Differential diagnostic factors of type 1 and type 2 myocardial infarction in patients with elevated cardiac troponin levels

Abstract

Objective Emergency physicians experience difficulty in determining the disposition of patients with elevated troponin I levels using emergency room tests. In this study, we aimed to investigate factors that could discriminate between the occurrence of type 1 myocardial infarction (T1MI) and type 2 myocardial infarction (T2MI) in patients with elevated troponin I levels. Methods Patients admitted to the emergency department between January 1, 2017 and June 30, 2017 with elevated troponin I levels who underwent subsequent cardiac biomarker testing were included. Samples for baseline blood tests, such as cardiac biomarker levels, were collected within approximately 10 minutes of admission. Electrocardiogram, transthoracic echocardiogra-phy, and percutaneous coronary intervention results were retrospectively examined via patient report and chart reviews. Results During the study period, 169 of 234 (72%) patients were diagnosed with T2MI and 65 (28%) were diagnosed with T1MI. Among various factors, typical chest pain (odds ratio [OR], 4.40; 95% confidence interval [CI], 1.46 to 13.24; P= 0.008), high troponin I levels (OR, 1.50; 95% CI, 1.19 to 1.90; P<0.001), high cholesterol (OR, 1.01; 95% CI, 1.00 to 1.02; P=0.008), and low D-dimer levels (OR, 0.87; 95% CI, 0.77 to 0.98; P=0.027) were significantly associated with T1MI incidence. Conclusion Our findings in this study indicate that typical chest pain, high levels of troponin I and cholesterol, and low levels of D-dimer were associated with the diagnosis of T1MI. Further studies are suggested to determine the cut-off values for accurate diagnosis of T1MI in the ED.