Outcomes of Undetected Myocardial Infarction Examined

Unrecognized MI detected by cardiac magnetic resonance imaging has similar mortality rates over the long term compared with recognized MI.

Unrecognized myocardial infarction (MI) found on cardiac magnetic resonance (CMR) imaging may have long-term mortality risks similar to recognized MI, according to study results published in JAMA Cardiology.

The researchers of this study relied on data from 935 participants in the population-based ICELAND MI cohort study distinguished with CMR at baseline from January 2004 to January 2007 and aged 67 to 93 years. Follow-up continued for up to 13.3 years. The researchers utilized Kaplan-Meier time-to-event analyses and a Cox regression to evaluate the relationships between unrecognized MI at baseline and death and future cardiac events, including major adverse cardiac events (MACE).

At 3 years, researchers found that participants with unrecognized MI and those with no MI showed similar mortality rates (3%), but that these rates were lower compared with those who had recognized MI rates (9%).

At 5 years, unrecognized MI mortality rates increased to 13% and were higher than in those with no MI (8%), but this number was still lower compared with recognized MI rates (19%). At 10-year follow up, unrecognized MI and recognized MI mortality rates were 49% and 51%, respectively, and statistically similar; both outcomes, however, were considerably higher than in those with no MI (30%) (P <.001).

Adjustments for age, sex, and diabetes showed that unrecognized MI by CMR had an increased risk of death (hazard ratio [HR], 1.61; 95% CI, 1.27-2.04), MACE (HR, 1.56; 95% CI, 1.26-1.93), MI (HR, 2.09; 95% CI, 1.45-3.03), and heart failure (HR, 1.52; 95% CI, 1.09-2.14) compared with those who had no MI and a statistically similar risk of death (HR, 0.99; 95% CI, 0.71-1.38) and MACE (HR, 1.23; 95% CI, 0.91-1.66) compared with those who had recognized MI.

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Researchers concluded that unrecognized MI detected by CMR has similar mortality rates over the long term compared with recognized MI. Researchers noted that early detection by “CMR could allow for the institution of risk factor management and thus reduce the associated long-term risks [and] merits further investigation.”

Disclosures: Multiple authors declare associations with the pharmaceutical industry. Please see original reference for a full list of disclosures.


Acharya T, Aspelund T, Jonasson TF, et al. Association of unrecognized myocardial infarction with long-term outcomes in community-dwelling older adults: The ICELAND MI study [published online October 10, 2018]. JAMA Cardiol. doi:10.1001/jamacardio.2018.3285