State of the Art in Imaging of Acute Coronary Syndrome with Nonobstructed Coronary Arteries.

Acute chest pain is a common concern for which patients present to the emergency department. Nonetheless, many patients with acute chest pain indicative of acute coronary syndrome (ACS) show nonobstructed coronary arteries at invasive coronary angiography or coronary CT angiography (CCTA), which is a clinical conundrum in day-to-day practice. Guidelines recommend that the initial course of action for patients experiencing acute chest pain is to exclude extracardiac and cardiac conditions that could cause nonischemic myocardial damage, including aortic dissection, pulmonary embolism, or septic shock. The generic term troponin-positive with nonobstructed coronary arteries (TpNOCA) was coined to refer to patients with nonobstructed coronary arteries who present with clinical symptoms and signs of ACS and increased cardiac troponin levels, electrocardiographic changes, or both. The causes of TpNOCA may be ischemic (eg, myocardial infarction with nonobstructed coronary arteries [MINOCA] or ischemia with nonobstructed coronary arteries [INOCA]) or nonischemic (eg, extracardiac and cardiac entities). MINOCA and INOCA are working diagnostic terms used until a definitive cause is established (eg, coronary plaque rupture, coronary artery dissection, or coronary microvascular disease). Noninvasive cardiac imaging techniques, notably CCTA and cardiac MRI, and ischemia testing are pivotal in evaluating and treating these patients through accurate identification of the underlying cause, improvement in risk stratification, and guidance for clinicians in decision making for treatment and follow-up. ©RSNA, 2025.