Novel biomarkers help discriminate type 2 MI from type 1 MI in noninvasive manner
The most common presentation of myocardial infarction (MI) tends to be type 1 myocardial infarction (T1MI). However, a substantial proportion has type 2 myocardial infarction (T2MI). Differentiating between type 1 and type 2 MI is clinically important, as the therapeutic focus differs. In a recent study, researchers evaluated 17 novel cardiovascular (CV) biomarkers and reported that these biomarkers provided modest discrimination in the early, noninvasive diagnosis of T2MI vs T1MI. The research has been published in the JAMA Cardiology on April 21, 2021.
Rapid and accurate noninvasive discrimination of T2MI, which is because of a supply-demand mismatch, from T1MI, which arises via plaque rupture, is essential because treatment differs substantially. Unfortunately, this is a major unmet clinical need because even high-sensitivity cardiac troponin (hs-cTn) measurement provides only modest accuracy. Dr Thomas Nestelberger and his team conducted a study to test the hypothesis that novel cardiovascular biomarkers quantifying different pathophysiological pathways involved in T2MI and/or T1MI may aid physicians in the rapid discrimination of T2MI vs T1MI.
It was an international, multicenter prospective diagnostic study of 5887 patients with acute chest discomfort in the emergency departments. The researchers evaluated the discrimination of hs-cTn T, hs-cTn I, and 17 novel cardiovascular biomarkers measured in subsets of consecutively enrolled patients against a reference standard (final diagnosis), centrally adjudicated by 2 independent cardiologists according to the fourth universal definition of MI, using all information, including cardiac imaging and serial measurements of hs-cTnT or hs-cTnI.
Key findings of the study were:
- Among 5,887 eligible patients, 1,106 (18.8%) had an adjudicated final diagnosis of MI and, of these, 246 patients (22.2%) had T2MI and 860 (77.8%) had T1MI.
- Upon analysis, the researchers found that most biomarkers had "comparable concentrations" in T1MI and T2MI, limiting their usefulness to differentiate one from the other
- They also found four novel biomarkers (MR-proANP, CT-proET-1, midregional proadrenomedullin, and GDF 15) were higher in T2MI vs T1MI and showed modest promise for the early discrimination of T2MI.
- They noted that none of the tested cardiovascular biomarkers had significantly higher diagnostic discrimination. However, upon multivariable regression analysis, they noted a possible additive value of MR-proANP to clinical variables.
The authors concluded, " In this study, biomarkers quantifying myocardial injury, endothelial dysfunction, microvascular dysfunction, and/or hemodynamic stress provided modest discrimination in early, noninvasive diagnosis of T2MI."
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