Infection with Helicobacter pylori is not a major independent risk factor for stable coronary heart disease - Lack of a role of cytotoxin-associated protein A-positive strains and absence of a systemic inflammatory response

Background-There is controversy about the association between Helicobacter pylori infection and manifestations of coronary heart disease (CHD), the po tential role of the more virulent H pylori strains, and whether or not a po sitive serostatus is related to increased levels of markers of systemic inf lammation, Methods and Results-We assessed the prevalence of an infection with H pylor i and in particular the anti-cytotoxin-associated protein A (CagA) antibody response of the more virulent strains expressing CagA in 312 patients with stable CHD and in 479 control subjects. Serological prevalence of H pylori infection (IgG titer) was significantly higher in patients than in control subjects after adjustment for age and sex (43.2% versus 31.3%, P < 0.001). After adjustment for various covariates in multiple logistic regression, t he odds ratio (OR) for CHD was 1.3 (95% CI, 0.9 to 1.9) given a positive Ig G serostatus. The prevalence of CagA-positive strains was 27.9% in patients and 21.7% in control subjects (P = 0.076 adjusted for age and sex). The OR for CHD in the fully adjusted model was 1.1 (95% CI. 0.7 to 1.7). None of the inflammatory markers (C-reactive protein, fibrinogen, plasma viscosity, or leukocytes) was significantly different according to serostatus. Conclusions-In this large case-control study, the association of H pylori i nfection with stable CHD was strongly reduced and was no longer statistical ly significant after controlling for potential confounders, We also found n o independent association between the more virulent strains and CHD, in add ition, a positive serostatus was not associated with a systemic inflammator y response. Thus, these data do not support the hypothesis that infection w ith H pylori might be a major risk factor for stable CHD.