Evidence for Age-Adjusted D-Dimer to Rule out Pulmonary Embolism: An Institutional Study

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S5-S5
Author(s):  
Ridin Balakrishnan ◽  
Daniel Casa ◽  
Morayma Reyes Gil
Keyword(s):  
Pulmonary Embolism ◽  
False Positive ◽  
False Positive Rate ◽  
Moderate Risk ◽  
Older Population ◽  
Statistical Measures ◽  
Positive Rate ◽  
Risk Patients ◽  
D Dimer ◽  
Rule Out

Abstract The diagnostic approach for ruling out suspected acute pulmonary embolism (PE) in the ED setting includes several tests: ultrasound, plasma d-dimer assays, ventilation-perfusion scans and computed tomography pulmonary angiography (CTPA). Importantly, a pretest probability scoring algorithm is highly recommended to triage high risk cases while also preventing unnecessary testing and harm to low/moderate risk patients. The d-dimer assay (both ELISA and immunoturbidometric) has been shown to be extremely sensitive to rule out PE in conjunction with clinical probability. In particularly, d-dimer testing is recommended for low/moderate risk patients, in whom a negative d-dimer essentially rules out PE sparing these patients from CTPA radiation exposure, longer hospital stay and anticoagulation. However, an unspecific increase in fibrin-degradation related products has been seen with increase in age, resulting in higher false positive rate in the older population. This study analyzed patient visits to the ED of a large academic institution for five years and looked at the relationship between d-dimer values, age and CTPA results to better understand the value of age-adjusted d-dimer cut-offs in ruling out PE in the older population. A total of 7660 ED visits had a CTPA done to rule out PE; out of which 1875 cases had a d-dimer done in conjunction with the CT and 5875 had only CTPA done. Out of the 1875 cases, 1591 had positive d-dimer results (>0.50 µg/ml (FEU)), of which 910 (57%) were from patients older than or equal to fifty years of age. In these older patients, 779 (86%) had a negative CT result. The following were the statistical measures of the d-dimer test before adjusting for age: sensitivity (98%), specificity (12%); negative predictive value (98%) and false positive rate (88%). After adjusting for age in people older than 50 years (d-dimer cut off = age/100), 138 patients eventually turned out to be d-dimer negative and every case but four had a CT result that was also negative for a PE. The four cases included two non-diagnostic results and two with subacute/chronic/subsegmental PE on imaging. None of these four patients were prescribed anticoagulation. The statistical measures of the d-dimer test after adjusting for age showed: sensitivity (96%), specificity (20%); negative predictive value (98%) and a decrease in the false positive rate (80%). Therefore, imaging could have been potentially avoided in 138/779 (18%) of the patients who were part of this older population and had eventual negative or not clinically significant findings on CTPA if age-adjusted d-dimers were used. This data very strongly advocates for the clinical usefulness of an age-adjusted cut-off of d-dimer to rule out PE.

scholarly journals D-Dimer and Exhaled CO2/O2to Detect Segmental Pulmonary Embolism in Moderate-Risk Patients

2010 ◽  
Vol 182 (5) ◽  
pp. 669-675 ◽  
Author(s):  
Jeffrey A. Kline ◽  
Melanie M. Hogg ◽  
D. Mark Courtney ◽  
Chadwick D. Miller ◽  
Alan E. Jones ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Moderate Risk ◽  
Risk Patients ◽  
D Dimer

Pulmonary Embolism Rule-out Criteria vs D-dimer testing in low-risk patients for pulmonary embolism: a retrospective study

2014 ◽  
Vol 32 (6) ◽  
pp. 609-613 ◽  
Author(s):  
J. Bokobza ◽  
A. Aubry ◽  
N. Nakle ◽  
C. Vincent-Cassy ◽  
D. Pateron ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Retrospective Study ◽  
Low Risk ◽  
Risk Patients ◽  
D Dimer ◽  
Rule Out

scholarly journals P039: Utilization of serum D-dimer assays and computed tomography pulmonary angiography (CTPA) scans in the diagnosis of pulmonary embolism among emergency department (ED) physicians

CJEM ◽  
2020 ◽  
Vol 22 (S1) ◽  
pp. S78-S78
Author(s):  
L. Salehi ◽  
P. Phalpher ◽  
H. Yu ◽  
M. Ossip ◽  
R. Valani ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Decision Rules ◽  
Pulmonary Angiography ◽  
Low Risk ◽  
Urgent Care ◽  
Computed Tomography Pulmonary Angiography ◽  
Risk Patients ◽  
D Dimer ◽  
Rule Out

Introduction: As the availability of Computed Tomography Pulmonary Angiography (CTPA) to rule out pulmonary embolism (PE) increases, so too does its utilization, and consequent overutilization. A variety of evidence-based algorithms and decision rules using clinical criteria and D-Dimer testing have been proposed as instruments to allow physicians to safely rule out a PE in low-risk patients. However, studies have shown mixed results with respect to both physician uptake of these decision rules and their impact on improving ordering practices among physicians. The objective of this study is to describe the prevalence of D-Dimer utilization among ED physicians and its impact on positive yield rates of CTPAs in a community setting. Methods: Data was collected on all CTPA studies ordered by ED physicians at two very high-volume community hospitals and an affiliated urgent care centre during the 2-year period between January 1, 2016 and December 31, 2017. For each CTPA, we determined if 1) a D-Dimer had been ordered prior to CTPA, if 2) the D-Dimer was positive, and if 3) the CTPA was positive for a PE. Using a chi-square test, we compared the diagnostic yield for those patients who had a D-Dimer prior to their CTPA and those who did not. Results: A total of 2,811 CTPAs were included in the analysis. Of these, 964 CTPAs (34.3%) were ordered without a D-Dimer. Of those 1,847 patients who underwent D-Dimer testing prior to the CTPA, 343 (18.7%) underwent a CTPA despite a negative D-Dimer. When compared as a group, those CTPAs preceded by a D-Dimer showed no significant difference in positive yields when compared to those CTPAs ordered without a prior D-Dimer (9.9% versus 11.3%, p = 0.26). Conclusion: The findings of this study present a complicated picture of the impact of D-Dimer utilization on CTPA ordering patterns. There is evidence of suboptimal uptake of routine D-Dimer ordering, and adherence to guidelines in terms of forgoing CTPAs in low-risk patients with negative D-Dimers. While this study design leaves unanswered the question of how many CTPAs were avoided as a result of a negative D-Dimer, the finding of a similar positive yield among those patients who had a D-Dimer ordered versus those who did not is interesting, and illustrative of the issues arising from the high false-positive rates associated with D-Dimer screening.

scholarly journals Age-Adjusted D-Dimer in the Prediction of Pulmonary Embolism: Systematic Review and Meta-analysis

2021 ◽  
Vol 12 ◽  
pp. 215013272110549
Author(s):  
Kenneth Iwuji ◽  
Hasan Almekdash ◽  
Kenneth M. Nugent ◽  
Ebtesam Islam ◽  
Briget Hyde ◽  
...  
Keyword(s):  
Systematic Review ◽  
Pulmonary Embolism ◽  
False Positive ◽  
Meta Analysis ◽  
False Positive Rate ◽  
Reference List ◽  
Suspected Pulmonary Embolism ◽  
Clinical Probability ◽  
Cutoff Values ◽  
D Dimer

Background: Pulmonary embolism (PE), depending on the severity, carries a high mortality and morbidity. Proper evaluation, especially in patients with low probability for PE, is important to avoid unnecessary diagnostic testing. Objective: To review the diagnostic utility of conventional versus age-adjusted D-dimer cutoff values in patients 50 years and older with suspected pulmonary embolism. Methods: Systematic review with univariant and bivariant meta-analysis. Data sources: We searched PubMed, MEDLINE, and EBSCO for studies published before September 20th, 2020. We cross checked the reference list of relevant studies that compares conventional versus age-adjusted D-dimer cutoff values in patients with suspected pulmonary embolism. Study selection: We included primary published studies that compared both conventional (500 µg/L) and age-adjusted (age × 10 µg/L) cutoff values in patients with non-high clinical probability for pulmonary embolism. Results: Nine cohorts that included 47 720 patients with non-high clinical probability were included in the meta-analysis. Both Age-adjusted D-dimer and conventional D-dimer have high sensitivity. However, conventional D-dimer has higher false positive rate than age-adjusted D-dimer. Conclusion: Age-adjusted D-dimer cutoffs combined with low risk clinical probability assessment ruled out PE diagnosis in suspected patients with a decreased rate of false positive tests.

A Prospective Blinded Study Evaluating the Role of Endoscopic Ultrasound before Endoscopic Retrograde Cholangiopancreatography in the Setting of “Positive” Intraoperative Cholangiogram during Cholecystectomy

2016 ◽  
Vol 82 (4) ◽  
pp. 343-347 ◽  
Author(s):  
Anjuli K. Luthra ◽  
Vipul Aggarwal ◽  
Girish Mishra ◽  
Jason Conway ◽  
John A. Evans
Keyword(s):  
Endoscopic Retrograde Cholangiopancreatography ◽  
Endoscopic Ultrasound ◽  
False Positive Rate ◽  
Moderate Risk ◽  
Endoscopic Retrograde ◽  
Cbd Stones ◽  
Blinded Study ◽  
Positive Rate ◽  
Risk Patients

During laparoscopic cholecystectomy, intraoperative cholangiography (IOC) is used to identify common bile duct (CBD) stones. In patients whose IOC is suspicious for stones, endoscopic retrograde cholangiopancreatography (ERCP) is the modality of choice for stone removal. However, IOC has a false positive rate of 30 to 60 per cent, and ERCP adverse events may occur in 11 per cent of patients. Endoscopic ultrasound (EUS) may serve as a noninvasive means of diagnosing suspected CBD stones. This study sought to assess the role of EUS in predicting the likelihood of choledocholithiasis at ERCP in patients found to have a positive IOC. This was a prospective blinded study of EUS before ERCP in patients with a positive IOC. Recruited subjects who underwent cholecystectomy and had an IOC with suspicion for obstruction were referred for ERCP within one month of their procedure. In patients with a positive IOC, EUS had a positive predictive value of 95 per cent in detecting choledocholithiasis. IOC with single or multiple filling defects more often correlated to the presence of CBD stones. At ERCP, choledocholithiasis was present in 65 per cent of patients who had an IOC suspicious for CBD stones. EUS should be used as a noninvasive method to correctly identify retained CBD stones in low-to-moderate risk patients with a positive IOC.

scholarly journals Age-Adjusted D-Dimer in the Prediction of Pulmonary Embolism: Does a Normal Age-Adjusted D-Dimer Rule Out PE?

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Jacob Ortiz ◽  
Rabia Saeed ◽  
Christopher Little ◽  
Saul Schaefer
Keyword(s):  
Pulmonary Embolism ◽  
Medical Center ◽  
Decision Rules ◽  
Clinical Decision ◽  
Pulmonary Angiography ◽  
Clinical Decision Rules ◽  
Risk Patients ◽  
D Dimer ◽  
Rule Out

Risk assessment for pulmonary embolism (PE) currently relies on physician judgment, clinical decision rules (CDR), and D-dimer testing. There is still controversy regarding the role of D-dimer testing in low or intermediate risk patients. The objective of the study was to define the role of clinical decision rules and D-dimer testing in patients suspected of having a PE. Records of 894 patients referred for computed tomography pulmonary angiography (CTPA) at a University medical center were analyzed. The clinical decision rules overall had an ROC of approximately 0.70, while signs of DVT had the highest ROC (0.80). A low probability CDR coupled with a negative age-adjusted D-dimer largely excluded PE. The negative predictive value (NPV) of an intermediate CDR was 86–89%, while the addition of a negative D-dimer resulted in NPVs of 94%. Thus, in patients suspected of having a PE, a low or intermediate CDR does not exclude PE; however, in patients with an intermediate CDR, a normal age-adjusted D-dimer increases the NPV.

scholarly journals P117: Does an age-adjusted D-dimer threshold provide adequate sensitivity in ED patients investigated for pulmonary embolism?

CJEM ◽  
2016 ◽  
Vol 18 (S1) ◽  
pp. S117-S117
Author(s):  
K.D. Senior ◽  
K. Burles ◽  
D. Grigat ◽  
D. Wang ◽  
G. Innes ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Predictive Value ◽  
Older Patients ◽  
False Positive Rate ◽  
High Sensitivity ◽  
Ct Imaging ◽  
Administrative Database ◽  
Positive Rate ◽  
Sensitivity Specificity ◽  
D Dimer

Introduction: The D-dimer assay is a high sensitivity, low specificity test used to rule out pulmonary embolism (PE) in low risk ED patients. Patients with a positive D-dimer result will likely undergo CT imaging to confirm the diagnosis. Given the time, cost, and radiation exposure associated with CT, and the higher false-positive rate in older patients, an age-adjusted D-dimer threshold may be preferred. Our objective was to evaluate the sensitivity and specificity of an age-adjusted D-dimer and approximate the downstream effect on CT imaging utilization. Methods: This was a retrospective cohort study conducted using administrative data from Calgary emergency departments between July 2013 and January 2015. Eligible patients were individuals aged 50 and older who were undergoing PE workup including D-dimer testing. Outcomes were ascertained using CT imaging reports and by searching the regional administrative database for subsequent diagnosis of PE within 30 days of the index visit. These data were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value of the D-dimer test using the standard threshold (500 ng/mL) and an age-adjusted threshold (10 ng/mL x patient age as an integer). From this, the potential reduction in CT imaging use and missed PE diagnoses were modeled. Results: Of 6669 patients aged 50 or older who had D-dimer testing for possible PE, 1504 (22.6%) underwent a CT scan, and 217 (14.4% of CT) received a discharge diagnosis of pulmonary embolism, which was confirmed on chart review. When test results were re-interpreted using an age-adjusted threshold, D-dimer specificity increased from 63.9% to 75.4%, while sensitivity decreased from 96.5% to 89.9%. This translates to 888 new true negatives, representing CT scans potentially avoided (a 59% reduction in CT utilization), but with 18 new missed PE diagnoses. Conclusion: The age-adjusted threshold may reduce use of CT imaging among older patients suspected of PE, but at the cost of more missed PE diagnoses.

scholarly journals Diagnostic Values of Some Fibrinolytic Indicators for Rejecting the Presence of Paroxysmal Atrial Fibrillation

2020 ◽  
Vol 2 (12) ◽  
pp. 1-6
Keyword(s):  
Atrial Fibrillation ◽  
Paroxysmal Atrial Fibrillation ◽  
Plasma Levels ◽  
False Positive Rate ◽  
True Positive Rate ◽  
Modern Medicine ◽  
Positive Rate ◽  
Diagnostic Values ◽  
D Dimer ◽  
Rule Out

Diagnostic tests are a cornerstone in modern medicine. They are used not only to confirm the presence of a disease but also to rule out the disease in healthy subjects. Tests with two outcome categories (i.e. presence/absence) are known as dichotomous tests. Their inherent validity is determined by sensitivity and specificity and the receiver operating characteristic (ROC) curve is known to be a simple, yet complete plot that displays the full picture of trade-off between the sensitivity (true positive rate) and (1- specificity) (false positive rate) across a series of cut-off points. Our study found that, even in the early hours of paroxysmal atrial fibrillation, there were significant changes in major indicators of fibrinolysis, namely plasminogen level, t-PA level, PAI-1 activity, α2-antiplasmin activity, vitronectin and D-dimer plasma levels. We believe that they are closely related and stem from the disease itself. This gave us reason, using these indicators as predictors, to search for a diagnostic option to rule out PAF. We used statistical models of logistic regression analysis and ROC to achieve this. Values of p<0.05 were considered statistically significant. Plasma levels of vitronectin have been found to be the most reliable predictor for ruling out PAF (specificity 88%, sensitivity 83%, AUC 0.96), while D-dimer levels had the lowest diagnostic values (37% specificity, 81% sensitivity, AUC 0.56). The obtained results are not only of pure scientific but also of applied nature. They could be used to improve identification of patients at risk for PAF embolism, and assist in the choice of thromboprophylaxis.

D-Dimer and CT Rule Out Pulmonary Embolism

2008 ◽  
Vol 1 (2) ◽  
pp. 11
Author(s):  
DAMIAN MCNAMARA
Keyword(s):  
Pulmonary Embolism ◽  
D Dimer ◽  
Rule Out

Improving diagnosis of acute appendicitis with atypical findings by Tc-99m HMPAO leukocyte scan

2002 ◽  
Vol 41 (01) ◽  
pp. 37-41 ◽  
Author(s):  
S. Shung-Shung ◽  
S. Yu-Chien ◽  
Y. Mei-Due ◽  
W. Hwei-Chung ◽  
A. Kao
Keyword(s):  
Acute Appendicitis ◽  
False Positive ◽  
False Positive Rate ◽  
Accurate Method ◽  
Clinical Findings ◽  
Pathological Findings ◽  
Lower Quadrant ◽  
Predictive Values ◽  
Positive Rate

Summary Aim: Even with careful observation, the overall false-positive rate of laparotomy remains 10-15% when acute appendicitis was suspected. Therefore, the clinical efficacy of Tc-99m HMPAO labeled leukocyte (TC-WBC) scan for the diagnosis of acute appendicitis in patients presenting with atypical clinical findings is assessed. Patients and Methods: Eighty patients presenting with acute abdominal pain and possible acute appendicitis but atypical findings were included in this study. After intravenous injection of TC-WBC, serial anterior abdominal/pelvic images at 30, 60, 120 and 240 min with 800k counts were obtained with a gamma camera. Any abnormal localization of radioactivity in the right lower quadrant of the abdomen, equal to or greater than bone marrow activity, was considered as a positive scan. Results: 36 out of 49 patients showing positive TC-WBC scans received appendectomy. They all proved to have positive pathological findings. Five positive TC-WBC were not related to acute appendicitis, because of other pathological lesions. Eight patients were not operated and clinical follow-up after one month revealed no acute abdominal condition. Three of 31 patients with negative TC-WBC scans received appendectomy. They also presented positive pathological findings. The remaining 28 patients did not receive operations and revealed no evidence of appendicitis after at least one month of follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values for TC-WBC scan to diagnose acute appendicitis were 92, 78, 86, 82, and 90%, respectively. Conclusion: TC-WBC scan provides a rapid and highly accurate method for the diagnosis of acute appendicitis in patients with equivocal clinical examination. It proved useful in reducing the false-positive rate of laparotomy and shortens the time necessary for clinical observation.

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