Prognostic value and clinical predictors of intramyocardial hemorrhage measured by CMR T2* sequences in STEMI

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Microvascular injury in myocardial infarction includes microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH).
• Quantitative assessment of IMH using T2* cardiovascular magnetic resonance imaging (CMR) shows promise for evaluating microvascular damage in reperfused ST-segment elevation myocardial infarction (STEMI).

Purpose of the Study:

• To investigate the feasibility of quantitative IMH assessment with T2* CMR in STEMI patients.
• To correlate IMH extent with clinical parameters and CMR-derived measures, including infarct size (IS), MVO, and left ventricular ejection fraction (LVEF).
• To evaluate the association between IMH and major adverse cardiac events (MACE).

Main Methods:

• A single-center observational cohort study included 94 patients with reperfused STEMI undergoing CMR 7 days post-percutaneous coronary intervention.
• Infarct size (IS) and MVO were assessed using late gadolinium enhancement sequences.
• IMH was quantified using whole left ventricle (LV) volume T2* mapping sequences.

Main Results:

• MVO was identified in 52% of patients (median 3% LV mass), and IMH in 28% (median 1.1% LV mass).
• IMH extent was independently associated with anterior myocardial infarction (p=0.022) and thrombectomy (p=0.049).
• IMH correlated significantly with MVO (R=0.62, p<0.001), necrosis (R=0.58, p<0.001), and LVEF (R=-0.21, p=0.04). Patients with IMH had a higher incidence of MACE, independent of LVEF (p=0.022).

Conclusions:

• T2* mapping is a feasible and useful imaging technique for assessing IMH in STEMI patients post-reperfusion.
• IMH extent is associated with specific infarction locations (anterior) and interventions (thrombectomy).
• IMH is an independent predictor of MACE, highlighting its clinical significance in STEMI management, irrespective of LVEF.