Heartbeat: Virtual histopathology after myocardial infarction

Inflammation plays a key role in outcomes after myocardial infarction yet we have few tools to directly visualise the cellular inflammatory response in clinical practice. In this issue of Heart, Stirrat and colleagues1 performed repeated MRI studies in 31 patients after myocardial infarction using ultra-small-super-paramagnetic particles of iron oxide (USPIO) to visualise macrophages within the myocardium. In combination with other MRI imaging sequences, this approach provides a virtual histopathologic view of the myocardium. In the infarcted myocardial segment, USPIO uptake peaked at 2–3 days and resolved by 10–16 days whereas myocardial oedema peaked later (day 3 to 9) and persisted for over 3 months. (figure 1) As the authors suggest: "This imaging technique holds promise as a non-invasive method of assessing and monitoring myocardial cellular inflammation with potential application to diagnosis, risk stratification and assessment of novel anti-inflammatory therapeutic interventions."

Figure 1

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