Pneumonia Vaccination Lowers the Risk of a Heart Attack

One hundred years ago scientists believed that heart attacks had an infectious origin. Since then, we’ve learned a lot more about other risk factors – high blood pressure, high cholesterol, smoking, obesity, and diabetes. More recently, inflammation has come back into the picture. Markers of inflammation in the body, such as C-reactive protein and the interleukins, indicate that inflammation is an important mediator in the progression of atherosclerosis. And medications like statins, which are used to prevent cardiovascular diseases, also appear to reduce inflammation.

A study published last year in the Canadian Medical Association Journal provides a practical way older persons can apply this information, and lower their chance of having a heart attack. Patients admitted to Quebec hospitals for treatment of a heart attack were compared with patients admitted to a surgical department in the same hospital for a different reason. The second group – controls – were matched the heart attack patients according to age, gender, and the year of hospitalization. The vaccination records of the patients in the two groups were obtained and their pneumococcal vaccine status evaluated.

Between 1997 and 2003 almost 1,000 heart attack patients were compared with 4,000 patients admitted for other reasons. The heart attack patients were about half as likely to have been given pneumococcal vaccine. In those patients where the vaccine had been given less than a year before the heart attack, the ‘protective effect’ was not pronounced – their risk of having a heart attack was only 85% that of non-vaccinated patients. However, if vaccination had occurred 2 years or more before hospital admission, the likelihood was reduced to 33%.

In Canada, the goal is to have over 90% of the over-65 population vaccinated; in fact, the actual numbers achieved are much lower. In the USA, the recommendation for older adults is similar. While such vaccination has been shown to lower mortality, it’s been difficult to show that it actually decreases the risk of death from pneumonia, but it’s known that in every ‘flu epidemic more people die of heart attack than pneumonia. Pneumococcal infection, if it enters the blood, generates an inflammatory response, according to one of the authors of this study. This can lead, as we originally stated, to progression of coronary atherosclerosis. With the threatened return of swine H1N1 flu in the fall, along with the inevitable ‘regular’ H1N1 epidemic, it makes sense for all persons over 65 to make sure they have had a pneumococcal vaccination shot.