Pneumococcal Vaccine Linked to Lower MI Risk

20 oct 2008--Pneumococcal vaccination is associated with reduced risk for myocardial infarction in high-risk patients, according to a case-control study in the Canadian Medical Association Journal.
Using hospital and government databases, researchers studied some 5000 patients with at least one cardiovascular risk factor. Roughly 1000 patients who were admitted for MI were matched with 4000 admitted to surgical departments. After multivariable adjustment, patients who experienced an MI were less likely than controls to have received a pneumococcal polysaccharide vaccine within the past decade (odds ratio, 0.53). The protective effect was even greater in an analysis limited to vaccination more than 2 years previously (OR, 0.33)
In discussing possible mechanisms for the observed effect, the authors cite a mouse study in which vaccination interfered with the absorption of oxidized LDL by macrophages, "thereby interrupting an early and crucial step leading to atherosclerosis."
LINK(S):
CMAJ article (Free)
CMAJ commentary (Free)