Incidence and predictors of post-thrombotic syndrome in patients with proximal DVT in a real-world setting: findings from the GARFIELD-VTE registry.

Although substantial progress has been made in the pathophysiology and management of the post-thrombotic syndrome (PTS), several aspects still need clarification. Among them, the incidence and severity of PTS in the real world, the risk factors for its development, the value of patient's self-evaluation, and the ability to identify patients at risk for severe PTS. Eligible participants (n = 1107) with proximal deep-vein thrombosis (DVT) from the global GARFIELD-VTE registry underwent conventional physician's evaluation for PTS 36 months after diagnosis of their DVT using the Villalta score. In addition, 856 patients completed a Villalta questionnaire at 24 months. Variable selection was performed using stepwise algorithm, and predictors of severe PTS were incorporated into a multivariable risk model. The optimistic adjusted c-index was calculated using bootstrapping techniques. Over 36-months, 27.8% of patients developed incident PTS (mild in 18.7%, moderate in 5.7%, severe in 3.4%). Patients with incident PTS were older, had a lower prevalence of transient risk factors of DVT and a higher prevalence of persistent risk factors of DVT. Self-assessment of overall PTS at 24 months showed an agreement of 63.4% with respect to physician's evaluations at 36 months. The severe PTS multivariable model provided an optimistic adjusted c-index of 0.68 (95% CI 0.59-0.77). Approximately a quarter of DVT patients experienced PTS over 36 months after VTE diagnosis. Patient's self-assessment after 24 months provided added value for estimating incident PTS over 36 months. Multivariable risk analysis allowed good discrimination for severe PTS.

Effectiveness of the Ad26.COV2.S vaccine in health-care workers in South Africa (the Sisonke study): results from a single-arm, open-label, phase 3B, implementation study.

BACKGROUND: We aimed to assess the effectiveness of a single dose of the Ad26.COV2.S vaccine (Johnson & Johnson) in health-care workers in South Africa during two waves of the South African COVID-19 epidemic. METHODS: In the single-arm, open-label, phase 3B implementation Sisonke study, health-care workers aged 18 years and older were invited for vaccination at one of 122 vaccination sites nationally. Participants received a single dose of 5 × 1010 viral particles of the Ad26.COV2.S vaccine. Vaccinated participants were linked with their person-level data from one of two national medical insurance schemes (scheme A and scheme B) and matched for COVID-19 risk with an unvaccinated member of the general population. The primary outcome was vaccine effectiveness against severe COVID-19, defined as COVID-19-related admission to hospital, hospitalisation requiring critical or intensive care, or death, in health-care workers compared with the general population, ascertained 28 days or more after vaccination or matching, up to data cutoff. This study is registered with the South African National Clinical Trial Registry, DOH-27-022021-6844, ClinicalTrials.gov, NCT04838795, and the Pan African Clinical Trials Registry, PACTR202102855526180, and is closed to accrual. FINDINGS: Between Feb 17 and May 17, 2021, 477 102 health-care workers were enrolled and vaccinated, of whom 357 401 (74·9%) were female and 119 701 (25·1%) were male, with a median age of 42·0 years (33·0-51·0). 215 813 vaccinated individuals were matched with 215 813 unvaccinated individuals. As of data cutoff (July 17, 2021), vaccine effectiveness derived from the total matched cohort was 83% (95% CI 75-89) to prevent COVID-19-related deaths, 75% (69-82) to prevent COVID-19-related hospital admissions requiring critical or intensive care, and 67% (62-71) to prevent COVID-19-related hospitalisations. The vaccine effectiveness for all three outcomes were consistent across scheme A and scheme B. The vaccine effectiveness was maintained in older health-care workers and those with comorbidities including HIV infection. During the course of the study, the beta (B.1.351) and then the delta (B.1.617.2) SARS-CoV-2 variants of concerns were dominant, and vaccine effectiveness remained consistent (for scheme A plus B vaccine effectiveness against COVID-19-related hospital admission during beta wave was 62% [95% CI 42-76] and during delta wave was 67% [62-71], and vaccine effectiveness against COVID-19-related death during beta wave was 86% [57-100] and during delta wave was 82% [74-89]). INTERPRETATION: The single-dose Ad26.COV2.S vaccine shows effectiveness against severe COVID-19 disease and COVID-19-related death after vaccination, and against both beta and delta variants, providing real-world evidence for its use globally. FUNDING: National Treasury of South Africa, the National Department of Health, Solidarity Response Fund NPC, The Michael & Susan Dell Foundation, The Elma Vaccines and Immunization Foundation, and the Bill & Melinda Gates Foundation.

Pregnancy Related Venous Thromboembolism-Associated with HIV Infection and Antiretroviral Therapy.

Human immunodeficiency virus (HIV) infection in pregnancy is associated with substantial morbidity and mortality. Improved access to effective antiretroviral therapy (ART) has shifted the spectrum of pregnancy-related complications among HIV-infected pregnant women. In addition to placental vascular complications and preterm delivery, increased rates of venous thromboembolism (VTE) have been described. HIV infection is characterized by immune activation, inflammation, and endothelial dysfunction, which contribute to the activation of coagulation and its prothrombotic consequences. Indeed, activated coagulation factors have been reported to be increased and natural anticoagulants reduced in HIV. Several mechanisms for this persistent prothrombotic balance on ART have been identified. These may include: co-infections, immune recovery, and loss of the gastrointestinal mucosal integrity with microbial translocation. In addition to the direct effects of HIV and ART, traditional venous and obstetric risk factors also contribute to the risk of VTE. A research priority has been to understand the mechanisms of VTE in HIV-infected pregnant women receiving suppressive ART and to translate this into HIV-specific thromboprophylaxis recommendations. Management requires a multidisciplinary approach and further studies are indicated to guide the prevention and management of pregnancy-associated VTE in this population. The current review describes the epidemiology, mechanisms, and management of VTE in HIV-infected women in pregnancy and the postpartum period.

Selected inflammatory and coagulation biomarkers pre-viral suppression in people with human immunodeficiency virus (HIV) infection without overt cardiovascular disease: Is there a need to redefine reference indices?

BACKGROUND: Human immunodeficiency virus (HIV) infection is prevalent in Africa and causes morbidity and mortality despite antiretroviral therapy (ART). Non-communicable complications of HIV infection include cardiovascular disease (CVD) with thromboses throughout the vascular tree. Ongoing inflammation and endothelial dysfunction in people living with HIV (PLWH) probably contribute significantly to HIV-related CVD. OBJECTIVES: A systematic review was conducted to inform interpretation of 5 biomarkers commonly measured in PLWH namely interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α), D-dimers, and soluble intracellular and vascular adhesion molecules-1 (sICAM-1 and sVCAM-1) to attempt to define a range for these values in ART naïve PLWH without overt CVD or additional comorbid diseases. METHODS: A systematic search was conducted for all studies documenting the levels of the above biomarkers in ART naïve PLWH published on the PubMed database from 1994 to 2020. RESULTS: The number of publications that reported medians above the assay values was: 4/15 for D-dimer; 0/5 for TNF-α, 8/16 for IL-6, 3/6 for sVCAM-1, and 4/5 for sICAM-1. CONCLUSION: The clinical utility of biomarkers is reduced by the lack of standardisation of the measurement of these parameters, absence of normal reference indices and the lack of uniformity of study protocols in different research centres. This review supports the ongoing use of D-dimers to predict thrombotic and bleeding events in PLWH since the weighted averages across study assays suggest that the median levels do not exceed the reference range. The role of inflammatory cytokine monitoring and measurement of endothelial adhesion markers is less clear.

Safety evaluation of the single-dose Ad26.COV2.S vaccine among healthcare workers in the Sisonke study in South Africa: A phase 3b implementation trial.

BACKGROUND: Real-world evaluation of the safety profile of vaccines after licensure is crucial to accurately characterise safety beyond clinical trials, support continued use, and thereby improve public confidence. The Sisonke study aimed to assess the safety and effectiveness of the Janssen Ad26.COV2.S vaccine among healthcare workers (HCWs) in South Africa. Here, we present the safety data. METHODS AND FINDINGS: In this open-label phase 3b implementation study among all eligible HCWs in South Africa registered in the national Electronic Vaccination Data System (EVDS), we monitored adverse events (AEs) at vaccination sites through self-reporting triggered by text messages after vaccination, healthcare provider reports, and active case finding. The frequency and incidence rate of non-serious and serious AEs were evaluated from the day of first vaccination (17 February 2021) until 28 days after the final vaccination in the study (15 June 2021). COVID-19 breakthrough infections, hospitalisations, and deaths were ascertained via linkage of the electronic vaccination register with existing national databases. Among 477,234 participants, 10,279 AEs were reported, of which 138 (1.3%) were serious AEs (SAEs) or AEs of special interest. Women reported more AEs than men (2.3% versus 1.6%). AE reports decreased with increasing age (3.2% for age 18-30 years, 2.1% for age 31-45 years, 1.8% for age 46-55 years, and 1.5% for age > 55 years). Participants with previous COVID-19 infection reported slightly more AEs (2.6% versus 2.1%). The most common reactogenicity events were headache (n = 4,923) and body aches (n = 4,483), followed by injection site pain (n = 2,767) and fever (n = 2,731), and most occurred within 48 hours of vaccination. Two cases of thrombosis with thrombocytopenia syndrome and 4 cases of Guillain-Barré Syndrome were reported post-vaccination. Most SAEs and AEs of special interest (n = 138) occurred at lower than the expected population rates. Vascular (n = 37; 39.1/100,000 person-years) and nervous system disorders (n = 31; 31.7/100,000 person-years), immune system disorders (n = 24; 24.3/100,000 person-years), and infections and infestations (n = 19; 20.1/100,000 person-years) were the most common reported SAE categories. A limitation of the study was the single-arm design, with limited routinely collected morbidity comparator data in the study setting. CONCLUSIONS: We observed similar patterns of AEs as in phase 3 trials. AEs were mostly expected reactogenicity signs and symptoms. Furthermore, most SAEs occurred below expected rates. The single-dose Ad26.COV2.S vaccine demonstrated an acceptable safety profile, supporting the continued use of this vaccine in this setting. TRIAL REGISTRATION: ClinicalTrials.gov NCT04838795; Pan African Clinical Trials Registry PACTR202102855526180.

HIV-associated thrombotic thrombocytopenic purpura (HIV-TTP): A practical guide and review of the literature.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP), a serious thrombotic microangiopathy (TMA), is prevalent in the South African HIV-infected population. The exact pathogenesis of HIV-associated TTP (HIV-TTP) is however still unclear with diagnostic and therapeutic inconsistancies. METHODS: A systematic review of the published literature regarding HIV-TTP was performed. RESULTS: HIV-TTP is still associated with significant morbidity and mortality in Africa despite the availability of anti-retroviral therpy (ART). Diagnosis of HIV-TTP requires the presence of a micro-angiopathic haemolytic anaemia with significant red blood cell schistocytes and thrombocytopenia in the absence of another TMA but background activation of the coagulation system and inflammation in HIV infected people can result in diagnostic anbiguity. Plasma therapy in the form of infusion or exchange is successful but expensive, associated with side-effects and not widely available. Adjuvant immunosuppression therapy may of benefit in patients with HIV-TTP and ART must always be optimised. Endothelial dysfunction caused by chronic inflammation and complement activation most likely contributes to the development of HIV-TTP. CONCLUSION: The role of adjuvant immunomodulating therpy, the therapeutic targets and pathogenic contribution from endothelial dysfunction in HIV-TTP requires further investigation.

Distinguishing and overlapping laboratory results of thrombotic microangiopathies in HIV infection: Can scoring systems assist?

BACKGROUND: Patients with Human Immunodeficiency Virus (HIV) infection are at risk of thrombotic microangiopathies (TMAs) notably thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC). Overlap between laboratory results exists resulting in diagnostic ambiguity. METHODS: Routine laboratory results of 71 patients with HIV-associated TTP (HIV-TTP) and 81 with DIC with concomitant HIV infection (HIV-DIC) admitted between 2015 and 2021 to academic hospitals in Johannesburg, South Africa were retrospectively reviewed. Both the PLASMIC and the International Society of Thrombosis and Haemostasis (ISTH) DIC scores were calculated. RESULTS: Patients with HIV-TTP had significantly (P < .001) increased schistocytes and features of hemolysis including elevated lactate dehydrogenase (LDH)/upper-limit-of-normal ratio (median of 9 (interquartile range [IQR] 5-12) vs 3 (IQR 2-5)) but unexpectedly lower fibrinogen (median 2.8 (IQR 2.2-3.4) vs 4 g/L (IQR 2.5-9.2)) and higher D-dimer (median 4.8 (IQR 2.4-8.1) vs 3.6 g/L (IQR 1.7-6.2)) levels vs the HIV-DIC cohort. Patients with HIV-DIC were more immunocompromised with frequent secondary infections, higher platelet and hemoglobin levels, more deranged coagulation parameters and less hemolysis. Overlap in scoring systems was however observed. CONCLUSION: The laboratory parameter overlap between HIV-DIC and HIV-TTP might reflect a shared pathogenesis including endothelial dysfunction and inflammation and further research is required. Fibrinogen in DIC may be elevated as an acute phase reactant and D-dimers may reflect the extensive hemostatic activation in HIV-TTP. Inclusion of additional parameters in TMA scoring systems such the LDH/upper-limit-of-normal ratio, schistocytes count and wider access to ADAMTS-13 testing may enhance diagnostic accuracy and ensure appropriate utilization of plasma.

Predictors of NOAC versus VKA use for stroke prevention in patients with newly diagnosed atrial fibrillation: Results from GARFIELD-AF.

INTRODUCTION: A principal aim of the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) was to document changes in treatment practice for patients with newly diagnosed atrial fibrillation during an era when non-vitamin K antagonist oral anticoagulants (NOACs) were becoming more widely adopted. In these analyses, the key factors which determined the choice between NOACs and vitamin K antagonists (VKAs) are explored. METHODS: Logistic least absolute shrinkage and selection operator regression determined predictors of NOAC and VKA use. Data were collected from 24,137 patients who were initiated on AC ±â€¯antiplatelet (AP) therapy (NOAC [51.4%] or VKA [48.6%]) between April 2013 and August 2016. RESULTS: The most significant predictors of AC therapy were country, enrolment year, care setting at diagnosis, AF type, concomitant AP, and kidney disease. Patients enrolled in emergency care or in the outpatient setting were more likely to receive a NOAC than those enrolled in hospital (OR 1.16 [95% CI: 1.04-1.30], OR: 1.15 [95% CI: 1.05-1.25], respectively). NOAC prescribing seemed to be favored in lower-risk groups, namely, patients with paroxysmal AF, normotensive patients, and those with moderate alcohol consumption, but also the elderly and patients with acute coronary syndrome. By contrast, VKAs were preferentially used in patients with permanent AF, moderate to severe kidney disease, heart failure, vascular disease, and diabetes and with concomitant AP. CONCLUSION: GARFIELD-AF data highlight marked heterogeneity in stroke prevention strategies globally. Physicians are adopting an individualized approach to stroke prevention where NOACs are favored in patients with a lower stroke risk but also in the elderly and patients with acute coronary syndrome.

Combination of acquired von Willebrand syndrome (AVWS) and Glanzmann thrombasthenia in monoclonal gammopathy of uncertain significance (MGUS), a case report.

BACKGROUND: Autoimmune paraphenomena, are associated with B-cell lymphoproliferative disorders, including monoclonal gammopathy of uncertain significance. These paraphenomena can rarely include acquired bleeding disorders. CASE PRESENTATION: This case study reports an unusual clinical presentation of 2 acquired bleeding disorders, Acquired von Willebrand syndrome (disease) and Acquired Glanzmann's thrombasthenia, in an elderly patient with monoclonal gammopathy of uncertain significance. CONCLUSIONS: Acquired bleeding disorders are often underdiagnosed and a high degree of clinical suspicion is required. The patient in this study demonstrated platelet aggregometry which was atypical for isolated Glanzmann's thrombosthenia because of the severe concomitant endogenous decrease in von Willebrand factor. There was an absence of platelet aggregation to all tested agonists including ristocetin. Once the diagnosis was made, however, the patient showed a partial response to intravenous immunoglobulin confirming the immunological pathogenesis in this case. This case highlights the need to consider acquired bleeding disorders in patients with a possible predisposing factor.

Hemoglobin glutamer-250 (bovine) in South Africa: consensus usage guidelines from clinician experts who have treated patients.

Hemopure (hemoglobin glutamer-250 [bovine]; HBOC-201) is a hemoglobin (Hb)-based oxygen carrier registered with the Medicines Control Council of South Africa. It is indicated for the treatment of adult patients who are acutely anemic, for the purpose of maintaining tissue oxygen delivery thus eliminating, delaying, or reducing the need for allogeneic red blood cells (RBCs). Hemopure is a volume expander, and circulatory volume must be carefully monitored for signs of fluid overload. Hemopure is not as effective as RBCs for restoring Hb content and concentration, but in cases of severe anemia where allogeneic blood is not an option or is unavailable, it may offer an immediate alternative for improving oxygen transport. This document provides clinical recommendations on the safe and effective use of Hemopure based on the postmarketing experience in South Africa as well as a better understanding of Hemopure properties reflected in recent publications.

Oral rivaroxaban for the treatment of symptomatic pulmonary embolism.

BACKGROUND: A fixed-dose regimen of rivaroxaban, an oral factor Xa inhibitor, has been shown to be as effective as standard anticoagulant therapy for the treatment of deep-vein thrombosis, without the need for laboratory monitoring. This approach may also simplify the treatment of pulmonary embolism. METHODS: In a randomized, open-label, event-driven, noninferiority trial involving 4832 patients who had acute symptomatic pulmonary embolism with or without deep-vein thrombosis, we compared rivaroxaban (15 mg twice daily for 3 weeks, followed by 20 mg once daily) with standard therapy with enoxaparin followed by an adjusted-dose vitamin K antagonist for 3, 6, or 12 months. The primary efficacy outcome was symptomatic recurrent venous thromboembolism. The principal safety outcome was major or clinically relevant nonmajor bleeding. RESULTS: Rivaroxaban was noninferior to standard therapy (noninferiority margin, 2.0; P=0.003) for the primary efficacy outcome, with 50 events in the rivaroxaban group (2.1%) versus 44 events in the standard-therapy group (1.8%) (hazard ratio, 1.12; 95% confidence interval [CI], 0.75 to 1.68). The principal safety outcome occurred in 10.3% of patients in the rivaroxaban group and 11.4% of those in the standard-therapy group (hazard ratio, 0.90; 95% CI, 0.76 to 1.07; P=0.23). Major bleeding was observed in 26 patients (1.1%) in the rivaroxaban group and 52 patients (2.2%) in the standard-therapy group (hazard ratio, 0.49; 95% CI, 0.31 to 0.79; P=0.003). Rates of other adverse events were similar in the two groups. CONCLUSIONS: A fixed-dose regimen of rivaroxaban alone was noninferior to standard therapy for the initial and long-term treatment of pulmonary embolism and had a potentially improved benefit-risk profile. (Funded by Bayer HealthCare and Janssen Pharmaceuticals; EINSTEIN-PE ClinicalTrials.gov number, NCT00439777.).

The impact of risk assessment on the implementation of venous thromboembolism prophylaxis in foot and ankle surgery.

BACKGROUND: The purpose of this prospective study was to determine whether the more frequently quoted procedure and patient specific risk factors have any impact in the implementation of venous thromboembolism (VTE) prophylaxis following foot and ankle surgery. METHODS: Two hundred and sixteen patients were included in the study. A variety of operative procedures was carried out with the common denominator being a below knee cast for at least 4 weeks and nonweightbearing for an average of 6 weeks in 130 patients. The remainder of the patients (88) had hallux surgery not requiring a cast and were allowed to weightbear. No patient received any form of thromboprophylaxis postoperatively. All patients were subjected to compression ultrasonography for deep vein thrombosis (DVT) between 2 and 6 weeks postoperatively. RESULTS: There was a 5.09% incidence of VTE (0.9% pulmonary embolism) overall. As no VTE (neither DVT nor pulmonary embolus) developed in the hallux subgroup, i.e. patients not requiring immobilization and were allowed to weightbear, the incidence of VTE in the cast/nonweightbearing group was 8.46%. The results are descriptive and only statistically analyzed where possible, as the sample size of the VTE group was small. There was no significant difference in number of risk factors and no association between gender in the VTE and non VTE groups. 90.9% of patients in the VTE group had a total risk factor score of 5 or more and 73.7% of patients in the non VTE group had a total risk factor score of 5 or more. The average timing to the diagnosis of VTE in this current study was 33.1 days. CONCLUSIONS: In view of the unacceptable incidence of VTE and the average total risk factor score of 5 or more (for which thromboprophylaxis is recommended) in the majority of the patients, the authors feel that the routine use of thromboprophylaxis in foot and ankle surgery requiring nonweightbearing in combination with short leg cast immobilization, is warranted. This prophylaxis should continue until the patient regains adequate mobility either by weightbearing (in or out of the cast) or removal of cast immobilization (weightbearing or nonweightbearing), usually between 28 and 42 days.

Anti-Xa Monitoring of Apixaban (ZyQuis) in Venous Thrombo-Embolism and Atrial Fibrillation.

Apixaban is a direct oral Xa inhibitor and is indicated for the treatment of venous thrombo-embolism (VTE) and prevention of stroke in atrial fibrillation (AF). Recently, a generic (ZyQuis, Zydus Lifesciences Limited, India) has received Food and Drug Administration approval. While bioequivalence has been demonstrated with Eliquis (Bristol-Myers Squibb/Pfizer, UK), it is necessary to monitor its effectiveness prior to acceptance in medical practice. This prospective study independently evaluated Apixaban (ZyQuis) at two accredited laboratories. Participants were converted from Warfarin or Rivaroxaban to Apixaban 5 mg bd for a duration of one month. Peak anti-Xa levels were measured 3-4 h post the morning dose. The samples were processed on the Atellica COAG 360 (Siemens Healthineers, Marburg, Germany) analyzers with a chromogenic anti-Xa assay (Innovance, reference interval 69-321 ng/mL). There were 26 participants; 5 men, 21 women; mean ± standard deviation age of 46 ± 12 years. Indications for anticoagulation included: VTE (88.5%) and AF (11.5%). 69.2% of the participants had at least one comorbidity. 96.2% of the anti-Xa levels were within the laboratory's 95% reference interval. Mean anti-Xa activity was 191 ± 69 ng/mL and 186 ± 68 ng/mL measured at respective laboratories. Mean differences in anti-Xa measurements represented by Bland-Altman statistics were small (bias of -2.6%, 95% confidence interval -1.11 to -4.09) and a strong correlation was observed on Deming regression analysis (0.995). Apixaban (ZyQuis) was effective for the management of VTE and AF as evidenced by anti-Xa activity.

Impact of patient selection in clinical trials: application of ROCKET AF and ARISTOTLE criteria in GARFIELD-AF.

BACKGROUND: The extent to which differences in results from Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) and Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial (ROCKET) atrial fibrillation (AF)-the landmark trials for the approval of apixaban and rivaroxaban, respectively, for non-valvular AF-were influenced by differences in their protocols is debated. The potential influence of selection criteria on trial results was assessed by emulating these trials in data from the Global Anticoagulant Registry in the Field (GARFIELD)-AF registry. METHODS: Vitamin K antagonist (VKA) and non-vitamin K oral antagonist (NOAC) users from GARFIELD-AF were selected according to eligibility for the original ARISTOTLE or ROCKET AF trials. A propensity score overlap weighted Cox model was used to emulate trial randomisation between treatment groups. Adjusted HRs for stroke or systemic embolism (SE) within 2 years of enrolment were calculated for each NOAC versus VKA. RESULTS: Among patients on apixaban, rivaroxaban and VKA, 2570, 3560 and 8005 were eligible for ARISTOTLE, respectively, and 1612, 2005 and 4368, respectively, for ROCKET AF. When selecting for ARISTOTLE criteria, apixaban users had significantly lower stroke/SE risk versus VKA (HR 0.57; 95% CI 0.34 to 0.94) while no reduction was observed with rivaroxaban (HR 0.98; 95% CI 0.68 to 1.40). When selecting for ROCKET AF criteria, safety and efficacy versus VKA were similar across the NOACs. CONCLUSION: Apixaban and rivaroxaban showed similar results versus VKA in high-risk patients selected according to ROCKET AF criteria, whereas differences emerged when selecting for the more inclusive ARISTOTLE criteria. Our results highlight the importance of trial selection criteria in interpreting trial results and underline the problems faced in comparing treatments across rather than within clinical trials.

Safety of a second homologous Ad26.COV2.S vaccine among healthcare workers in the phase 3b implementation Sisonke study in South Africa.

The Sisonke 2 study provided a homologous boost at least 6 months after administration of the priming dose of Ad26.COV2.S for healthcare workers enrolled on the Sisonke phase 3b implementation study. Safety monitoring was via five reporting sources: (i.) self-report through a web-link; (ii.) paper-based case report forms; (iii.) a toll-free telephonic reporting line; (iv.) healthcare professionals-initiated reports; and (v.) active linkage with National Disease Databases. A total of 2350 adverse events were reported by 2117 of the 240 888 (0.88%) participants enrolled; 1625 of the 2350 reported events are reactogenicity events and 28 adverse events met seriousness criteria. No cases of thrombosis with thrombocytopaenia syndrome were reported; all adverse events including thromboembolic disorders occurred at a rate below the expected population rates apart from one case of Guillain Barre Syndrome and one case of portal vein thrombosis. The Sisonke 2 study demonstrates that two doses of Ad26.COV2.S is safe and well tolerated; and provides a feasible model for national pharmacovigilance strategies for low- and middle-income settings.

Vascular thrombosis after single dose Ad26.COV2.S vaccine in healthcare workers in South Africa: open label, single arm, phase 3B study (Sisonke study).

Objective: To assess the rates of vascular thrombotic adverse events in the first 35 days after one dose of the Ad26.COV2.S vaccine (Janssen/Johnson & Johnson) in healthcare workers in South Africa and to compare these rates with those observed in the general population. Design: Open label, single arm, phase 3B study. Setting: Sisonke study, South Africa, 17 February to 15 June 2021. Participants: The Sisonke cohort of 477 234 healthcare workers, aged ≥18 years, who received one dose of the Ad26.COV2.S vaccine. Main outcome measures: Observed rates of venous arterial thromboembolism and vaccine induced immune thrombocytopenia and thrombosis in individuals who were vaccinated, compared with expected rates, based on age and sex specific background rates from the Clinical Practice Research Datalink GOLD database (database of longitudinal routinely collected electronic health records from UK primary care practices using Vision general practice patient management software). Results: Most of the study participants were women (74.9%) and median age was 42 years (interquartile range 33-51). Twenty nine (30.6 per 100 000 person years, 95% confidence interval 20.5 to 44.0) vascular thrombotic events occurred at a median of 14 days (7-29) after vaccination. Of these 29 participants, 93.1% were women, median age 46 (37-55) years, and 51.7% had comorbidities. The observed to expected ratios for cerebral venous sinus thrombosis with thrombocytopenia and pulmonary embolism with thrombocytopenia were 10.6 (95% confidence interval 0.3 to 58.8) and 1.2 (0.1 to 6.5), respectively. Because of the small number of adverse events and wide confidence intervals, no conclusions were drawn between these estimates and the expected incidence rates in the population. Conclusions: Vaccine induced immune thrombocytopenia and thrombosis after one dose of the Ad26.COV2.S vaccine was found in only a few patients in this South African population of healthcare workers. These findings are reassuring if considered in terms of the beneficial effects of vaccination against covid-19 disease. These data support the continued use of this vaccine, but surveillance is recommended to identify other incidences of venous and arterial thromboembolism and to improve confidence in the data estimates. Trial registration: ClinicalTrials.gov NCT04838795.

Enoxaparin for symptomatic COVID-19 managed in the ambulatory setting: An individual patient level analysis of the OVID and ETHIC trials.

BACKGROUND: Antithrombotic treatment may improve the disease course in non-critically ill, symptomatic COVID-19 outpatients. METHODS: We performed an individual patient-level analysis of the OVID and ETHIC randomized controlled trials, which compared enoxaparin thromboprophylaxis for either 14 (OVID) or 21 days (ETHIC) vs. no thromboprophylaxis for outpatients with symptomatic COVID-19 and at least one additional risk factor. The primary efficacy outcome included all-cause hospitalization and all-cause death within 30 days from randomization. Both studies were prematurely stopped for futility. Secondary efficacy outcomes were major symptomatic venous thromboembolic events, arterial cardiovascular events, or their composite occurring within 30 days from randomization. The same outcomes were assessed over a 90-day follow-up. The primary safety outcome was major bleeding (ISTH criteria). RESULTS: A total of 691 patients were randomized: 339 to receive enoxaparin and 352 to the control group. Over 30-day follow-up, the primary efficacy outcome occurred in 6.0 % of patients in the enoxaparin group vs. 5.8 % of controls for a risk ratio (RR) of 1.05 (95%CI 0.57-1.92). The incidence of major symptomatic venous thromboembolic events and arterial cardiovascular events was 0.9 % vs. 1.8 %, respectively (RR 0.52; 95%CI 0.13-2.06). Most cardiovascular thromboembolic events were represented by symptomatic venous thromboembolic events, occurring in 0.6 % vs. 1.5 % of patients, respectively. A similar distribution of outcomes between the treatment groups was observed over 90 days. No major bleeding occurred in the enoxaparin group vs. one (0.3 %) in the control group. CONCLUSIONS: We found no evidence for the clinical benefit of early administration of enoxaparin thromboprophylaxis in outpatients with symptomatic COVID-19. These results should be interpreted taking into consideration the relatively low occurrence of events.

Profile of antiphospholipid antibodies in HIV-infected and HIV-uninfected women with a history of thrombosis.

INTRODUCTION: Increased antiphospholipid antibodies (aPL) have been described in human immunodeficiency virus (HIV) infection. However, the association between aPL and the increased risk of thrombosis in HIV requires further clarification. METHODS: We reviewed the medical records of 215 consecutive women with a history of thrombosis and/or obstetric complications (158 HIV-uninfected and 57 HIV-infected) between July 2017 and March 2021. Participants (n = 215) without clinical criteria manifestations for antiphospholipid syndrome were included as matched controls. Testing for lupus anticoagulant (LAC), anticardiolipin (aCL) and anti-beta2-glycoprotein1 (aß2GP1) IgM and IgG was performed. RESULTS: Thirty-two (10.1%) HIV-uninfected and 15 (13.2%) HIV-infected participants were positive at baseline for one of the five criteria aPL, with no statistically significant difference. The profile of the HIV-infected participants with thrombosis (n = 11) included LAC in 15.8%, aCL IgG in 3.5% and aß2GP1 IgG in 1.8%. In contrast, the HIV-infected controls (n = 4), included aCL IgM in 1.8% and aß2GP1 IgM in 5.3%. Only LAC was significantly associated with thrombosis (p < 0.003). On repeat testing, in a HIV-infected sub-population, 2/7 with thrombosis were positive, while 3/3 controls tested negative. CONCLUSION: In contrast to earlier reports, the prevalence and expression of aPL in HIV-infected women with a history of thrombosis in the present study, in the era of antiretroviral therapy, were similar to HIV-uninfected women. Baseline LAC positivity was associated with a significantly increased risk for thrombosis in HIV. Future studies are recommended to explore additional coagulation abnormalities in HIV.

D-dimers in omicron versus delta: A retrospective analysis.

Background: Infection with SARS-CoV-2 has shown to cause an increase in D-dimers, which correlate with severity and prognosis for in-hospital mortality. The B.1.617.2 (delta) variant is known to cause a raised D-dimer level, with data on D-dimers in the B.1.1.529 (omicron) variant being scarce. Objectives: To determine the effect of age, gender and SARS-CoV-2 variant on the D-dimer in South Africans admitted to tertiary medical centres from May 2021 to December 2021. Method: The study was performed retrospectively on 16 010 adult patients with a SARS-CoV-2 infection. Age, gender, SARS-CoV-2 PCR and D-dimer levels on admission were collected from two national laboratories. Admissions from 01 May 2021 to 31 October 2021 were classified as B.1.617.2, whereas admissions from 01 November 2021 to 23 December 2021 were classified as B.1.1.529 infections. Results: Omicron infections had a median D-dimer level of 0.54 µg/mL (95% CI: 0.32, 1.08, p < 0.001). Multivariable regression analysis showed that infection with omicron had a 34.30% (95% CI: 28.97, 39.23) reduction in D-dimer values, compared with delta infections. Middle aged, aged and aged over 80 years had D-dimer results greater than the adult baseline (42.6%, 95% CI: 38.0, 47.3, 124.6%, 95% CI: 116.0, 133.7 and 216.1%, 95% CI: 199.5, 233.3). Males on average had a 7.1% (95% CI: 4.6, 9.6) lower D-dimer level than females. Conclusion: Infection with the B.1.1.529 variant, compared with B.1.617.2 variant, had significantly lower D-dimer levels, with age being a more significant predictor of D-dimer levels, than gender and SARS-CoV-2 variant of infection. Contribution: This study provides novel insight into the hypercoagulable impact of various SARS-CoV-2 variants, which can guide the management of patients.