USA: A cohort study of 8560 consecutive patients with STEMI revealed that compared with obstructive disease, 5-year mortality hazard risk was greater in patients with nonobstructive coronary arteries (MINOCA) and similar in patients with MINOCA mimickers.
The 5-year mortality risk was nearly twofold higher in true MINOCA patients than in those with obstructive CAD (HR 1.93). The findings were published online in JAMA Network Open on November 16, 2023.

"ST-segment elevation myocardial infarction (STEMI) without obstructive disease is a morbid disease, emphasizing the need to diagnose the underlying cause of MINOCA mimickers and MINOCA at the time of the event," the researchers reported.
Traditionally, MINOCA and mimickers are considered to be less lethal diseases. Therefore, these patients are often not given a diagnosis, they don't get the correct diagnostic test that exists for MINOCA, and they don't get the same treatment at discharge.
The precise definition of MINOCA has been debatable since the term's introduction less than a decade ago, plaguing the research. The American Heart Association (AHA) defines it as coronary artery plaque disruption, coronary embolism/thrombosis, or epicardial coronary spasm and excludes mimics. Still, a statement by the European Society of Cardiology includes the conditions that also mimic MINOCA.
With the lack of clarity, it has been challenging for physicians to identify and treat MINOCA and understand the long-term implications of the disease. Therefore, Odayme Quesada, The Christ Hospital Heart and Vascular Institute, Cincinnati, Ohio, and colleagues aimed to assess differences in 5-year mortality in patients presenting with STEMI due to MINOCA and MINOCA mimickers (myocarditis, takotsubo cardiomyopathy, or nonischemic cardiomyopathy) as compared with obstructive disease.
For this purpose, the researchers conducted a prospective registry-based cohort study of consecutive STEMI activations at 3 regional Midwest STEMI programs. STEMI without a culprit artery and increased troponin levels were categorized as MINOCA or MINOCA mimickers.
The 5-year mortality risk in STEMI patients presenting with MINOCA and MINOCA mimickers was assessed in comparison with obstructive disease using Adjusted Cox regression analysis.
The study led to the following findings:
Among 8560 consecutive patients with STEMI, the mean age was 62 years, and 30% were females.
The cohort included 8151 patients with STEMI due to obstructive disease, 120 patients with MINOCA, and 289 patients with MINOCA mimickers. Patients were followed up for a median of 7.1 years.
Patients with MINOCA and MINOCA mimickers were less likely to be discharged with cardiac medications compared with obstructive disease.
At 5-year follow-up, mortality in STEMI presenting with obstructive disease (16% of participants) was similar to MINOCA (18% of participants) and MINOCA mimickers (18% of participants).
In adjusted Cox regression analysis compared with obstructive disease, the 5-year mortality hazard risk was 1.93 times higher in MINOCA and similar in MINOCA mimickers (HR, 1.08).
"In contrast to the general prevailing sentiment, STEMI due to MINOCA mimickers and MINOCA are lethal as obstructive disease," the researchers wrote. "We demonstrate that the 5-year mortality risk is 1.93-fold higher in MINOCA as compared with obstructive disease."
"The current underutilization of cardiac magnetic resonance imaging (CMRI) and intravascular imaging restricts our ability to explore underlying MINOCA and MINOCA mimickers diagnosis, which could play an important role in guiding future management and prognosis," they concluded.
Reference:
Quesada O, Yildiz M, Henry TD, et al. Mortality in ST-Segment Elevation Myocardial Infarction With Nonobstructive Coronary Arteries and Mimickers. JAMA Netw Open. 2023;6(11):e2343402. doi:10.1001/jamanetworkopen.2023.43402