CV biomarkers may help noninvasively diagnose type 2 MI
CV biomarkers that quantify myocardial injury, endothelial dysfunction, microvascular dysfunction and/or hemodynamic stress successfully provided modest discrimination in a noninvasive diagnosis of type 2 MI, researchers reported.
“Because treatments differ substantially, the early and accurate discrimination of type 2 MI is a major yet largely unmet clinical need,” Thomas Nestelberger, MD, research fellow at the Cardiovascular Research Institute Basel and the department of cardiology at the University Hospital Basel, Switzerland, and the GREAT Network, Rome, and the division of cardiology at Vancouver General Hospital at the University of British Columbia, Canada, and colleagues wrote in JAMA Cardiology. “Unfortunately, established biomarkers of cardiomyocyte injury, including high-sensitivity cardiac troponin T and I levels, have only modest diagnostic discrimination.”
The international, multicenter prospective diagnostic study included 5,887 patients (mean age, 61 years; 34% women) who presented with acute chest discomfort in 12 EDs in Switzerland, Spain, Italy, Poland and the Czech Republic. Researchers quantified discrimination of 17 novel CV biomarkers and high-sensitivity cardiac troponin T and I levels and measured these results against a final diagnosis.
In the cohort, 18.8% of patients had an adjudicated final MI diagnosis and, of these, 77.8% had type 1 MI and 22.2% had type 2 MI.
Compared with patients with type 1 MI, those with type 2 MI had lower biomarker concentrations quantifying cardiomyocyte injury: high-sensitivity cardiac troponin T (30 ng/L vs. 58 ng/L), high-sensitivity cardiac troponin I (23 ng/L vs. 115 ng/L) and cardiac myosin-binding protein C (76 ng/L vs. 257 ng/L; P < .001 for all). However, patients with type 2 MI had higher biomarker concentrations quantifying endothelial dysfunction, microvascular dysfunction and/or hemodynamic stress, including C-terminal proendothelin 1 (97 pmol/L vs. 68 pmol/L), midregional proadrenomedullin (0.97 pmol/L vs. 0.72 pmol/L), midregional pro-A-type natriuretic peptide (378 pmol/L vs. 152 pmol/L) and growth differentiation factor 15 (2.26 ng/L vs. 1.56 ng/L).
The researchers wrote that the following biomarkers provided modest discrimination: high-sensitivity cardiac troponin T (area under the receiver operating characteristics [ROC] curve, 0.67; 95% CI, 0.64-0.71), high-sensitivity cardiac troponin I (ROC curve, 0.71; 95% CI, 0.67-0.74), cardiac myosin-binding protein C (ROC curve, 0.67; 95% CI, 0.61-0.71), C-terminal proendothelin 1 (ROC curve, 0.73; 95% CI, 0.63-0.83), midregional proadrenomedullin (ROC curve, 0.66; 95% CI, 0.6-0.73), midregional pro-A-type natriuretic peptide (ROC curve, 0.77; 95% CI, 0.68-0.87) and growth differentiation factor 15 (ROC curve, 0.68; 95% CI, 0.58-0.79).
“Given the suggestive findings observed for midregional pro-A-type natriuretic peptide, future studies are warranted to develop diagnostic models combining routinely available information such as high-sensitivity cardiac troponin-T or high-sensitivity cardiac troponin-I, medical history and the 12-lead ECG with selected biomarkers,” the researchers wrote. “Until these tools are derived and externally validated, however, most patients will still require coronary angiography and/or noninvasive functional or anatomic testing to achieve a high level of diagnostic discrimination.”