Serum Concentrations of Matrix Metalloproteinase‐1 and Procollagen Type I Carboxy Terminal Propeptide Discriminate Infarct‐Like Myocarditis and Non−ST‐Segment−Elevation Myocardial Infarction

Abstract

Background Biomarkers simplifying the diagnostic workup by discriminating between non–ST‐segment–elevation myocardial infarction (NSTEMI) and infarct‐like myocarditis are an unmet clinical need. Methods and Results A total of 105 subjects were categorized into groups as follows: ST‐segment−elevation myocardial infarction (n=36), NSTEMI (n=22), infarct‐like myocarditis (n=19), cardiomyopathy‐like myocarditis (n=18), and healthy control (n=10). All subjects underwent cardiac magnetic resonance imaging, and serum concentrations of matrix metalloproteinase‐1 (MMP‐1) and procollagen type I carboxy terminal propeptide (PICP) were measured. Biomarker concentrations in subjects presenting with acute coronary syndrome and non‐ST‐segment‐elevation, for example NSTEMI or infarct‐like myocarditis, categorized as the non−ST‐segment−elevation acute coronary syndrome−like cohort, were of particular interest for this study. Compared with healthy controls, subjects with myocarditis had higher serum concentrations of MMP‐1 and PICP, while no difference was observed in individuals with myocardial infarction. In the non−ST‐segment−elevation acute coronary syndrome−like cohort, MMP‐1 concentrations discriminated infarct‐like myocarditis and NSTEMI with an area under the receiver operating characteristic curve (AUC) of 0.95 (95% CI, 0.89−1.00), whereas high‐sensitivity cardiac troponin T performed inferiorly (AUC, 0.74 [95% CI, 0.58−0.90]; P =0.012). Application of an optimal MMP‐1 cutoff had 94.4% sensitivity (95% CI, 72.7%−99.9%) and 90.9% specificity (95% CI, 70.8%−98.9%) for the diagnosis of infarct‐like myocarditis in this cohort. The AUC of PICP in this context was 0.82 (95% CI, 0.68−0.97). As assessed by likelihood ratio tests, incorporating MMP‐1 or PICP with age and C‐reactive protein into composite prediction models enhanced their diagnostic performance. Conclusions MMP‐1 and PICP could potentially be useful biomarkers for differentiating between NSTEMI and infarct‐like myocarditis in individuals with non−ST‐segment−elevation acute coronary syndrome‐like presentation, though further research is needed to validate their clinical applicability.