The diagnostic utility of D-dimer and other clinical variables in pregnant and post-partum patients with suspected acute pulmonary embolism

Abstract

BackgroundPulmonary embolism (PE) during pregnancy remains one of the leading causes of maternal morbidity and mortality in the developed world. However, there is a paucity of high-quality evidence resulting in a lack of consensus in managing this group of patients. The aims of the study were to address the diagnostic utility of D-dimer for suspected PE in pregnant and post-partum patients and to identify any clinical presentation variables that are predictors of PE in this group of patients.MethodsA retrospective case note review of 152 pregnant and post-partum patients who underwent diagnostic imaging (ventilation/perfusion (V/Q) or computed tomographic pulmonary angiography (CTPA)) for suspected PE at a tertiary teaching hospital from 2007 to 2011 was conducted. The reference range for D-dimer was less than 0.5 mg/L as being normal. The following variables were also assessed in terms of their predictive capability for PE diagnosis in pregnancy: heart rate (HR), mean arterial pressure (MAP), shock index (SI) and A-a gradient.ResultsThe application of D-dimer testing for suspected PE in this study population had a sensitivity of 100% (95% CI, 73–100%), specificity of 42% (95% CI, 31–53%) and a likelihood negative ratio of 0. None of the clinical variables were significant predictors of PE according to regression analyses.ConclusionsThere is supportive evidence that a negative D-dimer result is useful as a means of ruling out PE in pregnant and post-partum patients. However, we need a larger prospective observational study to collaborate the findings.

ISIDOG Recommendations Concerning COVID-19 and Pregnancy

“…Complete blood count with differential, kidney function with electrolytes including calcium and magnesium levels, liver function tests (lactate dehydrogenase) and coagulation tests (INR, PTT, fibrinogen), C-reactive protein and procalcitonin, NT-proBNP, troponin should be done at admission [84]. D-dimers are generally elevated in pregnancy and thus not reliable [85]. Lymphopenia is common in COVID-19, but when presenting with increased neutrophil count, bacterial sur-infection is likely and should be treated accordingly.…”

Diagnostic management of inpatients with a positive D‐dimer test: developing a new clinical decision‐making rule for pulmonary embolism

“…4,5 Clinicians pay specific attention to patients with a positive D-dimer test because it has a sensitivity of approximately 97% for PE. However, the specificity of a positive D-dimer test for PE is only approximately 40%, 6,7 causing difficulty for clinicians, especially clinicians inexperienced with PE diagnosis, in determining the probability of PE and whether the gold standard CTPA test is needed for an accurate diagnosis. In addition, it is not feasible to extensively use CTPA to reduce the risk of a missed diagnosis in PE.…”

Comparison of the D-dimer concentration in pregnant women with or without pulmonary thromboembolism

“…D-dimer is a minor protein product, which is found in circulation in negligible amounts because of endogenous fibrinolysis. [ 11 ] Many studies have examined the level of D-dimer during pregnancy[ 10 11 12 ] and showed that D-dimer values were higher during pregnancy compared to nonpregnancy. In addition, increased levels of D-dimer were observed in the third trimester of normal pregnancy.…”

“…In addition, increased levels of D-dimer were observed in the third trimester of normal pregnancy. [ 10 ] However, the reason for the increase in the amount of D-dimer during pregnancy may be continuous coagulation, and fibrinolysis increases the production of intrinsic and extrinsic coagulation factors during normal placental growth. [ 13 14 ] This results in a physiological increase in the concentration of D-dimer in the blood of the mother during pregnancy until delivery, which is not necessarily associated with thromboembolic complications.…”

“…[ 9 ] Several studies have been carried out in recent years, including the study by Choi et al ., which examined the D-dimer level of 152 pregnant women suspected of having VTE with 100% dimer sensitivity and the specificity of this tests was 42%; they suggested that larger groups need to be studied to better evaluate the results. [ 10 ] However, the purpose of the current work is to evaluate D-dimer plasma concentration in pregnant women with or without pulmonary thromboembolism.…”