The combined use of D-dimer testing and the neutrophil-to-lymphocyte ratio in the early differential diagnosis of aortic dissection

BACKGROUND The study aimed to ascertain whether a diagnostic strategy combining D-dimer with the neutrophil-to-lymphocyte ratio (NLR) could improve the discriminative performance for aortic dissection (AD). RESEARCH DESIGN AND METHODS Baseline levels of D-dimer and NLR were measured in patients suspected of AD. The diagnostic performance and clinical usefulness of D-dimer, NLR, and their combination were assessed and compared using receiver operating characteristics (ROC) curve analysis, logistic regression analysis, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA). RESULTS The levels of D-dimer and NLR were both significantly higher in AD patients. The combined use displayed good discriminatory performance with an area under ROC curve (AUC) of 0.869, which was preferable to that of D-dimer. Although no meaningful improvement was found in the AUC by comparison with NLR alone, the combined use could significantly improve the discrimination power with a continuous NRI of 60.0% and an IDI of 4.9%. DCA demonstrated that the net benefit of the combined use was preferred over that of either single test. CONCLUSIONS The combined use of D-dimer and NLR could improve the discriminatory efficiency for AD with the potential in clinical application. This study may provide a novel diagnostic strategy for AD. More studies need to be done to confirm the findings of this study.