Assessments of the associations of thrombus localization with accompanying disorders, risk factors, D-dimer levels, and the red cell distribution width in pulmonary embolism

Prognostic Value of D-Dimer in Younger Patients with Pulmonary Embolism

In patients with pulmonary embolism (PE), the D-Dimer assay is commonly utilized as part of the diagnostic workup, but data on D-Dimer for early risk stratification and short-term mortality prediction are limited. The purpose of this study was to determine D-Dimer levels as a predictive biomarker of PE outcomes in younger (<50 years of age) compared to older patients. We conducted retrospective analysis for 930 patients diagnosed with PE between 2015 and 2019 as part of the Serbian University Multicenter Pulmonary Embolism Registry (SUPER).All patients had D-Dimer levels measured within 24 hours of hospital admission. The primary outcome was mortality at 30 days or during hospitalization. Patients were categorized into two groups based on age (≤ 50 and >50 years of age). Younger patients constituted 20.5% of the study cohort. Regarding all-cause mortality, 5.2% (10/191)of patients died in group under the 50 years of age; the short-term all-causemortality was 12.4% (92/739) in older group.We have found that there was significant difference in plasma D-Dimer level between patients ≤ 50 years of age and older group (>50), p= 0.006.D-Dimer plasma level had good predictive value for the primary outcome in younger patients (c-statistics 0.710; 95% CI, 0.640-0.773; p<0.031). The optimal cutoff level for D-Dimer to predict PE-cause death in patients aged > 50 years was found to be 8.8 mg/l FEU(c-statistics 0,580; 95% CI 0.544-0.616; p=0.049). In younger PE patients, D-Dimer levels have good prognostic performance for 30-day all-cause mortalityand concentrations above 6.3 mg/l FEU are associated with increased risk of death. D-Dimer in patients aged over 50 years does not have predictive ability for all-caused short-term mortality. The relationship between D-Dimer and age in patients with PE may need further evaluation.

Predictive Value of Red Blood Cell Distribution Width in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Embolism

Purpose

This study is aimed at investigating the relationship between red cell distribution width (RDW) and chronic obstructive pulmonary disease (COPD) patients with pulmonary embolism (PE).

Methods

We conducted a retrospective study enrolling a total of 125 patients from January 2013 to December 2019. The study group consisted of 40 COPD patients with PE, and the control group had 85 COPD patients without PE. Clinical data including demographic characteristics, comorbidities, and results of imaging examinations and laboratory tests were recorded. Blood biomarkers, including red blood cell distribution width standard deviation (RDW-SD), red blood cell distribution width coefficient of variation (RDW-CV), and D-Dimer, were included.

Results

RDW-SD and RDW-CV were higher in the COPD patients with the PE group (p < 0.001). A higher RDW-SD led to a significantly increased risk of PE than a lower RDW-SD (adjusted odds ratio (OR): 1.188; 95% confidence interval (CI): 1.048-1.348). The area under the curve (AUC) of RDW-SD used for predicting PE was 0.737. Using 44.55 as the cutoff value of RDW-SD, the sensitivity was 80% and the specificity was 64.7%. The prediction accuracy of RDW-SD combined with D-Dimer (AUC = 0.897) was higher than that of RDW-SD or D-Dimer alone. The optimal cutoff value of RDW-SD+D-Dimer for predicting PE was 0.266, which generated a sensitivity of 87.5% and specificity of 83.5%.

Conclusion

RDW is significantly increased in COPD patients with PE and may thus be useful in predicting the occurrence of PE in patients with COPD.

A narrative review of red blood cell distribution width as a marker for pulmonary embolism

Red blood cell distribution width (RDW) is a marker of variability in red blood cell size, and is routinely reported as part of a patient's complete blood count. RDW has been shown to be associated with the prediction, severity and prognosis of pulmonary embolism (PE) in recent studies. The underlying biomolecular mechanism of the relationship of RDW to PE is largely unknown, but is thought to be due to the relationship of RDW with acute inflammatory markers and variations in blood viscosity. This review substantiates that a high RDW level, defined using either an arbitrary number or according to receiver operator curve statistics, is associated with a higher risk of acute PE, increased severity (massive vs. submassive) of PE and increased mortality in patients with PE. Nevertheless, the comparison of current studies is limited due to the definition of high RDW (each study uses a different RDW cutoff level), the broad range of exclusion criteria and the inclusion of differing modalities used to diagnose a PE (computed tomography angiogram, ventilation-perfusion study, or clinical diagnosis). Despite the above limitations, these studies provide a promising future clinical use for RDW as a marker of PE.