Beyond the gut: a comprehensive meta-analysis on Helicobacter pylori infection and cardiovascular complications

BACKGROUND

Helicobacter pylori (H. pylori) is known to induce chronic inflammatory conditions, and interactions between the host immune system and pathogen have diverted attention toward investigating its correlation with extra-gastrointestinal disorders.

OBJECTIVE

The present study aimed to assess the rate of H. pylori infection in cardiovascular disease (CVD) through a systematic review and meta-analysis.

METHODS

We conducted a large-scale meta-analysis to determine the prevalence rates of H. pylori infection in vascular diseases. Articles from PubMed/Medline, Web of Science, and Embase databases published between 2000 and 2023 were included for analysis. We used multiple independent observers to extract data, calculated the pooled frequency of H. pylori in vascular diseases using a random effect model, and reported the results as a weighted average based on the study population. The main outcome measures were presented with 95% confidence intervals (CI).

RESULTS

In 87 included studies, the prevalence of H. pylori infection in vascular diseases was 56.7% worldwide. 14.25% of H. pylori isolates harbored the cagA gene. The predominant vascular complication was coronary artery disease (CAD) (31.07%), primarily documented in Europe. This meta-analysis revealed a declining emphasis on studying the association of H. pylori infection with vascular disease in recent times.

CONCLUSION

According to this meta-analysis, H. pylori infection has a high frequency in CVD and may increase the risk of vascular diseases. However, further research is required, particularly in nations with limited data.

Lessons from Cardiac and Vascular Biopsies from Patients with and without Inflammatory Rheumatic Diseases

Feiring Heart Biopsy Study enables searching for potential pathogenetic mechanisms, therapeutic targets, and biomarkers through the assessment of clinical data and multiple blood and tissue samples from patients with and without inflammatory rheumatic diseases (IRDs), undergoing coronary artery bypass grafting. Some of our findings, for example, more inflammation (including the presence of immune cells and expression of proinflammatory cytokines) in vessels and the heart, and the presence of certain bacteria and autoantigens in vessels, could contribute to the increased risk of ischemia, aneurysms, and/or cardiac dysfunction in IRDs. Furthermore, some of the detected factors could be involved in the pathomechanisms of these conditions in general.

Human cytomegalovirus infection and vascular disease risk: A meta-analysis

BACKGROUND

Human cytomegalovirus (HCMV) infection has been associated with the acceleration of vascular disease. Numbers studies were conducted to analyze the association between HCMV infection and risk of vascular disease, but no clear consensus had been reached. The aim of this study was to confirm this relationship precisely by doing a systematic review and meta-analysis.

METHODS

We identified relevant studies through a search of PubMed and Embase. Studies were eligible for inclusion if they fulfilled all of the following selection criteria: (1) evaluating the association between HCMV infection and vascular disease; (2) case-control studies or nested case-control studies; (3) and supply the numbers (or percentage) of positivity for HCMV infection in cases and controls, respectively. Data were extracted and analyzed independently by two investigators. Ultimately, We included data from 68 studies, which altogether enrolled 12027 cases and 15386 controls from 24 countries.

RESULTS

HCMV IgG was detected 7376 in 10611 cases, HCMV IgM was detected 153 in 1486 cases and HCMV DNA was detected 654 in 2139 cases. Overall, people exposed to HCMV infection had higher risk than those not exposed for vascular disease (OR 1.70 [95% CI 1.43-2.03] IgG-based HCMV tests, 2.88 [95% CI 1.87-4.43] IgM-based HCMV tests and 2.56 [95% CI 1.46-4.49 PCR-based HCMV tests]). HCMV infection was clearly identified as a risk factor for vascular disease in Asian group, Caucasian group and other group, especially Asian group(OR 1.86 [95% CI 1.33-2.60] IgG-based HCMV tests, 3.57 [95% CI 1.94-6.60] IgM-based HCMV tests and 4.09 [95% CI 3.10-5.40 PCR-based HCMV tests]).

CONCLUSION

This meta-analysis suggested that HCMV infection is associated with an increased risk for vascular disease.

Cytomegalovirus infection and atherosclerosis in candidate of coronary artery bypass graft

Background:

Although there is enough evidence that infectious agents such as Chlamydia pneumonia and Helicobacter pylori may play a pathogenic role in atherosclerosis, this role for cytomegalovirus (CMV) is yet controversial.

Objectives:

The aim of the present study was to detect CMV-DNA in atherosclerotic plaques in patients who underwent coronary artery bypass graft (CABG).

Patients and Methods:

In this case-control study, candidates for CABG (cases) and patients with valvular or congenital malformation but without atherosclerotic plaques (controls) were studied from 2012 to 2013 at Golestan hospital, Ahvaz, IR Iran. Demographic and laboratory data were collected. Atherosclerotic and histological samples were obtained from visible plaques and from aorta by the surgeon. All the samples were examined for the presence of CMV-DNA by polymerase chain reaction (PCR) method using a commercial kit (SinaClon, Tehran, IR Iran).

Results:

The mean ages in case and control groups were 60.8 ± 6.8 and 57.5 ± 11.5 years, respectively, with no significant difference (P = 0.09). Thirty patients (54.5%) in case and 32 (58.2%) in control groups were male with no significant difference (P = 0.7). CMV-DNA was present in 8 (14.5%) of the cases and 2 (4%) of the controls. CMV-DNA was associated with higher risk of atherosclerosis (OR: 7.7, 95% CI = 1.1-51.4, P = 0.03). Of the total normal aortic samples (55 in cases and 55 in controls), there was no individual with simultaneous positive CMV-DNA among aortic atherosclerotic and normal tissue samples.

Conclusions:

The presence of CMV-DNA in aortic plaques is associated with increased risk of atherosclerosis. CMV infection may be considered as an independent risk factor for this event.

Helicobacter pylori: Does it add to risk of coronary artery disease

Helicobacter pylori (H. pylori) is a known pathogen implicated in genesis of gastritis, peptic ulcer disease, gastric carcinoma and gastric lymphoma. Beyond the stomach, the organism has also been implicated in the causation of immune thrombocytopenia and iron deficiency anemia. Although an area of active clinical research, the role of this gram negative organism in causation of atherosclerosis and coronary artery disease (CAD) remains enigmatic. CAD is a multifactorial disease which results from the atherosclerosis involving coronary arteries. The major risk factors include age, diabetes mellitus, smoking, hypertension and dyslipidemia. The risk of CAD is believed to increase with chronic inflammation. Various organisms like Chlamydia and Helicobacter have been suspected to have a role in genesis of atherosclerosis via causation of chronic inflammation. This paper focuses on available evidence to ascertain if the role of H. pylori in CAD causation has been proven beyond doubt and if eradication may reduce the risk of CAD or improve outcomes in these patients.

Extragastric diseases and Helicobacter pylori

In the last year, several diseases from outside of the gastrointestinal tract have been associated with Helicobacter pylori infection. Indeed, this bacterium produces a low-grade inflammatory state, induces molecular mimicry mechanisms, and interferes with the absorbance of nutrients and drugs possibly influencing the occurrence or the evolution of many diseases. In addition to its role in some hematologic conditions, such as immune thrombocytopenic purpura, idiopathic sideropenic anemia, and vitamin B12 deficiency, which were included in the current guidelines, several other conditions such as cardiovascular diseases, diabetes mellitus, hepatobiliary diseases, and neurologic disorders have also shown promising results.