ASSOCIATION OF VIRULENT HELICOBACTER-PYLORI STRAINS WITH ISCHEMIC-HEART-DISEASE

Background-Previous studies have reported an association between chron ic Helicobacter pylori infection and ischemic heart disease. However, it is not clear whether this association is really due to the virulenc e of the bacterium or is merely the result of confounding factors tin particular, age and social class). Methods and Results-We assessed the prevalence of infection by Helicobacter pylori and by strains bearing the cytotoxin-associated gene-A (CagA), a strong virulence factor, in 88 patients with ischemic heart disease (age, 57+/-8 years; 74 men) a nd in 88 age-and sex-matched controls (age, 57+/-8 years; 74 men) with similar social background. Prevalence of Helicobacter infection was s ignificantly higher in patients than in controls (62% versus 40%; P=.0 04), with an odds ratio of 2.8 (95% CI, 1.3 to 7.4; P<.001) adjusted f or age, sex, main cardiovascular risk factors, and social class. Patie nts with ischemic heart disease also had a higher prevalence of CagA-p ositive strains (43% versus 17%; P=.0002), with an adjusted odds ratio of 3.8 (95% CI, 1.6 to 9.1; P<.001). Conversely, prevalence of CagA-n egative strains was similar in patients and controls (19% versus 23%), with an adjusted odds ratio of 0.8 (95% CI, 0.4 to 1.4). Conclusions- The association between Helicobacter pylori and ischemic heart disease seems to be due to a higher prevalence of more virulent Helicobacter strains in patients. These results support the hypothesis that Helicob acter pylori may influence atherogenesis through low-grade, persistent inflammatory stimulation.