Predictive value of pre-procedural autoantibodies against M2-muscarinic acetylcholine receptor for recurrence of atrial fibrillation one year after radiofrequency catheter ablation

Pre-procedural TMAO as a predictor for recurrence of atrial fibrillation after catheter ablation

BACKGROUND

Numerous studies have demonstrated the significance of trimethylamine-N-oxide (TMAO) in the progression of atrial fibrillation (AF). However, the association between TMAO and AF recurrence (RAF) post-catheter ablation is not yet fully understood. This study aims to elucidate the predictive capability of pre-procedural TMAO levels in determining RAF following catheter ablation (CA).

METHODS

This study was conducted as a prospective, single-center observational study. Between June 2021 and June 2022, 152 patients from the Department of Cardiology at The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University were enrolled. Baseline characteristics and serum TMAO levels were assessed for all participants. Patients with AF who underwent CA were monitored for recurrences of AF using electrocardiography (ECG) or 24-hour Holter monitoring during the follow-up period.

RESULTS

The study found that serum TMAO levels were significantly higher in persistent AF (PeAF) patients compared to those in sinus rhythm (SR) and paroxysmal AF (PaAF) patients (3.96 ± 1.69 vs. 1.81 ± 0.59, 3.02 ± 1.50 µM, P < 0.001 and P < 0.01, respectively). After a one-year follow-up, 29 (21.2%) AF patients experienced recurrence after CA. Multivariate Cox proportional hazards regression analysis revealed that pre-procedural serum TMAO was an independent predictor of recurrent AF (HR = 1.78, 95% CI = 1.43-2.21, P < 0.001). The receiver operating characteristic (ROC) curve analysis identified a cut-off value of 4.3µM for serum TMAO levels in predicting recurrent AF (area under the curve: 0.835, P < 0.001). The Kaplan-Meier plot demonstrated that patients with TMAO levels greater than 4.3µM had a significantly higher rate of recurrent AF (HR = 13.53, 95% CI = 6.19-29.56, P < 0.001).

CONCLUSION

Patients with AF exhibited elevated levels of circulating TMAO compared to patients with SR. The findings suggest a potential role of TMAO in the development of AF, with pre-procedural serum TMAO levels serving as a reliable predictor of recurrence of AF CA.

A novel nomogram for predicting the recurrence of atrial fibrillation in patients treated with first-time radiofrequency catheter ablation for atrial fibrillation

Introduction

The purpose of this study was to investigate the predictive factors of atrial fibrillation (AF) recurrence in patients after first-time radiofrequency catheter ablation (RFCA) and to develop a nomogram predictive model that can provide valuable information for determining the ablation strategy.

Methods

In total, 500 patients who had received first-time RFCA for AF were retrospectively enrolled in the study. The patients were divided into a training cohort (n = 300) and a validation cohort (n = 200) randomly at a 6:4 ratio. Lasso and multivariate logistic regression analyses were used to screen the predictors for AF recurrence during a 2-year follow-up. The C-index and a calibration plot were used to detect the discriminative ability and calibration of the nomogram. The performance of the nomogram was assessed compared with the APPLE score, CAAP-AF score, and MB-LATER score using the receiver operating characteristic (ROC) curve, decision curve analysis (DCA), integrated discrimination index (IDI), and net reclassification index (NRI).

Results

A total of 78 patients experienced the recurrence of AF after first-time RFCA in the training cohort. The six strongest predictors for AF recurrence in the training cohort were persistent AF, duration of AF, left atrial diameter (LAD), estimated glomerular filtration rate (eGFR), N-terminal pro-brain natriuretic peptide (NT-proBNP), and autoantibody against M2-muscarinic receptor (anti-M2-R). Based on the above six variables, a nomogram prediction model was constructed with a C-index of 0.862 (95% CI, 0.815-0.909), while the C-index was 0.831 (95% CI, 0.771-0.890) in the validation cohort. DCA showed that this nomogram had greater net benefits compared with other models. Furthermore, the nomogram showed a noticeable improvement in predictive performance, sensitivity, and reclassification for AF recurrence compared with the APPLE score, CAAP-AF score, or MB-LATER score.

Conclusion

We established a novel predictive tool for AF recurrence after the first-time RFCA during a 2-year follow-up period that could accurately predict individual AF recurrence.

Pathophysiology of Atrial Fibrillation and Approach to Therapy in Subjects Less than 60 Years Old

Atrial fibrillation (AF) is an arrhythmia that affects the left atrium, cardiac function, and the patients' survival rate. Due to empowered diagnostics, it has become increasingly recognized among young individuals as well, in whom it is influenced by a complex interplay of autoimmune, inflammatory, and electrophysiological mechanisms. Deepening our understanding of these mechanisms could contribute to improving AF management and treatment. Inflammation is a complexly regulated process, with interactions among various immune cell types, signaling molecules, and complement components. Addressing circulating antibodies and designing specific autoantibodies are promising therapeutic options. In cardiomyopathies or channelopathies, the first manifestation could be paroxysmal AF; persistent forms tend not to respond to antiarrhythmic drugs in these conditions. Further research, both in vitro and in vivo, on the use of genomic biotechnology could lead to new therapeutic approaches. Additional triggers that can be encountered in AF patients below 60 years of age are systemic hypertension, overweight, diabetes, and alcohol abuse. The aims of this review are to briefly report evidence from basic science and results of clinical studies that might explain the juvenile burden of the most encountered sustained supraventricular tachyarrhythmias in the general population.

Autoantibodies in Atrial Fibrillation-State of the Art

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia. To date, a lot of research has been conducted to investigate the underlying mechanisms of this disease at both molecular and cellular levels. There is increasing evidence suggesting that autoimmunity is an important factor in the initiation and perpetuation of AF. Autoantibodies are thought to play a pivotal role in the regulation of heart rhythm and the conduction system and, therefore, are associated with AF development. In this review, we have summarized current knowledge concerning the role of autoantibodies in AF development as well as their prognostic and predictive value in this disease. The establishment of the autoantibody profile of separate AF patient groups may appear to be crucial in terms of developing novel treatment approaches for those patients; however, the exact role of various autoantibodies in AF is still a matter of ongoing debate.

Targeting autonomic nervous system as a biomarker of well-ageing in the prevention of stroke

Stroke prediction is a key health issue for preventive medicine. Atrial fibrillation (AF) detection is well established and the importance of obstructive sleep apneas (OSA) has emerged in recent years. Although autonomic nervous system (ANS) appears strongly implicated in stroke occurrence, this factor is more rarely considered. However, the consequences of decreased parasympathetic activity explored in large cohort studies through measurement of ANS activity indicate that an ability to improve its activity level and equilibrium may prevent stroke. In support of these observations, a compensatory neurostimulation has already proved beneficial on endothelium function. The available data on stroke predictions from ANS is based on many long-term stroke cohorts. These data underline the need of repeated ANS evaluation for the general population, in a medical environment, and remotely by emerging telemedicine digital tools. This would help uncovering the reasons behind the ANS imbalance that would need to be medically adjusted to decrease the risk of stroke. This ANS unbalance help to draw attention on clinical or non-clinical evidence, disclosing the vascular risk, as ANS activity integrates the cumulated risk from many factors of which most are modifiable, such as metabolic inadaptation in diabetes and obesity, sleep ventilatory disorders, hypertension, inflammation, and lack of physical activity. Treating these factors may determine ANS recovery through the appropriate management of these conditions. Natural aging also decreases ANS activity. ANS recovery will decrease global circulating inflammation, which will reinforce endothelial function and thus protect the vessels and the associated organs. ANS is the whistle-blower of vascular risk and the actor of vascular health. Such as, ANS should be regularly checked to help draw attention on vascular risk and help follow the improvements in response to our interventions. While today prediction of stroke relies on classical cardiovascular risk factors, adding autonomic biomarkers as HRV parameters may significantly increase the prediction of stroke.

Urine Metabolites as a Predictor of Warfarin Response Based on INR in Atrial Fibrillation

Background:

Warfarin is an anticoagulant with wide inter-individual variations in drug responses monitored based on the International Normalized Ratio (INR). It is commonly prescribed for atrial fibrillation (AF) and stroke. Oral anticoagulants (e.g., warfarin) reduce the risk of getting a stroke but increase the risk of hemorrhage. The proton nuclear magnetic resonance (1H-NMR) pharmacometabonomics technique is useful for determining drug responses. Furthermore, pharmacometabonomics analysis can help identify novel biomarkers of warfarin outcome/INR stability in urine.

Objectives:

The focus of this research was to determine if urine metabolites could predict the warfarin response based on INR in patients who were already taking warfarin (identification; phase I) and to determine if urine metabolites could distinguish between unstable and stable INR in patients who had just started taking warfarin (validation; phase II).

Methods:

A cross-sectional study was conducted. Ninety urine samples were collected for phase 1, with 49 having unstable INR and 41 having stable INR. In phase II, 21 urine samples were obtained, with 13 having an unstable INR and eight having a stable INR. The metabolites associated with unstable INR and stable INR could be determined using univariate and multivariate logistic regression analysis.

Results:

Multivariate logistic regression (MVLR) analysis showed that unstable INR was linked with seven regions.

Discussion:

The urine pharmacometabonomics technique utilized could differentiate between the urine metabolite profiles of the patients on warfarin for INR stability.

Conclusion:

1H-NMR-based pharmacometabonomics can help lead to a more individualized, controlled side effect for warfarin, thus minimizing undesirable effects in the future.

The Role of Autoantibodies in Arrhythmogenesis

PURPOSE OF REVIEW

The role of autoantibodies in arrhythmogenesis has been the subject of research in recent times. This review focuses on the rapidly expanding field of autoantibody-mediated cardiac arrhythmias.

RECENT FINDINGS

Since the discovery of cardiac autoantibodies more than three decades ago, a great deal of effort has been devoted to understanding their contribution to arrhythmias. Different cardiac receptors and ion channels were identified as targets for autoantibodies, the binding of which either initiates a signaling cascade or serves as a biomarker of underlying remodeling process. Consequently, the wide spectrum of heart rhythm disturbances may emerge, ranging from atrial to ventricular arrhythmias as well as conduction diseases, irrespective of concomitant structural heart disease or manifest autoimmune disorder. The time has come to acknowledge autoimmune cardiac arrhythmias as a distinct disease entity. Establishing the autoantibody profile of patients will help to develop novel treatment approaches for patients.

Multiple Autoantibodies against Cardiovascular Receptors as Biomarkers in Hypertensive Heart Disease

OBJECTIVES

The pathogenesis of hypertensive heart disease (HHD) remains unclear, which might include autoimmunity. The aim of the present study was to determine whether a relationship exists between the presence of autoantibodies against β1, β2, α1 adrenoreceptors, M2-muscarinic receptors, angiotensin II type1 receptors and HHD.

METHODS

In the present study, 44 patients diagnosed with HHD, 36 patients with hypertension, and 40 controls were also enrolled. The measurement of these 5 autoantibodies was performed by enzyme-linked immunosorbent assay.

RESULTS

The frequencies of autoantibodies against β1, β2, α1 adrenoreceptors, autoantibodies against M2-muscarinic receptors and autoantibodies against angiotensin II type1 receptors were significantly higher in patients with HHD, when compared to patients with hypertension and normal controls (all p < 0.001). In addition, the titers of these 5 autoantibodies significantly increased in patients with HHD. Patients who were positive for all 5 autoantibodies had larger left ventricular end-diastolic diameter (60.5 ± 4.9 vs. 57.8 ± 5.0 vs. 52.5 ± 5.3 mm) and worse left ventricular ejection fraction (45.0 ± 11.0 vs. 56.6 ± 10.4 vs. 57.8 ± 5.3%), when compared to patients not positive for all the 5 autoantibodies and patients negative for all the 5 autoantibodies (χ2 = 9.524, p = 0.009 and χ2 = 7.689, p = 0.021). Furthermore, a significant positive correlation was observed between each 2 autoantibodies of these 5 autoantibodies (all p < 0.001).

CONCLUSION

Multiple autoantibodies of cardiovascular receptors may be involved in the pathogenesis and may be predictive factors of HHD.

Immunopathogenesis and biomarkers of recurrent atrial fibrillation following ablation therapy in patients with preexisting atrial fibrillation

INTRODUCTION

Recurrent atrial fibrillation (RAF) following ablation therapy occurs in about 50% of patients. The pathogenesis of RAF is unknown, but is believed to be driven by atrial remodeling in the setting of background inflammation. Structural, electrophysiological and mechanical remodeling has been associated with atrial fibrillation (AF). Inflammation and fibrotic remodeling are the major factors perpetuating AF, as mediators released from the atrial tissues and cardiomyocytes due to mechanical and surgical injury could initiate the inflammatory process. In this article, we have critically reviewed the key mediators that may serve as potential biomarkers to predict RAF. Areas covered: Damage associated molecular patterns, heat shock proteins, inflammatory cytokines, non-inflammatory markers, markers of inflammatory cell activity, and markers of collagen deposition and metabolism are evaluated as potential biomarkers with molecular treatment options in RAF. Expert commentary: Establishing biomarkers to predict RAF could be useful in reducing morbidity and mortality. Investigations into the role of DAMPs participating in a sterile immune response may provide greater insight into the pathogenesis of RAF. Markers evaluating immune cell activity, collagen deposition, and levels of heat shock proteins show the greatest promise as potential biomarkers to predict RAF and develop novel therapies.

Association of Autoantibodies against M2-Muscarinic Acetylcholine Receptor with Atrial Fibrosis in Atrial Fibrillation Patients

Objectives

To investigate the association of serum autoantibodies against M2-muscarinic acetylcholine receptor (anti-M2-R) with atrial fibrosis in long-standing persistent atrial fibrillation (AF) patients.

Methods

Twenty-four long-standing persistent AF patients, scheduled to undergo hybrid ablation surgery, were enrolled in the study. Twenty-six patients with sinus rhythm, scheduled to undergo coronary artery bypass grafting surgery, were enrolled into the non-AF group. We detected serum anti-M2-R levels. Left atrial appendages were subjected to histological and molecular biological assays. Patients in the AF group received follow-up for two years.

Results

The AF group showed significantly higher serum anti-M2-R levels compared to the non-AF group (496.2 ± 232.5 vs. 86.3 ± 25.7 pmol/L, p < 0.001). The AF group exhibited severe fibrosis in the left atrial appendages, as indicated by increased collagen volume fraction (45.2 ± 4.7% vs. 27.6 ± 8.3%, p < 0.001), and higher levels of collagen I (0.52 ± 0.04 vs. 0.24 ± 0.06, p < 0.001) and collagen III (0.51 ± 0.07 vs. 0.36 ± 0.09, p < 0.001). TGF-β1 and CTGF were also upregulated in the AF group. A positive correlation between serum anti-M2-R levels and fibrosis of the left atrial appendage and fibrogenic indexes was observed.

Conclusions

Serum anti-M2-R levels are higher in AF patients and are associated with the severity of atrial fibrosis. In addition, serum anti-M2-R levels are positively correlated to TGF-β1 and CTGF expression in the left atrial appendage.

The Effect of Autoantibody against M2-Muscarinic Acetylcholine Receptor in Heart Failure Patients on Digoxin Treatment

Background: Autoantibody against M2-muscarinic acetylcholine receptor (anti-M2AChR) has a biological effect similar to a vagus agonist. Digoxin has a function of vagus nervous system stimulation. We hypothesized that anti-M2AChR is highly correlated with digoxin in patients with chronic heart failure (CHF). Methods: Synthetic M2AChR peptides served as the target antigen in an ELISA were used to screen the sera of 80 CHF patients, who were separated into a negative (–) or positive (+) anti-M2AChR group according to their anti-M2AChR reactivity. Echocardiography and serum digoxin concentration (SDC) were performed at baseline and after 1 year of digoxin in combination with the standard treatment regime. The end-point events were compared over 1 year of follow-up. Results: Seventy-two CHF patients completed the final data analysis, including 32 (+)anti-M2AChR and 40 (–)anti-M2AChR patients. The resting heart rate of the positive group was higher than that of the negative group at baseline (p < 0.05; 89.0 ± 1.6 vs. 83.8 ± 1.1 bpm). Both groups showed improvement in the left ventricular end-diastolic and end-systolic dimensions and ejection fraction with digoxin in combination with the standard treatment regime for 1 year (all p < 0.01). However, the 32 patients with (–)anti-M2AChR had greater improvements than the 40 patients with (+)anti-M2AChR, and this was accompanied by a marked decrease of rehospitalization (all p < 0.01) but not of cardiovascular mortality after 1 year. The SDC of patients with (–)anti-M2AChR was significantly lower than that of patients with (+)anti-M2AChR (p < 0.05; 0.63 ± 0.05 vs.1.16 ± 0.06 ng/mL) and had a positive correlation with anti-M2AChR (r = 0.81, p < 0.001). Conclusion: These results suggested that anti-M2AChR could be a useful biomarker of vagus nerve overactivation and is associated with a poor response to digoxin treatment in CHF patients.

Association of pre-ablation level of potential blood markers with atrial fibrillation recurrence after catheter ablation: a meta-analysis

Aims

The meta-analysis was aimed to search for candidate blood markers whose pre-ablation level was associated with atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA).

Methods and results

A systematic literature search of PubMed, EMBASE, Springer Link, Web of Science, Wiley-Cochrane library, and supplemented with Google scholar search engine was performed. Thirty-six studies covering 11 blood markers were qualified for this meta-analysis. Compared with the nonrecurrence group, the recurrence group had increased pre-ablation level of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), N-terminal pro-brain natriuretic peptide (NT-pro-BNP), interleukin-6 (IL-6), C-reactive protein, low density lipoprotein (LDL), and tissue inhibitor of metal loproteinase-2 (TIMP-2) [standardized mean difference (95% confidence interval): 0.37 (0.13-0.61), 0.77 (0.40-1.14), 1.25 (0.64-1.87), 0.37 (0.21-0.52), 0.35 (0.10-0.60), 0.24 (0.07-0.42), 0.17 (0.00-0.34), respectively], while no statistical difference of pre-ablation level of white blood cell, total cholesterol, triglyceride, and transforming growth factor-β1 was found. Subgroup analysis demonstrated that ANP was associated with AF recurrence in participants who had no concomitant structural heart diseases (SHD); however, not in participants who had SHD, C-reactive protein was associated with AF recurrence in Asian studies, whereas not in European studies.

Conclusion

Increased pre-ablation level of ANP, BNP, NT-pro-BNP, IL-6, C-reactive protein, LDL, and TIMP-2 was associated with greater risk of AF recurrence after RFCA.

Baseline serum globulin as a predictor of the recurrence of lone atrial fibrillation after radiofrequency catheter ablation

Objective:

Inflammation and autoimmune responses play an important role in recurrence of atrial fibrillation (AF). Serum globulin levels are a commonly used clinical index that represents inflammation and autoimmune response. This study aimed to determine the relationship between baseline serum globulin levels and the risk of recurrence after ablation in lone AF patients.

Methods:

We enrolled 348 lone AF patients undergoing radiofrequency catheter ablation for the first time for whom complete follow-up data were available. Pre-ablation peripheral venous blood samples were obtained for measurement of serum globulin levels.

Results:

During the follow-up period of 22 months (range, 6–62), AF recurred in 129 patients (37.1%). Recurrence was associated with a low level of pre-ablation serum globulins. Multiple Cox proportional hazard regression analysis showed that persistent AF, AF duration, left atrial diameter, no amiodarone after ablation, and the serum globulin level in particular were independent predictors of AF recurrence. According to receiver operating characteristic curve analysis, the best diagnostic cut-off serum globulin level was 25.4 g/L, which showed 74.4% sensitivity, 71.3% specificity, and 73.3% accuracy.

Conclusion:

The baseline low serum globulin level is associated with AF recurrence after first-time ablation in lone AF patients. Therefore, it may be used as a predictor of AF recurrence in these patients.

Autoantibodies and cardiovascular dysfunction: cause or consequence?

There has been a long history of the exploration into autoimmunity as a possible pathogenic factor of cardiovascular diseases from unknown cause represented by dilated cardiomyopathy (DCM). Autoantibodies (AAbs) have emerged either as humoral responses provoked by the release of "self-antigens" due to tissue damage or dysregulated humoral immunity itself. The pathogenic roles of some AAbs have been suggested by the findings from basic research using in vitro and in vivo disease models as well as clinical studies including immunoadsorption studies removing AAbs from patients with DCM. In this context, the importance of AAbs belonging to IgG3 subclass has also been implicated. In this review article, we summarize the findings accumulated to date regarding AAbs which have been considered to be involved in the pathology of DCM or pregnancy-related cardiovascular disease. Furthermore, we discuss the significance of AAbs as a possible cause of DCM and their potential roles as a novel therapeutic target.

Lone AF: is There a Rationale?

Although atrial fibrillation (AF) development has been demonstrated to be associated with underlying cardiovascular conditions such as hypertension, valvular heart disease or diabetes mellitus; in a subset of relatively younger patients, no cardiopulmonary disease diagnosis can be established. AF patients younger than 60 years without clinical or echocardiographic evidence of cardiopulmonary disease are defined as lone AF patients. Despite the decrease in lone AF prevalence due to advances in understanding of AF pathogenesis, there are still issues yet to be resolved. Future studies are needed to demonstrate the cost- effectiveness of the routine use of more advanced diagnostic tools, such as non- invasive assessment of endothelial function, autoimmune markers or genetic screening and whether they would have clinical implications on treatment of lone AF. This review focuses on the suggested mechanisms in lone AF initiation and maintenance.

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.

Association of autoantibodies against the M2-muscarinic receptor with perinatal outcomes in women with severe preeclampsia

BACKGROUND

The goal of this study was to test the hypothesis that autoantibodies against M2-muscarinic acetylcholine receptor (M2-AAB) are associated with severe preeclampsia and increased risk of adverse perinatal outcomes.

METHODS

We conducted a case-control study comparing 60 women with severe preeclampsia to 60 women with normal pregnancy and 60 non-pregnant controls. A peptide, corresponding to amino acid sequences of the second extracellular loops of the M2 receptor, was synthesized as antigen to test for the presence of autoantibodies, using an enzyme-linked immunosorbent assay. The frequency and titer of M2-AAB were compared in the 3 groups. The risk of adverse perinatal outcomes among women with severe preeclampsia in the presence of M2-AAB was estimated.

RESULTS

M2-AAB were positive in 31.7% (19/60) of patients with severe preeclampsia, in 10.0% (6/60) (p=0.006) of normal pregnant women and in 8.3% (5/60) (p=0.002) of non-pregnant controls. The presence of M2-AAB was associated with increased risk of adverse pregnancy complications (OR, 3.6; 95%CI, 1.0-12.6; p=0.048), fetal growth restriction (OR, 6.8; 95% CI, 2.0-23.0; p=0.002), fetal distress (OR, 6.7; 95% CI, 1.7-26.6; p=0.007), low Apgar score (OR, 5.3; 95% CI, 1.4-20.7; p=0.017), and perinatal death (OR, 4.3; 95% CI, 1.0-17.6; p=0.044) among women with severe preeclampsia.

CONCLUSIONS

This study demonstrates, for the first time, an increase in M2-AAB in patients with severe preeclampsia. Women with severe preeclampsia who are M2-AAB positive are at increased risk for neonatal mortality and morbidity. We posit that M2-AAB may be involved in the pathogenesis of severe preeclampsia.

Perindopril treatment promote left ventricle remodeling in patients with heart failure screened positive for autoantibodies against angiotensin II type 1 receptor

Background

Autoantibodies specific to the angiotensin II type I receptor (anti-AT₁-AR) have been implicated in the pathology of congestive heart failure (CHF). Anti-AT₁-AR may be associated with left ventricular function in CHF patients treated with perindopril.

Methods

Synthetic angiotensin II type 1 receptor (AT₁-R) peptides served as the target antigen. ELISA was used to screen the sera of 156 CHF patients, which were divided into positive and negative groups based on their anti-AT₁-AR reactivity. Echocardiography and a 6-minute walk test were performed at baseline and after one year of perindopril therapy. The end-point events were compared over a 5-year follow-up.

Results

Final analysis covered 138 patients, including 82 positive and 56 negative. The frequency and geometric mean titre of anti-AT₁-AR were significantly lower in the positive group after one year of treatment (all P < 0.01, from 100% to 73.2% and from 1:125.3 ± 1.0 to 1:69.2 ± 1.1). Of these, 22 patients showed no antibodies. Both groups showed improvement in left ventricular end-diastole, end-systolic dimensions, ejection fraction, and a 6-minute walk test by perindopril in combination with standard treatment regime for one year (all P < 0.01). However, the 82 patients positive for anti-AT₁-AR showed more pronounced improvement than the 56 negative patients (all P < 0.05). However, after 5 years of follow-up, the rate of all causes and cardiovascular mortality attributable to any cause and the re-hospitalisation rate showed no significant differences between the two groups (all P > 0.05).

Conclusions

Perindopril treatment significantly decreased the frequency and geometric mean titre in patients positive for anti-AT₁-AR, even to complete ablation. These patients showed greater improvement in left ventricular remodeling and heart function than negative that in patients after one year of perindopril treatment in combination with standard treatment, but no significant differences in endpoint events were observed in the following 5 years. Anti-AT₁-AR might be a useful biomarker of over-activation of the renin-angiotensin-aldosterone system for clinical medication.