📄 Ischaemia–reperfusion injury: new insights from quantitative CMR
🔗 DOI:
doi.org/10.1093/ehjimp/qyaf1…
🫀 Reperfusion saves myocardium—but it can also cause additional injury.
This experimental CMR study provides high-resolution, time-resolved insights into what really happens in the myocardium during ischaemia and early reperfusion.
✨ Study design:
🔹 Swine model of acute MI (LAD occlusion → reperfusion)
🔹 Continuous CMR acquisition at:
baseline
during ischaemia
immediately after reperfusion
up to 2–3 hours
🔹 Quantitative T1 & T2 mapping pixel-wise analysis
✨ Key findings:
📈 During ischaemia:
➡️ Moderate increase in T1 and T2 ( ~11%)
👉 reflecting early oedema
📈 After reperfusion:
➡️ Marked increase in T1 and T2 ( ~23%)
👉 indicating rapid and significant tissue water accumulation
📊 Critical insight:
👉 The biggest myocardial change happens AFTER reperfusion
➡️ Not during ischaemia
➡️ But immediately after restoring flow
🧠 Three distinct reperfusion patterns identified:
1️⃣ Reperfusion MVO (microvascular obstruction)
👉 severe injury, largest signal increase
2️⃣ Reperfusion without MVO
👉 less severe but still significant oedema
3️⃣ No effective reperfusion
👉 blunted signal changes
📌 As shown in Figures 2–4 (page 5), each pattern has distinct T1/T2 evolution profiles
⚠️ Key paradigm shift:
👉 Post-reperfusion oedema:
❗ does NOT reflect pre-ischaemic tissue status
❗ does NOT predict final tissue outcome
➡️ Early imaging interpretation may be misleading
🤖 Methodological innovation:
✔ Pixel-wise standardised analysis
✔ Eliminates ROI bias
✔ Enables true spatial and temporal mapping of injury
💡 Clinical implications:
👉 Reperfusion injury is:
dynamic, heterogeneous, and not fully captured by traditional imaging timing
👉 Timing of CMR matters:
➡️ early post-reperfusion scans may reflect transient inflammation, not final infarct size
🚨 Bottom line:
In acute MI, the most dramatic myocardial changes occur after reperfusion—not during ischaemia—and early oedema does not define final injury.
#Cardiology #CMR #MyocardialInfarction #ReperfusionInjury #T1Mapping #T2Mapping #CardiacImaging #PrecisionMedicine #TranslationalResearch 🫀📊