Diagnostic and prognostic values of cardiac magnetic resonance imaging tissue mapping in acute myocardial infarction

Abstract

Background: The unique capacity to non-invasively examine the myocardium is unique to magnetic resonance imaging of the heart, which has emerged as the gold standard for determining myocardium viability.
Objective: In patients with ischemic heart disease, the native and post-contrast T1 maps of cardiac magnetic resonance imaging (CMRI) are extensively used, along with the T2 map, to diagnose myocardial edema and necrosis in cases following primary percutaneous coronary intervention (PCI) for patients acute myocardial infarction and their prognostic value is examined.
Patients and methods: Between December 2021 and April 2023, 90 individuals had elective CMRI appointments scheduled. Our patients arrived at the cardiology department with a clinical diagnosis of an acute myocardial infarction requiring amenable for primary PCI. One to two days after PCI, they were referred to the radiology department for CMRI as part of a research study. Three to four months later, a follow-up CMRI was carried out.
Results: The mean age of the 64 male participants and 26 female participants in this study was 55 (±5 years). With a P value of 0.001, distinct tissue mapping values in our investigation demonstrated a significant statistical difference between hyper-enhanced (HE) and remote segments. 70 patients (63%) had microvascular blockage, which we found. In patients with microvascular obstruction (MVO), there was a difference in tissue mapping values between segments with MVO and segments without MVO that was highly amplified, with a propensity to pseudo-normalize the tissue mapping values of the MVO segments, but this difference was not statistically significant. With 81% sensitivity, 72% specificity, 75% positive predictive value, 79% negative predictive value, and 77% accuracy, the suggested cutoff value for the T2 map was 53.2ms (millisecond).
Two recommended cut-off values for the native T1 map were: The first one had a 1076.9 ms time window, an accuracy of 77%, sensitivity of 69%, specificity of 81%, positive predictive value of 78%, and negative predictive value of 72%.
The second one had a 1069.3 ms time window, an accuracy of 75%, sensitivity of 76%, specificity of 74%, positive predictive value of 74%, and negative predictive value of 75%.
The extracellular volume (ECV) proposed cut-off value displayed 85% accuracy, 89% positive predictive value, 80% negative predictive value, 79% sensitivity, and 90% specificity.

Conclusion: the use of tissue mapping to identify STEMI individuals with salvageable myocardial tissue post-primary PCI, and obtain cutoff values with adequate sensitivity, specificity, and accuracy in the early and late follow-up of myocardial evaluation