Helicobacter pylori and atrial fibrillation: a possible pathogenic link

Is there a link between atrial fibrillation and Helicobacter pylori infections?

BACKGROUND

Atrial fibrillation (AF) is the most common rhythm disturbance seen in clinical practice. Evidence emerged that suggested inflammation was associated with risk of AF. Helicobacter pylori (HP) cause gastric and esophageal inflammation, as well as systemic and vascular inflammation. These local and systemic inflammatory effects may increase the risk of AF. The pathogenesis of atrial fibrillation (AF) remains unknown. However, many recent studies point to an association between AF and inflammation because of a demonstrable significant correlation between the dysrhythmia and various biomarkers of inflammation. Given the suggested involvement of inflammation with this dysrhythmia, an initiating factor for inflammation has been sought. Chronic bacterial infection is the most likely event to initiate and maintain an inflammatory process. Recently, bacterial infections have been hypothesized to be involved in the pathogenesis of AF, and Helicobacter pylori and Chlamydia pneumoniae are two bacteria that have aroused interest. The aim of this study was to compare the prevalence of H. Pylori infection, proven by gastric biopsy, between AF patients and control group and the role of CRP, MPV, age and sex in patients with HP associated AF.

METHODS

We investigated one hundred eighty patients with HP in whom gastroscopy was done and/or urea breathe test because of dyspepsia and epigastric discomfort for eventual detecting the presence of H. pylori infection, and the prevalence of fibrillation in patients with HP, and whether age, sex, inflammatory markers are different in the two groups. The study was enrolled in the Department of Internal Medicine, Ziv Medical Center, Safed, Israel, from 2015 until 2019.

RESULTS

The prevalence is more pronounced in men with both atrial fibrillation and H. pylori, in terms of age we see that the incidence of atrial fibrillation is more relative in the older age P<0.001. There is no statistically significant difference in the inflammatory marker MPV between the two groups P<0.005. The levels of high-sensitivity C-reactive protein (hs-CRP) have been shown to be higher among patients with H. pylori with AF compared with the control group HP without AF statistically significant P<0.001.

CONCLUSIONS

There is a correlation between HP and AF, AF is more related to age and to an increased inflammation marker CRP in patients diagnosed with HP.

Atrial Fibrillation and Dementia: Focus on Shared Pathophysiological Mechanisms and Therapeutic Implications

OBJECTIVES

Atrial fibrillation (AF) and dementia are highly prevalent chronic and debilitating conditions, especially affecting the older population. This review focuses on possible common pathophysiological mechanisms that could explain the association between the 2 conditions.

DESIGN

Narrative review.

SETTING AND PARTICIPANTS

Evidence from epidemiologic, observational, and interventional studies evaluating prevalence and incidence of cognitive impairment in patients with AF.

METHODS

Broad literature search between December 2022 and May 2023. Eligible categories for inclusion comprised interventional studies, observational studies, systematic reviews, and meta-analysis.

RESULTS

Evidence from different cohorts has shown that AF increases the risk of dementia, although the association with dementia subtypes is not always unequivocal. According to recent evidence, common pathophysiological mechanisms include thromboembolism and hypercoagulable states, proinflammatory state, infection, cerebral hypoperfusion, and brain atrophy. Moreover, we reviewed the evidence on therapeutic measures to prevent dementia in patients with AF.

CONCLUSIONS AND IMPLICATIONS

Screening for cognition in patients with AF is of paramount importance, given the shared risk factors and common pathophysiological mechanisms. More evidence is needed to clarify whether antiarrhythmic and anticoagulant therapy have an impact on cognitive outcomes in AF patients.

Inflammatory and Infectious Processes Serve as Links between Atrial Fibrillation and Alzheimer's Disease

Atrial fibrillation (AF) is one of the most prevalent forms of arrhythmia that carries an increased risk of stroke which, in turn, is strongly associated with cognitive decline. The majority of dementia cases are caused by Alzheimer's disease (AD) with obscure pathogenesis. While the exact mechanisms are unknown, the role of inflammatory processes and infectious agents have recently been implicated in both AD and AF, suggesting a common link between these maladies. Here, we present the main shared pathways underlying arrhythmia and memory loss. The overlapping predictive biomarkers and emerging joint pharmacological approaches are also discussed.

Association between atrial fibrillation and Helicobacter pylori

The connection between atrial fibrillation (AF) and H. pylori (HP) infection is still matter of debate. We performed a systematic review and metanalysis of studies reporting the association between AF and HF. A systematic review of all available reports in literature of the incidence of HP infection in AF and comparing this incidence with subjects without AF were analysed. Risk ratio and 95% confidence interval (CI) and risk difference with standard error (SE) were the main statistics indexes. Six retrospective studies including a total of 2921 were included at the end of the selection process. Nine hundred-fifty-six patients (32.7%) were in AF, whereas 1965 (67.3%) were in normal sinus rhythm (NSR). Overall, 335 of 956 patients with AF were HP positive (35%), whereas 621 were HP negative (65%). In addition, 643 of 1965 NSR patients (32.7%) were HP positive while 1,322 were negative (67.3%; Chi-square 2.15, p = 0.21). The Cumulative Risk Ratio for AF patients for developing an HP infection was 1.19 (95% CI 1.08-1.41). In addition, a small difference risk towards AF was found (0.11 [SE = 0.04]). Moreover, neither RR nor risk difference were influenced by the geographic area at meta-regression analysis. Finally, there was a weak correlation between AF and HP (coefficient = 0.04 [95% CI -0.01-0.08]). We failed to find any significant correlation between H. pylori infection and AF and, based on our data, it seems unlikely than HP can be considered a risk factor for AF. Further larger research is warranted.

Gastrointestinal and liver diseases and atrial fibrillation: a review of the literature

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with significant morbidity and mortality. A number of risk factors have been associated with AF, though few studies have explored the association between gastrointestinal and liver diseases and AF. Additionally, AF and treatment for AF may predispose to gastrointestinal and liver diseases. We review the current literature on the bidirectional associations between gastrointestinal and liver diseases and AF. We highlight the gaps in knowledge and areas requiring future investigation.

The Association between Arrhythmia and Helicobacter pylori Infection: A Meta-Analysis of Case-Control Studies

Arrhythmia is a common disease around the world and Helicobacter pylori (H. pylori) is a bacterium infecting 28% to 84% of subjects, depending on the population tested. However, the implication of H. pylori in cardiac arrhythmia is poorly understood. We performed this meta-analysis with an aim to identify the association between arrhythmia and H. pylori. We searched PubMed, Embase, Web of Science, and the Cochrane library databases to select studies on the association between arrhythmia and H. pylori. In the arrhythmia group, 392 (58.1%) were H. pylori-positive and in the control group 640 (47.8%) were H. pylori-positive. Compared to the controls, the infection rate of H. pylori was higher in patients with arrhythmia than in controls (odds ratio (OR) = 1.797, 95% confidence interval (CI): 1.081–2.988, p < 0.05). Subgroup analysis indicated that H. pylori infection was a risk factor for atrial fibrillation in Asia and Africa. Therefore, a correlation between H. pylori infection and arrhythmia may exist and H. pylori eradication may decrease the occurrence of arrhythmia, especially in Asia and Africa.

Cytotoxin-associated gene-A bearing strains of Helicobacter pylori and atrial fibrillation due to ischemic origin: is there a link?

Background Helicobacter pylori CagA

strains could increase the risk for atrial fibrillation in patients with coronary artery disease

Methods

Serological status for H. pylori CagA using enzyme-linked immunosorbent assay, C-reactive protein, total leucocytic count and atrial size were determined in 185 coronary artery disease patients (with and without atrial fibrillation) and 80 healthy subjects (control).

Results CagA

strain showed a higher prevalence in the atrial fibrillation group. Atrial dimension and C-reactive protein (independent predictors of atrial fibrillation) were significantly increased in the CagA seropositive subgroup Conclus ons There is a strong liaison between H. pylori CagA infection and atrial fibrillation in coronary artery disease. Increased C reactive protein and atrial size in atrial fibrillation patients may reflect atrial inflammatory remodeling.

Helicobacter pylori infection in Chinese patients with atrial fibrillation

Objective

To explore the relationship between Helicobacter pylori (Hp) infection and atrial fibrillation (AF) in Chinese patients.

Methods

A total of 285 hospitalized patients with AF and 300 patients from Health Screening Center who matched age and sex with AF group were enrolled. AF patients were divided into two groups: the short-standing AF category (less than a year) and the long-standing AF category (more than a year). All patients had laboratory testing of ¹³C urea breath test, high-sensitive C-reactive protein (hs-CRP) and left atrial diameter (LAD). We analyzed the difference of these factors in all groups and explored the correlation between Hp infection and AF using logistic regression analysis.

Results

Both AF groups had more hypertension, diabetes, and Hp infection than the control group. The Hp value and the hs-CRP level in patients with long-standing AF were higher than those in the short-standing AF and the control groups (for Hp value: P<0.001 for both and for hs-CRP level: P=0.003, 0.002, respectively). The LAD of patients in the long-standing AF group was significantly larger than those in the short-standing AF group and control group (P=0.001 and P<0.001, respectively). The values of Hp, hs-CRP, and LAD in the long-standing AF category were significantly higher than those in the short-standing AF category (all P<0.05). After controlling the potential confounders, Hp value ≥4‰, hs-CRP >5 mg/L, and LAD >36 mm were significantly related to long-standing AF.

Conclusion

The values of Hp in patients with long-standing AF were significantly higher than those in short-standing AF and control groups. Hp δ value ≥4‰ is an independent predictor for long-standing AF.

Association of Salivary Helicobacter pylori Infection with Oral Diseases: a Cross-sectional Study in a Chinese Population

OBJECTIVE

The aim of this study was to detect the prevalence of oral H.pylori among adults and to investigate the correlation between H.pylori infection and common oral diseases.

STUDY DESIGN

A cross-sectional study was performed among adults Chinese who took their annual oral healthy examination at The First Affiliated Hospital, Zhejiang University School of Medicine, China.

RESULTS

The study included 1050 subjects in total and oral H.pylori infection occurred in 60.29% of the subjects. The prevalence rates of oral H.pylori in patients with periodontal diseases (63.42%) and caries (66.91%) were significantly increased than those without oral diseases (54.07%), respectively (P < 0.05), while the difference between subjects with recurrent aphthous stomatitis and controls was not significant. In addition, the differences of positive rates of H.pylori with or without history of gastric ulcer were statistically significant (69.47% vs 58.26%, P<0.05). Presenting with periodontal diseases (OR 1.473;95% CI 1.021 to 2.124), caries (OR 1.717; 1.127 to 2.618), and having history of gastric ulcer (OR 1.631; 1.164 to 2.285) increased the risk of H.pylori infection.

CONCLUSIONS

Oral H.pylori infection is common in adult Chinese, which is significantly associated with oral diseases including periodontal diseases and caries.

Can Helicobacter pylori infection influence human reproduction?

Helicobacter pylori (H. pylori) infection could be associated with extra-digestive diseases. Here, we report the evidences concerning the decrease in reproductive potential occurring in individuals infected by H. pylori, especially by strains expressing CagA. This infection is more prevalent in individuals with fertility disorders. Infected women have anti-H. pylori antibodies in cervical mucus and follicular fluid that may decrease sperm motility and cross react immunologically with spermatozoa, conceivably hampering the oocyte/sperm fusion. Infection by CagA positive organisms enhances the risk of preeclampsia, which is a main cause of foetus death. These findings are supported by the results of experimental infections of pregnant mice, which may cause reabsorption of a high number of foetuses and alter the balance between Th1 and Th2 cell response. Infected men have decreased sperm motility, viability and numbers of normally shaped sperm and augmented systemic levels of inflammatory cytokines, such as tumor necrosis factor-α, which may damage spermatozoa. In countries where parasitic infestation is endemic, detrimental effects of infection upon spermatozoa may not occur, because the immune response to parasites could determine a switch from a predominant Th1 type to Th2 type lymphocytes, with production of anti-inflammatory cytokines. In conclusion, the evidences gathered until now should be taken into consideration for future studies aiming to explore the possible role of H. pylori infection on human reproduction.

Prevalence of virulent Helicobacter pylori strains in patients affected by idiopathic dysrhythmias

Helicobacter pylori virulent strains have been shown to affect cardiovascular diseases through molecular mimicry mechanisms. Silent autoimmune myocarditis has been hypothesized to be the cause of idiopathic dysrhythmias (IA). The aim of this study is to assess the prevalence of virulent H. pylori strains in patients affected by IA. In this study,54 patients (40 men, mean age 44 ± 17 years) affected by IA and 50 healthy subjects (34 men, mean age 45 ± 9) were evaluated. IA, defined as dysrhythmias with no evidence of other cardiac pathology, were either supraventricular (SVA, 23 patients; mean age 45 ± 15 years) or ventricular (VA, 31 patients; mean age 42 ± 18 years). H. pylori infection and gastrointestinal (GI) symptoms were evaluated. H. pylori strains expressing the cytotoxin-associated gene A (cagA) and the vacuolating-cytotoxin A (vacA) were also assessed through western blot. The prevalence of H. pylori is similar in IA patients and in controls (42 vs. 44%; p > 0.05); H. pylori infection is observed in 48 and 39% of the patients are affected by SVA and VA, respectively. The prevalence of CagA-positive strains is increased in IA patients compared to controls (65 vs. 42%; p < 0.01); similarly, the prevalence of VacA-positive strains is also increased in IA patients (74 vs. 46%; p < 0.006). Excluding belching, infected patients did not show any difference in GI symptoms, when compared to non-infected subjects. From this study it is concluded that there is an epidemiological link between CagA and VacA-positive H. pylori strains in IA patients.

The favourable effect of Helicobacter pylori eradication therapy in patients with recurrent angina-like chest pain and non-responsive to proton pump inhibitors - a preliminary study

INTRODUCTION

The outcome of Helicobacter pylori (Hp) eradication therapy from the aspect of prevention of chest pain recurrence is still uncertain. The aim of this study was to assess the influence of Hp eradication therapy on the risk of hospitalization due to acute coronary syndrome.

MATERIAL AND METHODS

The analysis was carried out in 63 consecutive patients with recurrent retrosternal symptoms: 28 (44%) with significant coronary artery narrowing in coronarography not qualified for revascularization by an invasive cardiologist, and 35 (56%) with no obstructive coronary artery lesions. In 33 (52%) of the patients, Hp infection was found and standard eradication therapy with omeprazole (2 × 20 mg), amoxicillin (2 × 1 g) and metronidazole (2 × 500 mg) was recommended. The mean follow-up period was 977 ±249 days.

RESULTS

Chest pain requiring hospitalization because of unstable angina within the follow-up period was observed in 9 (27%) of the Hp-infected individuals and in 15 (50%) subjects in whom a urease test and histology did not confirm this infection (p = 0.055). The recommendation of Hp-eradication treatment was a significant factor prolonging the hospitalization-free period, both in the two Kaplan-Meier curve analyses (Cox's F test = 1.96; p = 0.049) and the Cox proportional hazard model (beta = -1.18; p = 0.045), but was weaker than the effect of the non-obstructive coronary angiogram (beta = -1.45; p = 0.03).

CONCLUSIONS

The recommendation of Hp-eradication therapy may prolong the hospitalization-free period for patients with recurrent chest pain.

Increased inflammatory cell infiltration in the atrial myocardium of patients with atrial fibrillation

Atrial fibrillation (AF) may be caused by structural and electrophysiological changes in the atria induced by inflammation. This study analyzed 35 adult patients with symptomatic severe mitral valve disease and moderate-to-severe tricuspid valve disease and without coronary artery disease who underwent valve operations for congestive heart failure; 18 patients had persistent AF and 17 patients had no history or electrocardiogram examination of AF before surgery. Atrial appendageal tissues obtained during surgery were evaluated for histopathological changes. The number of inflammatory cells identified as CD45-positive cells in the right atrial myocardium in the AF group (7.5 +/- 7.5 cells per high power field) was significantly higher than that of normal controls (2.7 +/- 1.5 cells per high power field, p = 0.0018). The number of inflammatory cells in the right atrial myocardium did not differ between the sinus group and normal controls (2.7 +/- 1.5 vs 2.6 +/- 2.2 cells per high power field, p >0.05). Additionally, the number of inflammatory cells in the atrial myocardium did not differ between the right and left atria in patients with AF (7.5 +/- 7.5 cells per high power field for right atria vs 7.1 +/- 4.2 cells per high power field for left atria, p = 0.7563). Moreover, correlation analysis revealed a significant association between the number of inflammatory cells in the right atrial myocardium and the number of inflammatory cells in the left atrial myocardium in patients with AF (r = 0.6145, p = 0.0067). In conclusion, inflammatory cell infiltration increases in the atrial myocardium of patients with AF.

Frequency of helicobacter pylori seropositivity and C-reactive protein increase in atrial fibrillation in patients undergoing coronary angiography

Atrial fibrillation (AF) is the most common rhythm disturbance seen in clinical practice. Evidence emerged that suggested inflammation was associated with risk of AF. Helicobacter pylori causes gastric and esophageal inflammation, as well as systemic and vascular inflammation. These local and systemic inflammatory effects may increase the risk of AF. Study patients were consecutive patients who underwent angiography for suspicion of coronary artery disease. Patients' AF status was determined by a search of hospital discharge summaries for diagnostic International Classification of Diseases, Ninth Revision codes for AF, assessment of previous electrocardiograms at the index and previous admissions to LDS Hospital (Salt Lake City, Utah), and search of the electrocardiographic database of LDS Hospital. In addition to routine laboratory studies, serum was analyzed to determine H pylori serostatus and index C-reactive protein (CRP) level. A total of 943 patients with known AF status were studied. Those with AF tended to be older (70.9 +/- 9.5 vs 63.9 +/- 10.7 years; p <0.001) and had a higher prevalence of congestive heart failure (28% vs 11%; p <0.001). In addition, patients with AF were more likely to be seropositive for H pylori in comparison to the seronegative group (65% vs 55%; p = 0.049). Mean CRP was similar between those with and without AF (2.2 +/- 2.7 vs 2.3 +/- 2.4 mg/dl; p = 0.79). There was no apparent association between H pylori serostatus and CRP. Multivariate predictors of AF included age (hazard ratio [HR] 1.07 per year, 95% confidence interval [CI] 1.04 to 1.10, p <0.0001) and heart failure (HR 2.87, 95% CI 1.59 to 5.18, p <0.0001). H pylori added to the model was marginally associated with AF (HR 1.53, 95% CI 0.95 to 2.47, p = 0.08) when not accounting for age. However, younger patients (<50 years) who were H pylori seropositive had a higher relative risk of AF (8%) versus those who were seronegative (0%). In comparison, older patients seropositive for H pylori had only a modest increased risk of AF (17.5% vs 15.4%; p = 0.11). In conclusion, these data showed a general association of H pylori and AF in patients with multiple cardiovascular risk factors. The association did not persist after accounting for other risk factors. Although older age was highly associated with AF risk in this population, H pylori was additive across 3 distinct age groups, with the highest risk conveyed in the younger cohort.

Is there a link between atrial fibrillation and certain bacterial infections?

The pathogenesis of atrial fibrillation (AF), the most common cardiac dysrhythmia, remains unknown. However, many recent studies point to an association between AF and inflammation because of a demonstrable significant correlation between the dysrhythmia and various biomarkers of inflammation. For example, C-reactive protein (CRP), a sensitive biomarker of systemic inflammation, has been reported to be significantly higher in patients with AF compared with a control group with no history of atrial dysrhythmias. Histological anomalies in the atria of patients with AF have also been observed. These anomalies may have an inflammatory basis, although it is not known if the structural changes within the atria of patients with AF are a cause or consequence of the dysrhythmia. Given the suggested involvement of inflammation with this dysrhythmia, an initiating factor for inflammation has been sought. Chronic bacterial infection is the most likely event to initiate and maintain an inflammatory process. Recently, bacteria infections have been hypothesized to be involved in the pathogenesis of AF, and Helicobacter pylori and Chlamydia pneumoniae are two bacteria that have aroused interest. Here, we give a brief overview of AF and then specifically explore the recent evidence that suggests that AF may be caused by bacterial infection(s) in certain patients.

Recurrent supraventricular arrhythmias in a dog with atrial myocarditis and gastritis

This report describes a dog with recurrent atrial fibrillation and atrial flutter associated with chronic gastritis. Although no underlying structural heart disease was apparent antemortem or on gross post-mortem examination, chronic atrial myocarditis was seen on histopathological examination. Atrial myocarditis is a recognised cause of atrial fibrillation in human beings with presumed lone fibrillation, and an association between supraventricular tachyarrhythmias and infectious agents has been made.

Is Helicobacter pylori a cause of atrial fibrillation?

Inflammation has been implicated in the pathogenesis of cardiovascular diseases. C-reactive protein, a sensitive marker of systemic inflammation, has recently been reported to be significantly higher in patients with atrial fibrillation (AF) compared with a control group with no history of atrial arrhythmia. Elevated C-reactive protein levels in patients with AF reflects an underlying inflammatory process. Histological anomalies in the atria of patients with AF have also been observed. These anomalies may have an inflammatory basis, although it is not known if any structural changes within the atria are a cause or a consequence of the arrhythmia. Ongoing chronic infection(s) has been suggested as a possible cause of the inflammatory process demonstrated in patients with AF. Helicobacter pylori, a Gram-negative bacterium more commonly known for infecting the gastric mucosa and causing peptic ulcers, is a noncardiac factor that has been controversially reported to be associated with cardiovascular diseases. This article gives a brief overview of AF and specifically explores the recent evidence that suggests that Helicobacter pylori infection causes AF.