Myocardial infarction

Unrecognized MI Is Just as Deadly as Recognized MI

Long-term mortality risk in patients with unrecognized myocardial infarction (MI) can be just as high as in those with recognized MI, according to the results of a recent study.

 

Unrecognized MI is more prevalent than recognized MI in older populations, but the long-term prognosis of unrecognized MI is not known.

 

To explore these long-term risks, the researchers conducted a population-based prospectively enrolled cohort study involving 935 participants aged 67 to 93 years who were categorized using cardiac magnetic resonance (CMR) imaging at baseline. The primary outcome was all-cause mortality, and secondary outcomes were a composite of major adverse cardiac events.

 

After 3 years, mortality rates in patients with unrecognized and no MI were similar (3%) and lower than rates of recognized MI (9%). At 5 years, unrecognized MI mortality rates increased (13%) and were higher than those in patients without MI (8%) but were still lower than those with recognized MI (19%).

 

At 10 years, unrecognized MI and recognized MI mortality rates were not statistically different (49% and 51%, respectively) and were both significantly higher than no MI (30%).

 

After adjusting for age, sex, and diabetes, unrecognized MI was associated with an increased risk of death (hazard ratio [HR] 1.61), MACE (HR 1.56), MI (HR 2.09), and heart failure (HR 1.52) compared with no MI and had a statistically nondifferent risk of death (HR 0.99) and MACE (HR 1.23) compared with patients with recognized MI.

 

“Being more prevalent than recognized MI, unrecognized MI constitutes an underappreciated public health problem. Whether early detection of unrecognized MI by CMR could allow for the institution of risk factor management and thus reduce the associated long-term risks merits further investigation.”

 

—Michael Potts

 

Reference:

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