Clinical application of the Innovance D-dimer assay in the diagnosis of acute pulmonary thromboembolism

Abstract

Abstract.Patients with acute pulmonary thromboembolism (APTE) have a high short-term mortality rate. The current study aimed to investigate the use of D-dimer in the diagnosis of APTE in suspected APTE patients. All suspected APTE patients were classified into diagnosis or control groups according to the results of a computed tomography pulmonary angiogram. Mann-Whitney U and Kruskal-Wallis H tests were used to evaluate the association between D-dimer values and APTE. Area under the curve (AUC) values and the Youden Index were used to determine D-dimer cut-off levels for the prediction of APTE. The data of 112 suspected APTE patients (54.8% women; mean age, 70.5 years) were analyzed prospectively. There were no significant differences in age (74.5 vs. 73.5 years, P=0.538) or gender distribution (female ratio 56.5 vs. 53.0%, P=0.847) between the diagnosis and control groups. The incidence of symptoms including dyspnea (67.4 vs. 33.3%; P<0.01), chest distress (47.8 vs. 25.8%; P<0.05) and elevated D-dimer (8.49 vs. 0.97 mg/l; P<0.001) were significantly higher in patients with APTE compared with the control group. D-dimer values >3.32 mg/l fibrinogen equivalent units (FEU) were indicative of APTE and the Youden Index was 0.69. The maximum AUC was 0.87 (95% CI: 0.79-0.92), the sensitivity and specificity were 89.13 and 80.30%, respectively, the positive and negative likelihood ratios were 4.53 and 0.14, respectively, and the positive and negative predictive values were 75.90 and 91.40%, respectively. A D-dimer value <0.60 mg/l FEU was the optimal threshold for excluding APTE diagnosis, with a sensitivity of 100.0% and a specificity of 28.79%. The positive and negative likelihood ratios were 1.40 and 0.00, respectively, and the positive and negative predictive values were 49.50 and 100.00%, respectively. Thus, D-dimer levels, combined with clinical assessment, yield high sensitivity and specificity in diagnosing APTE. IntroductionPulmonary thromboembolism (PTE) is a pulmonary circulation dysfunction caused by thrombotic occlusion of the pulmonary artery (1-3). Acute PTE (APTE) is a cardiovascular emergency associated with high morbidity and mortality (4-9). Computed tomography pulmonary angiogram (CTPA) is the gold standard for APTE diagnosis, with a sensitivity of 90% and a specificity of 78-100% (10-12). However, CTPA is an expensive procedure and has some technical limitations, which restrains its clinical application in many hospitals. A plasma D-dimer test is commonly the first step in patient APTE risk assessment, and is considered to have clinical value (13-15).D-dimer is a soluble degradation product of crosslinked fibrin under the action of the fibrinolytic system. An elevated concentration of D-dimer is often suggestive of secondary fibrinolytic hyperthyroidism (15). The high negative predictive value of plasma D-dimer makes it an important criterion for excluding PTE diagnosis. However, since elevated concentrations of D-dimer are associated with a variety of diseases, its diagnosis specificity for PTE is ...

Predicting 7-day unplanned readmission in elderly patients with coronary heart disease using machine learning

“…This proves that aspirin improves prognosis in elderly patients with CHD. Furthermore, those elderly CHD patients with higher D-dimer had a higher risk of 7-day unplanned readmission because a higher D-dimer meant a higher risk of pulmonary thromboembolism ( 30 , 31 ).…”