Silent myocardial infarction and risk of heart failure: Current evidence and gaps in knowledge.

Coronary heart disease (CHD) is the most common underlying risk factor for heart failure (HF); up to one-third of the patients who are hospitalized for HF each year in the United States have a history of myocardial infarction (MI). Although silent MI (SMI) could account for up to one-half of all MIs, only a few studies examined the relationship between SMI and risk of HF. These few studies agreed on their conclusions that SMI is associated with increased risk of HF. However, there was less agreement on the magnitude of risk and the sex differences in the association between SMI and HF, which is probably due to the heterogeneity in how these studies defined SMI. This report summarizes and discusses the current evidence linking SMI to HF, the impact of the methods by which SMI is defined on the reported relationship between SMI and HF, the potential mechanisms for such relationship, the implications of these findings, and the gaps in knowledge that need to be addressed.