Low Detection Rate of Pulmonary Embolism in Patients Presenting to the Emergency Department With Suspected Coronavirus Disease 2019 (COVID-19): A Single-Centre UK Study

Has the Coronavirus Disease 2019 Pandemic Played a Role in the Early Detection of Pulmonary Embolism in Children?

OBJECTIVE

Pulmonary embolism (PE) poses a significant threat to children, and nonspecific symptoms lead to delayed diagnosis. The emergence of coronavirus disease 2019 (COVID-19) has increased the complexity as it is associated with similar symptoms and increased risk of thrombotic complications. This study aimed to assess the risk factors, clinical presentations, and diagnostic features of PE in pediatric patients and to examine the impact of the COVID-19 pandemic on children with PE.

MATERIALS AND METHODS

We conducted a retrospective descriptive study examining the clinical and diagnostic data of 44 pediatric patients with radiologically confirmed PE. The study compared and analyzed patients diagnosed before and during the COVID-19 pandemic.

RESULTS

In the study, 21 of 44 pediatric patients were diagnosed in the 4 years before the COVID-19 pandemic, and 23 were diagnosed with PE during the COVID-19 pandemic. The mean time to diagnosis was 8 (2 to 14) days before the pandemic and 1 (1 to 2) days during the pandemic ( P < 0.001). The most common associated condition in both groups was infection (65.9%). Dyspnea (65.9%) and tachypnea (50.0%) were common symptoms. Except for deep vein thrombosis, there were no significant differences according to associated conditions between the groups ( P = 0.001). Pulmonary emboli were anatomically detected using computed tomography angiography, showing bilateral involvement in 45.4% of patients, segmental artery involvement in 38.6%, and main artery involvement in 15.9%.

CONCLUSION

The COVID-19 pandemic heightened suspicion of pediatric PE and accelerated diagnosis. Standardized diagnostic guidelines are increasingly necessary to balance accurate diagnosis with avoiding excessive imaging.

D-dimer levels to exclude pulmonary embolism and reduce the need for CT angiography in COVID-19 in an outpatient population

OBJECTIVES

Emerging results indicate that, in COVID-19, thromboembolic complications contribute to the high mortality and morbidity. Previous research showed that the prevalence of pulmonary embolism (PE) is between 25-50% in COVID-19 patients, however, most of these reports are based on data from patients with severe pneumonia, treated in intensive care units.

MATERIALS AND METHODS

We conducted a retrospective, single-center, observational study to estimate the prevalence of PE in COVID-19 patients who underwent CT angiography and to identify the most important predictors. Adult outpatients with COVID-19, who presented at our COVID Outpatient Clinic between 1st and 31st of March in 2021 and underwent CTA examination were included in this study. Multiple linear regression analysis was used to identify predictors of PE in COVID-19 patients. The predictors were: age, gender, disease duration, CT severity index and log-transformed quantitative D-dimer (logQDDIM) value.

RESULTS

843 COVID-19 patients were included into the study. 82.56% (693 patients) of the infected patients had a pulmonary CTA examination and D-dimer levels (mean age: 59.82 years ± 15.66). 7.61% (53 patients) of the patients had PE. 2.02% (14 patients) of the patients had main branch or lobar PE. The multiple regression analysis found that only logQDDIM was a significant predictor. A logQDDIM cut-off value of 0.0169 (1.0171 ug/ml serum D-dimer) predicted PE with 99% sensitivity (p<0.0001, degree-of-freedom = 570, AUC = 0.72).

CONCLUSIONS

We demonstrated in a large cohort of COVID-19 patients that a cut-off value of QDDIM of 1ug/ml can exclude pulmonary embolism in an outpatient setting, implicating that QDDIM might potentially supersede CTA as a screening approach in COVID-19 outpatient clinics.

Advanced Imaging Supports the Mechanistic Role of Autoimmunity and Plaque Rupture in COVID-19 Heart Involvement

The cardiovascular system is frequently affected by coronavirus disease-19 (COVID-19), particularly in hospitalized cases, and these manifestations are associated with a worse prognosis. Most commonly, heart involvement is represented by myocarditis, myocardial infarction, and pulmonary embolism, while arrhythmias, heart valve damage, and pericarditis are less frequent. While the clinical suspicion is necessary for a prompt disease recognition, imaging allows the early detection of cardiovascular complications in patients with COVID-19. The combination of cardiothoracic approaches has been proposed for advanced imaging techniques, i.e., CT scan and MRI, for a simultaneous evaluation of cardiovascular structures, pulmonary arteries, and lung parenchyma. Several mechanisms have been proposed to explain the cardiovascular injury, and among these, it is established that the host immune system is responsible for the aberrant response characterizing severe COVID-19 and inducing organ-specific injury. We illustrate novel evidence to support the hypothesis that molecular mimicry may be the immunological mechanism for myocarditis in COVID-19. The present article provides a comprehensive review of the available evidence of the immune mechanisms of the COVID-19 cardiovascular injury and the imaging tools to be used in the diagnostic workup. As some of these techniques cannot be implemented for general screening of all cases, we critically discuss the need to maximize the sustainability and the specificity of the proposed tests while illustrating the findings of some paradigmatic cases.

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.

The Usefulness of Chest CT Imaging in Patients With Suspected or Diagnosed COVID-19: A Review of Literature

The COVID-19 pandemic has had devastating medical and economic consequences globally. The severity of COVID-19 is related, in a large measure, to the extent of pulmonary involvement. The role of chest CT imaging in the management of patients with COVID-19 has evolved since the onset of the pandemic. Specifically, the description of CT scan findings, use of chest CT imaging in various acute and subacute settings, and its usefulness in predicting chronic disease have been defined better. We performed a review of published data on CT scans in patients with COVID-19. A summary of the range of imaging findings, from typical to less common abnormalities, is provided. Familiarity with these findings may facilitate the diagnosis and management of this disease. A comparison of sensitivity and specificity of chest CT imaging with reverse-transcriptase polymerase chain reaction testing highlights the potential role of CT imaging in difficult-to-diagnose cases of COVID-19. The usefulness of CT imaging to assess prognosis, to guide management, and to identify acute pulmonary complications associated with SARS-CoV-2 infection is highlighted. Beyond the acute stage, it is important for clinicians to recognize pulmonary parenchymal abnormalities, progressive fibrotic lung disease, and vascular changes that may be responsible for persistent respiratory symptoms. A large collection of multi-institutional images were included to elucidate the CT scan findings described.

COVID-19 and venous thromboembolism: Known and unknown for imaging decisions

As we continue to fight against the current coronavirus disease-2019 (COVID-19) pandemic, healthcare professionals across the globe are trying to answer questions surrounding how to best help patients with the up-to-date available science while awaiting the development of new therapies and mass vaccination. Since early in the pandemic, studies indicated a heightened risk of venous thromboembolism (VTE) in COVID-19 infected patients. There have been differing expert opinions about how to assess pretest probability of VTE in this patient population. This has been partly due to the high prevalence of respiratory failure in this patient population and the use of D-dimer as a prognostic test which is also frequently elevated in patients with COVID-19 in absence of VTE. Some experts have argued for an approach similar to usual care with testing if clinical suspicion is high enough. Some have argued for more routine screening at different points of care. Others have even suggested empiric therapeutic anti-coagulation in moderate to severely ill COVID-19 patients. In the following article, we review and summarize the most current literature in hopes of assisting clinicians in decision making and guidance for when to be concerned for VTE in COVID-19 patients. We also discuss research gaps and share pathways currently being used within our institution.

Pulmonary embolism in patients with COVID-19 and value of D-dimer assessment: a meta-analysis

PURPOSE

To investigate, in a meta-analysis, the frequency of pulmonary embolism (PE) in patients with COVID-19 and whether D-dimer assessment may be useful to select patients for computed tomography pulmonary angiography (CTPA).

METHODS

A systematic literature search was performed for original studies which reported the frequency of PE on CTPA in patients with COVID-19. The frequency of PE, the location of PE, and the standardized mean difference (SMD) of D-dimer levels between patients with and without PE were pooled by random effects models.

RESULTS

Seventy-one studies were included. Pooled frequencies of PE in patients with COVID-19 at the emergency department (ED), general wards, and intensive care unit (ICU) were 17.9% (95% CI: 12.0-23.8%), 23.9% (95% CI: 15.2-32.7%), and 48.6% (95% CI: 41.0-56.1%), respectively. PE was more commonly located in peripheral than in main pulmonary arteries (pooled frequency of 65.3% [95% CI: 60.0-70.1%] vs. 32.9% [95% CI: 26.7-39.0%]; OR = 3.540 [95% CI: 2.308-5.431%]). Patients with PE had significantly higher D-dimer levels (pooled SMD of 1.096 [95% CI, 0.844-1.349]). D-dimer cutoff levels which have been used to identify patients with PE varied between 1000 and 4800 μg/L.

CONCLUSION

The frequency of PE in patients with COVID-19 is highest in the ICU, followed by general wards and the ED. PE in COVID-19 is more commonly located in peripheral than in central pulmonary arteries, which suggests local thrombosis to play a major role. D-dimer assessment may help to select patients with COVID-19 for CTPA, using D-dimer cutoff levels of at least 1000 μg/L.

KEY POINTS

• The frequency of PE in patients with COVID-19 is highest in the ICU, followed by general wards and the ED. • PE in COVID-19 is more commonly located in peripheral than in central pulmonary arteries. • D-dimer levels are significantly higher in patients with COVID-19 who have PE.