The value of D-dimer in different diagnosis between acute aortic dissection with elevated troponin I and acute myocardial infarction

Abstract

Objective To evaluate the performance of D-dimer in the differential diagnosis between acute aortic dissection (AAD)with elevated troponin-I(TNI)and acute myocardial infarction (AMI) in patients with acute chest pain diseases with elevated TNI. Methods The data of the 547 patients complaining acute chest pain who were diagnosed as acute myocardial infarction by thoracic and abdominal aorta CTA examination from January 2013 to September 2015 were analyzed. The comparison of data of D-dimer mass concentration and the general clinical information between 44 patients diagnosed as AAD with elevated TNI and without other underlying diseases which could cause increase in D-dimer mass concentration(AAD with elevated TNI group) and 50 patients diagnosed as acute myocardial infarction confirmed by using coronary angiography(AMI group) were carried out. Results Compared with AMI group, in the AAD with elevated TNI group, the type of Stanford A was 38 cases, accounting for 86.4%; the proportion of the patients with a history of hypertension was higher, and the average age was younger; the D-dimer mass concentration levels and the positive ratio of the D-dimer test were much higher[11.27 μg/mL(3.95, 20)μg/mL vs.0.28 μg/mL(0.22, 0.40)μg/mL, P<0.01; 100%vs.14%, P<0.01]. The area under the ROC curve to diagnosis of the AAD with elevated TNI was 0.997, and the optimal diagnostic threshold was 1.095 μg/mL.When the D-dimer mass concentration level was 1.095 μg/mL, the sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV), positive likelihood ratio(PLR), negative likelihood ratio(NLR)were 97.7%, 98%, 97.7%, 98%, 48.86, and 0.02, respctively. When the D-dimer mass concentration level was 0.5 μg/mL, which meant the D-dimer test was positive, the sensitivity, specificity, PPV, NPV, PLR, NLR were 100%, 86%, 86.3%, 100%, 7.14, and 1.16, respctively. Conclusion D-dimer is helpful to the differential diagnosis between the AAD with elevated TNI and the AMI in acute chest pain patients with elevated TNI. Key words: Acute chest pain disease; Acute myocardial infarction; Acute aortic dissection; Troponin I; D-dimer; Differential diagnosis