Patients given the seasonal flu jab in the past year were 19% less likely to suffer a first MI than those unvaccinated, the researchers showed.
Niroshan Siriwardena from the University of Lincoln and colleagues assessed the risk of first time MI using primary care data for 78,706 patients aged 40 or over.
Between November 2001 and May 2007 there were 16,012 cases of MI in this group. Among the remaining patients, 62,694 were used as controls. Influenza vaccination was received by just over half of patients in each group.