Values of D-dimer test in the diagnostics of pulmonary embolism.

Aim: To establish a value of D-dimer and compare findings of elevated and normal values with the golden standard, computed tomography (CT) of lungs in patients who had symptoms indicating pulmonary thromboembolism (PTE) at admission.

Methods: This retrospective/prospective study was conducted at the Department of Internal Diseases of the Cantonal Hospital Zenica, Bosnia and Herzegovina. A sample included 80 patients with symptoms indicating PTE at the time of admission, D-dimers and CT scan of thoracic organs were performed. The patients were divided into two groups: 40 examinees with PTE confirmed by CT scan and 40 patients (control group) whose PTE was not confirmed by the CT scan.

Results: Sensitivity of D-dimer according to statistical calculation was 87.5%. Specificity of D-dimer was 57.5%. The chance of a patient to have PTE in case of elevated values of D-dimer was 3.58 higher than in patients with normal D-dimer values. The positive predicative value of D-dimer was 0.54, the negative predicative value was 0.75. Test accuracy was 57.5%. Values of D-dimer >0.83 using a ROC curve and present clinical symptoms of the disease have indicated further diagnostic examination according algorithm and a need for CT scan (of thoracic organs )

Conclusion: D-dimer is important in the diagnostics of PTE, high sensitivity and low specificity have been proven. A positive D-dimer test indicates the presence of PTE. However, the test is not reliable. In order to set a diagnosis it is necessary to visualize a blood clot by computed tomography of lungs.