Pulmonary Embolism In COVID-19 Patients Research Articles

D-dimer levels as an associated factor for pulmonary embolism in COVID-19 patients in Critical Care Unit: A case-control study

Objective: Establish the association between the D-Dimer levels and pulmonary embolism (PE) in CT pulmonary angiogram (CTPA) in patients with COVID 19 in critical care. Methodology: Case Control study in patients with diagnosis of COVID 19 in three critical care units during 2021 in Medellin. All patients had CTPA as a diagnostic method for PE. Results: There were 135 cases and 136 controls, mean age 60 years old (IQ 51-70), 74.2 % were men. 39% had high blood pressure. Segmentary PE was found in 65.2%, lobar PE in 19.3% and 15.6% in the right or left pulmonary artery. We found that it is more likely to have PE if the D-Dimer value is more than 5000 ng/mL (ORa 7.8; IC95% 4.09-14.92). Conclusion: D-Dimer is an independent factor that is associated with PE in patients with COVID - 19 in critical care, especially if the value is over 5000 ng/mL.

Pulmonary embolism in COVID-19; a systematic review

Pulmonary embolism (PE) is the more severe clinical presentation of venous thromboembolism. Pulmonary embolism in COVID-19 patients varies from the classic pulmonary embolism without COVID-19 regarding clinical, demographic, and laboratory. However, there was an inconsistency in these findings. Hence this systemic review was conducted to assess the pulmonary embolism in COVID-19 patients by reviewing previous studies that reported pulmonary embolism during the COVID-19 era and conducted on COVID-19 patients. Studies related to the current study subject were explored using PubMed and Google Scholar databases. The included search keywords were "PE, Prevalence, COVID-19, Risk factors, and Predictors" and were used in various combinations. The inclusion criteria were original studies that reported pulmonary embolism conducted during COVID-19 on COVID-19 patients and full-text articles. A total of 528 articles were obtained, and only eight articles were eligible for the inclusion criteria. The involved studies were conducted on a total number of 2,067 participants and they all were retrospective studies. The prevalence of PE is increased by the emergence of COVID-19 infection which suggested a significant correlation. The risk factors of PE among COVID-19 patients vary from the classical ones. D-dimer was found to be a good predictor for PE among COVID-19 patients. The presence of PE among COVID-19 patients requires and predicts the need for mechanical ventilation.

CXCL10 May Be Responsible for Susceptibility to Pulmonary Embolism in COVID-19 Patients.

Although the potential of coronavirus disease 2019 (COVID-19) patients to develop pulmonary embolism (PE) is widely recognized, the underlying mechanism has not been completely elucidated. This study aimed to identify genes common to COVID-19 and PE to reveal the underlying pathogenesis of susceptibility to PE in COVID-19 patients. COVID-19 genes were obtained from the GEO database and the OMIM, CTD, GeneCards, and DisGeNET databases; PE genes were obtained from the OMIM, CTD, GeneCards, and DisGeNET databases. We overlapped the genes of COVID-19 and PE to obtain common genes for additional analysis, including functional enrichment, protein-protein interaction, and immune infiltration analysis. Hub genes were identified using cytoHubba, a plugin of Cytoscape, and validated using the independent datasets GSE167000 and GSE13535. The genes validated by the above datasets were further validated in clinical samples. We obtained 36 genes shared by PE and COVID-19. Functional enrichment and immune infiltration analyses revealed the involvement of cytokines and immune activation. Five genes (CCL2, CXCL10, ALB, EGF, and MKI67) were identified as hub genes common to COVID-19 and PE. CXCL10 was validated in both independent datasets (GSE167000 and GSE13535). Serum levels of CXCL10 in the COVID-19 group and the COVID-19 combined with PE group were significantly higher than those in the healthy control group (P<0.001). In addition, there were significant differences between the COVID-19 group and the COVID-19 combined with PE group (P<0.01). Our study reveals common genes shared by PE and COVID-19 and identifies CXCL10 as a possible cause of susceptibility to PE in COVID-19 patients.

Pulmonary Thromboembolism in Covid-19 Pneumonia: A Case Series and Update

BACKGROUND: COVID-19 is associated with lots of complications. Pulmonary thromboembolism is a rare complication of pneumonia that is showing a rising trend in the context of COVID-19. CASE PRESENTATION: We present the CTPA findings in 3 patients of pulmonary thromboembolism in patients with COVID-19 pneumonia. The patients had varying involvement of pulmonary arteries. We also provide and update on the published literature on covid pulmonary embolism in 2023. CONCLUSIONS: Pulmonary embolism can complicate Covid-19 pneumonia and lead to poorer prognosis. Hence, the correct diagnosis is imperative as prompt antithrombotic therapy can significantly reduce mortality and morbidity. There have been updates on pulmonary embolism in Covid-19 patients especially in late 2022 to early 2023 and they have been presented in this study.

Effect of Anticoagulants in Pulmonary Thromboembolism in Post-COVID-19 Patients.

Background and objective COVID-19 may predispose to both venous and arterial thromboembolism (VTE and ATE) due to excessive inflammation, immobilization, and hypoxia. The purpose of this study is to evaluate clinical and laboratory risk factors, as well as related medications such as anticoagulants, to predict the risk of thromboembolic disease and/or death in COVID-19 patients. Methods Over a period of 14 months (from August 2020 to September 2021), a total of 145 consecutive patients with signs and symptoms suspicious of pulmonary embolism (PE) were referred for perfusion single-photon emission computed tomography/computed tomography (Q SPECT/CT). All patients had a history of SARS‑CoV‑2 infection, diagnosed with a positive real-time polymerase chain reaction (RT-PCR) test. Results Among the 145 patients included in the study, the risk of PE was found to be greater in elderly patients (odds ratio [OR] [95% CI]: 1.05 [1.02‑1.07]; p<0.001) and in patients with higher maximum d-dimer levels (OR [95% CI]: 1.14 [1.01‑1.3]; p=0.04). We also analyzed the utility of the maximum d-dimer level for predicting acute PE with receiver operating characteristic (ROC) curve analysis. For d‑dimer = 0.5 mg/dL, cut-off sensitivity is 91%, specificity is 23%, and for d-dimer = 1 mg/dL, cut-off sensitivity is 79%, specificity is 43% Conclusion D-dimer titers were higher in the PE group in our study. Another significant finding was that, possibly due to thromboinflammation, anticoagulants did not prevent the development of PE in COVID-19 patients.

Systematic screening versus clinical gestalt in the diagnosis of pulmonary embolism in COVID-19 patients in the emergency department.

Diagnosing concomitant pulmonary embolism (PE) in COVID-19 patients remains challenging. As such, PE may be overlooked. We compared the diagnostic yield of systematic PE-screening based on the YEARS-algorithm to PE-screening based on clinical gestalt in emergency department (ED) patients with COVID-19. We included all ED patients who were admitted because of COVID-19 between March 2020 and February 2021. Patients already receiving anticoagulant treatment were excluded. Up to April 7, 2020, the decision to perform CT-pulmonary angiography (CTPA) was based on physician's clinical gestalt (clinical gestalt cohort). From April 7 onwards, systematic PE-screening was performed by CTPA if D-dimer level was ≥1000 ug/L, or ≥500 ug/L in case of ≥1 YEARS-item (systematic screening cohort). 1095 ED patients with COVID-19 were admitted. After applying exclusion criteria, 289 were included in the clinical gestalt and 574 in the systematic screening cohort. The number of PE diagnoses was significantly higher in the systematic screening cohort compared to the clinical gestalt cohort: 8.2% vs. 1.0% (3/289 vs. 47/574; p<0.001), even after adjustment for differences in patient characteristics (adjusted OR 8.45 (95%CI 2.61-27.42, p<0.001) for PE diagnosis). In multivariate analysis, D-dimer (OR 1.09 per 1000 μg/L increase, 95%CI 1.06-1.13, p<0.001) and CRP >100 mg/L (OR 2.78, 95%CI 1.37-5.66, p = 0.005) were independently associated with PE. In ED patients with COVID-19, the number of PE diagnosis was significantly higher in the cohort that underwent systematic PE screening based on the YEARS-algorithm in comparison with the clinical gestalt cohort, with a number needed to test of 7.1 CTPAs to detect one PE.

Strategies to safely rule out pulmonary embolism in COVID-19 outpatients: a multicenter retrospective study.

The objective was to define a safe strategy to exclude pulmonary embolism (PE) in COVID-19 outpatients, without performing CT pulmonary angiogram (CTPA). COVID-19 outpatients from 15 university hospitals who underwent a CTPA were retrospectively evaluated. D-Dimers, variables of the revised Geneva and Wells scores, as well as laboratory findings and clinical characteristics related to COVID-19 pneumonia, were collected. CTPA reports were reviewed for the presence of PE and the extent of COVID-19 disease. PE rule-out strategies were based solely on D-Dimer tests using different thresholds, the revised Geneva and Wells scores, and a COVID-19 PE prediction model built on our dataset were compared. The area under the receiver operating characteristics curve (AUC), failure rate, and efficiency were calculated. In total, 1369 patients were included of whom 124 were PE positive (9.1%). Failure rate and efficiency of D-Dimer > 500µg/l were 0.9% (95%CI, 0.2-4.8%) and 10.1% (8.5-11.9%), respectively, increasing to 1.0% (0.2-5.3%) and 16.4% (14.4-18.7%), respectively, for an age-adjusted D-Dimer level. D-dimer > 1000µg/l led to an unacceptable failure rate to 8.1% (4.4-14.5%). The best performances of the revised Geneva and Wells scores were obtained using the age-adjusted D-Dimer level. They had the same failure rate of 1.0% (0.2-5.3%) for efficiency of 16.8% (14.7-19.1%), and 16.9% (14.8-19.2%) respectively. The developed COVID-19 PE prediction model had an AUC of 0.609 (0.594-0.623) with an efficiency of 20.5% (18.4-22.8%) when its failure was set to 0.8%. The strategy to safely exclude PE in COVID-19 outpatients should not differ from that used in non-COVID-19 patients. The added value of the COVID-19 PE prediction model is minor. • D-dimer level remains the most important predictor of pulmonary embolism in COVID-19 patients. • The AUCs of the revised Geneva and Wells scores using an age-adjusted D-dimer threshold were 0.587 (95%CI, 0.572 to 0.603) and 0.588 (95%CI, 0.572 to 0.603). • The AUC of COVID-19-specific strategy to rule out pulmonary embolism ranged from 0.513 (95%CI: 0.503 to 0.522) to 0.609 (95%CI: 0.594 to 0.623).

PULMONARY EMBOLISM RISK STRATIFICATION IN PATIENTS WITH COVID-19 AND ACUTE PULMONARY EMBOLISM

PULMONARY EMBOLISM RISK STRATIFICATION IN PATIENTS WITH COVID-19 AND ACUTE PULMONARY EMBOLISM

Determining a D-dimer threshold for diagnosing acute pulmonary embolism in COVID-19 patients

Determining a D-dimer threshold for diagnosing acute pulmonary embolism in COVID-19 patients

Age-Adjusted D-Dimer Levels May Improve Diagnostic Assessment for Pulmonary Embolism in COVID-19 Patients.

Introduction: SARS-CoV-2 infection leads to a hypercoagulable state. The prevalence of pulmonary embolism (PE) seems to be higher in this subgroup of patients. Patients and methods: We combined data from two tertiary referral centers specialized in the management of PE. The aims of this study were as follows: (1) to evaluate the prevalence of PE among a large population of consecutive patients admitted for COVID-19 pneumonia in two centers, (2) to identify a plasma D-dimer threshold that may be useful in PE diagnostic assessment, (3) to characterize the abnormalities associated with PE and mortality in COVID-19 patients. Results: The incidence of symptomatic acute PE was 19.3%. For diagnosing PE in COVID-19 patients, based on ROC curve analysis, we identified a D-dimer concentration/patient’s age ratio of 70, which improved D-dimer diagnostic capacity for PE and led to a reclassification improvement of 14% (NRI 0.14, p = 0.03) when compared to a cut-off level of 1000 ng/mL. Especially in severe COVID-19 lung involvement, D-dimer/age ratio cut-off equal to 70 was characterized by high diagnostic feasibility (sensitivity, specificity, negative predictive value, positive predictive value of 83%, 94%, 96%, and 73%, respectively). Apart from PE status, lung involvement and troponin T concentration were also independent predictors of in-hospital mortality. In the subgroup of PE patients, mortality was comparable with non-PE patients (19/88 (21.5%) vs. 101/368 (27.4%) for non-PE, p = 0.26) and was associated with older age, higher Bova scores, and higher troponin T concentrations. Age was the sole independent predictor for mortality in this subgroup. Conclusions: PE in COVID-19 patients is common, but it may not influence mortality when managed at a specialized center. In suspected PE, age-adjusted D-dimer levels (upper limit of normal obtained from the formula patient’s age × 70) may still be a useful tool to start the diagnostic workup. In COVID-19 patients without PE, older age, more extensive parenchymal involvement, or higher D-dimer levels are factors predicting mortality.

FOLLOW-UP OF PULMONARY EMBOLISM IN PATIENTS WITH COVID-19

TYPE: Late Breaking Abstract TOPIC: Pulmonary Vascular Disease PURPOSE: Pulmonary embolism (PE) have a high prevalence in COVID-19 patients. Best medical therapy and follow-up of these patients are still undefined. METHODS: We conducted a retrospective single centre study in Alto Vicentino Hospital between March 1st, 2020, and January 31st, 2021 in 267 patients admitted for COVID-19 who underwent to computed tomography pulmonary angiogram (CTPA) for suspected PE. In 48 of them PE was diagnosed (18.7%). We followed these patients to look for deaths, recurrent thromboembolic events or relevant clinical hemorrhages. Type and duration of anticoagulation were analyzed. RESULTS: The median follow-up was 13 months (IQR 1-14) and 4 patients were lost to follow-up. 16 patients died (36.4%), 1 patient had a new thromboembolic event (2.3%) and 3 had relevant hemorrhagic events (6.8%). 26 were treated with direct oral anticoagulants (DOAC) (59.5%), 17 with other anticoagulant (39.5%). Baseline characteristics did not differ between patients treated with DOAC or with oter anticoagulants. Median duration of anticoagulation was 4 months (IQR ). Patients treated with DOAC presented a lower mortality then patients treated with other anticoagulants (3.8% vs 83.3%; p<0.001). CONCLUSIONS: PE in COVID-19 patients seems to be related to a relevant increased risk of death. Long term anticoagulation with DOAC in patients discharge at home appears to be safe and effective. CLINICAL IMPLICATIONS: Our result can guide clinician to best medical therapy in patients with COVID-19 who develope PE. DISCLOSURE: No significant relationships. KEYWORD: pulmonary embolism

MASSIVE PULMONARY EMBOLISM IN COVID-19 PNEUMONIA DIAGNOSED WITH POCUS

TYPE: Case Report TOPIC: Cardiovascular Disease INTRODUCTION: COVID19 patients have been known to be prone to systemic thromboembolism, and about 25% of COVID19 cases of pulmonary embolism (PE) have been reported. PE in these patients may be just the most prominent manifestation of the thrombophillic state of COVID19. CASE PRESENTATION: A 50 y/o male transferred from another facility where he was admitted for COVID pneumonia. His course there was complicated by worsening hypoxiemia requiring intubation. Shortly after arrival to our ICU, he decompensated. Initial resuscitation attempts were successful, but he progressed to refractory shock despite three (3) vasopressors and became persistently hypoxiemic. Focused US: severely hypokinetic and dilated right ventricle (RV) with flattening and deviation of the interventricular septum (IVS) towards the left ventricle (LV)—McConnell’s sign. IV resuscitation medications were seen swirling around the RV, with no forward flow. He received thrombolytic therapy, with the interventricular septum (IVS) returning to neutral position. He had additional episodes of arrest and died. DISCUSSION: The significance and role of POCUS was not explored in the diagnosis of PE in COVID19 pneumonia patients. McConnell’s sign is a specific clinical indicator of pulmonary embolism and can be assessed with bedside ultrasonography, which is now, an increasingly available diagnostic modality that can prove to be very effective in early assessment of cardiovascular function. CONCLUSIONS: This case highlights the importance of POCUS for the diagnosis and management of undifferentiated shock and PE in COVID19 patients. DISCLOSURE: Nothing to declare. KEYWORD: covid pulmonary embolism ultrasound

Mortality and Pulmonary Embolism in Acute Respiratory Distress Syndrome From COVID-19 vs. Non-COVID-19

PurposeThere may be a difference in respiratory mechanics, inflammatory markers, and pulmonary emboli in COVID-19 associated ARDS vs. ARDS from other etiologies. Our purpose was to determine differences in respiratory mechanics, inflammatory markers, and incidence of pulmonary embolism in patients with and without COVID-19 associated ARDS admitted in the same period and treated with a similar ventilation strategy.MethodsA cohort study of COVID-19 associated ARDS and non COVID-19 patients in a Saudi Arabian center between June 1 and 15, 2020. We measured respiratory mechanics (ventilatory ratio (VR), recruitability index (RI), markers of inflammation, and computed tomography pulmonary angiograms.ResultsForty-two patients with COVID-19 and 43 non-COVID patients with ARDS comprised the cohort. The incidence of “recruitable” patients using the recruitment/inflation ratio was slightly lower in COVID-19 patients (62 vs. 86%; p = 0.01). Fifteen COVID-19 ARDS patients (35.7%) developed a pulmonary embolism as compared to 4 (9.3%) in other ARDS patients (p = 0.003). In COVID-19 patients, a D-Dimer ≥ 5.0 mcg/ml had a 73% (95% CI 45–92%) sensitivity and 89% (95% CI 71–98%) specificity for predicting pulmonary embolism. Crude 60-day mortality was higher in COVID-19 patients (35 vs. 15%; p = 0.039) but three multivariate analysis showed that independent predictors of 60-day mortality included the ventilatory ratio (OR 3.67, 95% CI 1.61–8.35), PaO2/FIO2 ratio (OR 0.93; 95% CI 0.87–0.99), IL-6 (OR 1.02, 95% CI 1.00–1.03), and D-dimer (OR 7.26, 95% CI 1.11–47.30) but not COVID-19 infection.ConclusionCOVID-19 patients were slightly less recruitable and had a higher incidence of pulmonary embolism than those with ARDS from other etiologies. A high D-dimer was predictive of pulmonary embolism in COVID-19 patients. COVID-19 infection was not an independent predictor of 60-day mortality in the presence of ARDS.

Incidence of Pulmonary Embolism in Covid-19 Patients

Background: Pulmonary embolism (PE) is the blockage of a blood clot in the pulmonary arteries of the lungs. PE is a common phenomenon and requires prompt treatment. Despite advancement in the treatment and diagnosis it has a substantial mortality rate. Recent studies suggest that the novel Covid-19 infection is associated with rising trend of PE. Patients with Covid-19 may be at high risk of complications related to thrombotic condition in the consequences of stasis blood flow and irregular inflammatory response. The main objective of this article is to assess the incidence of PE in covid-19 hospitalized patients. Material and Method: We reviewed more than 160 medical records of the patients admitted to the Coivd-19 ward during the peak of first wave of Covid-19 pandemic. This study was conducted at Saidu Teaching Hospital Swat from June 2020 to Sep 2020in the time frame of 4 months. The real-time polymerase chain reaction was used to diagnose the Covid-19 in the patients and for the PE computed Tomography pulmonary angiogram(CPTA) was used. Results: In this study, 160 patients have participated of which 7 developed PE. This represents that the incidence of PE was 3% among individuals. Conclusion: In the Covid 19 Hospitalized patients Incidence of Pulmonary Embolism is a common phenomenon. For the patients having a high respiratory rate, smoking history, and low level of oxygen preventive measures should be considered. Keywords: Pulmonary Embolism, Covid-19, Computed tomography angiography, Intensive care unit, Risk factors,Incidence.

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

ObjectivesTo 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).MethodsThis 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.ResultsA 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.ConclusionThe 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.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00330-021-08377-9.

Pulmonary Embolism in COVID-19 Patients Is Not Related to a Deterioration of Tissue Oxygenation.

COVID-19 induces robust systemic inflammation. One of the main complications is the increased coagulation due to endotheliitis. There is an increased incidence of pulmonary embolism (PE) in COVID-19 patients. However, clinical characteristics for a strict analysis are yet to be determined. We evaluated oxygenation and characteristics in patients with COVID-19 PE (CPE). We evaluated 215 COVID-19 patients from 1 January to 30 April 2021. We found 18 patients affected by PE (CPE, 50.0% males, aged 67.00±10.86years). As controls, we used data from patients affected by PE evaluated in our ward between 1 January 2015 and 31 December 2019 (64 patients, 53.1% males, aged 70.88±16.44years). All patients underwent a complete physical examination, pulmonary computerised tomography, laboratory tests, D-dimers and blood gas analysis at the time of diagnosis. There were no differences in laboratory tests nor in D-dimers between the two groups. In the CPE group we found a significantly increased pO2 (92.83±42.52 vs. 76.11±32.58mmHg; p<0.05), difference of oxygen between alveoli and arteries (A-aDO2; 169.3±171.9 vs. 52.97±39.65mmHg; p<0.05), and oxygen saturation % (97.06±2.59 vs. 93.77±5.53%; p<0.05) compared to controls. No difference was found in pCO2 and the ratio between pO2 and percentage of inspired oxygen (P/F). Finally, a significantly decreased urate (3.67±1.49 vs. 5.60±2.10; p<0.05) was found in CPE compared to controls. In CPE, platelets count presents an inverse correlation to P/F (r=-0.389, p=0.02) but a direct correlation to A-aDO2 (r=0.699, p=0.001). No similar findings were present in controls. COVID-19 PE appears to have a different clinical setting. Reduced oxygenation described in PE may not to be considered as a sign of disease. The increased A-aDO2 may indicate that COVID-19 PE involved smaller vessels compared to classical PE. A possible diffuse capillary thrombosis could explain these results.

The Impact of Tobacco Use on COVID-19 Outcomes: A Systematic Review.

Introduction Tobacco use increases risks for numerous diseases, including respiratory illnesses. We examined the literature to determine whether a history of tobacco use increases risks for adverse outcomes among COVID-19 patients. Methods We conducted a systematic search of PubMed, LitCovid, Scopus, and Europe PMC (for preprints) using COVID-19 and tobacco-related terms. We included studies of human subjects with lab-confirmed COVID-19 infections that examined tobacco use history as an exposure and used multivariable analyses. The data was collected between March 31st, 2020, and February 20th, 2021. Outcomes included mortality, hospitalization, ICU admission, mechanical ventilation, and illness severity. Results Among the 39 studies (33 peer-reviewed, 6 preprints) included, the most common outcome assessed was mortality (n = 32). The majority of these studies (17/32) found that tobacco use increased risk, one found decreased risk, and 14 found no association. Tobacco use was associated with increased risk of hospitalization in 7 of 10 studies, ICU admission in 6 of 9 studies, mechanical ventilation in 2 of 6 studies, and illness severity in 3 of 9 studies. One study found that tobacco use history increased risk of pulmonary embolism in COVID-19 patients. Tobacco use was found to compound risks associated with diabetes (n = 1), cancer (n = 2), and chronic liver disease (n = 1). Conclusion There is strong evidence that tobacco use increases risks of mortality and disease severity/progression among COVID-19 patients. Public health efforts during the pandemic should encourage tobacco users to quit use and seek care early and promote vaccination and other preventive behaviors among those with a history of tobacco use.

Pulmonary Embolism in COVID-19 Patients: Which Diagnostic Algorithm Should We Use?

Introduction: Although pulmonary embolism (PE) is a frequent complication of the clinical course of COVID-19, there is a lack of explicit indications regarding the best algorithm for diagnosing PE in these patients. In particular, it is not clear how to identify subjects who should undergo computed tomography pulmonary angiography (CTPA), rather than simply X-ray and/or high resolution computed tomography (HRCT) of the chest.Methods: We retrospectively analyzed COVID-19 patients who presented to the Emergency Department (ED) of our University hospital with acute respiratory failure, or that developed acute respiratory failure during hospital stay, to determine how many of them had a theoretical indication to undergo CTPA for suspected PE according to current guidelines. Next, we looked for differences between patients who underwent CTPA and those who only underwent X-ray and/or HRCT of the chest. Finally, we determined whether patients with a confirmed diagnosis of PE had specific characteristics that made them different from those with a CTPA negative for PE.Results: Out of 93 subjects with COVID-19 and acute respiratory failure, 73 (78.4%) had an indication to undergo CTPA according to the revised Geneva and Wells scores and the PERC rule-out criteria, and 54 (58%) according to the YEARS algorithm. However, in contrast with these indications, only 28 patients (30.1%) underwent CTPA. Of note, they were not clinically different from those who underwent X-ray and/or HRCT of the chest. Among the 28 subjects who underwent CTPA, there were 10 cases of PE (35.7%). They were not clinically different from those with CTPA negative for PE.Conclusions: COVID-19 patients with acute respiratory failure undergo CTPA, X-ray of the chest, or HRCT without an established criterion. Nonetheless, when CTPA is performed, the diagnosis of PE is anything but rare. Validated tools for identifying COVID-19 patients who require CTPA for suspected PE are urgently needed.

55 Positivity Rates of CT Imaging for Pulmonary Embolism in COVID-19 Patients

Early evidence has suggested a high prevalence of acute pulmonary embolism (PE) in Coronavirus 19 (COVID). However, the bulk of existing data evaluates the population of COVID patients admitted to an intensive care unit (ICU). There has been limited evidence in the emergency department (ED) population and as a result, there is variability in diagnostic evaluation for patients presenting with COVID. The objective of this study was to describe the diagnostic evaluation of both COVID positive and negative patients in the ED.

Pulmonary embolism in patients with COVID-19: incidence, risk factors, clinical characteristics, and outcome.

AimsWe investigated the incidence, risk factors, clinical characteristics, and outcomes of pulmonary embolism (PE) in patients with COVID-19 attending emergency departments (EDs), before hospitalization.Methods and ResultsWe retrospectively reviewed all COVID-19 patients diagnosed with PE in 62 Spanish EDs (20% of Spanish EDs, case group) during the first COVID-19 outbreak. COVID-19 patients without PE and non-COVID-19 patients with PE were included as control groups. Adjusted comparisons for baseline characteristics, acute episode characteristics, and outcomes were made between cases and randomly selected controls (1:1 ratio). We identified 368 PE in 74 814 patients with COVID-19 attending EDs (4.92‰). The standardized incidence of PE in the COVID-19 population resulted in 310 per 100 000 person-years, significantly higher than that observed in the non-COVID-19 population [35 per 100 000 person-years; odds ratio (OR) 8.95 for PE in the COVID-19 population, 95% confidence interval (CI) 8.51–9.41]. Several characteristics in COVID-19 patients were independently associated with PE, the strongest being D-dimer >1000 ng/mL, and chest pain (direct association) and chronic heart failure (inverse association). COVID-19 patients with PE differed from non-COVID-19 patients with PE in 16 characteristics, most directly related to COVID-19 infection; remarkably, D-dimer >1000 ng/mL, leg swelling/pain, and PE risk factors were significantly less present. PE in COVID-19 patients affected smaller pulmonary arteries than in non-COVID-19 patients, although right ventricular dysfunction was similar in both groups. In-hospital mortality in cases (16.0%) was similar to COVID-19 patients without PE (16.6%; OR 0.96, 95% CI 0.65–1.42; and 11.4% in a subgroup of COVID-19 patients with PE ruled out by scanner, OR 1.48, 95% CI 0.97–2.27), but higher than in non-COVID-19 patients with PE (6.5%; OR 2.74, 95% CI 1.66–4.51). Adjustment for differences in baseline and acute episode characteristics and sensitivity analysis reported very similar associations.ConclusionsPE in COVID-19 patients at ED presentation is unusual (about 0.5%), but incidence is approximately ninefold higher than in the general (non-COVID-19) population. Moreover, risk factors and leg symptoms are less frequent, D-dimer increase is lower and emboli involve smaller pulmonary arteries. While PE probably does not increase the mortality of COVID-19 patients, mortality is higher in COVID-19 than in non-COVID-19 patients with PE.