Pneumonia Vaccine Linked to Lower Risk of Heart Attacks

A new study has found that pneumococcal (pneumonia) vaccination is associated with a 50% lower risk of heart attacks two years after vaccination.

Researchers from the University of Sherbrooke (Canada) conducted a case-control study of hospital-based health databases to obtain diagnoses and vaccination status of patients considered to be at risk of myocardial infarction (MI). The study included patients who had been admitted for treatment of MI, while the control group included patients admitted to a surgical department in the same hospital for reasons other than MI, between 1997 and 2003. A total of 43,209 patients at risk were identified; of these, 999 cases and 3,996 controls were matched according to age, sex, and year of hospital admission. The researchers found that patients who had received a vaccine were less likely than controls to have suffered an MI; this putative protective role of the vaccine was not observed for patients who had received the vaccine up to one year before myocardial infarction. In contrast, if vaccination had occurred two years or more before the hospital admission, a decrease of more than 50% in the rate of MI was identified. The study was published in the October 7, 2008, issue of the Canadian Medical Association Journal (CMAJ).

"We know that the pneumococcal vaccination can alter one of the complex mechanisms of atherosclerosis, one of the steps in the formation of atherosclerotic plaque, so we wanted to see if this could be replicated in clinic,” said lead author Danielle Pilon, M.D., M.Sc., a specialist in internal medicine and clinical pharmacology. "The hypothesis was that if the vaccination can alter one of the steps in atherosclerosis formation, perhaps it could decrease the risk of heart attack. And this is what we found.”

Previous research has demonstrated that pneumococcal pneumonia and other respiratory infections, including influenza and Severe Acute Respiratory Syndrome (SARS), have been shown to trigger an MI. In fact, during almost all influenza epidemics and pandemics (except the 1918 Spanish flu pandemic), about twice as many people died of cardiac causes as died of pneumonia, according to Mohammad Madjid, M.D., of the Texas Heart Institute (Houston; USA), in a commentary accompanying the study.

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University of Sherbrooke