Diagnostic accuracy of D-dimer assay in detection of pulmonary embolism in patients presenting in emergency department

Abstract

Background: Pulmonary embolism is the lethal condition that is associated with higher rate of mortality in cardia patients. The diagnosis of the acute pulmonary embolism is frequently observed in patients presenting in emergency department or during hospitalization. Level of D-dimer may be assessed by blood test to help the physicians to diagnose the thrombosis. Literature showed variable evidence regarding predictive accuracy of D-dimer for detection of pulmonary embolism. So to get local data, we conducted this study. Aim: To determine the diagnostic accuracy of D-dimer assay for detection of pulmonary embolism in patients of acute myocardial infarction presenting in emergency department taking CTPA as gold standard Methods: Cross - sectional study conducted in Cardiology Department , Punjab Institute of Cardiology, Lahore for a period of six months from 1-9-2018 to 1-3-2019. One hundred patients, fulfilled the selection criteria were enrolled from emergency. Then blood sample was taken for evaluation of D-dimer level. Reports were checked and D-dimer level was noted. Pulmonary embolism was labeled as positive on D-dimer, if D-dimer level ≥500 and was labeled as negative if D-dimer level <500. Then all patients underwent CTPA. Pulmonary embolism labeled as positive if there was mass filling defects detected as dark spot on angiogram. All the data was collected by using the proforma. Data analysis as done in SPSS v. 21. Results: The mean age of patients was 54.03±10.26years. There were 40 (40) males and 60 (60%) females. The mean BMI of patients was 27.57±4.35kg/m2. There were 46 (46%) patients with diabetes mellitus while 61 (61%) patients had hypertension. The sensitivity, specificity, PPV, NPV and diagnostic accuracy of D-dimer were 82.6%, 72.2%, 71.7%, 83.0% and 77.0%, respectively taking CTPA as gold standard. Conclusion: Thus the D-dimer is accurate enough that it can help to predict pulmonary embolism and can help to prevent at least negative cases to undergo CTPA. Keywords: Acute myocardial infarction, pulmonary embolism, D-dimer, computed tomography pulmonary angiography