Association of CagA⁺ Helicobacter pylori infection with aortic atheroma

Background: To investigate possible association between infection with CagA⁺ strains of Helicobacter pylori and aortic atheroma diagnosed by transesophageal echocardiography. Methods and results: One hundred and eighty-eight consecutive subjects prospectively examined for presence of aortic atheroma (localized intimal thickening of ≥3 mm) by transesophageal echocardiography were tested for serum IgG antibodies against H. pylori (enzyme-linked immunosorbent assay) and CagA protein (Western blot assay). The association between infection with H. pylori, CagA status of the infecting H. pylori strains, and aortic atherosclerosis was evaluated after adjusting for coronary artery disease risk factors. There was a linear trend for presence of atheroma in subjects with CagA-positive H. pylori infection (51/81, 63%) compared to subjects with CagA-negative H. pylori infection (21/45, 46.7%) and uninfected subjects (18/62, 29%) (p = 0.003). H. pylori seropositivity was not associated with aortic atheroma (OR 2.9; 95% CI, 0.8-10.3; p = 0.11) when CagA status is not taken into account. On multivariate analysis, parameters associated with risk of aortic atheroma were CagA-positive H. pylori seropositivity (OR 4.4; 95% CI, 1.4-14.7; p = 0.01), older age (OR 1.2; 95% CI, 0.9-14.7; p = 0.01), having ever smoked cigarettes (OR 3.6; 95% CI, 1.3-10.0; p < 0.001), and elevated serum triglyceride level (OR 3.4; 95% CI, 1.3-9.4; p = 0.02). Conclusions: After controlling for H. pylori infection and coronary artery disease risk factors, infection with a CagA-positive strain of H. pylori was independently associated with aortic atherosclerosis. This study suggests a gradient of atherosclerosis between uninfected individuals and patients with CagA-positive H. pylori infection and should prompt research into the role of CagA-positive H. pylori infection in the inflammatory atherosclerotic process.