Clinical Utility of an Age-Adjusted D-dimer in the Diagnosis of Venous Thromboembolism

The impact of using different age-adjusted cutoffs of D-dimer in the diagnosis of pulmonary thromboembolism

Background This study was conducted to evaluate the relationship of age-adjusted D-dimer value with different coefficients in diagnosis of pulmonary embolism (PE) in geriatric patients. Methods The emergency admissions of the patients aged 65 and over with suspected PE during 2018 were reviewed retrospectively. The demographic characteristics, laboratory tests and radiologic findings of computed tomography pulmonary angiogram (CTPA) or single photon emission computed tomography ventilation/perfusion scintigraphy (V/Q) were recorded. The characteristics of the patients with PE were statistically compared with the patients without PE. The specificity and sensitivity for higher cut-off levels (age × 10-15) were presented. Results PE was detected in 39.2% (n = 246) of 628 patients aged 65 years and older included in the study. The multivariate analysis revealed that higher D-dimer level (OR = 1,00011; p < 0.001) and BUN level (OR = 1.025; p = 0.013) were independent risk factors for PE diagnosis in elderly patients. Diagnostic statistics for D-dimer cut-off levels selected from ROC analysis and calculated values as 10-15 times of age showed that if the D-dimer cut-off value used is chosen higher, lower sensitivity rates are obtained. Our results also indicated that the patients with malignancy, renal failure, central PE on CTPA and PE with high probability on SPECT VQ were presented with higher D-dimer values. Conclusion Our results do not support the use of higher D-dimer cut-off levels such as 15 times the age in geriatric population. The impact of the location of PE and comorbidities on the outcomes of these patients must be clarified for determining cut-offs with higher specificity.

Age-adjusted D-dimer thresholds in the investigation of suspected pulmonary embolism: A retrospective evaluation in patients ages 50 and older using administrative data

Objectives

D-dimer testing is an important component of the workup for pulmonary embolism (PE). However, age-related increases in D-dimer concentrations result in false positives in older adults, leading to potentially unnecessary imaging utilization. The objective of this study was to quantify the test characteristics of an age-adjusted D-dimer cut-off for ruling out PE in older patients investigated in actual clinical practice.

Methods

This observational study used administrative data from four emergency departments from July 2013 to January 2015. Eligible patients were ages 50 and older with symptoms of PE who underwent D-dimer testing. The primary outcome was 30-day diagnosis of PE, confirmed by imaging reports. Test characteristics of the D-dimer assay were calculated using the standard reference value (500 ng/ml), the local reference value (470 ng/ml), and an age-adjusted threshold (10 ng/ml × patient’s age).

Results

This cohort includes 6,655 patients ages 50 and older undergoing D-dimer testing for a possible PE. Of these, 246 (3.7%) were diagnosed with PE. Age-adjusted D-dimer cut-offs were more specific than standard cut-offs (75.4% v. 63.8%) but less sensitive (90.3% v. 97.2%). The false-negative risk in this population was 0.49% using age-adjusted D-dimer cut-offs compared with 0.15% with traditional cut-offs.

Conclusion

Age-adjusted D-dimer cut-offs are substantially more specific than traditional cut-offs and may reduce CT utilization among older patients with suspected PE. We observed a loss of sensitivity, with an increased risk of false-negatives, using age-adjusted cut-offs. We encourage further evaluation of the safety and accuracy of age-adjusted D-dimer cut-offs in actual clinical practice.

Age-adjusted D-dimer cut-off leads to more efficient diagnosis of venous thromboembolism in the emergency department: a comparison of four assays

Essentials Age-adjusted D-dimer cut-offs decrease the false positives in the elderly. Four D-dimer assays were compared in venous thromboembolism outpatients in an emergency ward. Age-adjusted cut-off resulted in improved specificity with maintained sensitivity for all assays. There was a substantial decrease in false positive results, especially in the older population.

SUMMARY

Background The study compares different D-dimer assays and age-adjusted cut-offs in outpatients with suspected venous thromboembolism (VTE). The plasma concentration of this sensitive biomarker is increased by activated coagulation, but also by several conditions that are linked to an increased risk of VTE. One such condition is old age, which poses a common clinical problem where many prefer not to analyze D-dimer in elderly patients. Age-adjusted cut-offs have been validated for both deep venous thrombosis (DVT) and pulmonary embolism, aiming to increase specificity without notably decreasing sensitivity. Objectives We evaluated four common D-dimer assays in parallel, with and without applying age-adjusted cut offs for VTE. Patients/methods The prospective single-center study was conducted in 940 outpatients attending the emergency department with clinically suspected pulmonary embolism or DVT. Four automated D-dimer assays were compared (Siemens INNOVANCE® , Roche Tina-quant, Medirox MRX and STA® -Liatest® D-Di PLUS). Results All assays performed with areas under the ROC curve (AUC) > 0.9 and maintained their sensitivities after implementation of age-adjusted cut-offs. Specificities increased by 6-7% and number needed to test decreased by < 0.3. The rate of false positive results decreased by 6% overall and by 10-20% for patients ≥ 70. Conclusions Age-adjusted cut-offs resulted in maintained high sensitivity and a modest improvement in specificity and number needed to test for all evaluated D-dimer assays. There was a significant reduction in false positive results, which reflects avoidable unnecessary imaging without any compromise of clinical safety. This suggests a potential to benefit the management of VTE in elderly patients, both clinically and economically.

Deep Venous Thrombosis

Deep venous thrombosis (DVT) is a frequently encountered condition that is often diagnosed and treated in the outpatient setting. Risk stratification is helpful and recommended in the evaluation of DVT. An evidence-based diagnostic approach is discussed here. Once diagnosed, the mainstay of DVT treatment is anticoagulation. The specific type and duration of anticoagulation depend upon the suspected etiology of the venous thromboembolism, as well as risks of bleeding and other patient comorbidities. Both specific details and a standardized approach to this vast treatment landscape are presented.

Serum D-dimer is a potential predictor for thromboembolism complications in patients with renal biopsy

Renal biopsy has been widely recommended in clinic to determine the histological patterns of kidney disease. To prevent bleeding complications, patients should routinely stop anticoagulants prior to renal biopsy. However, patients with kidney disease are susceptible to thromboembolisms, particularly in those with severe hypoalbuminemia. This study was designed to investigate the application of serum D-dimer as a predictor for thrombotic events after renal biopsy. 400 consecutive native renal biopsies were prospectively included in this 2-month follow-up study. The overall incidence of bleeding and thrombotic complication is 4%, including hematuria or large perinephric hematoma (2.5%, n = 10) and thrombotic complication (1.5%, n = 6). Compared to low serum D-dimer (<2.00 μg/ml), subjects in the group of high serum D-dimer (≥2.00 μg/ml) were more incline to develop thrombotic complications (9.1% versus 0.3%; RR, 30.33; p < 0.001). D-dimer correlated positively with age (r_s = 0.258, P < 0.001). Inverse correlations were found for albumin (r_s = −0.339, P < 0.001). Taken together, patients with high serum D-dimer carry an increased risk of thrombotic complications after renal biopsy. Our findings suggest that serum D-dimer can serve as a potential predictor for thrombotic events in patients with kidney disease. Further cautions should be given to these subjects.