Pathophysiology of LV Remodeling Following STEMI: A Longitudinal Diffusion Tensor CMR Study

Area of Science:

• Cardiovascular Imaging
• Cardiac MRI
• Myocardial Infarction Research

Background:

• Adverse left ventricular (LV) remodeling post-ST-segment elevation myocardial infarction (STEMI) is linked to poor prognosis.
• Mechanisms of adverse LV remodeling post-STEMI are not fully understood.
• Diffusion tensor cardiac magnetic resonance (DT-CMR) offers in vivo myocardial architecture characterization.

Purpose of the Study:

• To evaluate associations between early DT-CMR findings and long-term adverse LV remodeling post-STEMI.
• To investigate the predictive value of myocardial architecture parameters in STEMI patients.

Main Methods:

• 100 STEMI patients underwent CMR (including DT-CMR) at 5 days and 12 months post-reperfusion.
• DT-CMR assessed fractional anisotropy (FA), secondary eigenvector angle (E2A), and helix angle (HA).
• Adverse remodeling defined as a 20% increase in LV end-diastolic volume at 12 months.

Main Results:

• 32 patients (32%) experienced adverse remodeling.
• Lower FA, E2A, and proportion of right-handed myocytes (RHM) in infarct zone at 5 days were associated with adverse remodeling.
• Infarct FA and E2A were independent predictors of adverse LV remodeling.

Conclusions:

• Early post-STEMI DT-CMR reveals cardiomyocyte disorganization (low FA, E2A) in the infarct zone.
• These architectural changes persist and are independently associated with long-term adverse LV remodeling.
• DT-CMR may identify patients at risk for adverse remodeling, guiding therapeutic strategies.