People suffering from influenza may be at six-fold increased risk of experiencing a heart attack particularly in first seven days warned a study emphasising the importance of vaccination. The risk may be higher for older adults patients with influenza B infections and patients experiencing their first heart attack. Our findings are important because an association between influenza and acute myocardial infarction reinforces the importance of vaccination said lead author Jeff Kwong a scientist at Institute for Clinical Evaluative Sciences (ICES) -- Canada-based non-profit. The study combined with previous evidence that influenza vaccination reduces cardiovascular events and mortality support international guidelines