Intro
A large Mayo Clinic community study shows that many heart attacks in adults ≤65—especially women—are not caused by classic plaque blockages. Non-atherosclerotic causes like SCAD, coronary embolism, coronary spasm, and supply–demand mismatch were frequent and often misdiagnosed. :contentReference[oaicite:1]{index=1}
Key Points
- Beyond plaque: In women ≤65, fewer than half of heart attacks were due to atherosclerosis; in men, about three-quarters were. :contentReference[oaicite:2]{index=2}
- SCAD matters: SCAD—often in younger, otherwise healthy women—was commonly missed when treated as a typical plaque MI. :contentReference[oaicite:3]{index=3}
- Triggers & mismatch: Conditions like anemia or infection can precipitate MI without major plaque and carry meaningful risk. :contentReference[oaicite:4]{index=4}
- Correct diagnosis = safer care: Some SCAD cases are best managed conservatively rather than with routine stenting. :contentReference[oaicite:5]{index=5}
Background
Researchers analyzed 15 years of Olmsted County (Rochester Epidemiology Project) data and adjudicated MI causes in patients ≤65 years. After excluding periprocedural events, 1,474 MIs were classified by underlying mechanism, revealing stark sex differences in causation. :contentReference[oaicite:6]{index=6}
Causes or Mechanisms
- Atherosclerotic MI (plaque rupture/erosion/embolization): Most common overall but <50% in women vs ~75% in men. :contentReference[oaicite:7]{index=7}
- SCAD: Arterial wall tear; predilection for women; may be misread on angiography without careful imaging. :contentReference[oaicite:8]{index=8}
- Coronary embolism & spasm: Non-plaque occlusions or transient constrictions. :contentReference[oaicite:9]{index=9}
- Supply–demand mismatch: Systemic stressors (e.g., anemia, infection) tipping the heart into ischemia/MI. :contentReference[oaicite:10]{index=10}
Diagnosis / Treatment / Options
- Imaging: Coronary angiography with consideration of OCT/IVUS to detect SCAD or subtle non-plaque causes.
- SCAD management: Often conservative if stable; stenting reserved for ongoing ischemia/left-main/proximal critical cases.
- Plaque MI: Rapid reperfusion (PCI) and guideline-directed antithrombotic/lipid-lowering therapy.
- Mismatch/triggered MI: Treat the underlying stressor (e.g., transfuse for severe anemia, treat infection) alongside cardiac care. :contentReference[oaicite:11]{index=11}
Risks / Benefits / Prognosis
- Misdiagnosis risk: Treating SCAD like plaque MI can expose patients to unnecessary stents and complications. :contentReference[oaicite:12]{index=12}
- Prognosis varies: Outcomes depend on cause (e.g., SCAD vs plaque vs mismatch) and timeliness of correct treatment. :contentReference[oaicite:13]{index=13}
FAQ
Q: I’m under 50 and had chest pain—could it be a heart attack without clogged arteries?
A: Yes. Non-plaque causes (like SCAD) are more common in younger women; seek emergency care and mention these possibilities. :contentReference[oaicite:14]{index=14}
Q: How do doctors tell SCAD from a typical heart attack?
A: Detailed angiography and sometimes OCT/IVUS help reveal arterial tears or other non-plaque features. :contentReference[oaicite:15]{index=15}
Q: Does treatment differ?
A: Yes. Some SCAD cases are better managed without stents; plaque MI usually requires rapid artery opening plus medications. :contentReference[oaicite:16]{index=16}
Q: What if my MI was triggered by illness like flu or severe anemia?
A: Treating the trigger is crucial along with cardiac care; your team will tailor meds and follow-up to your cause. :contentReference[oaicite:17]{index=17}
Q: Can this happen again?
A: Recurrence risk depends on the cause (e.g., SCAD recurrence is possible). Follow a specialist plan and attend all follow-ups. :contentReference[oaicite:18]{index=18}