A Shot for the Heart: Flu Vaccine Protects Cardiac Patients

New research is pointing to yet another reason pharmacists should be encouraging patients to get their flu shots, especially those with underlying conditions like diabetes and heart disease. Study findings appearing in the October edition of The Lancet Infectious Diseases report that the flu can actually trigger a heart attack, and the influenza vaccine offers protection for cardiac patients.

Cardiac complications of influenza infection, such as myocarditis, have long been recognized, but the role of the flu as a trigger of acute myocardial infarction is less clear. To find out more about a potential link-and whether flu vaccination is protective-British researchers conducted a meta-analysis of randomized controlled trials held between 1932 and 2008; 42 publications describing 39 studies were identified.

After reviewing all of the population-based studies, researchers found a consistent association between influenza and acute myocardial infarction and a weaker association with cardiovascular death. They found the proportion of additional influenza deaths due to heart disease averaged 35% to 50%. Several of the studies also pointed to a protective effect against heart attacks or cardiovascular events in individuals vaccinated against influenza.

Study authors noted that influenza is the only respiratory virus for which effective vaccination is available. "We believe influenza vaccination should be encouraged wherever indicated, especially in those people with existing cardiovascular disease," they concluded. They suggest further evidence is needed on the effectiveness of flu vaccines in reducing heart attacks in individuals without established vascular disease.

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