Infarct-Related Myocardial Resistance Before Reperfusion in Patients With Acute Myocardial Infarction to Predict...

Area of Science:

• Cardiology
• Biomedical Engineering
• Diagnostic Imaging

Background:

• Microvascular injury (MVI) in ST-elevation myocardial infarction (STEMI) is linked to heart failure and mortality.
• Early detection of MVI is crucial for timely intervention with experimental therapies.
• Current diagnostic methods for MVI in STEMI lack pre-reperfusion assessment capabilities.

Purpose of the Study:

• To evaluate the efficacy of invasively measured infarct-related absolute myocardial resistance (Rinfarction) in predicting MVI before reperfusion.
• To assess the diagnostic performance of Rinfarction for microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) using cardiac magnetic resonance imaging (CMR).

Main Methods:

• Rinfarction was calculated by measuring distal coronary pressure changes during saline infusion in the occluded artery.
• Diagnostic performance was assessed using Receiver Operating Characteristic (ROC) curves.
• Patients underwent CMR 2-7 days post-infarction to evaluate MVI.

Main Results:

• Rinfarction demonstrated strong predictive performance for MVO (Area Under Curve [AUC] 0.84) and IMH (AUC 0.78).
• An optimal cutoff of 1000 Wood units (WU) was identified for predicting both MVO and IMH.
• A trend towards increased mortality or heart failure hospitalization was observed in patients with Rinfarction ≥ 1000 WU.

Conclusions:

• Infarct-related resistance (Rinfarction) effectively predicts microvascular injury in STEMI patients prior to reperfusion.
• Rinfarction can serve as a valuable tool in clinical trials to stratify patients for experimental therapies.
• This invasive measurement offers a novel approach for early MVI detection in STEMI.