21  MINOCA

• Myocardial infarction with non-obstructive coronary arteries (MINOCA)
• MINOCA is defined as acute MI associated with a rise and fall of troponin on serial assessment with at least 1 value above the 99th percentile upper reference limit, combined with clinical evidence of infarction, nonobstructive coronary arteries on angiography, and no alternative etiology to explain the diagnosis.
• Affects ♀ > ♂
• Women are approximately 5 times more likely than men to have MINOCA (14.9%vs 3.5%), and patients who are “non-White” are approximately 1.5 times more likely than patients who are White to have MINOCA (14.9% vs 10.0%).
• MINOCA is present in approximately 5% to 6% of patients with MI.
• Diagnostic criteria:
  • acute myocardial infarction, i.e. EKG ∆, ↑ trops, CP
  • non-obstructive coronary aa. on cath
    • defined as stenosis < 50% in any potential infarct-related epicardial artery
  • no clinically overt alternative explanation, i.e. need to r/o other possible etiologies - coronary-mediated ischemia or myocardial injury

Conditions to exclude for Dx of MINOCA (Pasupathy et al., 2015 via BrighamChiefs, Aug 19, 2020)

General etiology	Diagnosis	Dx work-up
Ischemia	Coronary thrombosis and rapid clot lysis	Cath with IVUS
Ischemia	Micro and macro emboli	TTE, TEE
Ischemia	Coronary vasospasm	Hx (rest pain, recurrent episodic) UDS Acetylcholine provocation test
Ischemia	Coagulopathy	Thrombophilia screen (target based on hx)
Ischemia	Vasculitis	ESR, CRP
Ischemia	Coronary micovascular dysfunction	PET Coronary flow reserve
Myocardial injury	Myocarditis	ESR, CRP Cardiac MRI
Myocardial injury	PE (Right ❤️ strain) | CTA |
Myocardial injury	Cardiomyopathy (inc. Takotsubo)	Echo Cardiac MRI