Pulmonary embolism in COVID-19: D-dimer threshold selection should not be based on maximising Youden's index

Role of peak D-dimer in predicting mortality and venous thromboembolism in COVID-19 patients

Covid 19 patients often present with elevated D-dimer levels. The purpose of this study is to evaluate the role of D-Dimer levels in Covid 19 patients to predict mortality and venous thromboembolism (VTE) events. This is a retrospective chart review study from 1 April 2020 to 30 June 2020, during the peak Covid pandemic. A total of 350 patients were enrolled in this study; 69 (19.7%) patients died; 12 (3.4%) had a deep venous thrombosis; and 8 (2.3%) had a pulmonary embolism outcome. Peak D-dimer levels were collected with median levels of 765 ng/ml (266, 3135). Patients with VTE outcomes had significantly higher levels of peak D-dimers than patients in the non-VTE group (4876 vs 680, p < 0.0001). Patients who died had higher peak D-dimer levels than those who survived (4690 vs 501, p < 0.0001). The optimal cutoff point in peak D-dimer in predicting VTE events was 1437, yielding a sensitivity of 84.2% and a specificity of 65.0%. The optimal cutoff point in peak D-dimer in predicting mortality was 2004, yielding a sensitivity of 71.0% and a specificity of 77.9%. This study suggests that D-dimer levels can be elevated in Covid 19 hospitalized patients and can serve as indicators for mortality and VTE events.

Distinct age-adjusted D-dimer threshold to rule out acute pulmonary embolism in outpatients and inpatients

INTRODUCTION

The diagnosis of acute pulmonary embolism (PE) is combinations of clinical probability assessments, plasma D-dimer (DD) test results, and/or computed tomographic pulmonary angiography (CTPA).

OBJECTIVE

The aim of this study is to explore the appropriate DD cutoff using the immunoturbidimetric method in outpatients and inpatients.

METHODS

We retrospectively enrolled 2689 patients with suspected PE between January 2014 and December 2019. All patients underwent clinical probability assessments, DD tests, and CTPA. We investigated the appropriate cutoff level for plasma DD tests in the correlation analysis and receiver operating characteristic (ROC) curves.

RESULTS

Among all patients, 1263 were confirmed acute PE. The age-adjusted DD level was determined to be age × 10 μg/L (for patients aged >50 years) in outpatients. This cutoff value resulted in a sensitivity of 96.75% and a specificity of 87.02%, with the area under the curve (AUC) of 0.908 and the number needed to treat (NNT) of 1.18. For inpatients, the age-adjusted cutoff values for the biomarker DD demonstrated poor specificity (13.34%) and NNT (9.88). However, when the DD cutoff was adjusted to 2 × the upper limit of normal (ULN), the sensitivity increased to 93.19%, while the specificity remained at 29.55%, with the AUC of 0.610 and the NNT of 4.76. The optimal DD cut-off value was 3010 μg/L (about 5 × ULN), resulting in a sensitivity of 75.22% and specificity of 61.72%, with the AUC of 0.727 and the NNT of 2.7.

CONCLUSION

Using the immunoturbidimetric method to measure DD, an age-adjusted DD cutoff (age × 10 μg/L, if aged >50 years) should be considered for outpatients with suspected PE. For inpatients, increasing the DD cutoff value to at least 2 × ULN yields the best test performance.

Pulmonary CT angiography in the first wave of the COVID-19 pandemic: Comparison between patients with and without infection and with a pre-pandemic series

BACKGROUND AND AIMS

To analyze the diagnostic performance of pulmonary CT angiography and to compare different D-dimer cutoffs for the diagnosis of acute pulmonary embolism in patients with and without SARS-CoV-2 infections.

MATERIALS AND METHODS

We retrospectively analysed all consecutive pulmonary CT angiography studies done for suspected pulmonary embolism in a tertiary hospital during two time periods: the first December 2020 through February 2021 and the second December 2017 through February 2018. D-dimer levels were obtained less than 24 h before the pulmonary CT angiography studies. We analysed the sensitivity, specificity, positive and negative predictive values, area under the receiver operating curve (AUC), and pattern of pulmonary embolism for six different values of D-dimer and the extent of the embolism. During the pandemic period, we also analysed whether the patients had COVID-19.

RESULTS

After excluding 29 poor-quality studies, 492 studies were analysed; 352 of these were done during the pandemic, 180 in patients with COVID-19 and 172 in patients without COVID-19. The absolute frequency of pulmonary embolism diagnosed was higher during the pandemic period (34 cases during the prior period and 85 during the pandemic; 47 of these patients had COVID-19). No significant differences were found in comparing the AUCs for the D-dimer values. The optimum values calculated for the receiver operating characteristic curves differed between patients with COVID-19 (2200 mcg/l), without COVID-19 (4800 mcg/l), and diagnosed in the prepandemic period (3200 mcg/l). Peripheral distribution of the emboli was more common in patients with COVID-19 (72%) than in those without COVID-19 and than in those diagnosed before the pandemic [OR 6.6, 95% CI: 1.5-24.6, p < 0.05 when compared to central distribution].

CONCLUSIONS

The number of CT angiography studies and the number of pulmonary embolisms diagnosed during the pandemic increased due to SARS-CoV-2 infection. The optimal d-dimer cutoffs and the distribution of the pulmonary embolisms differed between the groups of patients with and without COVID-19.

Predictors and outcomes of acute pulmonary embolism in COVID-19; insights from US National COVID cohort collaborative

OBJECTIVES

To investigate whether COVID-19 patients with pulmonary embolism had higher mortality and assess the utility of D-dimer in predicting acute pulmonary embolism.

PATIENTS AND METHODS

Using the National Collaborative COVID-19 retrospective cohort, a cohort of hospitalized COVID-19 patients was studied to compare 90-day mortality and intubation outcomes in patients with and without pulmonary embolism in a multivariable cox regression analysis. The secondary measured outcomes in 1:4 propensity score-matched analysis included length of stay, chest pain incidence, heart rate, history of pulmonary embolism or DVT, and admission laboratory parameters.

RESULTS

Among 31,500 hospitalized COVID-19 patients, 1117 (3.5%) patients were diagnosed with acute pulmonary embolism. Patients with acute pulmonary embolism were noted to have higher mortality (23.6% vs.12.8%; adjusted Hazard Ratio (aHR) = 1.36, 95% CI [1.20-1.55]), and intubation rates (17.6% vs. 9.3%, aHR = 1.38[1.18-1.61]). Pulmonary embolism patients had higher admission D-dimer FEU (Odds Ratio(OR) = 1.13; 95%CI [1.1-1.15]). As the D-dimer value increased, the specificity, positive predictive value, and accuracy of the test increased; however, sensitivity decreased (AUC 0.70). At cut-off D-dimer FEU 1.8 mcg/ml, the test had clinical utility (accuracy 70%) in predicting pulmonary embolism. Patients with acute pulmonary embolism had a higher incidence of chest pain and history of pulmonary embolism or deep vein thrombosis.

CONCLUSIONS

Acute pulmonary embolism is associated with worse mortality and morbidity outcomes in COVID-19. We present D-dimer as a predictive risk tool in the form of a clinical calculator for the diagnosis of acute pulmonary embolism in COVID-19.

Optimal body composition indices cutoff values based on all-cause mortality in the elderly

The cutoffs of body composition indices are inconclusive in older populations. This study is designed toward determining the optimal cutoffs of the body composition indices based on the association with all-cause mortality. During 2009 and 2010, a cohort population of 1200 was enrolled in central western Taiwan. Of the 1200 subjects, 428 older subjects (mean age: 72.5 ± 5.4 yrs.; 47.7 % were women) were censored in this study. The waist circumference (WC) and body mass index (BMI) were measured using standard anthropometric methods. A multi-frequency bioelectrical impedance analysis device was utilized to estimate each participant's body composition indices, including percent body fat (PBF) and skeletal muscle mass index (SMMI). All claims records of death from 2009 to 2018 in the National Health Insurance Research Databank were identified. A receiver operating characteristic curve method and the highest Youden index were used to identify the optimal cutoffs. A Cox proportional hazards regression analysis was used to model associations between each of the recommended cutoff values with all-cause mortality. The all-cause mortality rate was 20.09 % after a follow-up period of 5.86 ± 2.39 person-years. The significant indices cutoff value was identified to be WC (86.7 cm) for older women and BMI (23.8 kg/m²) and as WC (77.6 cm), and SMMI (8.7 kg/m²) for older men. The recommended optimal cutoffs of the body composition indices were gender-specific and can be utilized to predict the risk of all-cause mortality.

Managing two waves of the COVID-19 pandemic in northern emergency departments in Paris: COVIDORG II

Context

Objective

Methods

Results

Conclusion

Pulmonary Thromboembolism in Patients After COVID-19: Predictive Indicators for Correct Diagnosis

Background: Infection caused by SARS-CoV-2 can lead to significant procoagulant events, sometimes involving life-threatening pulmonary thromboembolism (PE). Additional conditions complicating the diagnosis are the presence of risk factors for PE in almost all patients with COVID-19 and the overlap of clinical presentation between PE and COVID-19. Objectives: We conducted a single-center study at the Heart and Brain Hospital, Pleven, from December 2020 to February 2021. It included 27 consecutively hospitalized patients with recent pneumonia caused by COVID-19 and clinical presentations corresponding to PE. Methods: The cohort was divided into two groups with and without a definitive diagnosis of PE, proven by CT pulmoangiography. The aim was to find the indicators predicting the presence of PE in patients with acute or post-acute COVID-19 conditions. Results: Our results showed that some ECG criteria, including S-wave over 1.5 mm in leads I and aVL (P = 0.007), Q-wave in leads III and aVF (P = 0.020), and D-dimer as a quantitative variable (P = 0.025), were independent predictors of PE. The RV/LV diameter ratios ≥ 1.0 and right ventricular dysfunction showed a sensitivity (Se) of 62.5%, specificity (Sp) of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 86.4% to verify the PE diagnosis. Besides, the D-dimer cutoff value of 1,032 ng/mL had an optimal Se of 87.5%, Sp of 57.9%, PPV of 46.7%, and NPV of 91.7% for PE diagnosis (P = 0.021). Conclusions: Against the background of acute and post-acute COVID-19 conditions, ECG and EchoCG criteria remain the PE predictors. We suggest that a higher D-dimer cutoff value be applied in COVID-19 and post-COVID-19 patients to confirm/dismiss PE diagnosis.

What level of D-dimers can safely exclude pulmonary embolism in COVID-19 patients presenting to the emergency department?

OBJECTIVES

To identify which level of D-dimer would allow the safe exclusion of pulmonary embolism (PE) in COVID-19 patients presenting to the emergency department (ED).

METHODS

This retrospective study was conducted on the COVID database of Assistance Publique - Hôpitaux de Paris (AP-HP). COVID-19 patients who presented at the ED of AP-HP hospitals between March 1 and May 15, 2020, and had CTPA following D-dimer dosage within 48h of presentation were included. The D-dimer sensitivity, specificity, and positive and negative predictive values were calculated for different D-dimer thresholds, as well as the false-negative and failure rates, and the number of CTPAs potentially avoided.

RESULTS

A total of 781 patients (mean age 62.0 years, 53.8% men) with positive RT-PCR for SARS-Cov-2 were included and 60 of them (7.7%) had CTPA-confirmed PE. Their median D-dimer level was significantly higher than that of patients without PE (4,013 vs 1,198 ng·mL^-1, p < 0.001). Using 500 ng·mL^-1, or an age-adjusted cut-off for patients > 50 years, the sensitivity and the NPV were above 90%. With these thresholds, 17.1% and 31.5% of CTPAs could have been avoided, respectively. Four of the 178 patients who had a D-dimer below the age-adjusted cutoff had PE, leading to an acceptable failure rate of 2.2%. Using higher D-dimer cut-offs could have avoided more CTPAs, but would have lowered the sensitivity and increased the failure rate.

CONCLUSION

The same D-Dimer thresholds as those validated in non-COVID outpatients should be used to safely rule out PE.

KEY POINTS

• The median D-dimer level was significantly higher in COVID-19 patients with PE as compared to those without PE (4,013 ng·mL^-1 vs 1,198 ng·mL^-1 respectively, p < 0.001). • Using 500 ng·mL^-1, or an age-adjusted D-dimer cut-off to exclude pulmonary embolism, the sensitivity and negative predictive value were above 90%. • Higher cut-offs would lead to a reduction in the sensitivity below 85% and an increase in the failure rate, especially for patients under 50 years.

Clinical and operational impact of rapid point-of-care SARS-CoV-2 detection in an emergency department

Study objective

Rapid point-of-care (POC) SARS-CoV-2 detection with Abbott ID NOW™ COVID-19 test has been implemented in our Emergency Department (ED) for several months. We aimed to evaluate the operational impact and potential benefits of this innovative clinical pathway.

Methods

We conducted a prospective, descriptive, interventional, non-randomized study, before-after trial with the comparison of patient cohorts from two consecutive periods of seven weeks (observational pre-POC period vs interventional POC period).

Results

In 2020, throughout weeks 37 to 50, 3333 patients were assessed for eligibility and among them 331 (9.9%) were positive for SARS-CoV-2 infections. Among the included patients, 136 (9.2%) were positive for SARS-CoV-2 infection in the pre-POC period and 195 (10.5%) in the POC period. Among positive patients for SARS-CoV-2 related infection in-hospital mortality rate was similar between the two groups but the hospitalization rate was higher in the POC group (81.6% vs. 65.4%; p < 0.001). More patients in the POC period were able to leave the ED within 6 h. We examined rates of antibiotic, anticoagulant, and corticosteroid prescriptions among patients tested for SARS-CoV-2 in the ED. Only the rate of prescribed anticoagulants was found to be higher in the POC period (40% vs. 24.2%; p < 0.003).

Conclusion

We demonstrated that COVID-19 point-of-care testing speeds up clinical decision-making, improving use of recommended treatments for COVID-19, such as anticoagulants. Moreover, it improves the boarding time and significantly shortened the length of stay in the ED for patients requiring outpatient care.

Pulmonary Embolism in COVID-19 Patients: A Retrospective Case-Control Study

Background: Coagulopathy is a well-recognized complication in patients with coronavirus disease 2019 (COVID-19). Pulmonary embolism (PE) has substantial morbidity and mortality if the diagnosis is missed or the management is delayed. Computed tomography pulmonary angiography (CT-PA) is the imaging modality of choice for PE. Therefore, this study aimed to investigate the positive rate of CT-PA for PE among patients with COVID-19.

Methods: We conducted a retrospective study examining the diagnostic yield of CT-PA in patients with confirmed COVID-19 and compared it with that in patients without COVID-19. The study included all adult patients with confirmed COVID-19 who presented from June 2020 to June 2021.

Results: The study included 316 patients, including 158 patients with COVID-19, who underwent CT-PA for ruling out PE. Overall, 76 patients were found to have PE on the CT-PA scan, yielding a positive rate of 24.1%, with a significant difference between patients with COVID-19 (8.2%) and those without COVID-19 (39.9%). Further, 138 (87.3%) patients with COVID-19 had elevated D-dimer levels compared with 34 (21.5%) patients without COVID-19. A multivariable regression analysis model revealed that the smoking status (odds ratio [OR] = 1.94; 95% confidence interval [CI]: 1.4-3.8) and obesity (OR = 4.1; 95% CI: 1.5-8.9) were independent predictors of PE among patients with COVID-19. However, the elevated D-dimer level was not significantly associated with PE among patients with COVID-19 (OR = 0.7; 95% CI: 0.4-1.8).

Conclusion: The study found that the positive rate of CT-PA for PE was lower among patients with PE indicating probable overutilization of investigation in these patients. Additionally, patients with COVID-19 had a higher proportion of elevated D-dimer levels that may be a contributor to the increased investigation for PE. Lastly, patients with COVID-19 who were current smokers had a higher tendency of having PE.

Routine screening for pulmonary embolism in COVID-19 patients at the emergency department: impact of D-dimer testing followed by CTPA

COVID-19 patients have increased risk of pulmonary embolism (PE), but symptoms of both conditions overlap. Because screening algorithms for PE in COVID-19 patients are currently lacking, PE might be underdiagnosed. We evaluated a screening algorithm in which all patients presenting to the ED with suspected or confirmed COVID-19 routinely undergo D-dimer testing, followed by CT pulmonary angiography (CTPA) if D-dimer is ≥ 1.00 mg/L. Consecutive adult patients presenting to the ED of two university hospitals in Amsterdam, The Netherlands, between 01-10-2020 and 31-12-2020, who had a final diagnosis of COVID-19, were retrospectively included. D-dimer and CTPA results were obtained. Of 541 patients with a final diagnosis of COVID-19 presenting to the ED, 25 (4.6%) were excluded because D-dimer was missing, and 71 (13.1%) because they used anticoagulation therapy. Of 445 included patients, 185 (41.6%; 95%CI 37.0–46.3) had a D-dimer ≥ 1.00 mg/L. CTPA was performed in 169 of them, which showed PE in 26 (15.4%; 95%CI 10.3–21.7), resulting in an overall detection rate of 5.8% (95%CI 3.9–8.4) in the complete study group. In patients with and without PE at CTPA, median D-dimer was 9.84 (IQR 3.90–29.38) and 1.64 (IQR 1.17–3.01), respectively (p < 0.001). PE prevalence increased with increasing D-dimer, ranging from 1.2% (95%CI 0.0–6.4) if D-dimer was 1.00–1.99 mg/L, to 48.6% (95%CI 31.4–66.0) if D-dimer was ≥ 5.00 mg/L. In conclusion, by applying this screening algorithm, PE was identified in a considerable proportion of COVID-19 patients. Prospective management studies should assess if this algorithm safely rules-out PE if D-dimer is < 1.00 mg/L.