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2.
Curr Opin Nephrol Hypertens ; 31(1): 36-46, 2022 01 01.
Article in English | MEDLINE | ID: covidwho-1612725

ABSTRACT

PURPOSE OF REVIEW: Severe COVID-19 disease is often complicated by acute kidney injury (AKI), which may transition to chronic kidney disease (CKD). Better understanding of underlying mechanisms is important in advancing therapeutic approaches. RECENT FINDINGS: SARS-CoV-2-induced endothelial injury initiates platelet activation, platelet-neutrophil partnership and release of neutrophil extracellular traps. The resulting thromboinflammation causes ischemia-reperfusion (I/R) injury to end organs. Severe COVID-19 induces a lipid-mediator storm with massive increases in thromboxane A2 (TxA2) and PGD2, which promote thromboinflammation and apoptosis of renal tubular cells, respectively, and thereby enhance renal fibrosis. COVID-19-associated AKI improves rapidly in the majority. However, 15-30% have protracted renal injury, raising the specter of transition from AKI to CKD. SUMMARY: In COVID-19, the lipid-mediator storm promotes thromboinflammation, ischemia-reperfusion injury and cytotoxicity. The thromboxane A2 and PGD2 signaling presents a therapeutic target with potential to mitigate AKI and transition to CKD. Ramatroban, the only dual antagonist of the thromboxane A2/TPr and PGD2/DPr2 signaling could potentially mitigate renal injury in acute and long-haul COVID. Urgent studies targeting the lipid-mediator storm are needed to potentially reduce the heavy burden of kidney disease emerging in the wake of the current pandemic.


Subject(s)
Acute Kidney Injury , COVID-19 , Renal Insufficiency, Chronic , Thrombosis , Acute Kidney Injury/etiology , COVID-19/complications , Fibrosis , Humans , Inflammation , Kidney/pathology , Lipids , Renal Insufficiency, Chronic/pathology , SARS-CoV-2 , Thrombosis/pathology
3.
PLoS One ; 17(1): e0262352, 2022.
Article in English | MEDLINE | ID: covidwho-1606851

ABSTRACT

INTRODUCTION: COVID-19 infection has been hypothesized to precipitate venous and arterial clotting events more frequently than other illnesses. MATERIALS AND METHODS: We demonstrate this increased risk of blood clots by comparing rates of venous and arterial clotting events in 4400 hospitalized COVID-19 patients in a large multisite clinical network in the United States examined from April through June of 2020, to patients hospitalized for non-COVID illness and influenza during the same time period and in 2019. RESULTS: We demonstrate that COVID-19 increases the risk of venous thrombosis by two-fold compared to the general inpatient population and compared to people with influenza infection. Arterial and venous thrombosis were both common occurrences among patients with COVID-19 infection. Risk factors for thrombosis included male gender, older age, and diabetes. Patients with venous or arterial thrombosis had high rates of admission to the ICU, re-admission to the hospital, and death. CONCLUSION: Given the ongoing scientific discussion about the impact of clotting on COVID-19 disease progression, these results highlight the need to further elucidate the role of anticoagulation in COVID-19 patients, particularly outside the intensive care unit setting. Additionally, concerns regarding clotting and COVID-19 vaccines highlight the importance of addressing the alarmingly high rate of clotting events during actual COVID-19 infection when weighing the risks and benefits of vaccination.


Subject(s)
COVID-19/pathology , Thrombosis/pathology , Aged , COVID-19/mortality , Cohort Studies , Comorbidity , Female , Hospitalization , Humans , Male , New Jersey , Retrospective Studies , Thrombosis/mortality , United States
4.
QJM ; 114(9): 619-620, 2021 Nov 13.
Article in English | MEDLINE | ID: covidwho-1584068

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) has been associated with coagulation dysfunction which predisposes patients to an increased risk of both venous and arterial thromboembolism, increasing the short-term morbidity and mortality. Current data evidenced that the rate of post-discharge thrombotic events in COVID-19 patients is lower compared to that observed during hospitalization. Rather than 'true thrombotic events', these complications seem more probably 'immunothrombosis' consequent to the recent infection. Unfortunately, the absence of data from randomized controlled trials, large prospective cohorts and ambulatory COVID-19 patients, left unresolved the question regarding the need of post-discharge thromboprophylaxis due to the absence of strong-level recommendations.


Subject(s)
COVID-19 , Thrombosis , Venous Thromboembolism , Aftercare , Anticoagulants , Humans , Patient Discharge , Prospective Studies , SARS-CoV-2 , Thrombosis/epidemiology , Thrombosis/etiology
5.
PLoS One ; 16(12): e0261113, 2021.
Article in English | MEDLINE | ID: covidwho-1581761

ABSTRACT

BACKGROUND: Complement activation contributes to lung dysfunction in coronavirus disease 2019 (COVID-19). We assessed whether C5 blockade with eculizumab could improve disease outcome. METHODS: In this single-centre, academic, unblinded study two 900 mg eculizumab doses were added-on standard therapy in ten COVID-19 patients admitted from February 2020 to April 2020 and receiving Continuous-Positive-Airway-Pressure (CPAP) ventilator support from ≤24 hours. We compared their outcomes with those of 65 contemporary similar controls. Primary outcome was respiratory rate at one week of ventilator support. Secondary outcomes included the combined endpoint of mortality and discharge with chronic complications. RESULTS: Baseline characteristics of eculizumab-treated patients and controls were similar. At baseline, sC5b-9 levels, ex vivo C5b-9 and thrombi deposition were increased. Ex vivo tests normalised in eculizumab-treated patients, but not in controls. In eculizumab-treated patients respiratory rate decreased from 26.8±7.3 breaths/min at baseline to 20.3±3.8 and 18.0±4.8 breaths/min at one and two weeks, respectively (p<0.05 for both), but did not change in controls. Between-group changes differed significantly at both time-points (p<0.01). Changes in respiratory rate correlated with concomitant changes in ex vivo C5b-9 deposits at one (rs = 0.706, p = 0.010) and two (rs = 0.751, p = 0.032) weeks. Over a median (IQR) period of 47.0 (14.0-121.0) days, four eculizumab-treated patients died or had chronic complications versus 52 controls [HRCrude (95% CI): 0.26 (0.09-0.72), p = 0.010]. Between-group difference was significant even after adjustment for age, sex and baseline serum creatinine [HRAdjusted (95% CI): 0.30 (0.10-0.84), p = 0.023]. Six patients and 13 controls were discharged without complications [HRCrude (95% CI): 2.88 (1.08-7.70), p = 0.035]. Eculizumab was tolerated well. The main study limitations were the relatively small sample size and the non-randomised design. CONCLUSIONS: In patients with severe COVID-19, eculizumab safely improved respiratory dysfunction and decreased the combined endpoint of mortality and discharge with chronic complications. Findings need confirmation in randomised controlled trials.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , COVID-19/therapy , Continuous Positive Airway Pressure , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , COVID-19/drug therapy , COVID-19/mortality , COVID-19/physiopathology , Case-Control Studies , Complement Membrane Attack Complex/analysis , Female , Humans , Male , Middle Aged , Retrospective Studies , Thrombosis/drug therapy , Treatment Outcome
6.
Int J Mol Sci ; 22(24)2021 Dec 20.
Article in English | MEDLINE | ID: covidwho-1580687

ABSTRACT

COVID-19 infection is associated with a broad spectrum of presentations, but alveolar capillary microthrombi have been described as a common finding in COVID-19 patients, appearing as a consequence of a severe endothelial injury with endothelial cell membrane disruption. These observations clearly point to the identification of a COVID-19-associated coagulopathy, which may contribute to thrombosis, multi-organ damage, and cause of severity and fatality. One significant finding that emerges in prothrombotic abnormalities observed in COVID-19 patients is that the coagulation alterations are mainly mediated by the activation of platelets and intrinsically related to viral-mediated endothelial inflammation. Beyond the well-known role in hemostasis, the ability of platelets to also release various potent cytokines and chemokines has elevated these small cells from simple cell fragments to crucial modulators in the blood, including their inflammatory functions, that have a large influence on the immune response during infectious disease. Indeed, platelets are involved in the pathogenesis of acute lung injury also by promoting NET formation and affecting vascular permeability. Specifically, the deposition by activated platelets of the chemokine platelet factor 4 at sites of inflammation promotes adhesion of neutrophils on endothelial cells and thrombogenesis, and it seems deeply involved in the phenomenon of vaccine-induced thrombocytopenia and thrombosis. Importantly, the hyperactivated platelet phenotype along with evidence of cytokine storm, high levels of P-selectin, D-dimer, and, on the other hand, decreased levels of fibrinogen, von Willebrand factor, and thrombocytopenia may be considered suitable biomarkers that distinguish the late stage of COVID-19 progression in critically ill patients.


Subject(s)
Blood Platelets/physiology , COVID-19/blood , Thrombosis/pathology , Blood Coagulation , Blood Coagulation Disorders/etiology , Blood Platelets/metabolism , Blood Platelets/virology , COVID-19/metabolism , Cytokine Release Syndrome , Endothelial Cells/pathology , Fibrin Fibrinogen Degradation Products , Hemostasis , Humans , Inflammation , Phenotype , Platelet Activation/physiology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Thrombocytopenia/metabolism , Thrombosis/metabolism , Thrombosis/virology
8.
Hamostaseologie ; 41(6): 428-432, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1585711

ABSTRACT

Thrombus formation has been identified as an integral part in innate immunity, termed immunothrombosis. Activation of host defense systems is known to result in a procoagulant environment. In this system, cellular players as well as soluble mediators interact with each other and their dysregulation can lead to the pathological process of thromboinflammation. These mechanisms have been under intensified investigation during the COVID-19 pandemic. In this review, we focus on the underlying mechanisms leading to thromboinflammation as one trigger of venous thromboembolism.


Subject(s)
COVID-19 , Thrombosis , Venous Thromboembolism , Humans , Immunity, Innate , Inflammation , Pandemics , SARS-CoV-2
10.
Clin Appl Thromb Hemost ; 27: 10760296211068487, 2021.
Article in English | MEDLINE | ID: covidwho-1575876

ABSTRACT

BACKGROUND: Cases of thrombosis with thrombocytopenia syndrome (TTS) have been reported following vaccination with AZD1222 or Ad26.COV2.S. This review aimed to explore the pathophysiology, epidemiology, diagnosis, management, and prognosis of TTS. METHODS: A systematic review was conducted to identify evidence on TTS till 4th September 2021. Case reports and series reporting patient-level data were included. Descriptive statistics were reported and compared across patients with different sexes, age groups, vaccines, types of thrombosis, and outcomes. FINDINGS: Sixty-two studies reporting 160 cases were included from 16 countries. Patients were predominantly females with a median age of 42.50 (22) years. AZD1222 was administered to 140 patients (87·5%). TTS onset occurred in a median of 9 (4) days after vaccination. Venous thrombosis was most common (61.0%). Most patients developed cerebral venous sinus thrombosis (CVST; 66.3%). CVST was significantly more common in female vs male patients (p = 0·001) and in patients aged <45 years vs ≥45 years (p = 0·004). The mortality rate was 36.2%, and patients with suspected TTS, venous thrombosis, CVST, pulmonary embolism, or intraneural complications, patients not managed with non-heparin anticoagulants or IVIG, patients receiving platelet transfusions, and patients requiring intensive care unit admission, mechanical ventilation, or inpatient neurosurgery were more likely to expire than recover. INTERPRETATION: These findings help to understand the pathophysiology of TTS while also recommending diagnostic and management approaches to improve prognosis in patients. FUNDING: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.


Subject(s)
COVID-19 Vaccines/adverse effects , Thrombocytopenia/chemically induced , Thrombosis/chemically induced , Adult , Aged , Female , Humans , Male , Middle Aged , Syndrome
11.
Clin Appl Thromb Hemost ; 27: 10760296211069082, 2021.
Article in English | MEDLINE | ID: covidwho-1575453

ABSTRACT

BACKGROUND: The association between coronavirus infection 2019 (COVID-19) and thrombosis has been explicitly shown through numerous reports that demonstrate high rates of thrombotic complications in infected patients. Recently, much evidence has shown that patients who survived COVID-19 might have a high thrombotic risk after hospital discharge. This current systematic review and meta-analysis was conducted to better understand the incidence of thrombosis, bleeding, and mortality rates among patients discharged after COVID-19 hospitalization. METHODS: Using a search strategy that included terms for postdischarge, thrombosis, and COVID-19, 2 investigators independently searched for published articles indexed in the MEDLINE, Embase, and Scopus databases that were published before August 2021. Pooled incidences and 95% confidence intervals were calculated using the DerSimonian-Laird random-effects model with a double arcsine transformation. RESULTS: Twenty articles were included in the meta-analysis. They provided a total of 19 461 patients discharged after COVID-19 hospitalization. The weighted pooled incidence of overall thrombosis among the patients was 1.3% (95 CI, 0. 6-2; I2 90.5), with a pooled incidence of venous thrombosis of 0.7% (95 CI, 0. 4-1; I2 73.9) and a pooled incidence of arterial thrombosis of 0.6% (95 CI, 0. 2-1; I2 88.1). The weighted pooled incidences of bleeding and mortality were 0.9% (95 CI, 0. 1-1.9; I2 95.1) and 2.8% (95 CI, 0. 6-5; I2 98.2), respectively. CONCLUSIONS: The incidences of thrombosis and bleeding in patients discharged after COVID-19 hospitalization are comparable to those of medically ill patients.


Subject(s)
COVID-19/complications , Hemorrhage/etiology , Thrombosis/etiology , Aged , Aged, 80 and over , Female , Hemorrhage/physiopathology , Humans , Incidence , Male , Middle Aged , Patient Discharge , Risk Factors , Thrombosis/physiopathology
12.
Clin Appl Thromb Hemost ; 27: 10760296211066945, 2021.
Article in English | MEDLINE | ID: covidwho-1574469

ABSTRACT

INTRODUCTION: Argatroban is licensed for patients with heparin-induced thrombocytopenia and is conventionally monitored by activated partial thromboplastin time (APTT) ratio. The target range is 1.5 to 3.0 times the patients' baseline APTT and not exceeding 100 s, however this baseline is not always known. APTT is known to plateau at higher levels of argatroban, and is influenced by coagulopathies, lupus anticoagulant and raised FVIII levels. It has been used as a treatment for COVID-19 and Vaccine-induced Immune Thrombocytopenia and Thrombosis (VITT). Some recent publications have favored the use of anti-IIa methods to determine the plasma drug concentration of argatroban. METHODS: Plasma of 60 samples from 3 COVID-19 patients and 54 samples from 5 VITT patients were tested by APTT ratio and anti-IIa method (dilute thrombin time dTT). Actin FS APTT ratios were derived from the baseline APTT of the patient and the mean normal APTT. RESULTS: Mean APTT ratio derived from baseline was 1.71 (COVID-19), 1.33 (VITT) compared to APTT ratio by mean normal 1.65 (COVID-19), 1.48 (VITT). dTT mean concentration was 0.64 µg/ml (COVID-19) 0.53 µg/ml (VITT) with poor correlations to COVID-19 baseline APTT ratio r2 = 0.1526 p <0.0001, mean normal r2 = 0.2188 p < 0.0001; VITT baseline APTT ratio r2 = 0.04 p < 0.001, VITT mean normal r2 = 0.0064 p < 0.001. CONCLUSIONS: We believe that dTT is a superior method to monitor the concentration of argatroban, we have demonstrated significant differences between APTT ratios and dTT levels, which could have clinical impact. This is especially so in COVID-19 and VITT.


Subject(s)
Arginine/analogs & derivatives , COVID-19/drug therapy , Partial Thromboplastin Time/methods , Pipecolic Acids/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Sulfonamides/therapeutic use , Thrombocytopenia/drug therapy , Thrombosis/drug therapy , Aged , Arginine/pharmacology , Arginine/therapeutic use , COVID-19/complications , Female , Humans , Male , Middle Aged , Pipecolic Acids/pharmacology , Platelet Aggregation Inhibitors/pharmacology , SARS-CoV-2 , Sulfonamides/pharmacology , Thrombocytopenia/chemically induced , Thrombosis/chemically induced
13.
Front Immunol ; 12: 729251, 2021.
Article in English | MEDLINE | ID: covidwho-1573871

ABSTRACT

Introduction: The World Health Organization declared the coronavirus disease 2019 (COVID-19) pandemic on March 11, 2020. Two vaccine types were developed using two different technologies: viral vectors and mRNA. Thrombosis is one of the most severe and atypical adverse effects of vaccines. This study aimed to analyze published cases of thrombosis after COVID-19 vaccinations to identify patients' features, potential pathophysiological mechanisms, timing of appearance of the adverse events, and other critical issues. Materials and Methods: We performed a systematic electronic search of scientific articles regarding COVID-19 vaccine-related thrombosis and its complications on the PubMed (MEDLINE) database and through manual searches. We selected 10 out of 50 articles from February 1 to May 5, 2021 and performed a descriptive analysis of the adverse events caused by the mRNA-based Pfizer and Moderna vaccines and the adenovirus-based AstraZeneca vaccine. Results: In the articles on the Pfizer and Moderna vaccines, the sample consisted of three male patients with age heterogeneity. The time from vaccination to admission was ≤3 days in all cases; all patients presented signs of petechiae/purpura at admission, with a low platelet count. In the studies on the AstraZeneca vaccine, the sample consisted of 58 individuals with a high age heterogeneity and a high female prevalence. Symptoms appeared around the ninth day, and headache was the most common symptom. The platelet count was below the lower limit of the normal range. All patients except one were positive for PF4 antibodies. The cerebral venous sinus was the most affected site. Death was the most prevalent outcome in all studies, except for one study in which most of the patients remained alive. Discussion: Vaccine-induced thrombotic thrombocytopenia (VITT) is an unknown nosological phenomenon secondary to inoculation with the COVID-19 vaccine. Several hypotheses have been formulated regarding its physiopathological mechanism. Recent studies have assumed a mechanism that is assimilable to heparin-induced thrombocytopenia, with protagonist antibodies against the PF4-polyanion complex. Viral DNA has a negative charge and can bind to PF4, causing VITT. New experimental studies have assumed that thrombosis is related to a soluble adenoviral protein spike variant, originating from splicing events, which cause important endothelial inflammatory events, and binding to endothelial cells expressing ACE2. Conclusion: Further studies are needed to better identify VITT's pathophysiological mechanisms and genetic, demographic, or clinical predisposition of high-risk patients, to investigate the correlation of VITT with the different vaccine types, and to test the significance of the findings.


Subject(s)
/immunology , COVID-19/immunology , SARS-CoV-2/physiology , Thrombosis/epidemiology , /adverse effects , Antigen-Antibody Complex/metabolism , COVID-19/complications , COVID-19/epidemiology , Cerebral Veins/metabolism , Cerebral Veins/pathology , Female , Headache , Humans , Mass Vaccination , Platelet Factor 4/immunology , Sex Factors , Survival Analysis , Thrombosis/etiology , Thrombosis/mortality
14.
Nagoya J Med Sci ; 83(4): 883-891, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1562255

ABSTRACT

A 76-year-old woman was admitted to the emergency room of Nagano Municipal Hospital with the complain of severe back pain. Chest and abdominal enhanced computed tomography scans showed bilateral adrenal infarction and minute pulmonary nodules, but she had no respiratory symptoms. After admission, a family member of the patient was found to have been in close contact with a coronavirus disease 2019 (COVID-19) patient. Thus, polymerase chain reaction and antigen tests of severe acute respiratory syndrome coronavirus 2 were conducted, and both tests returned positive. D-dimer levels were normal on admission but increased 2 days thereafter. Anticoagulation therapy and steroid replacement were started, and the patient improved over about two weeks. One month after the onset of adrenal infarction, a rapid adrenocorticotropic hormone loading test was conducted, which revealed that the primary adrenal insufficiency due to adrenal infarction might have been caused by the COVID-19 infection. This case was rare and suggestive of adrenal infarction with COVID-19, which usually presents at the severe stage. In patients with COVID-19, attention should be paid to the onset of thrombosis, even with mild respiratory infection. We also suggest that patients with thrombosis should be suspected of having COVID-19 even in the absence of respiratory infectious symptoms in a situation of COVID-19 epidemic.


Subject(s)
Adrenal Glands/blood supply , COVID-19/complications , Infarction , Thrombosis/etiology , Aged , COVID-19/blood , COVID-19/diagnosis , COVID-19 Nucleic Acid Testing , Female , Humans , Infarction/etiology , Respiratory Tract Infections , SARS-CoV-2/isolation & purification
15.
Ann Intern Med ; 174(1): 139-140, 2021 01.
Article in English | MEDLINE | ID: covidwho-1554303
16.
Viruses ; 13(12)2021 12 06.
Article in English | MEDLINE | ID: covidwho-1554939

ABSTRACT

Mid-regional pro-adrenomedullin (MR-proADM), methemoglobin (MetHb), and carboxyhemoglobin (COHb) levels have been associated with sepsis. In this study, we assessed the role of this potential biomarkers in critically ill COVID-19 patients. Outcomes were mortality and a combined event (mortality, venous or arterial thrombosis, and orotracheal intubation (OTI)) during a 30-day follow-up. A total of 95 consecutive patients were included, 51.6% required OTI, 12.6% patients died, 8.4% developed VTE, and 3.1% developed arterial thrombosis. MetHb and COHb levels were not associated with mortality nor combined event. Higher MR-proADM levels were found in patients with mortality (median of 1.21 [interquartile range-IQR-0.84;2.33] nmol/L vs. 0.76 [IQR 0.60;1.03] nmol/L, p = 0.011) and combined event (median of 0.91 [IQR 0.66;1.39] nmol/L vs. 0.70 [IQR 0.51;0.82] nmol/L, p < 0.001); the positive likelihood ratio (LR+) and negative likelihood ratio (LR-) for mortality were 2.40 and 0.46, respectively. The LR+ and LR- for combined event were 3.16 and 0.63, respectively. MR-proADM ≥1 nmol/L was the optimal cut-off for mortality and combined event prediction. The predictive capacity of MR-proADM showed an area under the ROC curve of 0.73 (95% CI, 0.62-0.81) and 0.72 (95% CI, 0.62-0.81) for mortality and combined event, respectively. In conclusion, elevated on-admission MR-proADM levels were associated with higher risk of 30-day mortality and 30-day poor outcomes in a cohort of critically ill patients with COVID-19.


Subject(s)
Adrenomedullin , Biomarkers , COVID-19 , Carboxyhemoglobin , Methemoglobin , Aged , COVID-19/mortality , COVID-19 Testing , Critical Illness , Female , Humans , Male , Middle Aged , Prognosis , Prospective Studies , SARS-CoV-2 , Sepsis , Thrombosis
17.
Am J Case Rep ; 22: e933225, 2021 Nov 25.
Article in English | MEDLINE | ID: covidwho-1534576

ABSTRACT

BACKGROUND COVID-19 caused by SARS-CoV-2 infection has been associated with a hypercoagulable state in which patients can be at risk for developing venous and arterial thromboembolic events at a rate as high as 31%. A free-floating aortic thrombus (FFT) is a rare life-threatening complication of a hypercoagulable state. These thrombi require medical, endovascular, or surgical treatment. The optimal treatment modality for FFT occurring in the setting of COVID-19 remains unknown. We present a patient with a COVID-19-associated free-floating descending aortic thrombus that was treated with percutaneous vacuum-assisted thrombectomy (angio-VAC). CASE REPORT A 61-year-old man presented to the hospital with dyspnea and hypoxia and was diagnosed with severe COVID-19 pneumonia. Initial chest computed tomography angiography (CTA) did not show pulmonary emboli or thrombi. Inflammatory markers (D-dimer, lactate dehydrogenase, ferritin, fibrinogen) were tracked every other day. After several measurements of decreasing D-dimer values, there was a noticeable increase in D-dimer level and continued dependence on high levels of supplemental oxygen. A repeat chest CTA showed an FFT, confirmed by transesophageal echocardiogram. Cardiothoracic surgery and interventional radiology teams performed successful angio-VAC percutaneous removal, confirmed with intravascular ultrasound. The patient was subsequently discharged with a 3-month supply of apixaban. CONCLUSIONS Minimally invasive endovascular removal of an FFT is a therapeutic option, as anticoagulation alone carries the risk of partial lysis and repeat embolization. Clinicians can consider this endovascular treatment option paired with therapeutic anticoagulation. Further guidelines on monitoring and treatment of possible COVID-19-associated thrombosis are needed, particularly when the risk of embolization is high.


Subject(s)
COVID-19 , Thrombosis , Aorta , Humans , Male , Middle Aged , SARS-CoV-2 , Thrombectomy
19.
JAMA ; 326(17): 1703-1712, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1525396

ABSTRACT

Importance: Acutely ill inpatients with COVID-19 typically receive antithrombotic therapy, although the risks and benefits of this intervention among outpatients with COVID-19 have not been established. Objective: To assess whether anticoagulant or antiplatelet therapy can safely reduce major adverse cardiopulmonary outcomes among symptomatic but clinically stable outpatients with COVID-19. Design, Setting, and Participants: The ACTIV-4B Outpatient Thrombosis Prevention Trial was designed as a minimal-contact, adaptive, randomized, double-blind, placebo-controlled trial to compare anticoagulant and antiplatelet therapy among 7000 symptomatic but clinically stable outpatients with COVID-19. The trial was conducted at 52 US sites between September 2020 and June 2021; final follow-up was August 5, 2021. Prior to initiating treatment, participants were required to have platelet count greater than 100 000/mm3 and estimated glomerular filtration rate greater than 30 mL/min/1.73 m2. Interventions: Random allocation in a 1:1:1:1 ratio to aspirin (81 mg orally once daily; n = 164), prophylactic-dose apixaban (2.5 mg orally twice daily; n = 165), therapeutic-dose apixaban (5 mg orally twice daily; n = 164), or placebo (n = 164) for 45 days. Main Outcomes and Measures: The primary end point was a composite of all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause. The primary analyses for efficacy and bleeding events were limited to participants who took at least 1 dose of trial medication. Results: On June 18, 2021, the trial data and safety monitoring board recommended early termination because of lower than anticipated event rates; at that time, 657 symptomatic outpatients with COVID-19 had been randomized (median age, 54 years [IQR, 46-59]; 59% women). The median times from diagnosis to randomization and from randomization to initiation of study treatment were 7 days and 3 days, respectively. Twenty-two randomized participants (3.3%) were hospitalized for COVID-19 prior to initiating treatment. Among the 558 patients who initiated treatment, the adjudicated primary composite end point occurred in 1 patient (0.7%) in the aspirin group, 1 patient (0.7%) in the 2.5-mg apixaban group, 2 patients (1.4%) in the 5-mg apixaban group, and 1 patient (0.7%) in the placebo group. The risk differences compared with placebo for the primary end point were 0.0% (95% CI not calculable) in the aspirin group, 0.7% (95% CI, -2.1% to 4.1%) in the 2.5-mg apixaban group, and 1.4% (95% CI, -1.5% to 5.0%) in the 5-mg apixaban group. Risk differences compared with placebo for bleeding events were 2.0% (95% CI, -2.7% to 6.8%), 4.5% (95% CI, -0.7% to 10.2%), and 6.9% (95% CI, 1.4% to 12.9%) among participants who initiated therapy in the aspirin, prophylactic apixaban, and therapeutic apixaban groups, respectively, although none were major. Findings inclusive of all randomized patients were similar. Conclusions and Relevance: Among symptomatic clinically stable outpatients with COVID-19, treatment with aspirin or apixaban compared with placebo did not reduce the rate of a composite clinical outcome. However, the study was terminated after enrollment of 9% of participants because of an event rate lower than anticipated. Trial Registration: ClinicalTrials.gov Identifier: NCT04498273.


Subject(s)
Aspirin/therapeutic use , COVID-19/drug therapy , Factor Xa Inhibitors/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Pyrazoles/therapeutic use , Pyridones/therapeutic use , Thrombosis/prevention & control , Adult , Aspirin/adverse effects , COVID-19/complications , Dose-Response Relationship, Drug , Double-Blind Method , Early Termination of Clinical Trials , Factor Xa Inhibitors/administration & dosage , Factor Xa Inhibitors/adverse effects , Female , Hemorrhage/chemically induced , Hospitalization , Humans , Male , Middle Aged , Platelet Aggregation Inhibitors/adverse effects , Pyrazoles/administration & dosage , Pyrazoles/adverse effects , Pyridones/administration & dosage , Pyridones/adverse effects
20.
J Thromb Haemost ; 19(12): 3139-3153, 2021 12.
Article in English | MEDLINE | ID: covidwho-1526388

ABSTRACT

OBJECTIVE: Heightened inflammation, dysregulated immunity, and thrombotic events are characteristic of hospitalized COVID-19 patients. Given that platelets are key regulators of thrombosis, inflammation, and immunity they represent prime candidates as mediators of COVID-19-associated pathogenesis. The objective of this study was to understand the contribution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the platelet phenotype via phenotypic (activation, aggregation) and transcriptomic characterization. APPROACH AND RESULTS: In a cohort of 3915 hospitalized COVID-19 patients, we analyzed blood platelet indices collected at hospital admission. Following adjustment for demographics, clinical risk factors, medication, and biomarkers of inflammation and thrombosis, we find platelet count, size, and immaturity are associated with increased critical illness and all-cause mortality. Bone marrow, lung tissue, and blood from COVID-19 patients revealed the presence of SARS-CoV-2 virions in megakaryocytes and platelets. Characterization of COVID-19 platelets found them to be hyperreactive (increased aggregation, and expression of P-selectin and CD40) and to have a distinct transcriptomic profile characteristic of prothrombotic large and immature platelets. In vitro mechanistic studies highlight that the interaction of SARS-CoV-2 with megakaryocytes alters the platelet transcriptome, and its effects are distinct from the coronavirus responsible for the common cold (CoV-OC43). CONCLUSIONS: Platelet count, size, and maturity associate with increased critical illness and all-cause mortality among hospitalized COVID-19 patients. Profiling tissues and blood from COVID-19 patients revealed that SARS-CoV-2 virions enter megakaryocytes and platelets and associate with alterations to the platelet transcriptome and activation profile.


Subject(s)
COVID-19 , Thrombosis , Blood Platelets , Humans , SARS-CoV-2 , Severity of Illness Index
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