Thrombotic events following Covid-19 vaccines compared to Influenza vaccines.

IMPORTANCE: The actual risk of thrombotic events after Covid-19 vaccination is unknown. OBJECTIVE: To evaluate the risk of thrombotic events after Covid-19 vaccination. DESIGN: Retrospective cohort study which included consecutive adult patients vaccinated with the first dose of Covid-19 vaccine between January 1 and May 30, 2021, and a historic control group, defined as consecutive patients vaccinated with influenza vaccine between March 1 and July 30, 2019. SETTING: Hospital Italiano de Buenos Aires, a tertiary hospital in Argentina. PARTICIPANTS: Non-Hospitalized Adults vaccinated with the first dose of a Covid-19 vaccine. EXPOSURE: Vaccination with Covid-19 vaccines available during the study period: Gam-COVID-Vac (Sputnik), ChAdOx1 nCoV-19 (AstraZeneca/Oxford or Covishield), BBIBP-CorV (Beijing Institute of Biological Products) (Sinopharm). Active comparator group exposure was Influenza vaccine. MAIN OUTCOME: Primary endpoint was cumulative incidence of any symptomatic thrombotic event at 30 days, defined as the occurrence of at least one of the following: symptomatic acute deep venous thrombosis (DVT); symptomatic acute pulmonary embolism (PE); acute ischemic stroke (AIS); acute coronary syndrome (ACS) or arterial thrombosis. RESULTS: From a total of 29,985 adult patients who received at least a first dose of Covid-19 vaccine during study period and 24,777 who received Influenza vaccine in 2019, we excluded those who were vaccinated during hospitalization. We finally included 29,918 and 24,753 patients respectively. Median age was 73 years old (IQR 75-81) and 67% were females in both groups. Thirty six subjects in the Covid-19 vaccination group (36/29,918) and 15 patients in the Influenza vaccination group (15/24,753) presented at least one thrombotic event. The cumulative incidence of any thrombotic event at 30 days was 12 per 10,000 (95%CI 9-17) for Covid-19 group and 6 per 10,000 (95%CI 4-10) for Influenza group (p-value=0.022). CONCLUSIONS AND RELEVANCE: This study shows a significant increase in thrombotic events in subjects vaccinated with Covid-19 vaccines in comparison to a control group. The clinical implication of these findings should be interpreted with caution, in light of the high effectiveness of vaccination and the inherent risk of thrombosis from Covid-19 infection itself.

Predictors of recurrence of venous thromboembolic disease after discontinuing of anticoagulation: a prospective cohort study. / Predictores de recurrencia de enfermedad tromboembólica venosa post suspensión de anticoagulación: estudio de cohorte prospectiva.

OBJECTIVE: We aim to evaluate factors associated with the recurrence of thromboembolic episodes among patients with a first episode of venous thromboembolic disease during anticoagulation treatment and at least one year after treatment suspension. METHODS: A prospective cohort of patients with a first episode of deep vein thrombosis confirmed by Doppler ultrasound and initiated anticoagulation treatment. Participants were registered in the Institutional Registry of Thromboembolic Disease between June 2015 and March 2019. Patients with cancer, with permanent inferior vena cava filter implant, and those who refused to participate or did not provide informed consent were excluded. All patients were evaluated within treatment at 30 days and at least one year after the suspension of anticoagulation with a D-dimer study and an ultrasound. All patients were evaluated for recurrence, bleeding (major and minor), and death. RESULTS: A total of 304 patients were recruited during the study period. Seventy-three percent were female, and the median age was 80 years. The rate of recurrence rate during anticoagulation treatment was 5% (N = 16/303; 95% confidence interval: 3 to 8), and 5% during post-suspension follow-up (N = 11/202; 95%CI: 3 to 9). The overall bleeding rate was 13% (N = 39; 95%CI: 9 to 17), and 5% for major bleeding. Patients who recurred had higher basal D-dimer mean, higher neutrophils and monocytes, and a higher prevalence of age-adjusted D-dimer ratio greater than 0.5 before discontinuation. In addition, they more frequently had complete leg involvement by ultrasound and received a shorter treatment. CONCLUSIONS: Although some baseline and pre-suspension parameters had a higher recurrence incidence, statistical significance was not reached, probably due to small statistical power and a short-term follow-up.

OBJETIVO: Evaluar factores asociados a la recurrencia de episodios tromboembólicos en pacientes con un primer evento de enfermedad tromboembólica venosa intra-tratamiento, al año de suspendida la anticoagulación. MÉTODO: Cohorte prospectiva con todos los pacientes consecutivos con un primer episodio de trombosis venosa profunda confirmado por eco Doppler, que iniciaron tratamiento anticoagulante incluidos en el Registro Institucional de Enfermedad Tromboembólica, entre junio de 2015 y marzo de 2019. Se excluyeron los pacientes con cáncer, con implante de filtro de vena cava inferior permanente y quienes se negaron a participar o no entregaron el consentimiento informado. Todos los pacientes fueron evaluados a los 30 días, pre-suspensión de anticoagulación con estudio de dímero D y la realización de una ecografía, y al menos un año de suspendida la anticoagulación. Todos los pacientes fueron evaluados para recurrencia, sangrado (mayor y menor) y muerte. RESULTADOS: Se reclutó a 304 pacientes durante el periodo de estudio. La tasa de recurrencia durante la anticoagulación fue de 5% (N = 16/303; intervalo de confianza 95%: 3 a 8), y durante el seguimiento post suspensión fue también 5% (N = 11/220; 95%: 2 a 9). La tasa de sangrado global fue del 13% (N = 39; 95%: 9 a 17), siendo mayor del 5% para sangrado. Los pacientes que recurrieron tenían una media más elevada de dímero D, neutrófilos, monocitos basales y mayor prevalencia de razón de dímero D ajustada por edad mayor a 0,5 previo a la suspensión. Además, presentaban más afectación de la pierna completa por ecografía y recibieron tratamiento anticoagulante de menor duración. CONCLUSIÓN: Si bien algunos parámetros basales y pre-suspensión dieron valores más altos, no se alcanzó significación estadística, probablemente debido al tamaño muestral y a la baja tasa de recurrencia post suspensión asociada al corto seguimiento.

Acquired factor XIII deficiency in patients under therapeutic plasma exchange: A poorly explored etiology.

INTRODUCTION: Factor XIII (FXIII) deficiency may cause bleeding under certain clinical circumstances. Therapeutic plasma exchange (TPE) may lead to a transient deficiency. OBJECTIVES: To describe the clinical evolution of patients with acquired FXIII deficiency secondary to TPE. METHODS: We respectively studied a cohort of consecutive patients from 2014 to 2019 who were treated with TPE with FXIII levels <50%. The FXIII was measured after the start of the TPE course, on days between the TPE sessions, due to suspected acquired deficiency. All TPE were performed using continuous flow cell separator. In all cases, the initial replacement fluid applied was albumin. Apheresis procedures were held at 24to 48 hours intervals. RESULTS: Eighteen patients were included, 13 of them were recipients of kidney transplants. The main TPE prescription was humoral rejection. Median FXIII at diagnosis (measured on days between sessions of the TPE course) was 19%(IQR17-25). The median of apheresis procedures before measurement of FXIII was 3(IQR2-4). Among the total cohort, 10 patients suffered hemorrhages. None of the patients without history of kidney transplants had bleeding (n = 5), however, 10/13 with kidney transplants did. Five kidney transplant patients received therapy with FXIII concentrate because of life-threatening bleeding. In all cases, the bleeding stopped within the first 24 hours. All patients had their FXIII levels measured again after finishing the TPE course, with normal results. CONCLUSIONS: TPE is an under-diagnosed cause of acquired FXIII deficiency since routine coagulation tests remain unaltered. It might cause major bleeding, particularly in patients with a recent history of surgery like kidney transplants.

Nonimmune-acquired factor XIII deficiency: a cause of high volume and delayed postoperative hemorrhage.

: Factor XIII (FXIII) levels may decrease because of surgical consumption. Acquired FXIII deficiency could be a cause of postoperative hemorrhage usually underdiagnosed in clinical practice. To determine the diagnosis confirmation rate of acquired FXIII deficiency in postsurgical patients with clinical suspicion and to compare the characteristics and evolution of patients with or without FXIII deficiency. We performed a retrospective cohort study, which included 49 inpatients who were attended at our university hospital from 2014 to 2018 with suspicion of acquired FXIII deficiency because of disproportionate postoperative hemorrhage. FXIIIA levels less than 50% was considered a deficiency. Persistence of bleeding for more than 48 h, drop in hematocrit points, red blood cells transfused units, hemoglobin levels 12-36 h after bleeding, and time elapsed from the procedure to the bleeding were assessed as outcome variables. Logistic regression was employed for both univariate and multivariate analyses. Of the 49 patients included, 27(55%) had FXIII deficiency, with a median level of 34% [interquartile range (IQR) 19-42]. Abdominal surgery was the most common [n = 21 (43%)]. All patients had routine coagulation tests within the hemostatic range. FXIII deficiency was associated with a drop of more than 4 points in hematocrit [OR 59.69 (95% CI 4.71-755.30)], red blood transfused units >2 [OR 45.38 (95% CI 3.48-590.65)], and delayed bleeding >36 h after surgery [OR 100.90 (95% CI 3.78-2695.40)]. Plasma-derived FXIII concentrate was administered to eight patients with life-threatening bleeding with resolution within 24 h. Only one deficient patient died from bleeding. FXIII levels were measured 15 days after diagnosis or more in 20 out of 27 deficient patients, with normal results. Acquired FXIII deficiency may be a frequent underdiagnosed entity that should be considered when high-volume and delayed postoperative hemorrhage is present in patients with hemostatic routine coagulation test results.