Cardiac troponin T and creatine kinase predict mid-term infarct size and left ventricular function after acute myocardial infarction: a cardiac MR study

Area of Science:

• Cardiology
• Biomarkers
• Cardiovascular Imaging

Background:

• Acute myocardial infarction (AMI) poses significant risks to left ventricular function and infarct size.
• Biomarkers like cardiac troponin T (cTnT) and creatine kinase (CK) are crucial in assessing myocardial damage.
• Contrast-enhanced MRI (CE-MRI) provides detailed assessment of infarct size and cardiac function.

Purpose of the Study:

• To evaluate the relationship between cTnT and CK release and infarct size and left ventricular function.
• To assess these relationships in the subacute phase and four months post-AMI using CE-MRI.
• To determine if early biomarker levels can predict long-term cardiac outcomes.

Main Methods:

• Cardiovascular MRI (CMR) was performed on 80 patients within 8 days and at 4 months after ST-elevation AMI.
• Serial measurements of CK and cTnT were taken from admission up to day 4 post-symptom onset.
• Correlations between biomarker concentrations and CE-MRI derived infarct size, ejection fraction (EF%), and end-systolic volume (ESV) were analyzed.

Main Results:

• CK and cTnT concentrations significantly correlated with infarct size, EF%, and ESV at all assessment times (r = 0.43 to 0.79, P < 0.001).
• Patients with cTnT < 3.26 μg/L at 48 hours showed significant improvement in global EF (P < 0.0001).
• Patients with cTnT ≥ 3.26 μg/L did not exhibit significant functional recovery (P = 0.09).

Conclusions:

• Early measurements (within 4 days) of cTnT and CK accurately predict infarct size and left ventricular function post-AMI.
• These biomarkers are valuable tools for predicting long-term cardiac outcomes after myocardial infarction.
• CE-MRI remains a key imaging modality for comprehensive assessment of myocardial damage and function.