involved in the initiation and progression of cardiovascular disease. Enhanced expression of these receptors on monocytes has been shown in patients with acute coronary syndrome (ACS). However, expression on platelets in this group of patients has not been evaluated yet. We aimed to demonstrate the possible relationship of platelet TLR-2 and TLR-4 expressions with stable coronary artery disease and ACS pathogenesis. In this observational case-control study, 40 patients diagnosed with ACS (unstable angina pectoris, non-ST-segment elevation and ST-segment elevation ACS), 40 patients diagnosed with stable coronary artery disease, and 40 age- and gender-matched subjects with normal coronary arteries were involved. Platelet TLR-2 and TLR-4 expressions were evaluated by flow cytometry in peripheral venous blood samples obtained before coronary angiography. A total of 120 patients (60.7 ± 12.3 years, 50% men) were included. Median platelet TLR-2 and TLR-4 expressions were greater in patients with ACS compared to those with stable angina pectoris and normal coronary arteries (29.5% vs 10.5% vs 3.0%, p <0.001 and 40.5% vs 11.5% vs 3.0%, p <0.001, respectively). Median platelet TLR-2 and TLR-4 expressions were also greater in patients with stable angina pectoris compared to those with normal coronary arteries (p <0.05). In conclusion, this is the first study demonstrating enhanced TLR-2 and TLR-4 expressions on platelets in patients with ACS. These findings may suggest that platelet TLR expression as a novel potential prophylactic and therapeutic target in ACS.

Cancer associated fibroblasts have phenotypic and functional characteristics similar to the fibrocytes that represent a novel MDSC subset.

Circulating fibrocytes were reported to represent a novel myeloid-derived suppressor cell (MDSC) subset and they were also proposed to be involved in the tumor immune escape. This novel fibrocyte subset had a surface phenotype resembling non-monocytic MDSCs (CD14-CD11chiCD123-) and exhibited immunomodulatory roles. Most effector functions of fibrocytes (circulating fibroblast-progenitors) are accomplished as tissue fibroblasts, likewise in the tumor microenvironment. Therefore, fibroblasts at tumor tissues should be evaluated whether they display similar molecular/gene expression patterns and functional roles to the blood-borne fibrocytes. A chemically induced rat breast carcinogenesis model was utilized to obtain cancer associated fibroblasts (CAFs). CAFs and normal tissue fibroblasts (NFs) were isolated from cancerous and healthy breast tissues, respectively, using a previously described enzymatic protocol. Both CAFs and NFs were analyzed for cell surface phenotypes by flow cytometry and for gene expression profiles by gene set enrichment analysis (GSEA). PBMCs were cocultured with either NFs or CAFs and proliferations of PBMCs were assessed by CFSE assays. Morphological analyses were performed by immunocytochemistry stainings with vimentin. CAFs were spindle shaped cells unlike their blood-borne counterparts. They did not express CD80 and their MHC-II expression was lower than NFs. Although CAFs expressed the myeloid marker CD11b/c, its expression was lower than that on the circulating fibrocytes. CAFs did not express granulocytic/neutrophilic markers and they seemed to have developed in an environment containing THELPER2-like cytokines. They also showed immunosuppressive effects similar to their blood-borne counterparts. In summary, CAFs showed similar phenotypic and functional characteristics to the circulating fibrocytes that were reported to represent a unique MDSC subset.

CXCL7-induced macrophage infiltration in lung tumor is independent of CXCR2 expression: CXCL7-induced macrophage chemotaxis in LLC tumors.

Chemokines play diverse roles in modulating the immune response during tumor development. Levels of CXC chemokine ligand 7 (CXCL7) protein vary during tumorigenesis, and the evidence suggests that this chemokine serves as a novel biomarker of early-stage lung cancer. We investigated the effect of CXCL7 gene expression on the infiltration of myeloid cells into the tumor microenvironment in Lewis lung carcinoma (LLC). Tumors established from LLC cells overexpressing CXCL7 (CXCL7-LLC tumors) increased the infiltration of CD206(+) M2 macrophages at the early stages of tumorigenesis. This infiltration was independent of CXCR2 expression on either tumor cells or macrophages. CXCL7-LLC tumors developed faster than control-LLC tumors (IRES-LLC tumor) did. The extent of CD4(+) T cell, CD8(+) T cell, and natural killer T cell infiltration was similar between the two tumor groups. Our findings suggest that CXCL7 attracts macrophages especially at the tumor site and may accelerate lung tumor development in the early stages.

Granulocytic subset of myeloid derived suppressor cells in rats with mammary carcinoma.

Limited knowledge is available on myeloid derived suppressor cells (MDSCs) of rat origin. We examined the myeloid cells from peripheral blood, bone marrow and spleens of healthy and mammary tumor bearing rats employing a novel immunophenotyping strategy with CD172a, HIS48, and Rp-1 antibodies. We addressed rat granulocytes by Rp-1 positivity and used HIS48 in discrimination of two mononuclear cell subsets. An expansion of granulocyte numbers was detected in peripheral blood and spleens of mammary tumor-bearing animals. The purified granulocytes were able to impair antigen-specific helper T-cell proliferation, and therefore nominated as granulocytic MDSCs of this rat tumor model. HIS48(+) mononuclear cell numbers were also increased in the blood and spleens of mammary tumor bearing rats with a lower MHC class II positivity. Despite the lack of an antigen specific suppression of CD4(+) T cells, HIS48(+) monocytes resemble monocytic MDSCs with their inflammatory phenotype. Together, these results provide evidence for the existence and phenotypic characterization of a granulocytic MDSC subset in a rat model of mammary carcinoma.

Cardiac Autoantibody Levels Predict Recurrence Following Cryoballoon-Based Pulmonary Vein Isolation in Paroxysmal Atrial Fibrillation Patients.

INTRODUCTION: Recent evidence has suggested that autoantibodies may play an important role in the development of atrial fibrillation (AF). The predictive value of preprocedural autoantibodies against beta-1 adrenergic receptor (anti-ß1-R) and M2-muscarinic acetylcholine receptor (anti-M2-R) for AF recurrence following cryoballoon-based pulmonary vein isolation (PVI) is still unclear. We aimed to determine the predictive value of preprocedural anti-ß1-R and anti-M2-R levels for AF recurrence. METHODS: Eighty patients (mean age 54.25 ± 7.70 years; 40% female) with paroxysmal AF and preserved left ventricular function who underwent cryoballoon-based PVI were included in the study. Preprocedural anti-M2-R and anti-ß1-R levels were measured with ELISA. RESULTS: At 1-year follow-up after ablation, late AF recurrence was observed in 17 (21.25%) patients. In the Cox regression model, including number of antiarrhythmic drugs, early AF recurrence, anti-ß1-R levels >159.88 ng/mL, anti-M2-R levels >277.65 ng/mL, AF duration, and left atrial volume index, only anti-ß1-R levels >159.88 ng/mL (HR: 4.281, P = 0.039) and anti-M2-R levels >277.65 ng/mL (HR: 4.313, P = 0.030) were found to be independent predictors of late AF recurrence. Anti-ß1-R level >159.88 ng/mL was shown to predict late AF recurrence with a sensitivity of 70.59% and specificity of 90.48%. A cut-off value of 277.65 ng/mL for anti-M2-R level predicted AF recurrence with a sensitivity of 70.59% and specificity of 95.24%. CONCLUSION: Preprocedural serum anti-ß1-R and anti-M2-R levels are independent predictors of late AF recurrence following cryoballoon-based PVI in paroxysmal AF patients. Detection of preprocedural anti-ß1-R and anti-M2-R levels may serve as a novel method for determination of paroxysmal AF patients who may not benefit from cryoballoon-based PVI.

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

INTRODUCTION: Left atrial (LA) interstitial fibrosis is known to have a role in the initiation and maintenance of atrial fibrillation (AF). The role of galectin-3 in the pathogenesis of cardiac fibrosis has been demonstrated in previous studies. We aimed to determine whether serum galectin-3 level is associated with markers of atrial remodeling, including the extent of LA fibrosis detected by delayed enhancement magnetic resonance imaging (DE-MRI) and atrial electromechanical delay (AEMD) in paroxysmal AF patients with preserved left ventricular (LV) functions. METHODS AND RESULTS: Thirty-three patients (58 [28-74] years, 51.5% male) with paroxysmal AF who underwent DE-MRI prior to cryoballoon-based AF ablation were included in the study. Serum galectin-3 levels were measured with ELISA. LA volume index (B ± SE: 0.424 ± 0.504, 95% CI: 0.560-2.627, P = 0.004) and serum galectin-3 levels (B ± SE: 0.549 ± 7.745, 95% CI: 16.874-47.550, P < 0.001) were found to be independently correlated with extent of LA fibrosis detected with DE-MRI in paroxysmal AF patients with preserved LV function. Correlation analysis between AEMD parameters and baseline characteristics showed that galectin-3 was significantly correlated with intra-left (ρ = 0.432, P = 0.012) and inter-AEMD (ρ = 0.395, P = 0.023). Duration of AF, LAD, and extent of LA fibrosis were also found to be significantly correlated with AEMD parameters. CONCLUSION: This is a hypothesis-generating study pointing out that serum galectin-3 level is significantly associated with atrial remodeling in paroxysmal AF patients with preserved LV function. Further studies are necessary to provide exact pathophysiological mechanisms.

Effects of persistent atrial fibrillation on serum galectin-3 levels.

Galectin-3 is known to play an important role in a number of fibrotic conditions, including cardiac fibrosis. Many studies have focused on the association between galectin-3 levels and cardiac fibrosis in heart failure. However, the role of galectin-3 in the pathogenesis of atrial fibrillation (AF) has not been evaluated thoroughly yet. The aim of this study was to determine whether serum galectin-3 levels were elevated in patients with AF and preserved left ventricular function. Seventy-six patients with paroxysmal or persistent AF and preserved left ventricular systolic function and 75 age- and gender-matched control subjects were enrolled in this observational study. Galectin-3 levels were measured by enzyme-linked immunosorbent assay. Serum galectin-3 (median 0.6 ng/ml [interquartile range 0.2 to 1.4] vs 0.5 ng/ml [interquartile range 0.1 to 0.7], p <0.001) and left atrial volume index (LAVI) (mean 29.5 ± 3.5 vs 26.5 ± 2.5 ml/m(2), p <0.001) were significantly greater in patients with AF compared with the control group. Serum galectin-3 levels were also significantly higher in patients with persistent AF than those with paroxysmal AF (median 0.8 ng/ml [interquartile range 0.4 to 1.4] vs 0.5 ng/ml [interquartile range 0.2 to 0.9], p <0.001). Multivariate regression analysis demonstrated that serum galectin-3 (odds ratio 87.53, 95% confidence interval 6.06 to 1,265.03, p = 0.001) and LAVI (odds ratio 1.38, 95% confidence interval 1.19 to 1.60, p <0.001) were independent predictors of AF. Only LAVI was independently correlated with serum galectin-3 levels in patients with AF in linear regression analysis. In conclusion, serum galectin-3 is significantly elevated and is also significantly correlated with LAVI in patients with AF with preserved left ventricular function.

M2-muscarinic acetylcholine receptor autoantibody levels predict left atrial fibrosis severity in paroxysmal lone atrial fibrillation patients undergoing cryoablation.

AIMS: Atrial fibrosis has been found to be associated with recurrent atrial fibrillation (AF) following catheter ablation. Autoantibodies against M2-muscarinic receptors (anti-M2-R) may play a role in the development of AF by inducing left atrial (LA) fibrosis. In this study, we aim to compare anti-M2-R levels between paroxysmal lone AF patients and healthy control subjects and to investigate the relationship between pre-ablation anti-M2-R level, LA fibrosis quantified by delayed enhancement magnetic resonance imaging (DE-MRI), and AF recurrence following cryoablation. METHODS AND RESULTS: Thirty-one patients with paroxysmal lone AF (53.4 ± 8.0 years, 61% male), who underwent cryoballoon-based ablation, along with 31 healthy control subjects were included. Enzyme-linked immunosorbent assay tests to measure serum anti-M2-R levels were performed in both groups and DE-MRI was done to quantify LA fibrosis prior to the ablation in the patients. Anti-M2-R levels were higher in the study population when compared with control subjects [212.4 (103.2-655.5) vs. 73.0 (39.5-299.1) ng/mL, P < 0.001]. Anti-M2-R level predicted moderate-extensive LA fibrosis independent of other measures [odds ratio: 1.26 (95% confidence interval (CI): 1.04-1.53), P = 0.017]. At a mean follow-up of 35.2 ± 3.5 months, nine patients (29.0%) had AF recurrence. In the Cox regression model including pre-ablation anti-M2-R level, LA diameter, LA volume index, and moderate-extensive LA fibrosis, only moderate-extensive LA fibrosis predicted late AF recurrence independent of other measures [hazard ratio: 29.41 (95% CI: 3.52-250.00), P = 0.002]. CONCLUSION: Serum anti-M2-R levels may be associated with the severity of LA fibrosis and may be implicated in the pathophysiology of AF recurrence following cryoablation. Detection of anti-M2-R levels may help select appropriate patients for the procedure.

Elevated M2-muscarinic and ß1-adrenergic receptor autoantibody levels are associated with paroxysmal atrial fibrillation.

BACKGROUND: Pathophysiologic mechanisms underlying lone atrial fibrillation (AF) have not been clearly demonstrated yet. Emerging evidence has indicated that autoimmunity may play a role in the development of AF. Relationship between serum anti-M2-muscarinic receptor autoantibody (anti-M2-R) and anti-ß1-adrenergic receptor autoantibody (anti-ß1-R) levels and lone paroxysmal atrial fibrillation (PAF) has not been investigated. We aimed to compare anti-M2-R and anti-ß1-R levels between lone PAF patients and healthy control subjects. METHODS AND RESULTS: 75 patients with lone PAF (age: 52.80 ± 6.80 years, 53 % male) and 75 healthy control subjects (age: 53.30 ± 6.80 years, 54 % male) were enrolled in the study. Serum anti-M2-R and anti-ß1-R levels were measured by ELISA and compared between two groups. Anti-M2-R [142.30 (77.65-400.00) vs. 69.00 (39.48-299.04) ng/mL; p < 0.001) and anti-ß1-R [102.56 (65.18-348.41) vs. 44.17 (30.89-158.54) ng/mL; p < 0.001] levels were significantly higher in patients with lone PAF compared to healthy controls. Multivariate regression analysis showed that left atrial diameter (OR: 1.471, p < 0.001), hs-CRP(OR: 1.940, p < 0.001), anti-M2-R (OR: 1.158, p < 0.001) and anti-ß1-R (OR: 1.296, p < 0.001) levels were independent predictors for the presence of lone PAF. Using a cut-off level of 101.83 ng/mL, anti-M2-R levels predicted presence of lone PAF with a sensitivity of 94.68 % and specificity of 81.33 %. Anti-ß1-R levels predicted presence of lone PAF with a sensitivity of 92.00 % and specificity of 73.30 %, using a cut-off level of 72.16 ng/mL. CONCLUSION: Our results demonstrated that higher serum anti-M2-R and anti-ß1-R levels are associated with lone PAF. Autoantibodies related to autonomic system may play an important role in the development of lone AF.