Pneumococcal vaccine not linked to reduced risk of heart attack

Men aged 45 years or older who received pneumococcal vaccine were not less likely to have a heart attack or stroke compared to men who did not receive the vaccine, according to a new study.
Researchers examined the association between the administration of pneumococcal vaccine and the risk of developing acute heart attack and stroke in men, taking into accountimportant confounders. The study included 84,170 participants aged 45-69 years from the California Men’s Health Study, who were recruited between January 2002 and December 2003, and followed up until December 31, 2007. Demographic and detailed lifestyle characteristics were collected from the surveys.

During follow-up, there were 1,211 first myocardial infarctions (MIs) in vaccinated persons (rate of 10.7 per 1000 person-years) compared with 1,494 first MI events in unvaccinated individuals (6.07 per 1000 person-years).
For stroke, there were 651 events in vaccinated persons (5.3 per 1000 person-years) compared with 483 events in unvaccinated persons (1.9 per 1000 person-years).
After analysis of the data, the researchers found no evidence for an association between pneumococcal vaccination and reduced risk of acute MI or stroke. “In addition, association was not observed either in the current smokers, men with history of diabetes, men with history of hypertension, or men of the low-risk group,” the researchers reported.
In an accompanying editorial, doctors at the Baylor College of Medicine said the results represented “another important reminder of the complexities involved in evaluating observational studies examining the relationship between vaccine administration and clinical outcomes, and the need for more robust study designs”.
“Until rigorous data from trials are available to determine whether pneumonia vaccine can prevent MI, physicians should strictly adhere to available guidelines for optimising vaccination rates in recommended target groups, because these rates are still far from optimal,” said the doctors.
JAMA 2010;303:1699-1706, 1751-1752