The number of unrecognized myocardial infarction scars detected at DE-MRI increases during a 5-year follow-up.

Objectives: In an elderly population, the prevalence of unrecognized myocardial infarction (UMI) scars found via late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging was more frequent than expected. This study investigated whether UMI scars detected with LGE-CMR at age 70 would be detectable at age 75 and whether the scar size changed over time.

Methods: From 248 participants that underwent LGE-CMR at age 70, 185 subjects underwent a follow-up scan at age 75. A myocardial infarction (MI) scar was defined as late enhancement involving the subendocardium.

Results: In the 185 subjects that underwent follow-up, 42 subjects had a UMI scar at age 70 and 61 subjects had a UMI scar at age 75. Thirty-seven (88 %) of the 42 UMI scars seen at age 70 were seen in the same myocardial segment at age 75. The size of UMI scars did not differ between age 70 and 75.

Conclusions: The prevalence of UMI scars detected at LGE-CMR increases with age. During a 5-year follow-up, 88 % (37/42) of the UMI scars were visible in the same myocardial segment, reassuring that UMI scars are a consistent finding. The size of UMI scars detected during LGE-CMR did not change over time.

Key Points: • UMI scars detected by LGE-CMR are frequent in elderly. • The prevalence of UMI scars detected with LGE-CMR increases with age. • UMI scar size does not change over time.