Pulmonary Embolism and Deep Vein Thrombosis in COVID-19: A Systematic Review and Meta-Analysis

Excess burden of respiratory and abdominal conditions following COVID-19 infections during the ancestral and Delta variant periods in the United States: An EHR-based cohort study from the RECOVER program

IMPORTANCE

The frequency and characteristics of post-acute sequelae of SARS-CoV-2 infection (PASC) may vary by SARS-CoV-2 variant.

OBJECTIVE

To characterize PASC-related conditions among individuals likely infected by the ancestral strain in 2020 and individuals likely infected by the Delta variant in 2021.

DESIGN

Retrospective cohort study of electronic medical record data for approximately 27 million patients from March 1, 2020-November 30, 2021.

SETTING

Healthcare facilities in New York and Florida.

PARTICIPANTS

Patients who were at least 20 years old and had diagnosis codes that included at least one SARS-CoV-2 viral test during the study period.

EXPOSURE

Laboratory-confirmed COVID-19 infection, classified by the most common variant prevalent in those regions at the time.

MAIN OUTCOME(S) AND MEASURE(S)

Relative risk (estimated by adjusted hazard ratio [aHR]) and absolute risk difference (estimated by adjusted excess burden) of new conditions, defined as new documentation of symptoms or diagnoses, in persons between 31-180 days after a positive COVID-19 test compared to persons without a COVID-19 test or diagnosis during the 31-180 days after the last negative test.

RESULTS

We analyzed data from 560,752 patients. The median age was 57 years; 60.3% were female, 20.0% non-Hispanic Black, and 19.6% Hispanic. During the study period, 57,616 patients had a positive SARS-CoV-2 test; 503,136 did not. For infections during the ancestral strain period, pulmonary fibrosis, edema (excess fluid), and inflammation had the largest aHR, comparing those with a positive test to those without a COVID-19 test or diagnosis (aHR 2.32 [95% CI 2.09 2.57]), and dyspnea (shortness of breath) carried the largest excess burden (47.6 more cases per 1,000 persons). For infections during the Delta period, pulmonary embolism had the largest aHR comparing those with a positive test to a negative test (aHR 2.18 [95% CI 1.57, 3.01]), and abdominal pain carried the largest excess burden (85.3 more cases per 1,000 persons).

CONCLUSIONS AND RELEVANCE

We documented a substantial relative risk of pulmonary embolism and a large absolute risk difference of abdomen-related symptoms after SARS-CoV-2 infection during the Delta variant period. As new SARS-CoV-2 variants emerge, researchers and clinicians should monitor patients for changing symptoms and conditions that develop after infection.

CT pulmonary angiography in the emergency department: utilization and positivity rates during various phases of the COVID-19 pandemic

PURPOSE

To evaluate the trends in utilization and results of computed tomography pulmonary angiography (CTPA study) for detection of acute pulmonary embolism (PE) in the Emergency Department (ED) during different phases of COVID-19 public health emergency.

METHODS

We conducted a retrospective review of CTPA studies ordered through our ED in the months of March through May during five consecutive years from 2019 to 2023, designated as pre-pandemic, early, ongoing, recovery, and post-pandemic periods respectively. Collected characteristics included patient age, patient sex, and result of the study.

RESULTS

The utilization of CTPA studies for ED patients increased during the early, ongoing, and recovery periods. CTPA study utilization in the post-pandemic period was not significantly different from the pre-pandemic period (p = 0.08). No significant difference in CTPA study utilization was noted in the other periods when stratified by age group or sex, compared to the pre-pandemic period. The positivity rate of acute PE in ED patients was not significantly different in other periods compared to the pre-pandemic period.

CONCLUSION

At our institution, the utilization and positivity rates of CTPA studies for the ED patients were not significantly different in the post-pandemic period compared to the pre-pandemic period. While studies spanning a larger timeframe and involving multiple institutions are needed to test the applicability of this observation to a wider patient population beyond our defined post-pandemic period, we conclude that our study provides some confidence to the ordering provider and the radiologist in embracing the end of COVID-19 public health emergency by the WHO and the United States HHS with respect to CTPA studies.

The Short and Long of COVID-19: A Review of Acute and Chronic Radiologic Pulmonary Manifestations of SARS-2-CoV and Their Clinical Significance

Coronavirus disease 2019 (COVID-19) pneumonia has had catastrophic effects worldwide. Radiology, in particular computed tomography (CT) imaging, has proven to be valuable in the diagnosis, prognostication, and longitudinal assessment of those diagnosed with COVID-19 pneumonia. This article will review acute and chronic pulmonary radiologic manifestations of COVID-19 pneumonia with an emphasis on CT and also highlighting histopathology, relevant clinical details, and some notable challenges when interpreting the literature.

Pronounced benefits of JAK inhibition with baricitinib in COVID-19 pneumonia in obese but not lean subjects

OBJECTIVE

Obesity and age are strongly linked to severe COVID-19 pneumonia where immunomodulatory agents including Janus kinase inhibitors have shown benefits but the efficacy of such therapy in viral pneumonia is not well understood. We evaluated the impact of obesity and age on survival following baricitinib therapy for severe COVID-19.

METHODS

A post hoc analysis of the COV-BARRIER multicentre double-blind randomised study of baricitinib versus placebo (PBO) with an assessment of 28-day mortality was performed. All-cause mortality by day 28 was evaluated in a Cox regression analysis (adjusted to age) in three different groups according to body mass index (BMI) (<25 kg/m2, 25-30 kg/m2 and >30 kg/m2) and age <65 years and ≥65 years.

RESULTS

In the high BMI group (>25 kg/m2), baricitinib therapy showed a significant survival advantage compared with PBO (incidence rate ratio (IRR) for mortality by day 28 0.53 (95% CI 0.32 to 0.87)) and 0.66 (95% CI 0.46 to 0.94) for the respective <65 years and ≥65 years, respectively. The 28-day all-cause-mortality rates for BMI over 30 were 5.62% for baricitinib and 9.22% for PBO (HR=0.6, p<0.05). For BMI under 25 kg/m2, irrespective of age, baricitinib therapy conferred no survival advantage (IRR of 1.89 (95% CI 0.49 to 7.28) and 0.95 (95% CI 0.46 to 1.99) for <65 years and ≥65 years, respectively) ((mortality 6.6% baricitinib vs 8.1 in PBO), p>0.05).

CONCLUSION

The efficacy of baricitinib in COVID-19 pneumonia is linked to obesity suggesting that immunomodulatory therapy benefit is associated with obesity-associated inflammation.

Thrombosis of the vasa vasorum of the large and medium size pulmonary artery and vein leads to pulmonary thromboembolism in COVID-19

The vasa vasorum of the large pulmonary vessels is involved in the pathology of COVID-19. This specialized microvasculature plays a major role in the biology and pathology of the pulmonary vessel walls. We have evidence that thrombosis of the vasa vasorum of the large and medium-sized pulmonary vessels during severe COVID-19 causes ischemia and subsequent death of the pulmonary vasculature endothelium. Subsequent release of thrombi from the vasa interna into the pulmonary circulation and pulmonary embolism generated at the ischemic pulmonary vascular endothelium site, are the central pathophysiological mechanisms in COVID-19 responsible for pulmonary thromboembolism. The thrombosis of the vasa vasorum of the large and medium-sized pulmonary vessels is an internal event leading to pulmonary thromboembolism in COVID-19.

Diagnosis and treatment of cardiovascular manifestations of COVID-19: a narrative review

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was the main pathogen in the COVID-19 pandemic. This viral infection has been associated with several respiratory and non-respiratory complications contributing to a higher mortality rate, especially in patients with underlying heart diseases worldwide. Once considered a respiratory tract disease, it is now well-known that COVID-19 patients may experience a wide range of cardiac manifestations. Because of its remarkable direct and indirect effects on the cardiovascular system, herein, we examined the published literature that studied the hypothetical mechanisms of injury, manifestations, and diagnostic modalities, including changes in molecular biomarkers with a predictive value in the prognostication of the disease, as well as emerging evidence regarding the long-term cardiac complications of the disease.

Mechanisms of Pulmonary Vasculopathy in Acute and Long-Term COVID-19: A Review

Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 may predispose patients to thrombotic disease in both venous and arterial circulation, and many cases of severe acute pulmonary embolism have been reported. The demonstrated presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the endothelial cells suggests that direct viral effects, in addition to indirect effects of perivascular inflammation and coagulopathy, may contribute to pulmonary vasculopathy in COVID-19. In this review, we discuss the pathological mechanisms leading to pulmonary vascular damage during acute infection, which appear to be mainly related to thromboembolic events, an impaired coagulation cascade, micro- and macrovascular thrombosis, endotheliitis and hypoxic pulmonary vasoconstriction. As many patients develop post-COVID symptoms, including dyspnea, we also discuss the hypothesis of pulmonary vascular damage and pulmonary hypertension as a sequela of the infection, which may be involved in the pathophysiology of long COVID.

Predicting Acute Cardiovascular Complications in COVID-19: Insights from a Specialized Cardiac Referral Department

BACKGROUND COVID-19 increases the risk of acute cardiovascular diseases (CVDs), including acute coronary syndrome (ACS), acute pulmonary embolism (APE), and acute myocarditis (AMyo). The actual impact of CVDs on mortality of patients with COVID-19 remains unknown. This study aimed to determine whether CVDs influence the course of COVID-19 pneumonia and if they can be easily detected by using common tests and examinations. MATERIAL AND METHODS Data of 249 consecutive patients with COVID-19 hospitalized in a dedicated cardiology department were analyzed. On admission, clinical status, biomarkers, computed tomography, and bedside echocardiography were performed. RESULTS D-dimer level predicted APE (AUC=0.850 95% CI [0.765; 0.935], P<0.001) with sensitivity of 69.4% and specificity of 96.2% for a level of 4968.0 ng/mL, and NT-proBNP predicted AMyo (AUC=0.692 95% CI [0.502; 0.883], P=0.004) and showed sensitivity of 54.5%, with specificity of 86.5% for the cut-off point of 8970 pg/mL. Troponin T levels were not useful for diagnostic differentiation between CVDs. An extent of lung involvement predicted mortality (OR=1.03 95% CI [1.01;1.04] for 1% increase, P<0.001). After adjusting for lung involvement, ACS increased mortality, compared with COVID-19 pneumonia only (OR=5.27 95% CI [1.76; 16.38] P=0.003), while APE and AMyo did not affect risk for death. CONCLUSIONS D-dimer and NT-proBNP, but not troponin T, are useful in differentiating CVDs in patients with COVID-19. ACS with COVID-19 increased in-hospital mortality independently from extent of lung involvement, while coexisting APE or AMyo did not.

Antithrombotic Use Patterns in COVID-19 Patients from Spain: A Real-World Data Study

Antithrombotics have been widely used to treat and prevent COVID-19-related thrombosis; however, studies on their use at population levels are limited. We aimed to describe antithrombotic use patterns during the pandemic in Spanish primary care and hospital-admitted patients with COVID-19. Methods: A real-world data study was performed. Data were obtained from BIFAP's electronic health records. We investigated the antithrombotic prescriptions made within ±14 days after diagnosis between March 2020 and February 2022, divided their use into prior and new/naive groups, and reported their post-discharge use. Results: We included 882,540 individuals (53.4% women), of whom 78,499 were hospitalized. The median age was 44.7 (IQR 39-59). Antithrombotics were prescribed in 37,183 (4.6%) primary care subjects and 42,041 (53.6%) hospital-admitted patients, of whom 7505 (20.2%) and 20,300 (48.3%), respectively, were naive users. Prior users were older and had more comorbidities than new users. Enoxaparin was the most prescribed antithrombotic in hospitals, with higher prescription rates in new than prior users (2348.2, IQR 2390-3123.1 vs. 1378, IQR 1162-1751.6 prescriptions per 10,000 cases, p = 0.002). In primary care, acetylsalicylic acid was the most used antithrombotic, with higher use rates in prior than in naïve users. Post-discharge use occurred in 6686 (15.9%) subjects (median use = 10 days, IQR 9-30). Conclusions: Our study identified a consensus on prescribing antithrombotics in COVID-19 patients, but with low use rates in hospitals.

The Effect of Pulmonary Hypertension on Mortality and Intensive Care Unit Admission in Patients With SARS-CoV-2 Infection: A Systematic Review and Meta-Analysis

AIM

Severe COVID-19 can cause acute respiratory distress syndrome, hypoxia, systemic complications, and increased mortality. Pulmonary hypertension (PH) is a major global health issue associated with worsening symptoms and increased mortality. This systematic review aimed to assess the influence of PH onset among COVID-19 patients on all-cause mortality and intensive care unit (ICU) admission.

METHOD

An unrestricted search of five databases up to June 2022 was undertaken. Pulmonary hypertension was assessed using transthoracic echocardiogram, computed tomography, or right heart catheterisation. After duplicate screening, data extraction, and risk of bias assessment, random effects meta-analyses of odds ratios (OR) and their 95% confidence intervals (CI) were performed for all-cause mortality and ICU admission.

RESULTS

From the 26 studies that were included (3,373 patients, 76% males, median age 62.6 years), PH in COVID-19 patients was significantly associated with higher odds for all-cause mortality (26 studies; OR 3.89; 95% CI 2.85-5.31; p<0.001) and higher odds for ICU admission (six studies; OR 2.50; 95% CI 1.69-3.70; p<0.001). Meta-regression/subgroup analyses by patient demographics, comorbidities, or therapeutic regimens, and sensitivity analyses did not find any differences.

CONCLUSION

Evidence from observational studies indicates that PH in COVID-19 patients is associated with increased odds of mortality and ICU admission.

Trajectories of functional and structural myocardial parameters in post-COVID-19 syndrome-insights from mid-term follow-up by cardiovascular magnetic resonance

Introduction

Myocardial tissue alterations in patients with post-Coronavirus disease 2019 syndrome (PCS) are often subtle and mild. Reports vary in the prevalence of non-ischemic and ischemic injuries as well as the extent of ongoing myocardial inflammation. The exact relevance of these myocardial alterations is not fully understood. This study aimed at describing the trajectories of myocardial alterations in PCS patients by mid-term follow-up with cardiovascular magnetic resonance (CMR).

Methods

This study entails a retrospective analysis of symptomatic PCS patients referred for follow-up CMR between August 2020 and May 2023 due to mildly affected or reduced left or right ventricular function (LV and RV, respectively) and structural myocardial alterations, e.g., focal and diffuse fibrosis, on baseline scans. Follow-up CMR protocol consisted of cine images and full coverage native T1 and T2 mapping. Baseline and follow-up scans were compared using t-tests or Wilcoxon tests. Post-hoc analysis was carried out in a subgroup based on the change of LV stroke volume (SV) between scans.

Results

In total, 43 patients [median age (interquartile range) 46 (37-56) years, 33 women] received follow-ups 347 (167-651) days after initial diagnosis. A decrease in symptoms was recorded on follow-ups (p < 0.03) with 23 patients being asymptomatic at follow-ups [symptomatic at baseline 43/43 (100%) vs. symptomatic at follow-up 21/43 (49%), p < 0.001]. Functional improvement was noted for LV-SV [83.3 (72.7-95.0) vs. 84.0 (77.0-100.3) ml; p = 0.045], global radial [25.3% (23.4%-27.9%) vs. 27.4% (24.4%-33.1%); p < 0.001], and circumferential strains [-16.5% (-17.5% to -15.6%) vs. -17.2% (-19.5% to -16.1%); p < 0.001]. In total, 17 patients had an LV-SV change >10% on follow-up scans (5 with a decrease and 12 with an increase), with LV-SV, RV-SV, and global longitudinal strain being discriminatory variables on baseline scans (p = 0.01, 0.02, and 0.04, respectively). T1- or T2-analysis revealed no changes, remaining within normal limits.

Conclusion

Symptomatic load as well as blood pressures decreased on follow-up. CMR did not detect significant changes in tissue parameters; however, volumetric, specifically LV-SV, and deformation indexes improved during mid-term follow-up.

Early pandemic in-hospital outcomes and mortality risk factors in COVID-19 solid organ transplant patients

Background

Solid organ transplant (SOT) recipients with COVID-19 have a higher risk of mortality than those without COVID-19. However, it is unclear how SOT patient outcomes compare to the general population without SOT who contract COVID-19.

Methods

We used the National Inpatient Sample from January to December 2020 to investigate inpatient outcomes seen in SOT recipients after contracting COVID-19 compared to nontransplant patients. We identified our study sample using ICD-10 CM and excluded those <18 years of age and those with dual organ transplants. Inpatient outcomes were compared in SOT and non-SOT COVID cohorts, and we further evaluated predictors of mortality in the SOT with COVID population.

Results

Out of the 1,416,445 COVID-19 admissions included in the study, 8315 (0.59%) were single SOT recipients. Our analysis that adjusted for multiple baseline characteristics and comorbidities demonstrated that COVID-19 in SOT patients was associated with higher rates of acute kidney injury (adjusted odds ratio [aOR] 2.34, 95% confidence interval [CI] 1.81-3.02, P < 0.01), lower rates of acute respiratory distress syndrome (aOR 0.68, 95% CI 0.54-0.85, P < 0.01), and similar rates of cardiac arrest, pulmonary embolism, circulatory shock, cerebrovascular events, and in-hospital mortality. Age >65 was associated with mortality in SOT patients.

Conclusion

In this nationally representative sample, SOT patients presenting with COVID-19 experienced similar rates of mortality compared to those without SOT. SOT patients were more likely to develop acute kidney injury. Further research is needed to understand the complex relationship between transplant patient outcomes and COVID-19.

NT-proBNP ratio is a potential predictor for COVID-19 outcomes in adult Chinese patients: a retrospective study

Despite the progressive decline in the virulence of the novel coronavirus, there has been no corresponding reduction in its associated hospital mortality. Our aim was to redefine an accurate predictor of mortality risk in COVID-19 patients, enabling effective management and resource allocation. We conducted a retrospective analysis of 2917 adult Chinese patients diagnosed with COVID-19 who were admitted to our hospital during two waves of epidemics, involving the Beta and Omicron variants. Upon admission, NT-proBNP levels were measured, and we collected demographic, clinical, and laboratory data. We introduced a new concept called the NT-proBNP ratio, which measures the NT-proBNP level relative to age-specific maximum normal values. The primary outcome was all-cause in-hospital mortality. Our analysis revealed a higher in-hospital mortality rate in 2022, as shown by the Kaplan-Meier Survival Curve. To assess the predictive value of the NT-proBNP ratio, we employed the time-dependent receiver operating characteristic (ROC) curve. Notably, the NT-proBNP ratio emerged as the strongest predictor of mortality in adult Chinese hospitalized COVID-19 patients (area under the curve, AUC = 0.826; adjusted hazard ratio [HR], 3.959; 95% confidence interval [CI] 3.001-5.221; P < 0.001). This finding consistently held true for both the 2020 and 2022 subgroups. The NT-proBNP ratio demonstrates potential predictive capability compared to several established risk factors, including NT-proBNP, hsCRP, and neutrophil-to-lymphocyte ratio, when it comes to forecasting in-hospital mortality among adult Chinese patients with COVID-19.Trial registration Clinical Trial Registration: www.clinicaltrials.gov NCT05615792.

External validation of the CHEDDAR score for suspected pulmonary embolism in patients with SARS-CoV-2 infection in an independent cohort

The accuracy of the classic scores that help stratify the pretest clinical probability of pulmonary embolism (PE) in SARS-CoV-2 infection (COVID-19) is low. Therefore, to estimate the risk of PE in these patients, a new set of guidelines must be established. The recently published CHEDDAR score proposes a new diagnostic strategy to reduce the use of computed tomography pulmonary angiography (CTPA) in non-critically ill SARS-COV-2 patients with suspected PE. According to the nomogram, patients are segregated into low-risk (< 182 points) or high-risk (≥ 182 points) based on the best cut-off value to discard PE in the original cohort. We aimed to externally validate this diagnostic strategy in an independent cohort. We analyzed data from two retrospective cohorts of hospitalized non-critically ill COVID-19 patients who underwent a CTPA due to suspicion for PE. CHEDDAR score was applied. As per the CHEDDAR nomogram, patients were classified as having a low or high clinical pre-test probability. Of the 270 patients included, 69 (25.5%) had PE. Applying the CHEDDAR score, 182 (67.4%) patients could have had PE excluded without imaging. Among 58 patients classified as having high clinical pre-test probability, 39 (67.2%) had PE. Sensitivity, specificity, positive and negative predictive values, and AUC were 56%, 90%, 67%, 85%, and 0.783 (95% CI 0.71-0.85), respectively. We provide external validation of the CHEDDAR score in an independent cohort. Even though the CHEDDAR score showed good discrimination capacity, caution is required in patients classified as having low clinical pre-test probability with a D-dimer value > 3000 ng/mL, and a RALE score ≥ 4.

Multiparametric Cardiovascular Magnetic Resonance in Nonhospitalized COVID-19 Infection Subjects: An Intraindividual Comparison Study

PURPOSE

To investigate intraindividual cardiac structural and functional changes before and after COVID-19 infection in a previously healthy population with a 3T cardiac magnetic resonance (CMR).

MATERIALS AND METHODS

A total of 39 unhospitalized patients with COVID-19 were recruited. They participated in our previous study as non-COVID-19 healthy volunteers undergoing baseline CMR examination and were recruited to perform a repeated CMR examination after confirmed COVID-19 infection in December 2022. The CMR parameters were measured and compared between before and after COVID-19 infection with paired t tests. The laboratory measures including myocardial enzymes and inflammatory indicators were also collected when performing repeated CMR.

RESULTS

The median duration was 393 days from the first to second CMR and 26 days from clinical symptoms onset to the second CMR. Four patients (10.3%, 4/39) had the same late gadolinium enhancement pattern at baseline and repeated CMR and 5 female patients (12.8%, 5/39) had myocardial T2 ratio >2 (2.07 to 2.27) but with normal T2 value in post-COVID-19 CMR. All other CMR parameters were in normal ranges before and after COVID-19 infection. Between before and after the COVID-19 infection, there were no significant differences in cardiac structure, function, and tissue characterization, no matter with or without symptoms (fatigue, chest discomfort, palpitations, shortness of breath, and insomnia/sleep disorders) (all P >0.05). The laboratory measures at repeated CMR were in normal ranges in all participants.

CONCLUSIONS

These intraindividual CMR studies showed unhospitalized patients with COVID-19 with normal myocardial enzymes had no measurable CMR abnormalities, which can help alleviate wide social concerns about COVID-19-related myocarditis.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Absence of a causal link between COVID-19 and deep vein thrombosis: Insights from a bi-directional Mendelian randomisation study

Background

Several large-scale observational studies have found deep vein thrombosis (DVT) to be related with coronavirus disease 2019 (COVID-19). However, whether there is a clear causal connection between the two is unknown.

Methods

Our primary analytical method was the inverse variance-weighted (IVW) approach, complemented by the Mendelian randomisation-Egger (MR-Egger) and weighted median methods. We also used MR-Egger to examine the presence of pleiotropy and the Mendelian randomisation pleiotropy residual sum and outlier (MR-PRESSO) approach to analyse for heterogeneity in the data.

Results

We did not observe a direct causal relationship between COVID-19 susceptibility (odds ratio (OR) = 1.023; 95% confidence interval (CI) = 0.828-1.264, standard error (SE) = 0.108, P = 0.833), hospitalisation (OR = 1.030; 95% CI = 0.943-1.125, SE = 0.374, P = 0.720), severity (OR = 0.994; 95% CI = 0.923-1.071, SE = 0.038, P = 0.877), and DVT. The results of the reverse Mendelian randomisation (MR) for DVT and COVID-19 susceptibility exhibited heterogeneity and horizontal pleiotropy. Even after removing outliers, we detected no direct causal relationship between the two (OR = 1.015; 95% CI = 0.954-1.080, SE = 0.032, P = 0.630). Similarly, we found no direct causal relationship between DVT and COVID-19 hospitalisation (OR = 0.999; 95% CI = 0.907-1.102, SE = 0.050, P = 0.999) or severity (OR = 1.014; 95% CI = 0.893-1.153, SE = 0.065, P = 0.826).

Conclusions

In this MR study, we identified no direct causal impact in a European population between DVT and the COVID-19 susceptibility, severity, or hospitalisation.

Chronic Lung Injury after COVID-19 Pneumonia: Clinical, Radiologic, and Histopathologic Perspectives

With the COVID-19 pandemic having lasted more than 3 years, concerns are growing about prolonged symptoms and respiratory complications in COVID-19 survivors, collectively termed post-COVID-19 condition (PCC). Up to 50% of patients have residual symptoms and physiologic impairment, particularly dyspnea and reduced diffusion capacity. Studies have also shown that 24%-54% of patients hospitalized during the 1st year of the pandemic exhibit radiologic abnormalities, such as ground-glass opacity, reticular opacity, bronchial dilatation, and air trapping, when imaged more than 1 year after infection. In patients with persistent respiratory symptoms but normal results at chest CT, dual-energy contrast-enhanced CT, xenon 129 MRI, and low-field-strength MRI were reported to show abnormal ventilation and/or perfusion, suggesting that some lung injury may not be detectable with standard CT. Histologic patterns in post-COVID-19 lung disease include fibrosis, organizing pneumonia, and vascular abnormality, indicating that different pathologic mechanisms may contribute to PCC. Therefore, a comprehensive imaging approach is necessary to evaluate and diagnose patients with persistent post-COVID-19 symptoms. This review will focus on the long-term findings of clinical and radiologic abnormalities and describe histopathologic perspectives. It also addresses advanced imaging techniques and deep learning approaches that can be applied to COVID-19 survivors. This field remains an active area of research, and further follow-up studies are warranted for a better understanding of the chronic stage of the disease and developing a multidisciplinary approach for patient management.

Prevalence of Pneumonia Among Patients Who Died with COVID-19 Infection in Ancestral Versus Omicron Variant Eras

RATIONALE AND OBJECTIVES

The Omicron variant of COVID-19 is less severe than the ancestral strain, leading to the potential for deaths in patients infected with the virus but who die of other causes. This study evaluated the difference in rates of pneumonia among patients who died with SARS-CoV-2 infection in the ancestral vs Omicron eras.

MATERIALS AND METHODS

We identified patients who died within 30days of a positive SARS-CoV-2 test, from March 2020 through December 2022; variants were assigned based on the prevalent variant in the US at that time. We also obtained a control group from patients who died within 30days of a negative SARS-CoV-2 test in January 2022. The first CT after the test was reviewed in a blinded fashion and assigned a category from the RSNA Consensus Reporting Guidelines. The primary outcome was the difference in rates of positive (typical or indeterminate) COVID-19 findings in the ancestral vs Omicron eras.

RESULTS

A total of 598 patients died during the ancestral era and 400 during the Omicron era, and 347 decedents comprised the control group. The rate of positive COVID-19 findings was 67/81 (83%) in the ancestral era and 43/81 (53%) in the Omicron era (P < .001), an absolute difference of 30% (95% CI 16%-43%). The rate of positive findings in the control group was 23/76 (30%).

CONCLUSION

During the Omicron era, 30% fewer SARS-CoV-2-associated deaths were associated with COVID-19 pneumonia and were caused either by nonpulmonary effects of the infection or were unrelated to the infection.

Incidence and Outcomes Associated with Menopausal Status in COVID-19 Patients: A Systematic Review and Meta-analysis

OBJECTIVE

 Menopause causes several changes in the body that may affect the response to COVID -19. We aimed to investigate the possible association between menopausal status and incidence and outcomes in COVID-19 patients.

METHODS

 Combinations of keywordsCOVID-19, menopause, and estrogen were used to search the PubMed, Embase, Web-of-Science, and Scopus databases for articles reporting the incidence and outcomes of COVID-19 (discharge, length-of-admission, intensive care, or mortality) in premenopausal women, available through December 29, 2022. Data from studies comparing the incidence of COVID-19 infection with the age-matched male population were pooled and meta-analyzed using a random-effects model.

RESULTS

 Overall, 1,564 studies were retrieved, of which 12 were finally included in the systematic review to compare disease outcomes, and 6 were meta-analyzed for the incidence of COVID-19 in premenopausal and postmenopausal women. All studies reported better COVID-19-associated outcomes in premenopausal women compared with postmenopausal women. After adjusting for confounding factors, three studies found better outcomes in postmenopausal women, and two found no association between menopausal status and COVID-19 outcomes. Our meta-analysis found a higher incidence of COVID-19 infection among premenopausal women than postmenopausal women, when compared with age-matched men (odds ratio = 1.270; 95% confidence interval: 1.086-1.486; p = 0.003).

CONCLUSION

 The incidence of COVID-19 was significantly higher in premenopausal women than in postmenopausal women when compared with age-matched men. Although premenopausal women may have more favorable COVID-19-associated outcomes, the presumed preventive effect of estrogens on the incidence and related outcomes of COVID-19 in premenopausal women cannot be proven at present. Further longitudinal studies comparing pre- and post-menopausal women are required to provide further insight into this matter.

Simple demographic, laboratory and chest radiograph variables can identify COVID-19 patients with pulmonary thromboembolism: a retrospective multicentre United Kingdom study

OBJECTIVES

To (1) identify discriminatory demographic, laboratory and initial CXR findings; (2) explore correlation between D-dimer and radiographic severity scores; and (3) assess accuracy of published D-dimer thresholds to identify pulmonary thromboembolism (PTE) in COVID-19 patients.

METHODS

Retrospective study including all COVID-19 patients admitted from 1st to 30th April 2020 meeting inclusion criteria from 25 (blinded) hospitals. Demographics, blood results, CXR and CTPA findings were compared between positive and negative PTE cohorts using uni- and multivariable logistic regression. Published D-dimer cut-offs were applied.

RESULTS

389 patients were included [median age 63; 237 males], of which 26.2% had a PTE. Significant univariable discriminators for PTE were peak D-dimer, sex, neutrophil count at the time of the D-dimer and at admission, abnormal CXR, and CXR zonal severity score. Only neutrophil count at peak D-dimer remained significant for predicting PTE on multivariable analysis (p = 0.008). When compared with the published literature, sensitivity for PTE were lower than those published at all cut-off values, however specificity at different cut-offs was variable.

CONCLUSIONS

In this multicentre COVID-19 cohort, univariable admission factors that could indicate pulmonary thromboembolism were male sex, high neutrophil count and abnormal CXR with a greater CXR zonal severity score. The accuracy levels of published D-dimer thresholds were not reproducible in our population.

ADVANCES IN KNOWLEDGE

This is a large multicentre study looking at the discriminatory value of simple variables to determine if a patient with COVID-19 has PTE or not, in addition to comparing D-dimer cut off values against published values.

Incidence and severity of pulmonary embolism in COVID-19 infection: Ancestral, Alpha, Delta, and Omicron variants

Little information is available regarding incidence and severity of pulmonary embolism (PE) across the periods of ancestral strain, Alpha, Delta, and Omicron variants. The aim of this study is to investigate the incidence and severity of PE over the dominant periods of ancestral strain and Alpha, Delta, and Omicron variants. We hypothesized that the incidence and the severity by proximity of PE in patients with the newer variants and vaccination would be decreased compared with those in ancestral and earlier variants. Patients with COVID-19 diagnosis between March 2020 and February 2022 and computed tomography pulmonary angiogram performed within a 6-week window around the diagnosis (-2 to +4 weeks) were studied retrospectively. The primary endpoints were the associations of the incidence and location of PE with the ancestral strain and each variant. Of the 720 coronavirus disease 2019 patients with computed tomography pulmonary angiogram (58.6 ± 17.2 years; 374 females), PE was diagnosed among 42/358 (12%) during the ancestral strain period, 5/60 (8%) during the Alpha variant period, 16/152 (11%) during the Delta variant period, and 13/150 (9%) during the Omicron variant period. The most proximal PE (ancestral strain vs variants) was located in the main/lobar arteries (31% vs 6%-40%), in the segmental arteries (52% vs 60%-75%), and in the subsegmental arteries (17% vs 0%-19%). There was no significant difference in both the incidence and location of PE across the periods, confirmed by multivariable logistic regression models. In summary, the incidence and severity of PE did not significantly differ across the periods of ancestral strain and Alpha, Delta, and Omicron variants.

An optimized D-dimer cut-off value to predict pulmonary thromboembolism in COVID-19 patients

Pulmonary thromboembolism (PTE) is a common complication in coronavirus disease 2019 (COVID-19) patients. Elevated D-dimer levels are observed even in the absence of PTE, reducing its discriminative ability as a screening test. It is unknown whether conventional D-dimer cut-off values, as used in the YEARS algorithm, apply to COVID-19 patients. This study aimed to determine the optimal D-dimer cut-off value to predict PTE in COVID-19 patients. All confirmed COVID-19 patients with a computed tomography pulmonary angiography (CTPA) performed ≤5 days after admission due to suspicion of PTE between March 2020 and February 2021, at Medisch Spectrum Twente, The Netherlands, were retrospectively analyzed. The association between PTE and D-dimer levels prior to CTPA, and other potential predictors, was analyzed using logistic regression analyses. The optimal cut-off value was identified using receiver operating characteristic (ROC) curve analyses. In 142 patients, PTE prevalence was 20.4%. The optimal cut-off value was 750 ng/mL (sensitivity 100%; specificity 19.5%; negative predictive value 100%; positive predictive value 24.2%). In total, 15 of 113 (13%) patients without PTE had a D-dimer level ≥500 and <750 ng/mL. In our population of patients hospitalized with COVID-19, a D-dimer level <750 ng/mL safely excluded PTE. Compared to the YEARS 500 ng/mL cut-off value, 13% fewer patients are in need of a CTPA, with similar sensitivity. Future research is required for external validation.

Gender disparities, causes and predictors of immediate and short-term cardiovascular readmissions following COVID-19-related hospitalisations in the USA

OBJECTIVES

In this study, we aimed to identify the causes, predictors and gender disparities of 30-day and 90-day cardiovascular readmissions after COVID-19-related hospitalisations using National Readmission Database (NRD) 2020.

SETTING

We used the NRD from 2020 to identify hospitalised adults with a principal diagnosis of COVID-19 infection.

PARTICIPANTS

We included subjects who were readmitted within 30 days and 90 days after index admission. We excluded subjects with elective and traumatic admissions. We used a multivariate Cox regression model to identify independent predictors of readmission.

PRIMARY AND SECONDARY OUTCOMES MEASURES

Our outcomes were inpatient mortality, 30-day and 90-day cardiovascular readmission rates following COVID-19 infection.

RESULTS

During the study period, there were 1 024 492 index hospitalisations with a primary diagnosis of COVID-19 infection in the 2020 NRD database, 644 903 (62.9%) were included for 30-day readmission analysis, and 418 122 (40.8%) were included for 90-day readmission analysis. Of patients involved in the 30-day analysis, 7140 (1.1%) patients had a readmission within 30 days; of patients involved in the 90-day analysis, 8379 (2.0%) had a readmission within 90 days due to primarily cardiovascular causes. Cox regression analysis revealed that the female sex (aHR 0.89; 95% CI 0.82 to 0.95; p=0.001) was associated with a lower hazard of 30-day cardiovascular readmissions; however, congestive heart failure (aHR 2.45; 95% CI 2.2 to 2.72; p<0.001), arrhythmias (aHR 2.45; 95% CI 2.2 to 2.72; p<0.001) and valvular disease (aHR 2.45; 95% CI 2.2 to 2.72; p<0.001) had a higher hazard. The most common causes of cardiovascular readmissions were heart failure (34.3%), deep vein thrombosis/pulmonary embolism (22.5%) and atrial fibrillation (9.5%).

CONCLUSION

Our study demonstrates that male gender, heart failure, arrhythmias and valvular disease carry higher hazards of 30-day and 90-day cardiovascular readmissions. Identifying risk factors and common causes of readmission may assist with lowering the burden of cardiovascular disease in patients with COVID-19 infection.

Cognitive dysfunction in post-COVID-19 condition: Mechanisms, management, and rehabilitation

The long-term effects of COVID-19 on cognitive function have become an area of increasing concern. This paper provides an overview of characteristics, risk factors, possible mechanisms, and management strategies for cognitive dysfunction in post-COVID-19 condition (PCC). Prolonged cognitive dysfunction is one of the most common impairments in PCC, affecting between 17% and 28% of the individuals more than 12 weeks after the infection and persisting in some cases for several years. Cognitive dysfunctions can be manifested as a wide range of symptoms including memory impairment, attention deficit, executive dysfunction, and reduced processing speed. Risk factors for developing PCC, with or without cognitive impairments, include advanced age, preexisting medical conditions, and the severity of acute illness. The underlying mechanisms remain unclear, but proposed contributors include neuroinflammation, hypoxia, vascular damage, and latent virus reactivation not excluding the possibility of direct viral invasion of the central nervous system, illustrating complex viral pathology. As the individual variation of the cognitive impairments is large, a neuropsychological examination and a person-centered multidimensional approach are required. According to the World Health Organization, limited evidence on COVID-19-related cognitive impairments necessitates implementing rehabilitation interventions from established practices of similar conditions. Psychoeducation and compensatory skills training are recommended. Assistive products and environmental modifications adapted to individual needs might be helpful. In specific attention- and working memory dysfunctions, cognitive training-carefully monitored for intensity-might be effective for people who do not suffer from post-exertional malaise. Further research is crucial for evidence-based interventions specific to COVID-19-related cognitive impairments.

Safety and effectiveness of COVID-19 vaccines in patients with IgA nephropathy: a retrospective cohort study from the TriNetX global collaborative networks

Background

This study aimed to evaluate the renal safety and effectiveness of COVID-19 vaccination in patients with immunoglobulin A nephropathy (IgAN).

Methods

We conducted a global and retrospective collaborative network analysis using TriNetX data from September 11, 2018 to September 11, 2023, to address this question. The study recorded diagnoses of IgAN, COVID-19 vaccinations, and outcomes of effectiveness using International Classification of Diseases, Tenth Revision, Clinical Modification codes and procedure codes. Propensity score matching (PSM) created matched groups (1:1). Hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated for outcomes of effectiveness, and Kaplan-Meier method assessed survival probability. Safety outcomes regarding renal function were compared with estimated glomerular filtration rate (eGFR), proteinuria, and hematuria. Subgroup analyses were based on sex and age group. Sensitivity analysis was done before the outbreak of Omicron (from September 11, 2018 to October 31, 2021).

Findings

The study involved 1010 vaccinated and 2776 unvaccinated patients with IgAN without COVID-19 infection at baseline. After PSM (1:1) with 25 variables, both groups consisted of well-matched 979 patients who were relatively young (around 55 years old) and in good health (eGFR: 78-80 ml/min/1.732 m2). Compared to the non-vaccinated group, vaccinated patients had significantly lower risks of COVID-19 infection and complications, including COVID-19 infection (HR: 0.050, 95% CI: 0.026, 0.093), COVID-19 pneumonia (HR: 0), severe lung complication (0.647, 95% CI: 0.421, 0.994), acute respiratory failure (0.625, 95% CI: 0.400, 0.978), sepsis (0.545, 95% CI: 0.334, 0.890), emergency department visits (0.716, 95% CI: 0.615, 0.833), all hospitalizations (0.573, 95% CI: 0.459, 0.715), and mortality (0.595, 95% CI: 0.366, 0.969). However, one month after the follow-up, the vaccinated group exhibited a slightly, but statistically significantly, lower eGFR compared to the non-vaccinated group (73.58 vs. 83.05 ml/min/1.732 m2, p = 0.047). Nine months after the follow-up, the difference in eGFR between the two groups disappeared. The lower risk of COVID-19 infection was observed across genders (male and female) and age groups (young and old). For the period before Omicron outbreak, results were also similar.

Interpretation

In the largest TriNetX matched cohort study of IgAN, COVID-19 vaccination was associated with a reduced risk of COVID-19 infection and associated complications. However, careful monitoring of renal function, especially GFR, is advisable.

Funding

This study was supported by grant TCVGH-1103602C, TCVGH-1103601D, and TCVGH-1113602D from Taichung Veterans General Hospital.

Risk Factors for Postdischarge Major Thromboembolism and Mortality in Hospitalized Patients with COVID-19 with Cardiovascular Comorbidities: Insights from the CORE-19 Registry

BACKGROUND

 Coronavirus disease 2019 (COVID-19) is associated with venous and arterial thromboembolism (VTE and ATE) and all-cause mortality (ACM) in hospitalized patients. High-quality data are needed on postdischarge outcomes in patients with cardiovascular disease.

OBJECTIVES

 To analyze outcomes and identify risk factors for ATE, VTE, and ACM in a high-risk subgroup of hospitalized COVID-19 patients with baseline cardiovascular disease.

METHODS

 We investigated postdischarge rates and associated risk factors of ATE, VTE, and ACM in 608 hospitalized COVID-19 patients with coronary artery disease, carotid artery stenosis (CAS), peripheral arterial disease (PAD), or ischemic stroke.

RESULTS

 Through 90 days postdischarge, outcome rates were: ATE 27.3% (10.2% myocardial infarction, 10.1% ischemic stroke, 13.2% systemic embolism, 12.7% major adverse limb event); VTE 6.9% (4.1% deep vein thrombosis, 3.6% pulmonary embolism); composite of ATE, VTE, or ACM 35.2% (214/608). Multivariate analysis showed significant association between this composite endpoint and age >75 years (odds ratio [OR]: 1.90, 95% confidence interval [CI]: 1.22-2.94, p = 0.004), PAD (OR: 3.23, 95% CI: 1.80-5.81, p ≤ 0.0001), CAS (OR: 1.74, 95% CI: 1.11-2.75, p = 0.017), congestive heart failure (CHF) (OR: 1.84, 95% CI: 1.02-3.35, p = 0.044), previous VTE (OR: 3.08, 95% CI: 1.75-5.42, p < 0.0001), and intensive care unit (ICU) admission (OR: 2.93, 95% CI: 1.81-4.75, p < 0.0001).

CONCLUSION

 COVID-19 inpatients with cardiovascular disease experience high rates of ATE, VTE, or ACM through 90 days postdischarge. Age >75 years, PAD, CAS, CHF, previous VTE, and ICU admission are independent risk factors.

Pulmonary arterial hypertension and COVID-19: Piecing the puzzle

COVID-19 remains a health care concern despite the end of the pandemic. Patients with cardiovascular disease (CVD) are at a higher risk for developing severe COVID-19 complications. Studies investigating the COVID-19 clinical characteristics in pulmonary arterial hypertension (PAH) patients have reported discordant conclusions so far. In this review, we summarize the literature pertaining to the clinical presentation of COVID-19 in patients with PAH. In addition, we discuss common pathological aspects and disease mechanisms between PAH and COVID-19. We present an overview of the different types of PAH-approved therapy and their potential utilization as a treatment in the context of COVID-19. Moreover, we summarize the clinical trials that assessed the safety and efficiency of PAH-approved drugs in COVID-19 patients. Finally, we conclude with proposals for prospective research studies.

Impact of Co-existing Paroxysmal Atrial Fibrillation on Different Outcomes of Hospitalized COVID-19 Patients: Nationwide Inpatient Sample Analysis (2020) With Propensity Score Matching

Various studies in the medical literature reported significant cardiovascular involvement in patients with coronavirus disease 2019 (COVID-19) pneumonia. Atrial fibrillation (AF) was identified as the most commonly observed arrhythmia complicating COVID-19 infection with an increased risk of short-term mortality. We used the National Inpatient Sample Database (NIS) of 2020 to conduct this retrospective cohort study. Our study's population consisted of adult patients hospitalized for COVID-19 Pneumonia with or without the presence of paroxysmal atrial fibrillation (PAF). Encounters with COVID-19 and co-existing PAF had higher adjusted odds of inpatient mortality (Adjusted odds ratio [aOR]: 1.19, 95% CI: 1.11-1.28, P < 0.001), longer mean length of hospital stay (LOS) of 1.17 days (95% confidence interval [CI]: 1.03-1.38, P < 0.001), and higher odds of different in-hospital complications. Based on these results, conducting more prospective/retrospective cohort studies with an emphasis on long-term follow-up on patients who develop PAF following COVID-19 infection is warranted.

Update on Pediatric Nuclear Medicine in Acute Care

Various radiopharmaceuticals are available for imaging pediatric patients in the acute care setting. This article focuses on the common applications used on a pediatric patient in acute care. To confirm the clinical diagnosis of brain death, brain scintigraphy is considered accurate and has been favorably compared with other methods of detecting the presence or absence of cerebral blood flow. Ventilation-perfusion lung scans are easy and safe to perform with less radiation exposure than computed tomography pulmonary angiography and remain an appropriate procedure to perform on children with suspected pulmonary embolism as a first imaging test in a hemodynamically stable patient with no history of lung disease and normal chest radiograph. 99mTc-pertechnetate scintigraphy (Meckel's scan) is the best noninvasive procedure to establish the diagnosis of ectopic gastric mucosa in Meckel's diverticulum. 99mTcred blood cell scintigraphy generally is useful for assessing lower GI bleeding in patients from any cause. Hepatobiliary scintigraphy is the most accurate diagnostic imaging modality for acute cholecystitis. 99mTc-dimercaptosuccinic acid scintigraphy is the simplest, and the most reliable and sensitive method for the early diagnosis of focal or diffuse functional cortical damage. 99mTcmercaptoacetyltriglycine scintigraphy is used to evaluate for early and late complications of renal transplantation. Bone scintigraphy is a sensitive and noninvasive technique for diagnosis of bone disorders such as osteomyelitis and fracture. 18F-fluorodeoxyglucose-positron emission tomography could be valuable in the evaluation of fever of unknown origin in pediatric patients, with better sensitivity and significantly less radiation exposure than a gallium scan. Moving forward, further refinement of pediatric radiopharmaceutical administered activities, including dose reduction, greater radiopharmaceutical applications, and updated consensus guidelines is warranted, with the use of radionuclide imaging likely to increase.

An ABC approach to cardiothoracic complications and sequelae of COVID-19: a tertiary centre experience

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused unprecedented challenges to healthcare professionals (HCPs) worldwide. HCPs faced an unknown disease causing many complications, including now well-established acute respiratory distress syndrome (ARDS) and pulmonary artery thromboembolic disease, and some not so well known, for instance, tracheobronchomalacia, tracheal tear or dehiscence, granulation tissue formation and pulmonary hypertension. Many of these complications require highly specialist care warranting early recognition of complications and involvement of appropriately trained professionals. Here, we review the complications and sequelae encountered at our tertiary care centre with follow-up data and potential management strategies using the A (Airway), B (Breathing), C (Circulation) approach. This will not only familiarise HCPs with the different complications of COVID-19, but also arm them with a systematic approach to these complications.

COVID-19-Associated Pulmonary Embolism: Review of the Pathophysiology, Epidemiology, Prevention, Diagnosis, and Treatment

COVID-19 is associated with endothelial activation in the setting of a potent inflammatory reaction and a hypercoagulable state. The end result of this thromboinflammatory state is an excess in thrombotic events, in particular venous thromboembolism. Pulmonary embolism (PE) has been of special interest in patients with COVID-19 given its association with respiratory deterioration, increased risk of intensive care unit admission, and prolonged hospital stay. The pathophysiology and clinical characteristics of COVID-19-associated PE may differ from the conventional non-COVID-19-associated PE. In addition to embolic events from deep vein thrombi, in situ pulmonary thrombosis, particularly in smaller vascular beds, may be relevant in patients with COVID-19. Appropriate prevention of thrombotic events in COVID-19 has therefore become of critical interest. Several changes in viral biology, vaccination, and treatment management during the pandemic may have resulted in changes in incidence trends. This review provides an overview of the pathophysiology, epidemiology, clinical characteristics, and risk factors of COVID-19-associated PE. Furthermore, we briefly summarize the results from randomized controlled trials of preventive antithrombotic therapies in COVID-19, focusing on their findings related to PE. We discuss the acute treatment of COVID-19-associated PE, which is substantially similar to the management of conventional non-COVID-19 PE. Ultimately, we comment on the current knowledge gaps in the evidence and the future directions in the treatment and follow-up of COVID-19-associated PE, including long-term management, and its possible association with long-COVID.

Incidence and Risk Factors Associated with Thromboembolic Events among Patients with COVID-19 Inpatients: A Retrospective Study

Aims and objectives

Despite thromboprophylaxis, some severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients develop thrombotic complications with poor prognosis. Our goal is to comprehensively assess the incidence, risk factors, and clinical outcomes associated with thromboembolic events (TE) among adult patients presenting with coronavirus disease-2019 (COVID-19).

Materials and methods

The study was conducted as an observational and retrospective study across COVID-19 patients (n = 207) in a tertiary care hospital in the Middle East and North Africa (MENA) region. Electronic health records were collected from the COVID-19 Database from April 2020 to December 2020 which included clinical history and TE.

Results

Fifty-six (27.05%) out of 207 patients (age: 54.42 ± 15.01 years) developed TE despite the anticoagulant therapy. The incidence of venous thromboembolism (VTE) was significantly higher for patients aged >50 years compared to <50 years (73.21% vs 26.79%, p < 0.05). There were no differences in the incidence of VTE between genders (p = 0.561). 165 patients (79.71%) received anticoagulant therapy, yet 48 (29%) developed TE. The most commonly used anticoagulant was low-molecular-weight heparin (LMWH, 47.34%). In spite of efficient treatment and medical management, the majority of patients with TE (45 out of 56 patients, 80.35%) experienced mortality. The comorbidities that significantly increase the risk of TE include hypertension (HTN) and ischemic heart disease (IHD). The laboratory parameters that were associated with an increased risk of VTE include ferritin, lactate dehydrogenase (LDH), and creatinine.

Conclusion

The COVID-19 patients develop thrombotic complications. Future studies should clarify the underlying mechanisms of TE and optimize the antithrombotic regimens in COVID-19 patients.

How to cite this article

Tashkandi WA. Incidence and Risk Factors Associated with Thromboembolic Events among Patients with COVID-19 Inpatients: A Retrospective Study. Indian J Crit Care Med 2023;27(11):830-836.

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

Background

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.

Methods

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.

Results

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).

Conclusion

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.

Renal artery infarction in the SARS-Cov-2 era: A systematic review of case reports

AIM

Renal artery infarction (RI) is the presence of blood clot in the main renal artery or its branches causing complete or partial obstruction of the blood supply. Its etiology is either related with disorders of the renal vasculature or with cardiovascular diseases. Recently, the SARSCoV- 2 virus is an emerging cause of thromboembolic events and the incidence of RI is anticipated to increase after the pandemic.

METHODS

A systematic review based on COVID-19 associated RI was conducted.

PROTOCOL

A systematic review of the Medline/Pubmed and Scopus databases was conducted in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (the PRISMA statement). Search strategy and information sources: A hand-search was performed using the terms "SARS-Cov-2" OR "COVID-19" AND "renal thrombosis" OR "renal infarction" OR "renal "thromboembolism".

ELIGIBILITY CRITERIA

all types of publications (case reports, case series, letters to the editor, short communications) were evaluated for relevance. Inclusion criteria were: confirmed SARS-Cov-2 infection irrespectively of the age, diagnosis of RI during or after the onset of viral infection, and exclusion of other potential causes of thromboembolic event except of SARS-Cov-2. Patients with renal transplantation were also considered. Study criteria selection: after checking for relevance based on the title and the abstract, the full texts of the selected papers were retrieved and were further evaluated. Duplicated and irrelevant cases were excluded. Any disagreement was resolved by consensus with the involvement of a third reviewer. Quality of studies: The assessment of the quality case reports was based on four different domains: selection, ascertainment, casualty and reporting. Each paper was classified as "Good", "Moderate" and "Poor" for any of the four domains. Data extractions: Crucial data for the conduct of the study were extracted including: age, sex, time from SARS-Cov-2 infection till RI development, medical history, previous or current antithrombotic protection or treatment, laterality and degree of obstruction, other sites of thromboembolism, treatment for thromboembolism and SARS-Cov-2 and final outcome.

DATA ANALYSIS

methods of descriptive statistics were implicated for analysis and presentation of the data.

RESULTS

The systematic review retrieved 35 cases in 33 reports. In most cases, RI was diagnosed within a month from the SARSCov- 2 infection albeit 17 out of 35 patients were receiving or had recently received thromboprophylaxis. Right, left, bilateral and allograft obstruction was diagnosed in 7, 15, 8 and 5 patients respectively. 17 cases experienced additional extrarenal thromboembolism primarily in aorta, spleen, brain and lower limbs. Low molecular weight heparins (LMWH) (usually 60-80 mg enoxaparine bid) was the primary treatment, followed by combinations of unfractionated heparin and salicylic acid, apixaban and rivaraxaban, warfarin, acenocoumarol or clopidogrel. Kidney replacement therapy was offered to five patients while invasive therapies with thrombus aspiration or catheter directed thrombolysis were performed in two. Regarding the outcomes, five of the patients died. The total renal function was preserved in 17 cases and renal impairment with or without hemodialysis was recorded in 5 patients, two of them having lost their kidney allografts.

LIMITATIONS

The majority of included studies are of moderate quality. The results and the conclusions are based on case-reports only and crucial data are dissimilarly presented or missing through the relevant publications.

CONCLUSIONS

Thromboprophylaxis may not offer adequate protection against SARS-Cov-2 induced thrombosis. Most patients could be effectively treated with conservative measures, while in more severe cases aggressive treatment could be recommended.

IMPLICATIONS OF KEY FINDINGS

Therapeutic doses of LMWH could be considered for protection against RI in SARS-Cov-2 cases. Interventional treatment could be offered in a minority of more severe cases after carful balancing the risks and benefits.

A retrospective multicenter cohort study of the association between anti-Factor Xa values and death, thromboembolism, and bleeding in patients with critical COVID-19

BACKGROUND

Patients with critical COVID-19 have a high risk of thromboembolism, but intensified thromboprophylaxis has not been proven beneficial. The activity of low-molecular-weight heparins can be monitored by measuring anti-Factor Xa. We aimed to study the association between anti-Factor Xa values and death, thromboembolism, and bleeding in patients with critical COVID-19.

METHOD

This retrospective cohort study included adult patients with critical COVID-19 admitted to an intensive care unit at three Swedish hospitals between March 2020 and May 2021 with at least one valid peak and/or trough anti-Factor Xa value. Within the peak and trough categories, patients' minimum, median, and maximum values were determined. Logistic regressions with splines were used to assess associations.

RESULTS

In total, 408 patients had at least one valid peak and/or trough anti-Factor Xa measurement, resulting in 153 patients with peak values and 300 patients with trough values. Lower peak values were associated with thromboembolism for patients' minimum (p = 0.01), median (p = 0.005) and maximum (p = 0.001) values. No association was seen between peak values and death or bleeding. Higher trough values were associated with death for median (p = 0.03) and maximum (p = 0.002) values and with both bleeding (p = 0.01) and major bleeding (p = 0.02) for maximum values, but there were no associations with thromboembolism.

CONCLUSIONS

Measuring anti-Factor Xa activity may be relevant for administrating low-molecular-weight heparin to patients with critical COVID-19. Lower peak values were associated with an increased risk of thromboembolism, and higher trough values were associated with an increased risk of death and bleeding. Prospective studies are needed to confirm the results.

TRIAL REGISTRATION

The study was retrospectively registered at Clinicaltrials.gov, NCT05256524, February 24, 2022.

Effects of inflammation on thrombosis and outcomes in COVID-19: secondary analysis of the ATTACC/ACTIV-4a trial

Background

Patients hospitalized for COVID-19 are at high risk of thrombotic complications and organ failure, and often exhibit severe inflammation, which may contribute to hypercoagulability.

Objectives

To determine whether patients hospitalized for COVID-19 experience differing frequencies of thrombotic and organ failure complications and derive variable benefits from therapeutic-dose heparin dependent on the extent of systemic inflammation and whether observed benefit from therapeutic-dose anticoagulation varies depending on the degree of systemic inflammation.

Methods

We analyzed data from 1346 patients hospitalized for COVID-19 enrolled in the ATTACC and ACTIV-4a platforms who were randomized to therapeutic-dose heparin or usual care for whom levels of C-reactive protein (CRP) were reported at baseline.

Results

Increased CRP was associated with worse patient outcomes, including a >98% posterior probability of increased organ support requirement, hospital length of stay, risk of 28-day mortality, and incidence of major thrombotic events or death (patients with CRP 40-100 mg/L or ≥100 mg/L compared to patients with CRP <40 mg/L). Patients with CRP 40 to 100 mg/L experienced the greatest degree of benefit from treatment with therapeutic doses of unfractionated or low molecular weight heparin compared with usual-care prophylactic doses. This was most significant for an increase in organ support-free days (odds ratio: 1.63; 95% confidence interval, 1.09-2.40; 97.9% posterior probability of beneficial effect), with trends toward benefit for other evaluated outcomes.

Conclusion

Moderately ill patients hospitalized for COVID-19 with CRP between 40 mg/L and 100 mg/L derived the greatest benefit from treatment with therapeutic-dose heparin.

Prolonged-release pirfenidone in patients with pulmonary fibrosis as a phenotype of post-acute sequelae of COVID-19 pneumonia. Safety and efficacy

INTRODUCTION

One of the major concerns with post-acute sequelae of COVID-19 (PASC) is the development of pulmonary fibrosis, for which no approved pharmacological treatment exists. Therefore, the primary aim of this open-label study was to evaluate the safety and the potential clinical efficacy of a prolonged-release pirfenidone formulation (PR-PFD) in patients having PASC-pulmonary fibrosis.

METHODS

Patients with PASC-pulmonary fibrosis received PR-PFD 1800 mg/day (1200 mg in the morning after breakfast and 600 mg in the evening after dinner) for three months. Blood samples were taken to confirm the pharmacokinetics of PR-PFD, and adverse events (AEs) were evaluated monthly using a short questionnaire. Symptoms, dyspnea, and pulmonary function tests (spirometry, diffusing capacity for carbon monoxide, plethysmography, and 6-min walk test [6MWT]) were evaluated at baseline, and one and three months after having started the PR-PFD treatment.

RESULTS

Seventy subjects with mild to moderate lung restriction were included. The most common AEs were diarrhea (23%), heartburn (23%), and headache (16%), for which no modifications in the drug study were needed. Two patients died within the first 30 days of enrolment, and three opted not to continue the study, events which were not associate with PR-PFD. Pulmonary function testing, 6MWT, dyspnea, symptoms, and CT scan significantly improved after three months of treatment with PR-PFD.

CONCLUSION

In patients with PASC pulmonary fibrosis, three months' treatment with PR-PFD was safe and showed therapeutic efficacy. Still, it remains to be seen whether the pulmonary fibrotic process remains stable, becomes progressive or will improve.

The diagnostic accuracy of perfusion-only scan in the diagnosis of pulmonary embolism in the era of COVID-19: A single-center study of 434 patients

INTRODUCTION

There is a paucity of data in the literature regarding the diagnostic accuracy of perfusion (Q)-only studies in the absence of ventilation images. This study aims to assess the diagnostic accuracy of Q-only imaging in the pandemic era.

METHODS

Patients who underwent Q-only imaging for pulmonary embolism between March 2020 and February 2021 were analyzed. Patients who underwent lung quantification analysis were excluded. Q-only test results were reported as per modified PIOPED II criteria and single positron emission tomography/computed tomography (SPECT/CT) imaging was performed as needed. Patients were considered concordant or discordant by correlating the Q-only results with CT angiogram (CTA) or clinical diagnosis made through chart review. The diagnostic accuracy was calculated after excluding intermediate probability and nondiagnostic studies.

RESULTS

Four hundred and thirty-four patients were identified. One hundred and twenty-eight patients (29.4%) underwent ultrasound Doppler, 37 patients (8.5%) underwent CTA, and 16 patients (3.6%) underwent both. After excluding patients with intermediate probability or nondiagnostic studies and who did not have follow-up (a total of 87 patients [20%]), 347 patients were enrolled in the final analysis. The combined planar and SPECT/CT sensitivity and specificity were 85.4% (72.2%-93.9% confidence interval [CI]) and 98.7% (96.9%-98.6% CI), respectively. The positive predictive value (PPV) of the Q-only imaging was 89.1% (77.3%-95.1% CI) and the negative predictive value (NPV) was 98.2% (96.4%-99% CI). The sensitivity with SPECT/CT reached 100% (CI: 71.5%-100%) with a specificity of 92.3% (CI: 64%-99.8%). The PPV was 85.7% (CI: 62.1%-95.6%) and the NPV was 100%.

CONCLUSION

Q-only imaging provides clinically acceptable results. The sensitivity of the Q-only scan is increased when coupled with SPECT/CT.

Evaluation of clinical features and laboratory findings in critical intensive care unit patients with severe coronavirus disease-19 who underwent extracorporeal cytokine adsorption

AIM

To evaluate the inflammatory parameters and oxygenation in severe coronavirus disease-19 patients who underwent extracorporeal cytokine adsorption (CA).

METHODS

Patients who underwent extracorporeal CA for cytokine storm were included in the study. The changes in oxygenation, laboratory parameters, and mortality rates were investigated.

RESULTS

Thirty-six patients were included in the study. The hemoglobin, thrombocyte, and C-reactive protein (CRP) decreased, and PaO2 /FiO2 ratio increased (p < 0.001; p < 0.01; p < 0.001; p = 0.04, respectively). Twelve (33.3%) patients received a single session, 24 (66.6%) received 2 or more sessions. CRP and fibrinogen levels decreased, and PaO2 /FIO2 ratio increased in the single session group (p = 0.04; p = 0.04; p = 0.01, respectively). In the multi-session group, the hemoglobin, platelet, procalcitonin, and CRP levels decreased, and PaO2 /FIO2 ratio increased (p < 0.01; p = 0.02; p = 0.02; p < 0.01; p = 0.01, respectively). Day 15, 30, and 90 mortality rates were 61.1%, 83.3%, and 88.9%.

CONCLUSION

CA with hemoperfusion reduced CRP and improved oxygenation; however, mortality rates were high.

Crosstalk between Platelets and SARS-CoV-2: Implications in Thrombo-Inflammatory Complications in COVID-19

The SARS-CoV-2 virus, causing the devastating COVID-19 pandemic, has been reported to affect platelets and cause increased thrombotic events, hinting at the possible bidirectional interactions between platelets and the virus. In this review, we discuss the potential mechanisms underlying the increased thrombotic events as well as altered platelet count and activity in COVID-19. Inspired by existing knowledge on platelet-pathogen interactions, we propose several potential antiviral strategies that platelets might undertake to combat SARS-CoV-2, including their abilities to internalize the virus, release bioactive molecules to interfere with viral infection, and modulate the functions of immune cells. Moreover, we discuss current and potential platelet-targeted therapeutic strategies in controlling COVID-19, including antiplatelet drugs, anticoagulants, and inflammation-targeting treatments. These strategies have shown promise in clinical settings to alleviate the severity of thrombo-inflammatory complications and reduce the mortality rate among COVID-19 patients. In conclusion, an in-depth understanding of platelet-SARS-CoV-2 interactions may uncover novel mechanisms underlying severe COVID-19 complications and could provide new therapeutic avenues for managing this disease.

Rationale for combined therapies in severe-to-critical COVID-19 patients

An unprecedented global social and economic impact as well as a significant number of fatalities have been brought on by the coronavirus disease 2019 (COVID-19), produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute SARS-CoV-2 infection can, in certain situations, cause immunological abnormalities, leading to an anomalous innate and adaptive immune response. While most patients only experience mild symptoms and recover without the need for mechanical ventilation, a substantial percentage of those who are affected develop severe respiratory illness, which can be fatal. The absence of effective therapies when disease progresses to a very severe condition coupled with the incomplete understanding of COVID-19's pathogenesis triggers the need to develop innovative therapeutic approaches for patients at high risk of mortality. As a result, we investigate the potential contribution of promising combinatorial cell therapy to prevent death in critical patients.

Pulmonary embolism in COVID-19 pneumonia patients admitted to temporary hospital - The follow-up study

PURPOSE

Coronavirus disease 2019 (COVID-19) is linked with major coagulation disorders, especially higher risk of developing pulmonary embolism (PE). Our study summarizes COVID-19 patients' management with concomitant PE during the first weeks of pandemic and underlines the importance of D-dimer concentration assessment at admission in terms of prognosis.

MATERIAL AND METHODS

Study group consisted of 107 outpatients (mean age 68.91 ​± ​12.83 years) admitted to the Temporary COVID-19 Hospital in Bialystok, Poland with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and suspicion of PE based on elevated D-dimer concentration (>500 ​μg/l) and/or low saturation rate (<90%). The clinical follow-up lasted 6 months. Death or re-hospitalization were used as composite clinical endpoint (CEP).

RESULTS

Cumulative incidence of PE was 62.3% (73/107 patients). Most of the patients were in the intermediate PE risk group according to the pulmonary embolism severity index (PESI) score. The mean total computed tomography (CT) lung involvement of COVID-19 findings was 48.42 ​± ​27.71%. Neither D-dimers nor NT-proBNP concentrations correlated significantly with the percentage of lung abnormalities in CT. Patients with baseline D-dimer concentration higher than 1429 ​μg/l had worse prognosis in 6-months observation, log-rank test, p ​= ​0.009.

CONCLUSIONS

Ongoing SARS-CoV-2 infection along with massive involvement of lung tissue and concomitant thrombi in pulmonary arteries are challenging for physicians. It seems that simple D-dimer concentration assessment at admission may be a helpful tool not only to predict PE but also to estimate the long-term prognosis.

CD36 mediates SARS-CoV-2-envelope-protein-induced platelet activation and thrombosis

Aberrant coagulation and thrombosis are associated with severe COVID-19 post-SARS-CoV-2 infection, yet the underlying mechanism remains obscure. Here we show that serum levels of SARS-CoV-2 envelope (E) protein are associated with coagulation disorders of COVID-19 patients, and intravenous administration of the E protein is able to potentiate thrombosis in mice. Through protein pull-down and mass spectrometry, we find that CD36, a transmembrane glycoprotein, directly binds with E protein and mediates hyperactivation of human and mouse platelets through the p38 MAPK-NF-κB signaling pathway. Conversely, the pharmacological blockade of CD36 or p38 notably attenuates human platelet activation induced by the E protein. Similarly, the genetic deficiency of CD36, as well as the pharmacological inhibition of p38 in mice, significantly diminishes E protein-induced platelet activation and thrombotic events. Together, our study reveals a critical role for the CD36-p38 axis in E protein-induced platelet hyperactivity, which could serve as an actionable target for developing therapies against aberrant thrombotic events related to the severity and mortality of COVID-19.

The central role of neutrophil extracellular traps (NETs) and by-products in COVID-19 related pulmonary thrombosis

Extracellular trap networks (neutrophil extracellular traps [NETs]) of polymorphonuclear neutrophils are mesh-like substances that prevent the spread of pathogens. They primarily consist of DNA skeletons, histones, granule components, and cytoplasmic proteins. NETs formation requires a certain environment and there are different pathways for NETs production. However, it is still not clear how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) promotes NETs. NETs exert antiinflammatory effects through immune response, while they can also lead to certain adverse outcomes, such as the development of immunothrombosis. Coronavirus disease 2019 (COVID-19) is an inflammatory reaction affecting various organs caused by SARS-CoV-2, especially the lungs. NETs production and disease severity are linked with unique neutrophil clusters by single-cell RNA sequencing. NETs might exert an anti-inflammatory role in the initial stage of lung tissue inflammation. Nevertheless, numerous studies and cases have shown that they can also result in pulmonary thrombosis. There is mounting evidence that NETs are tightly related with COVID-19 pulmonary thrombosis, and many studies on the mechanisms are involved. The role and mechanism of NETs in the development of pulmonary thrombosis will be the main topics of this manuscript. Additionally, we address the potential targeting of NETs in COVID-19 patients.

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

OBJECTIVES

The objective was to define a safe strategy to exclude pulmonary embolism (PE) in COVID-19 outpatients, without performing CT pulmonary angiogram (CTPA).

METHODS

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.

RESULTS

In total, 1369 patients were included of whom 124 were PE positive (9.1%). Failure rate and efficiency of D-Dimer > 500 µg/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 > 1000 µg/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%.

CONCLUSIONS

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.

KEY POINTS

• 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).

Protection against Severe Illness versus Immunity-Redefining Vaccine Effectiveness in the Aftermath of COVID-19

Anti-SARS-CoV-2 vaccines have played a pivotal role in reducing the risk of developing severe illness from COVID-19, thus helping end the COVID-19 global public health emergency after more than three years. Intriguingly, as SARS-CoV-2 variants emerged, individuals who were fully vaccinated did get infected in high numbers, and viral loads in vaccinated individuals were as high as those in the unvaccinated. However, even with high viral loads, vaccinated individuals were significantly less likely to develop severe illness; this begs the question as to whether the main effect of anti-SARS-CoV-2 vaccines is to confer protection against severe illness or immunity against infection. The answer to this question is consequential, not only to the understanding of how anti-SARS-CoV-2 vaccines work, but also to public health efforts against existing and novel pathogens. In this review, we argue that immune system sensitization-desensitization rather than sterilizing immunity may explain vaccine-mediated protection against severe COVID-19 illness even when the SARS-CoV-2 viral load is high. Through the lessons learned from COVID-19, we make the case that in the disease's aftermath, public health agencies must revisit healthcare policies, including redefining the term "vaccine effectiveness."