Myocardial Ischemia: Differentiating between Epicardial Coronary Artery Atherosclerosis, Microvascular Dysfunction and Vasospasm in the Catheterization Laboratory

Figures

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  Figure A1. INOCA Diagnostic workflow. A proposed workflow chronologically based on the clinical suspicion.

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  Figure 1. Myocardial ischemia determinants. FFR: fractional flow reserve; NHPR: non-hyperemic pressure ratio; CFR: coronary flow reserve; IMR: index of microvascular resistance: ACh: Acetylcholine, PCI: percutaneous coronary intervention: CABG: coronary artery bypass graft; CCB: calcium-channel blockers.

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  Figure 2. Epicardial Disease. Scan of a 72-year-old man presenting with acute chest pain and anterior STEMI at ECG. Basal angiography documented LAD occlusion and visually moderate RCA stenosis (A, black arrow). Functional evaluation was performed on the latter, non-culprit lesion. FFR came out positive (B) and a significant pressure drop was documented at pullback (C). In presence of a focal, significant lesion, PCI was therefore performed, resulting in an optimal angiographic result (D).

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  Figure 3. Microvascular Disease. The results of a 65-year-old woman presenting with exertional chest discomfort. Angiography revealed no epicardial stenosis (A). Functional evaluation was performed (B) and normal RFR and FFR were documented. CFR was found to be altered (<2.0), as was as IMR (>25). Microvascular structural disease was diagnosed and medical therapy was optimized, introducing lipid-lowering therapy, ACE inhibitors, and beta-blockers.

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  Figure 4. Vasomotor impairment. Results of a 45-year-old woman presenting with acute chest pain and STEMI at ECG. Basal angiography (A) and ECG (B) performed during symptom regression documented no epicardial stenosis and no electrocardiographic alterations. Black arrows mark a large second marginal branch; green arrows mark LAD. Full physiology documented negative FFR, CFR and IMR (C). Acetylcholine test was subsequently performed: arrows point out how both LAD and MO2 undergo important vasospasm (D); contextual ST-elevation is documented at 12-lead ECG monitoring (E) and intense chest discomfort was reported by the patient. Calcium-channel blockers were introduced.