Influenza vaccination reduces the risk of myocardial infarction by 20%
Vaccination against influenza reduces the risk of a first heart attack by around 20%; however, vaccination with the pneumococcal vaccine does not affect the risk of myocardial infarction.
To explain the incidence of acute myocardial infarction (MI) in winter, various theories have been proposed: the influence of climatic and metabolic factors, respiratory infections causing lesions of atherosclerotic plaques. In this regard, it has been suggested that influenza vaccination could reduce the risk of acute myocardial infarction.
A case-control study in the UK suggests that influenza vaccination reduces the risk of a first heart attack by around 20%. At the same time, vaccination with the pneumococcal vaccine does not affect the risk of myocardial infarction (MI).
Researchers found that people who got the flu were 19% less likely to develop a first heart attack than people who didn't get the flu vaccine. These differences were noted in equivalent groups in the presence of generally recognized risk factors for cardiovascular disease. The study analyzed data from 78,706 patients in the United Kingdom's General Practice Research Database, of which 16,012 were first MI cases, recorded between 2001 and 2007, in patients of the age of 40 and over. 62694 "controls" corresponded to these cases. About half of people in both groups received the flu vaccine in the past year.
Flu vaccination in the past year has been shown to be associated with a significant decrease in the incidence of acute myocardial infarction (adjusted odds ratio - OR = 0.87). A similar effect was exerted by influenza vaccination during the current vaccination season (adjusted OR = 0.80). Early seasonal influenza vaccination compared to late (after mid-November) was associated with a more significant reduction in the risk of acute myocardial infarction (by 22% and 12%, respectively). Revaccination against influenza has been associated with a reduced risk of acute myocardial infarction (OS = 0.79) compared to the absence of vaccination in the past 5 years.
In the UK, influenza vaccination is recommended for people 65 years of age or older, as well as for younger patients with CAD, chronic respiratory disease, kidney disease or diabetes. At the same time, when analyzing data from the subpopulation of patients aged 40 to 65, researchers found a similar reduction in risk in people vaccinated against influenza, regardless of the presence or absence of other risk factors.
Unfortunately, the study design does not prove the presence of a causal relationship between influenza vaccination and the effect detected. Further studies are planned to identify the relationship between vaccination and the risk of stroke, as well as clinical studies of the influenza vaccine in groups of patients 40 to 65 years of age with risk factors for cardiovascular disease.
In general, the data obtained can be considered as an additional argument in favor of the annual influenza vaccination, especially in people with risk factors for cardiovascular events.