Atrial Fibrillation and Use of Rivaroxaban: Performance of the Prothrombin Time / INR as a Function of Time After Blood Collection

Abstract Background Traditionally, the most effective therapy in the prevention of stroke in patients with atrial fibrillation (AF) has been oral anticoagulation with vitamin K inhibitors, particularly warfarin, whose disadvantages and adverse effects have led to their replacement by "direct oral anticoagulants", as factor X inhibitor. Objectives This study aimed to conduct a brief approach on atrial fibrillation (AF) and use of Rivaroxaban, and to comparatively evaluate the prothrombin time / International Normalized Ratio (PT/INR) in patients with AF in use of this oral anticoagulant, depending on the time elapsed between the last administration of the drug and the time of blood sample venipuncture. Methods We evaluated 34 patients with AF in use of Rivaroxaban by using PT / INR, distributed into a subgroup with blood collection time ≤ 12 hours (n = 7) and > 12 hours after the last drug intake (n = 27). Mann-Whitney test was used to compare the groups and p < 0.05 was considered significant. Results An analysis as a function of time between the Rivaroxaban intake and blood collection, revealed that PT / INR suffers the greatest effect up to 12 hours after ingestion of the drug, dropping to levels close to normal in subsequent hours before the next dose. Conclusion We concluded that, in contrast to warfarin, the knowledge of the time interval between drug intake and blood collection from patients taking Rivaroxaban is essential to properly interpret a laboratory test to assess hemostasis, particularly PT and its derivatives. Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0

Rivaroxabana para profilaxia de tromboembolismo venoso em abdominoplastia após grande perda ponderal: 396 casos / Rivaroxaban for venous thromboembolism prophylaxis in abdominoplasty after massive weight loss: 396 cases

Introdução: Abdominoplastia consiste em um dos procedimentos estéticos mais populares realizados no Brasil. Pacientes pósbariátricos representam um desafio peculiar ao cirurgião plástico, uma vez que não só requerem reconstruções complexas, mas também apresentam comorbidades residuais e deficiências nutricionais. O tromboembolismo venoso (TEV) constitui uma complicação grave e potencialmente fatal da abdominoplastia. Apesar da pequena frequência desta complicação, os métodos aceitos como padrões para prevenção de TEV em pacientes após abdominoplastia, incluindo quimioprofilaxia, permanecem controversos. Objetivo: Avaliar a experiência do autor com rivaroxabana para profilaxia de TEV em pacientes submetidos a abdominoplastia após grande perda ponderal. Métodos: Uma série de 396 casos foi conduzida retrospectivamente. Todos os pacientes submetidos à abdominoplastia após cirurgia bariátrica que receberam rivaroxabana foram incluídos. A dose profilática foi de 10mg por dia. Dados demográficos, comorbidades, tipo de cirurgia e complicações foram registrados. Resultados: 396 casos de pacientes pós-bariátricos (356 mulheres e 40 homens) foram submetidos à abdominoplastia e receberam rivaroxabana no pós-operatório, de julho de 2015 a julho de 2018. A média de idade dos pacientes foi de 39,1 anos. O índice de massa corporal médio no momento da abdominoplastia foi de 27,2kg/m². Houve apenas um caso de tromboembolismo venoso (0,25%). Treze pacientes apresentaram hematoma com necessidade de drenagem. Conclusões: A quimioprofilaxia de rotina com rivaroxabana para pacientes submetidos à abdominoplastia após grande perda ponderal revela uma baixa incidência de TEV. Esta medicação oral é bem tolerada e apresenta um perfil de complicação aceitável.

Introduction: Abdominoplasty is one of the most popular aesthetic procedures performed in Brazil. Postbariatric patients present a challenge to the plastic surgeon as not only do they have complex reconstructive challenges but also they have residual medical comorbidities and nutritional deficiencies. A serious and potentially fatal complication of abdominoplasty is venous thromboembolism (VTE). Despite the frequency of this serious complication, the accepted standard methods to prevent VTE in abdominoplasty patients, including chemoprophylaxis, remain controversy. Objective: To evaluate the author experience with rivaroxaban, for VTE prophylaxis in abdominoplasty patients after massive weight loss. Methods: A retrospective 396 cases series were conducted. All patients who underwent abdominoplasty after bariatric surgery and received rivaroxaban were included. The prophylactic dose was 10 mg daily for 30 days, beginning 24 hours postoperatively. Patient demographics, comorbidities, type of surgery and complications were recorded. Results: From July 2015 until July 2018, 396 post bariatric patients (356 women and 40 men) underwent abdominoplasty and received rivaroxaban postoperatively. The mean body mass index prior to their weight loss procedure was 43.8kg/m2 (range, 37.3- 61.9kg/m2) and mean BMI was 27.2kg/m² at the time of the abdominoplasty. Mean patient age was 39.1 years. Only one patient had a symptomatic PTE event. Thirteen patients had a hematoma requiring operative evacuation, and all went on to heal without sequel. Conclusions: Routine chemoprophylaxis with rivaroxaban for abdominoplasty patients after massive weight loss has a low rate of VTE events. This oral medication is well tolerated and has an acceptable complication profile.

Evaluación de la anticoagulación con rivaroxaban, en pacientes con fibrilación auricular no valvular de reciente diagnóstico / Evaluation of oral anticoagulation with rivaroxaban, in patients with new onset non valvular atrial fibrillation

Background: Atrial fibrillation (AF) generates a hypercoagulable state with an increased thrombin generation and raised levels of thrombin-antithrombin complexes, which results in a high risk of stroke and thromboembolism. Aim: To evaluate the anticoagulant effect of rivaroxaban by anti-Xa factor activity and its correlation with thrombin-antithrombin complexes, thrombin generation and prothrombin time in patients newly diagnosed with non-valvular AF. Patients and Methods: Prospective study in patients with indication of anticoagulation. Demographic variables, cardiovascular risk factors, CHA2DS2-VASc and HAS-BLED scores were recorded. Blood samples were taken at baseline, at 3 and 24 hours after the administration of the drug and at 30 days. Rivaroxaban levels, anti-Xa activity, prothrombin time, thrombin generation and plasma levels of thrombin-antithrombin complexes were determined. Results: We studied 20 patients aged 76.3 ± 8.0 years (60% female) with a CHA2DS2-VASc score > 2 points. The anti-Xa factor activity correlated with rivaroxaban plasma levels at 3 hours (r = 0.61, p < 0.01), at 24 hours (r = 0.85, p < 0.01) and at 30 days (r = 0.99, p < 0.01), with prothrombin time at 3 hours (r = -0.86, p = 0.019) and at 30 days (r = -0.63, p = 0.02) and with a sustained decrease in thrombin generation at 30 days of follow-up (r = -0.74, p < 0.01). There was no correlation with thrombin-antithrombin complexes (r = -0.02, p = 0.83). Conclusions: Rivaroxaban consistently inhibited the mild pro-coagulant state found in newly diagnosed non-valvular AF patients through the first 24 hours and this effect was maintained at 30 days. Plasma levels of the drug correlated with anti-Xa factor activity, thrombin generation and prothrombin time

Nuevos anticoagulantes y anestesia regional / New anticoagulants and regional anesthesia

En los últimos años se ha producido un incremento de la práctica de la anestesia regional en pacientes que reciben fármacos que afectan el sistema fisiológico de la coagulación. La posibilidad de producirse un hematoma espinal, luego de una punción neuroaxial, en este tipo de pacientes, intranquiliza al médico anestesista. Por lo tanto, es indispensable que el médico anestesista conozca los mecanismos de acción de los diferentes anticoagulantes, sus propiedades farmacológicas y farmacocinéticas para poder así definir el intervalo entre la administración de los fármacos anticoagulantes y el bloqueo neuroaxial, la retirada del catéter y el reinicio de la anticoagulación permitiendo asociar la anestesia regional y la anticoagulación de forma segura para el paciente¹. Este trabajo tiene como objetivo principal realizar una revisión de los nuevos fármacos anticoagulantes y analizar las recomendaciones existentes como para poder hacer un uso racional y seguro en nuestra práctica diaria.

New anticoagulants and regional anesthesia In recent years there has been an increase in the practice of regional anesthesia in patients receiving drugs affecting the physiological coagulation system. The possibility of a spinal hematoma occurs after neuraxial puncture in these patients, uneasy the anesthesiologist. Therefore, it is essential that the anesthesiologist know the mechanism of action of different anticoagulants, their pharmacological and pharmacokinetic properties to well define the interval between administration of anticoagulants and neuraxial blockade, catheter removal and resetting anticoagulation allowing associate regional anesthesia and anticoagulation safely for patient1. This work has as main objective to carry out a review of the new anticoagulant drugs and analyze existing recommendations as to make rational and safe use in our daily practice.