A large portion of myocardial infarction (MI) cases are unrecognized MI. Although unrecognized MI can be identified by cardiac magnetic resonance (CMR), the prognosis of the disease in older adults is poor. This study aims to evaluate the long-term outcomes of unrecognized MI compared with clinically recognized MI and no MI.
This population-based, prospectively enrolled cohort study included a total of 935 patients with unrecognized MI, recognized MI, or no MI. The patients were followed up for up to 13.3 years. The primary outcome of the study was all-cause mortality, along with a composite of major cardiac events, such as death, nonfatal MI, and heart failure.
At 3 years, mortality rates of unrecognized MI and no MI were similar (3%), which were lower than the mortality rate associated with recognized MI (9%). At 5 years, the mortality rate among unrecognized MI patients was 13%, as compared with 8% in no MI patients and 19% in recognized MI patients. At 10 years, the mortality rates in unrecognized MI and recognized MI patients were statistically similar (49% and 51%) but were significantly higher than patients with no MI (30%).
The research concluded that older patients with unrecognized MI were at a lower risk of mortality in the short-term but at a similar risk of mortality in the long term when compared with patients with recognized MI.