Table 2

Key differential features among obstructive and non-obstructive coronary artery diseases leading to clinical presentation of ACS

Obstructive CADMyocardial infarction in absence of obstructive coronary artery disease
Incidence75%–80%6%–15%
Mean age61 years58 years
Women25%–30%50%
Specific causesAtherosclerotic plaqueAtherosclerotic plaque disruptionSCADTakotsubo
syndrome
Embolism
Thrombosis
Vascular dysfunction
Incidence within ACS75%–80%1%–5%1%–4%
35% among women <50 years of age
2%–3%<1%Macrovascular
<2% (whites)
5%–8% (Asians) Microvascular
3%–8%
Women25%–30%50%90%80%–90%50%80%–90%
Specific features and triggersTypical finding is more frequent single-vessel CAD in STEMI while multivessel CAD in NSTEMIFrequently observed in young women who died suddenlyStrong association with fibromuscular dysplasia
Triggered by pregnancy/partum emotional stress extreme physical activity
It has a temporary course with yearly recurrence rate <1%
Triggered by emotional (mostly negative life events) and physical stressors in 70% of cases
Inherited thrombophilia particularly factor V Leiden (5% of general population) increases the infarct risk by a factor of 1.7–3.7.Very frequent among Asian people and observed in 50% of patients with coronary atherosclerosis
Additional diagnostic toolsFFR for non-culprit lesions
OCT/IVUS in case of uncertainness
OCTOCT
IVUS
Echocardiography contrast CMRITEE
Check for hypercoagulable disorders
Intracoronary acetylcholine test coronary flow reserve in response to adenosine corrected TIMI frame count
  • ACS, acute coronary syndrome; CAD, coronary artery disease; CMRI, cardiac MRI; FFR, fractional flow reserve; IVUS, intravascular ultrasound; (N)STEMI, (non) ST-segment elevation myocardial infarction; OCT, optical coherence tomography; SCAD, spontaneous coronary artery dissection; TEE, trans-oesophageal echocardiography; TIMI, thrombolysis in myocardial infarction.