Prospective analysis of the association of infection with CagA bearing strains of Helicobacter pylori and coronary heart disease

Abstract

Objective: To see whether it was possible to replicate in a prospective study the association recently reported between infection with the more virulent (type 1) cytotoxin associated gene A (CagA) antigen carrying strains of Helicobacter pylori and increased risk of coronary heart disease. Design and setting: Nested case-control study in a clinical outcomes trial. Subjects: Participants in the West of Scotland coronary prevention study. Methods: H pylori CagA serological status was determined in plasma samples of 201 subjects (cases) who subsequently had a coronary event during follow up and in 414 subjects (controls) matched for age and smoking who remained event-free, using a semiquantitative commercial enzyme linked immunosorbent assay (ELISA) kit against the p120 antigen of CagA. Results: 105 (52%) in the case group and 176 (43%) in the control group were seropositive (odds ratio (OR) 1.49, 95% confidence interval (CI) 1.06 to 2.10, p = 0.022). The association remained significant after adjustment for blood pressure, body mass index, plasma concentrations of low density lipoprotein and high density lipoprotein cholesterol, history of hypertension and diabetes, statin treatment, and socioeconomic status (OR 1.51, 95% CI 1.06 to 2.16, p = 0.023). Baseline inflammatory markers (white cell count, C reactive protein, fibrinogen) were not significantly increased in either H pylori CagA positive cases or controls. Conclusions: The findings provide support from a prospective study for the hypothesis that there is an association between infection with CagA bearing strains of H pylori and coronary heart disease. The mechanism(s) underlying the association remain to be elucidated.

Increased thrombin generation and circulating levels of tumour necrosis factor‐α in patients with chronic Helicobacter pylori‐positive gastritis

“…It has been suggested [27][28][29] that the association between H. pylori infection and ischaemic heart disease appears to be related to CagA-positive strains able to produce more marked inflammation, resulting in severe gastritis that more readily evolves into chronic atrophic gastritis which induce B 12 and folic acid malabsorption and hyperhomocysteinaemia. 30 Moderately raised levels of homocysteinaemia are associated with an increased risk of coronary heart disease: 31 in vitro studies on endothelial cells in culture demonstrated that homocysteine induces expression of procoagulant factors; 32,33 in vivo studies showed that homocysteine affects vascular functions and predisposes to vasospasm.…”

Early prognosis of unstable angina patients with positive Helicobacter pylori IgG values

“…Helicobacter pylori, Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenza are some of these organisms. The association between H. pylori infection and coronary artery disease was described by Mendel et al in 1994 and has further been tested by several studies 4,5,6,7,8,9,10 . Our study was conducted because of the conflicting results available from the study results published from different parts of world and also because the lack of studies in India till now testing the effect of H. pylori seropositivity on the prognosis of the patients with unstable angina.…”

Helicobacter Pylori Infection Associated Diseases – A Systematic Review

“…Danesh et al conducted a meta-analysis and observed no significant positive association between H. pylori and CHD [47] . Some studies reported that more serious coronary atherosclerosis was observed in patients with H. pylori CagA+ strains infection [48][49][50] .…”