Factor XII Deficiency in Mexico: High Prevalence in the General Population and Patients with Venous Thromboembolic Disease.

INTRODUCTION: Thrombosis is one of the leading causes of morbidity and mortality worldwide. Venous thromboembolic disease (VTD) is considered a new epidemic. FXII deficiency is supposed to be a cause of thrombosis. To search for unknown causes of thrombosis in our population, our aim was to determine if FXII deficiency can be considered a risk factor for VTD. METHODS: Young adult Mexican patients with at least one VTD episode and healthy controls were included in this prospective, observational, controlled study. Liver and renal function tests, blood cytometry, and blood coagulation assays were performed. Plasma FXII activity and its concentration were evaluated. RESULTS: Over a two-year period, 250 patients and 250 controls were included. FXII activity was significantly lower in the control group compared to patients with VTD (p = 0.005). However, percentage of patients and controls with FXII deficiency was 8.8 and 9.2%, respectively (p = 1.000). No significant association was found between FXII deficiency and VTD (p = 1.0). FXII plasma concentration was lower in controls vs. patients with VTD: 4.05 vs. 6.19 ng/mL (p <0.001). Percentage of patients with low FXII plasma concentration was 1.6% and 6.0% in patients and controls, respectively (p = 0.010). CONCLUSIONS: FXII deficiency is a frequent finding in patients with VTD and controls in Mexico. Some patients with FXII deficiency had normal APTT result, an effect not described above. FXII plasma concentration was lower in patients with low activity.

Abo Blood Group, Atherothrombotic Comorbidities, and COVID-19: A Case-Control Study of their Association in the Mexican Population.

BACKGROUND: COVID-19 has been associated with negative results in patients with A blood group and with a better evolution in O blood group individuals. AIM: Because the evidence regarding ABO blood groups and COVID was empirically not that clear in our country, we tested the association regarding COVID-19 and blood groups. MATERIAL AND METHODS: Adult patients were enrolled in this prospective, case-control, observational multicenter study. Patients with a confirmed diagnosis of COVID-19 were assigned to one of three groups based on the clinical presentation of the infection. Age, gender, ABO and Rh blood groups, body mass index, history of diabetes mellitus or high blood pressure, and smoking were recorded directly or from their clinical charts. ABO blood group was obtained from 5,000 blood donors (50% each gender). Atherothrombotic variables were compared with a nation-wide data collection. RESULTS: A total of 2,416 patients with COVID-19 were included (women:39.6%; men:60.4%). There were no significant differences between cases and controls in terms of age. O blood group was the most frequently found in healthy donors and COVID-19 patients, but this blood group was significantly higher in COVID-19 patients vs. healthy donors. ABO blood group was not associated with the final health status in COVID-19 patients. Obesity, diabetes mellitus, hypertension and smoking were significantly more frequent among COVID-19 patients. CONCLUSION: The proposed protective effect of the O blood group in COVID-19 patients could not be reproduced in the Mexican population while some atherothrombotic risk factors had a significant effect on the clinical evolution.

Analysis of the quality of anticoagulation with vitamin K antagonists in three clinical scenarios in Mexico.

INTRODUCTION: Vitamin K antagonists (VKA) are a therapeutic alternative in patients with venous thromboembolic disease; however, numerous factors affect their pharmacology. OBJECTIVE: To evaluate the quality of VKA anticoagulation at three different time periods in Mexico. METHODS: Prospective study, nested in patient cohorts at three different clinical scenarios between 2013 and 2019. Outpatients with indication for treatment with VKAs for at least 12 months were included. Patients were managed according to the criteria of the treating physician. RESULTS: Patient general characteristics were similar between groups, except for the VKA indication. The results of 4,148 patients and 38,548 INR assessments were analyzed. The times in therapeutic range during the three phases of the study and pooled data were significantly higher for the anticoagulation clinic. Only the number of patient visits was significantly associated with the results, unlike age, gender, and type of VKA. CONCLUSIONS: VKAs are widely used, but it is difficult for therapeutic goals to be achieved, especially in non-specialized clinical services. Creation of anticoagulation clinics is an urgent need for the Mexican health system.

INTRODUCCIÓN: Los antagonista de la vitamina K (AVK) son una alternativa terapéutica en los pacientes con enfermedad tromboembólica venosa; sin embargo, numerosos factores afectan su farmacología. OBJETIVO: Evaluar la calidad de la anticoagulación AVK durante tres diferentes periodos en México. MÉTODOS: Estudio prospectivo, anidado en cohortes de pacientes en tres escenarios clínicos entre los años 2013-2019. Se incluyeron pacientes no hospitalizados con indicación para recibir AVK por al menos 12 meses, quienes fueron manejados de acuerdo con el criterio del médico tratante. RESULTADOS: Las características generales de los pacientes fueron similares entre los grupos, excepto por la indicación para usar los AVK. Se analizaron los resultados de 4148 pacientes y 38 548 evaluaciones de INR. Los tiempos en rango terapéutico durante las tres fases del estudio y los datos acumulados fueron significativamente mayores en la clínica de anticoagulación. Solo el número de visitas de control de los pacientes se asoció significativamente con los resultados, a diferencia de la edad, el sexo y el tipo de AVK. CONCLUSIONES: Los AVK se utilizan ampliamente, pero es difícil alcanzar la meta terapéutica, sobre todo en servicios clínicos no especializados. La creación de clínicas de anticoagulación es una necesidad urgente en el sistema mexicano de salud.

Análisis de la calidad de la anticoagulación con antagonistas de la vitamina K en tres escenarios clínicos en México / Analysis of the quality of anticoagulation with vitamin K antagonists in three clinical scenarios in Mexico

Resumen Introducción: Los antagonista de la vitamina K (AVK) son una alternativa terapéutica en los pacientes con enfermedad tromboembólica venosa; sin embargo, numerosos factores afectan su farmacología. Objetivo: Evaluar la calidad de la anticoagulación AVK durante tres diferentes periodos en México. Métodos: Estudio prospectivo, anidado en cohortes de pacientes en tres escenarios clínicos entre los años 2013-2019. Se incluyeron pacientes no hospitalizados con indicación para recibir AVK por al menos 12 meses, quienes fueron manejados de acuerdo con el criterio del médico tratante. Resultados: Las características generales de los pacientes fueron similares entre los grupos, excepto por la indicación para usar los AVK. Se analizaron los resultados de 4148 pacientes y 38 548 evaluaciones de INR. Los tiempos en rango terapéutico durante las tres fases del estudio y los datos acumulados fueron significativamente mayores en la clínica de anticoagulación. Solo el número de visitas de control de los pacientes se asoció significativamente con los resultados, a diferencia de la edad, el sexo y el tipo de AVK. Conclusiones: Los AVK se utilizan ampliamente, pero es difícil alcanzar la meta terapéutica, sobre todo en servicios clínicos no especializados. La creación de clínicas de anticoagulación es una necesidad urgente en el sistema mexicano de salud.

Abstract Introduction: Vitamin K antagonists (VKA) are a therapeutic alternative in patients with venous thromboembolic disease; however, numerous factors affect their pharmacology. Objective: To evaluate the quality of VKA anticoagulation at three different time periods in Mexico. Methods: Prospective study, nested in patient cohorts at three different clinical scenarios between 2013 and 2019. Outpatients with indication for treatment with VKAs for at least 12 months were included. Patients were managed according to the criteria of the treating physician. Results: Patient general characteristics were similar between groups, except for the VKA indication. The results of 4,148 patients and 38,548 INR assessments were analyzed. The times in therapeutic range during the three phases of the study and pooled data were significantly higher for the anticoagulation clinic. Only the number of patient visits was significantly associated with the results, unlike age, gender, and type of VKA. Conclusions: VKAs are widely used, but it is difficult for therapeutic goals to be achieved, especially in non-specialized clinical services. Creation of anticoagulation clinics is an urgent need for the Mexican health system.

Effects of Rivaroxaban on Platelet Aggregation.

Rivaroxaban is a direct oral anti-factor Xa anticoagulant. It has recently been suggested that rivaroxaban may affect platelet function in vitro; however, little is known about the clinical impact of this likely antiplatelet effect and whether this probable phenomenon is dose-dependent. Our aim was to determine whether rivaroxaban at 4 different doses inhibits direct platelet aggregation. We included adult patients of both sexes and who were allocated to one of the following groups depending on the prescribed daily dose of rivaroxaban: 5, 10, 15, and 20 mg. In 80 patients (20 patients/group), the percentage of platelet aggregation was determined by means of platelet aggregometry tests before and after rivaroxaban use. Basal samples were obtained before starting rivaroxaban and 1 month after treatment, both 2 and 24 hours after the last dose of the drug (12 hours after in the case of rivaroxaban 5 mg). We used 5 platelet agonists: adenosine diphosphate, epinephrine, arachidonic acid, collagen, and thrombin. There were no significant changes in the percentage of platelet aggregation before and after rivaroxaban use independently of the dose administered and the agonist used. Our results have clearly shown that rivaroxaban, even at a high dose, does not directly affect platelet aggregation.

von Willebrand Disease and other hereditary haemostatic factor deficiencies in women with a history of postpartum haemorrhage.

INTRODUCTION: Postpartum haemorrhage (PPH) is the main cause of maternal morbidity and mortality globally, but it is far more important in non-developed countries. PPH represents 25% of all maternal deaths worldwide. Women with von Willebrand disease (VWD) and other inherited haemorrhagic disorders are at increased risk of PPH. Our aim was to establish a probable association of severe PPH in women with a history of haemostatic abnormalities. METHODS: An observational, controlled study of adult women with a one or more episodes of severe PPH requiring treatment in an intensive care unit or >10 units of blood products during the 24-hour period after diagnosis and their controls. The tests performed were blood cell count, blood group, renal, viral, liver function and haemostatic tests, fibrinogen, activity of the plasma factors and specific test to diagnose and classify VWD. RESULTS: We included 124 women with 133 PPH events and their controls. The median age at the first event was 25.5 years old. Results were significantly different between the groups in terms of fibrinogen concentration, VWF:Ag, VWF:RCo and FVIII. A specific diagnosis was established in 69 (55.6) and 4 (3.2%) patients in the PPH group and controls, respectively. Of 61 patients with VWD, 57 had type 1, two had type 2A, and another two had type 2B. CONCLUSION: Our results show a relationship between PPH and inherited haemostatic disorders. VWD was the most frequent diagnosis. Appropriate and opportune diagnosis before pregnancy of inherited haemostatic disorders may be important to effectively prevent and treat PPH.

Impact of Classical Risk Factors for Arterial or Venous Thrombosis in Patients With Antiphospholipid Syndrome.

There are classical risk factors associated with arterial thrombosis (AT) or venous thromboembolic disease (VTD). However, less is known about these risk factors and AT or VTD episodes in patients with antiphospholipid syndrome (APS). Our aim was to elucidate whether APS-related thrombotic episodes are associated with the same risk factors as the non-APS population. We gathered demographics, medical history, complications, and causes of death associated with the risk factors for AT or VTD in patients with APS. We analyzed 677 thrombotic events in 386 patients. Type 2 diabetes mellitus and grade 3 obesity were associated with VTD instead of AT. There were no significant differences between the groups for almost all laboratory tests analyzed, although lupus anticoagulant was significantly higher in the VTD group. We suggest that thrombosis in APS is due to the APS itself and that the risks factors for AT or VTD do not have a main role. Our findings may have an ethnical background. Therefore, it may be difficult to elaborate predictive thrombotic clinical scores applicable to patients with different ethnical background.

Safety of the oral methionine load test: effects on the clinical performance and laboratory tests.

INTRODUCTION: Hyperhomocysteinemia is a prothrombotic risk factor. Homocysteine is evaluated during fasting and after an oral methionine load (OML). AIM: To determine the safety of the OML test according to the general performance status and clinical laboratory tests. We studied healthy nonsmoking volunteers and patients with several thrombotic conditions. Before and after receiving an OML, blood samples were obtained to perform several laboratory tests. We also evaluated acute and subacute adverse effects and 30-day associated morbidity and mortality. Of 353 individuals, three were eliminated because they did not tolerate the OML. We studied 175 healthy individuals and 175 patients without age differences. After OML, mild to moderate clinical abnormalities were recorded in 78 subjects (22.1%): nausea (n = 69; 88.5%), dizziness (n = 13; 16.7%) and decreased or increased blood pressure (n = 8; 10.2%). Nausea always disappeared after breakfast in affected individuals. Prevalence of complications was similar in patients and controls. No patient required hospitalization and there was no mortality during the 30-day study period. In conclusion, OML test had no significant undesirable effects on the clinical status or the general laboratory tests of patients and healthy controls. Some mild and moderate symptoms associated with OML tests were observed, and OML test did not negatively affect general laboratory tests. OML test is a safe diagnostic procedure in patients with previous thrombotic events (and with the consequent associated risk factors such as diabetes mellitus or dyslipidemia) and in healthy subjects.

Activated protein C resistance and factor V Leiden in Mexico.

A common cause of hereditary thrombophilia is activated protein C resistance (APCR), and most cases result from factor V Leiden mutation. An APCR phenotype without association with factor V Leiden has been described. This transversal, observational, nonrandomized study evaluated these 2 phenomena in healthy indigenous and mestizo Mexican subjects (n = 4345), including 600 Mexican natives. No indigenous subjects had APCR, but 82 mestizo subjects did. After retesting, 50 subjects had a negative test. The remaining 32 subjects had factor V Leiden, giving a 0.85% prevalence of factor V Leiden in the mestizo Mexican population. Only 31% of APCR carriers had factor V Leiden. These results show a very low prevalence of APCR and factor V Leiden in Mexico. Except for factor V Leiden, there are no other mutations in the factor V gene responsible for the APCR phenotype. Acquired APCR is nearly twice as prevalent as the inherited variant.

Effect of combined administration of clopidogrel and lysine acetylsalicylate versus clopidogrel and aspirin on platelet aggregation and activated GPIIb/IIIa expression in healthy volunteers.

Platelet activation contributes to thrombotic events in cardiovascular disease. Acetylsalicylic acid (ASA) is used in combination with clopidogrel to reduce cardiovascular events. Lysine acetylsalicylate (L-ASA), also inhibits platelet activation with fewer gastrointestinal side effects than ASA. Dual therapy with L-ASA and clopidogrel may result in an antiplatelet effect with fewer side effects. We compared the antiplatelet effect of combined ASA/clopidogrel versus L-ASA/clopidogrel in healthy subjects. Fourteen volunteers (seven men and seven women, aged 25-45 years) received antiplatelet therapy during 14-day periods in the following sequence: 75 mg ASA; 160 mg L-ASA; 75 mg clopidogrel; 160 mg L-ASA plus 75 mg clopidogrel, and 75 mg ASA plus 75 mg clopidogrel. We evaluated platelet aggregation and glycoprotein IIb/IIIa activation. Our results show that administration of L-ASA/clopidogrel is as effective as ASA/clopidogrel combination.