Scar extent, left ventricular end-diastolic volume, and wall motion abnormalities identify high-risk patients with...

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Patients with previous myocardial infarction (MI) are at risk for adverse cardiac events.
• Accurate risk stratification is crucial for guiding patient management and therapeutic decisions.
• Current risk assessment models may not fully capture the complex pathophysiology post-MI.

Purpose of the Study:

• To evaluate if combining left ventricular (LV) volumes, regional wall motion abnormalities, and scar tissue extent from cardiac magnetic resonance (CMR) improves risk stratification in patients with prior MI.
• To determine the independent prognostic value of these CMR-derived parameters.

Main Methods:

• A cohort of 231 patients with previous MI underwent cine CMR and late gadolinium enhancement (LGE) imaging.
• LV volumes, regional wall motion abnormalities (wall motion score index), and scar extent (LGE percentage) were quantified.
• Patients were followed for a median of 3.2 years for cardiac events (cardiac death or appropriate ICD shocks).

Main Results:

• An LGE extent >12.7%, LV end-diastolic volume >105 mL/m², and a wall motion score index >1.7 were independently associated with adverse cardiac events.
• Patients with none of these factors had a significantly lower risk (HR=0.112) compared to those with all three.
• The cumulative 4-year event rate was 3.5% for patients with no factors, 7.7% for one or two factors, and 29.6% for all three factors.

Conclusions:

• A multiparametric CMR approach integrating scar extent, LV volumes, and regional wall motion abnormalities significantly enhances risk stratification in patients post-MI.
• This comprehensive imaging strategy provides more accurate prediction of future cardiac events than individual parameters alone.
• This method can aid clinicians in identifying high-risk individuals needing closer monitoring or intervention.