Rational use of D-dimer measurement to exclude acute venous thromboembolic disease

The Relationship Between Diabetes Mellitus and COVID-19 Prognosis: A Retrospective Cohort Study in Wuhan, China

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that first appeared in Wuhan, China, and quickly spread throughout the world. We aimed to understand the relationship between diabetes mellitus and the prognosis of COVID-19.

METHODS

Demographic, clinical, laboratory, radiologic, treatments, complications, and clinical outcomes data were extracted from electronic medical records and compared between diabetes (n = 84) and nondiabetes (n = 500) groups. Kaplan-Meier method and multivariate Cox analysis were applied to determine the risk factors for the prognosis of COVID-19.

RESULTS

Compared with nondiabetic patients, diabetic patients had higher levels of neutrophils (P = .014), C-reactive protein (P = .008), procalcitonin (P < .01), and D-dimer (P = .033), and lower levels of lymphocytes (P = .032) and albumin (P = .035). Furthermore, diabetic patients had a significantly higher incidence of bilateral pneumonia (86.9%, P = .020). In terms of complications and clinical outcomes, the incidence of respiratory failure (36.9% vs 24.2%, P = .022), acute cardiac injury (47.4% vs 21.2%, P < .01), and death (20.2% vs 8.0%, P = .001) in the diabetes group was significantly higher than that in the nondiabetes group. Kaplan-Meier survival curve showed that COVID-19 patients with diabetes had a shorter overall survival time. Multivariate Cox analysis indicated that diabetes (hazard ratio 2.180, P = .031) was an independent risk factor for COVID-19 prognosis. In subgroup analysis, we divided diabetic patients into insulin-required and non-insulin-required groups according to whether they needed insulin, and found that diabetic patients requiring insulin may have a higher risk of disease progression and worse prognosis after the infection of severe acute respiratory syndrome coronavirus 2.

CONCLUSIONS

Diabetes is an independent risk factor for the prognosis of COVID-19. More attention should be paid to the prevention and treatment for diabetic patients, especially those who require insulin therapy.

Clinical analysis of preoperative deep vein thrombosis risk factors in patients with colorectal cancer: Retrospective observational study

AIM

Deep vein thrombosis (DVT) is a major complication of cancer. The postoperative prevalence of DVT in colorectal cancer (CRC) surgery is high, but the preoperative prevalence and the risk factors have not been clarified in detail. The objective of this retrospective study was to investigate the preoperative prevalence and risk factors of DVT in patients admitted to hospital for CRC surgery.

METHODS

From January 2013 to March 2017, 1006 patients admitted for CRC surgery were deemed eligible for this retrospective study. Diagnosis of preoperative DVT was confirmed by compression ultrasonography. Prevalence of silent DVT in lower limbs in patients before CRC surgery was assessed, and the risk factors for preoperative DVT were investigated regarding the correlation of DVT with the patient's background.

RESULTS

Preoperative DVT and asymptomatic pulmonary thromboembolism were diagnosed in 136 (13.5%) and in 10 (1.0%) of 1006 patients overall, respectively. Multivariate analysis showed that increased age (≥75 years), female gender, and an elevated d-dimer level (>1.0 μg/mL) were independent risk factors for preoperative DVT in this study. Notably, the prevalence of preoperative DVT exceeded 50% in patients with all three predictors.

CONCLUSIONS

A high prevalence (13.5%) of preoperative DVT was found in patients admitted to the hospital for CRC surgery. The present results suggest that instrumental screening should be encouraged, at least in subgroups at a higher risk of preoperative DVT.

Fc-Silent Anti-CD154 Domain Antibody Effectively Prevents Nonhuman Primate Renal Allograft Rejection

The advent of costimulation blockade provides the prospect for targeted therapy with improved graft survival in transplant patients. Perhaps the most effective costimulation blockade in experimental models is the use of reagents to block the CD40/CD154 pathway. Unfortunately, successful clinical translation of anti-CD154 therapy has not been achieved. In an attempt to develop an agent that is as effective as previous CD154 blocking antibodies but lacks the risk of thromboembolism, we evaluated the efficacy and safety of a novel anti-human CD154 domain antibody (dAb, BMS-986004). The anti-CD154 dAb effectively blocked CD40-CD154 interactions but lacked crystallizable fragment (Fc) binding activity and resultant platelet activation. In a nonhuman primate kidney transplant model, anti-CD154 dAb was safe and efficacious, significantly prolonging allograft survival without evidence of thromboembolism (Median survival time 103 days). The combination of anti-CD154 dAb and conventional immunosuppression synergized to effectively control allograft rejection (Median survival time 397 days). Furthermore, anti-CD154 dAb treatment increased the frequency of CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells. This study demonstrates that the use of a novel anti-CD154 dAb that lacks Fc binding activity is safe without evidence of thromboembolism and is equally as potent as previous anti-CD154 agents at prolonging renal allograft survival in a nonhuman primate preclinical model.

Admission D-dimer testing for differentiating acute aortic dissection from other causes of acute chest pain

INTRODUCTION

The present study aims to evaluate the utility of D-dimer testing for differentiating the causes of acute chest pain, including acute aortic dissection (AAD), pulmonary embolism (PE), acute myocardial infarction (AMI), unstable angina (UA), and other uncertain diagnoses of chest pain.

MATERIAL AND METHODS

Consecutive patients admitted for acute chest pain within 24 h from symptom onset were enrolled prospectively, and plasma D-dimer levels were measured on admission. Diagnoses of AAD, PE, AMI, and UA were confirmed by standard methods.

RESULTS

A total of 790 patients were enrolled, including 202 AAD, 43 PE, 315 AMI, 136 UA, and 94 cases of other uncertain diagnoses. D-dimer levels were significantly higher in patients with AAD and PE than in those with AMI, UA, and other uncertain diagnoses (p < 0.001), but they were comparable between patients with AAD and PE (p = 0.065). Moreover, patients with type A AAD had higher D-dimer levels than those with type B AAD (p = 0.022). Receiver operating characteristic (ROC) curve analysis showed that a D-dimer level < 0.5 µg/ml was a good predictor for ruling out AAD, with a sensitivity of 94.0% and a specificity of 56.8%. At a cut-off level of 0.5 µg/ml, the negative and positive likelihood ratios were 0.10 and 2.18, respectively, with a positive predictive value of 42.6% and a negative predictive value of 96.6%.

CONCLUSIONS

The D-dimer level within 24 h after symptom onset might be helpful for differentiating AAD from other causes of chest pain.

D-Dimer assay as a non invasive test for the diagnosis of left atrial Thrombi in Indian patients with Rheumatic MS

BACKGROUND

Systemic embolism is a serious and sometime fatal complication of rheumatic MS.

OBJECTIVE

We assessed the predictive power of D-Dimer level to predict occurrence of left atrial (LA) thrombi in patients with rheumatic mitral stenosis (MS).

METHODS

D-dimer levels were analyzed for 24 patients with rheumatic MS with LA clot and 22 patients with rheumatic MS with no LA clot undergoing transeosophageal echocardiography. A level more than 4 µg/ml was taken as elevated to predict the presence of LA clot in the study groups.

RESULTS

For a cut-off value of 4 µg/ml, sensitivity was 66.67 % and specificity 100 % for prediction of LA clot and AUC 0.710. A cut-off value of less than 1 µg/ml, sensitivity was 91.67 % and 87. 5 % negative predictive value for ruling out presence of LA clot and AUC 0.721.

CONCLUSION

A higher value of D-dimer can predict the possible presence of a LA clot and very low value can predict absence of clot in patients with rheumatic MS.

Physiological changes as a result of hip arthroscopy performed with traction

PURPOSE

To evaluate the physiological effects of hip arthroscopy using traction on venous blood flow, nerve conduction, soft-tissue injury, fibrinolysis, and patient pain.

METHODS

Thirty subjects were prospectively analyzed in an institutional review board-approved study. The visual analog scale pain score, creatine phosphokinase (CPK)-MM level, and D-dimer test were obtained preoperatively, postoperatively, and 5 days postoperatively. Doppler ultrasound (group A) (n = 15) of femoral and popliteal venous blood flow and somatosensory evoked potentials (SSEPs) (group B) (n = 15) of the posterior tibial nerve and superficial peroneal nerve were monitored intraoperatively.

RESULTS

Mean operation and traction times were 131.7 and 27.3 minutes, respectively. During traction (mean, 57.7 lb), decreased blood flow was determined at the popliteal vein (15 of 15 subjects) and femoral vein (4 of 15 subjects). Blood flow returned to baseline after traction in all subjects. Mean CPK-MM levels were 86.0 ± 29.6 mU/mL preoperatively, 232.1 ± 224.6 mU/mL postoperatively, and 138.1 ± 109.3 mU/mL at 5 days postoperatively. The number of subjects positive for D-dimer was 7 preoperatively, 12 postoperatively, and 21 at 5 days postoperatively. SSEPs showed a greater than 50% decrease in amplitude on the operative (8 of 15) and nonoperative (9 of 15) limbs. No significant correlations were determined between visual analog scale pain score, body mass index, CPK-MM level, traction time, or operating room time.

CONCLUSIONS

Doppler ultrasound showed decreased blood flow of the popliteal vein with traction, which returned to normal after traction. SSEPs showed changes with and without traction on operative and nonoperative legs. Consideration should be given for knee flexion of the contralateral leg after traction to protect nerve function. Hip arthroscopy resulted in an increase in a positive D-dimer test from immediately postoperatively to postoperative day 5. There is variability in the soft-tissue damage with hip arthroscopy, which is independent of time (<2 hours), body mass index, or pain. Traction affects the vascular and neurologic structures of the operative and nonoperative extremity independent of time.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Struggling to bring clinical prediction rules to the point of care: missed opportunities to impact patient care

Clinical prediction rules can help clinicians make personalized and complex decisions at the point of care. They have the potential to improve patient care outcomes and reduce healthcare costs, but remain underutilized. There are a number of well-derived and validated clinical prediction rules. Few, however, have been studied by means of an impact analysis or successfully integrated into provider workflow. A heavily identified area of opportunity for integration is the electronic health record. There are, however, a number of barriers to adoption at both the infrastructure and organizational levels. Research efforts should focus on impact analysis and how to successfully implement existing, well-validated clinical prediction rules into daily practice. Recommendations include emphasis on a collaborative framework, using existing technologies, and utilization of usability and workflow integration methodology.

[Clinical usefulness of three quantitative D-dimers tests in outpatients with suspected deep vein thrombosis]

BACKGROUND AND OBJECTIVE

The diagnostic approach in outpatients with suspected deep vein thrombosis (DVT) of the lower limbs includes D-dimer measurement (DD). Elevated DD is not a diagnostic value for DVT. However, a normal value contributes to ruling out DVT. We do not know the best method to determine DD. Therefore, we have analyzed the clinical utility of three quantitative assays to determine DD in outpatients with suspected DVT.

PATIENTS AND METHODS

Consecutive outpatients with suspected DVT of the lower limbs who were referred to the DVT medical consultation were enrolled in the study. We used a diagnostic algorithm that included determining the pretest clinical probability (PCP) (Wells scale), DD level using three different quantitative methods (ELISA mini-VIDAS(®), Acure-care DDMR and DD-Plus). The DVT diagnosis was confirmed by seriated compression ultrasonography of the lower limbs. We analyzed the concordance between the three analytic methods to quantify DD and the characteristics.

RESULTS

A total of 306 patients (mean age 60 years, 62% women) with suspected DVT of the lower limbs were included. The compression ultrasonography confirmed the diagnosis of DVT in 23.8% of the patients. Anticoagulation treatment was not performed in patients in whom DVT was ruled out, and no thromboembolic event occurred during the 3 months of follow-up. The best concordance test results were between ELISA mini-VIDAS(®) and Acure-care DDMR assays. Both assays demonstrated elevated sensibility and a negative predictive value. ELISA mini-VIDAS(®) was the best analytic method for the subgroup of patients with low clinical probability.

CONCLUSIONS

The ELISA mini-VIDAS(®) method to determine DD rules out DVT in patients with low clinical probability.

Predictive Value of the Rapid Whole Blood Agglutination D-Dimer Assay (AGEN SimpliRED) in Community Outpatients with Suspected Deep Venous Thrombosis

CONTEXT

D-dimer assay has been used to screen patients with deep venous thrombosis (DVT). Because both the predictive value and sensitivity/specificity of the test vary according to the type of assay, prevalence, and pretest probability of DVT, clinicians must know the local performance of the d-dimer assay.

OBJECTIVE

To evaluate the predictive value of the rapid whole blood agglutination d-dimer Assay (AGEN SimpliRED) in community outpatients with suspected DVT in the Kaiser Permanente (KP) Mid-Atlantic Region.

DESIGN

Retrospective, randomized, cross-sectional review of electronic medical records of patients with suspected DVT who underwent d-dimer testing for venous thromboembolism.

METHODOLOGY

A total of 5104 patients with suspected venous thromboembolism underwent d-dimer testing using AGEN SimpliRED from April 2001 to December 2002. A total of 551 electronic medical records were reviewed, and results of d-dimer assay and compression ultrasonography were tabulated. Records were analyzed to determine later diagnosis of DVT or unexplained death occurring as late as six months after initial testing.

RESULTS

Electronic records showed a 5.3% disease prevalence. Ten patients were excluded from data analysis. A total of 129 (23.8%) patients had positive d-dimer; the positive predictive value was 20.2% (CI, 13.2% to 27%). A total of 412 (76.1%) patients had negative test results; three of these patients had DVT shown by compression ultra-sonography; negative predictive value was 99.3% (CI, 98.4% to 100%). Calculated sensitivity was 89.7%; specificity was 79.9%.

CONCLUSION

In the outpatient setting, the rapid whole blood agglutination d-dimer assay (AGEN SimpliRED) used in combination with both clinical judgment and compression ultrasonography exhibited a high negative predictive value comparable with previously reported values.

Pitfalls in the evaluation of shortness of breath

This article illustrates the challenges practitioners face evaluating shortness of breath, a common emergency department complaint. Through a series of patient encounters, pitfalls in the evaluation of shortness of breath are reviewed and discussed.

Is D-dimer helpful in evaluating stroke patients? A systematic review

D-dimer (DD) is a fibrin degradation product present in negligible amounts in healthy individuals, but in thrombotic/fibrinolytic conditions substantially increases in plasma. Over the last two decades numerous studies have explored whether DD measurements would help stroke clinicians. An easy, reliable, and inexpensive test for stroke diagnosis, determination of stroke subtype, severity, prognosis, and recurrence risk is being sought. We searched the database, of studies indexed in English on MEDLINE, using the keywords 'cerebral venous thrombosis, D-dimer, deep vein thrombosis, intracerebral hemorrhage, ischemic stroke, outcome, prognosis, and subarachnoid hemorrhage' for relevant studies. Here, we systematically review current evidence on plasma DD levels in patients with ischemic and hemorrhagic strokes, transient ischemic attacks, and cerebral venous thrombosis. Numerous studies showed that patients with various strokes and stroke-related diseases had acutely increased plasma DD levels. Plasma DD levels, however, are neither sensitive nor specific enough to be utilized in stroke diagnostics and cannot replace either clinical or radiological evaluation. Regarding prediction of patient outcome, good clinical evaluation is clearly superior to DD testing.

D-Dimer in the Early Diagnosis of Acute Mesenteric Ischemia Secondary to Arterial Occlusion in Rats

BACKGROUND

Early diagnosis of mesenteric ischemia can be life saving. The aim of this study is to investigate the time-dependent diagnostic value of plasma D-dimer and other ancillary laboratory evaluations such as creatine phosphokinase, lactic dehydrogenase, aspartate aminotransferase, alanine aminotransferase, amylase, and leukocyte count in an experimental superior mesenteric arterial occlusion (SMA-O) model in rats.

METHODS

Forty male Wistar-Albino rats were separated into 4 groups: 2-, 4-, 6-, and 12-hour SMA-O groups. After laparotomy, the SMA was identified and ligated for 2, 4, 6 and 12 h in the 4 respective study groups. Blood samples were taken for laboratory tests 2 h after laparotomy in the control group and at the end of the ischemic period in the study groups.

RESULTS

The longer the duration of mesenteric ischemia, the higher were the serum D-dimer levels in the study groups, and statistical significance was obtained at 2 h (p = 0.021). Sensitivity, positive predictive value, negative predictive value, and accuracy of the relation were 88.8, 88.8, 100 and 90%, respectively. Leukocyte count was significantly higher than controls after 12 h. No other laboratory parameter correlated positively with the duration of mesenteric ischemia.

CONCLUSION

Serum D-dimer measurements may be a valuable diagnostic parameter in the early diagnosis of mesenteric ischemia.

D-dimer levels in the prediction of the degree of intestinal necrosis of etrangulated hernias in rats

PURPOSE

The aim of this study was to investigate the time-dependent relation between plasma D-dimer levels and the degree of intestinal necrosis and to compare these parameters with leukocyte counts in an experimental etrangulated hernia model in rats.

RESULTS

When the duration of intestinal ischemia was prolonged, serum D-dimer levels increased relative to the control group, with the difference being statistically significant at hour 2 (P = 0.027). In contrast, leukocyte counts in the 2- and 4-h strangulation group were higher that those of the control group, but the difference was not statistically significant (P = 0.625 and P = 0.846, respectively). However, in the 6-h strangulation group the levels of leukocytes were significantly higher that those of the control group (P = 0.015).

CONCLUSION

Serum D-dimer measurements may be used as a more valuable diagnostic parameter than leukocyte count in the early diagnosis of intestinal ischemia, including strangulated hernia.

D-dimer concentration increases with age reducing the clinical value of the D-dimer assay in the elderly

BACKGROUND

The D-dimer assay is used as an exclusion test in the assessment of suspected venous thromboembolic disease; patients with a negative result have a low probability of thrombosis. We reviewed the D-dimer results from a hospital and community laboratory using the vidas D-dimer test to assess the influence of age on the D-dimer assay.

METHODS

D-dimer results from 6631 unselected patients aged more than 16 years were analysed in four age groups and it was shown that the median D-dimer concentration increased with age (16-40 years, 294 ng/mL; 40-60 years, 387 ng/mL; 60-80 years; 854 ng/mL; >80 years, 1397 ng/mL). To test the effect of age on the assay specificity, a cohort of 1897 patients with suspected venous thromboembolic disease was analysed separately. Patients with a negative D-dimer were discharged without further investigation. Patients with a positive result and a clinical suspicion of thrombosis underwent further investigation. One hundred and sixty-five deep vein thrombosis or pulmonary embolus cases were identified.

RESULTS

The assay specificity decreased with age from 70% in patients less than 40 years to below 5% in patients more than 80 years. Receiver operator curves were prepared for each age group and the effect of altering the threshold value was analysed. In patients 60-80 years old a threshold value of 1000 ng/mL increased assay specificity to 55% without loss of assay sensitivity.

CONCLUSION

The vidas D-dimer assay with a threshold value of 500 ng/mL has little clinical value as an exclusion test in patients more than 80 years old. The assay specificity is poor (26%) in patients aged 60-80 years but could be improved by increasing the threshold value to 1000 ng/mL. We believe that this should be tested in a prospective trial.

Initial approach to the patient who has chest pain

The last decade has seen extraordinary advances in the cardiovascular arena, particularly in the evaluation and management of the patient who has acute coronary syndromes. From bedside markers of myocardial damage to drug-eluting stents, technical advances are proliferating. Efforts in developing an international registry for acute aortic dissection have helped elucidate the acute presentation, management, and prognosis of this uncommon but lethal disease. Finally, the multiple research efforts in coordinating clinical decision-making with serologic markers and advanced imaging for the diagnosis of pulmonary embolism is changing the approach to the patient at risk for thromboembolic disease.

Venous Thromboembolic Complications Following Air Travel: What's the Quantitative Risk? A Literature Review

OBJECTIVES

To quantify the risk of venous thromboembolism (VTE) following air travel and assess methods of prevention.

DESIGN

Review of literature.

METHODS

We reviewed Pubmed, Medline, Embase and Cochrane Databases for studies that have assessed the risk of VTE associated with air travel.

RESULTS

There is an association of VTE with air travel with pooled odds ratio of 1.59 (confidence interval 1.04-2.43) from three case control studies and relative risk of 2.93 (confidence interval 1.5-5.58) from two controlled cohort studies. The incidence of symptomatic pulmonary embolism (PE) is extremely low but there is substantial increase when the distance travelled is more than 5,000 miles (1.5 PE per million passengers) or time of flight is more than 8h duration (2.57 PE per million passengers). The quantitative risk of lower limb venous thrombosis in high-risk subjects is 5% per flight and 1.6% per flight for low risk subjects following long haul flights. All six randomised trials to test the below knee compression stockings with ankle pressures of 14-30 mmHg have shown reduction in lower limb venous thrombosis.

CONCLUSION

VTE is more common in those with additional risk factors when the risk is about 5% per air travel for long haul flights. Class I or II below knee compression stockings are effective in the prevention of lower limb venous thrombosis.

Initial Evaluation of Chest Pain

Chest pain is among the most frequently evaluated presenting complaints in the emergency department (ED). Diagnostic etiologies range from benign to life-threatening. Failure to diagnose the life-threatening chest emergencies-specifically acute coronary syndrome, aortic dissection, and pulmonary embolism-can lead to catastrophic medical and legal outcomes for the patient and physician respectively. This article focuses on clinical and risk management strategies to minimize misdiagnosis and produce favorable medical and medicolegal outcomes.

[D-dimer levels in venous thromboembolism]

Venous thromboembolism (VTE) is associated with substantial morbidity and mortality. The clinical signs and symptoms are unspecific, widely varying from asymptomatic to sudden death. The diagnostic algorithm of VTE is an evolving field, in which D-dimers (DD) determination has been used as one of the preferred screening tests. Clinical management studies are clarifying the role of DD in the diagnostic paradigm of VTE. Published reports support the use of plasma DD determination in patients with a low clinical probability of VTE. Patients with moderate or high clinical probability of VTE show a higher probability of false negative plasma DD values. This fact forces the clinician to use more complex diagnostic test in order to either confirm or exclude VTE. A variety of different qualitative and semi-quantifiable assays are available for plasma DD determination. There is a wide variation in performance and there are discrepancies in the comparability of the different assays. Therefore, in order to both appropriately incorporate plasma DD determination in the diagnostic strategies of VTE and to reduce unnecessary investigations, clinicians should ensure that they are familiar with the diagnostic performance of the assay used in their own institution allowing a safer and cost-effective procedure.

Combined use of rapid D-dimer testing and estimation of clinical probability in the diagnosis of deep vein thrombosis: systematic review

OBJECTIVE

To summarise the evidence supporting the use of rapid d-dimer testing combined with estimation of clinical probability to exclude the diagnosis of deep venous thrombosis among outpatients.

DATA SOURCES

Medline (June 1993 to December 2003), the Database of Abstracts and Reviews (DARE), and reference lists of studies in English.

SELECTION OF STUDIES

We selected 12 studies from among 84 reviewed. The selected studies included more than 5000 patients and used a rapid D-dimer assay and explicit criteria to classify cases as having low, intermediate, or high clinical probability of deep vein thrombosis of the lower extremity among consecutive outpatients.

REVIEW METHODS

Diagnosis required objective confirmation, and untreated patients had to have at least three months of follow up. The outcome was objectively documented venous thromboembolism. Two authors independently abstracted data by using a data collection form.

RESULTS

When the less sensitive SimpliRED D-dimer assay was used the three month incidence of venous thromboembolism was 0.5% (95% confidence interval 0.07% to 1.1%) among patients with a low clinical probability of deep vein thrombosis and normal D-dimer concentrations. When a highly sensitive D-dimer assay was used, the three month incidence of venous thromboembolism was 0.4% (0.04% to 1.1%) among outpatients with low or moderate clinical probability of deep vein thrombosis and a normal D-dimer concentration.

CONCLUSIONS

The combination of low clinical probability for deep vein thrombosis and a normal result from the SimpliRED D-dimer test safely excludes a diagnosis of acute venous thrombosis A normal result from a highly sensitive D-dimer test effectively rules out deep vein thrombosis among patients classified as having either low or moderate clinical probability of deep vein thrombosis.