Influenza and cardiovascular disease pathophysiology: strings attached

A link between influenza infection and cardiovascular morbidity has been known for almost a century. This narrative review examined the cardiovascular complications associated with influenza and the potential mechanisms behind this relationship. The most common reported cardiovascular complications are cardiovascular death, myocardial infarction, and heart failure hospitalization. There are multiple proposed mechanisms driving the increased risk of cardiovascular complications. These mechanics involve influenza-specific effects such as direct cardiac infection and endothelial dysfunction leading to plaque destabilization and rupture, but also hypoxaemia and systemic inflammatory responses including increased metabolic demand, biomechanical stress, and hypercoagulability. The significance of the individual effects is unclear, and thus whether influenza directly or indirectly causes cardiovascular events is unknown. In conclusion, the risk of acute cardiovascular morbidity and mortality is elevated during influenza infection. The proposed underlying pathophysiological mechanisms support this association, but systemic responses to infection may drive this relationship.