Warfarin – ABC CARDIOL

IJCS

Original Article

Association Between Functional Health Literacy and the Quality of Oral Anticogulation

Gustavo Chaves de Souza et al. Josiane Moreira da Costa Mayara Cristina Oliveira Ortiz Philipe Dias de Avila Lima … Pollyanna Evelyn de Freitas Nogueira Carla Jorge Machado Maria Auxiliadora Parreiras Martins

Abstract

Background:

Low functional health literacy in anticoagulated patients using warfarin has been widely discussed in medical literature.

Objective:

To identify the quality of oral anticoagulation (QOA) over time and to analyze the association between this variable and functional health literacy.

Methods:

Prospective cohort study conducted at an anticoagulation clinic (AC) in Minas Gerais, in a high-complexity hospital. The study included 81 patients, whose data were collected by direct consultation of medical records or by asking questions while patients were waiting for care. The QOA was assessed at 6, 9, 12, 15, and 18 months after the beginning of this study, and analyses of the association between this variable and functional health literacy were performed at the different time points. The QOA was identified by calculating the Therapeutic Time Range (TTR), with good quality being obtained with TTR values >59%. The incidence analysis of the TTR was performed for each of the five time points of the study through univariate Poisson regression. The significance level adopted in the statistical analysis was 5%.

Results:

Throughout the study, inadequate control of oral anticoagulation was observed, with only 20% of the patients showing persistent improvement in TTR values. No statistically significant association was identified at the different measurement times between TTR and functional health literacy.

Conclusion:

There was no direct association between the QOA and functional health literacy. However, the low incidence of persistent quality of anticoagulation in patients with low literacy suggests the development of specific educational actions for this subgroup of patients.

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IJCS

Original Article

Factors Associated with Variation in Time in Therapeutic Range in Two Anticoagulation Clinics in Brazil

Josiane Moreira da Costa et al. Milena S. Marcolino Carla Jorge Machado Leandro Pinheiro Cintra … Izabella Fernanda Bastos Siqueira Daniel Dias Ribeiro Maria Auxiliadora Parreiras Martins

Abstract

Background

Time in therapeutic range (TTR) plays an important role in the effectiveness of anticoagulant therapy with vitamin K antagonists.

Objective

To identify factors associated with variation in TTR.

Methods

The study sites were anticoagulation clinics at two university hospitals in Minas Gerais, with a total of 1357 patients studied. TTR was calculated using the Rosendaal method. Binary logistic regressions were carried out with the study variables, followed by multiple regression with those that were significant for the model, adopting a significance level of 5%.

Results

The outpatient clinics presented different values in mean TTR; one corresponded to the expected percentage, while the other did not. Multiple regression identified the variable male sex as a protective factor in relation to TTR < 60% (odds ratio [OR]: 0.42; p = 0).

Conclusion

The identification of variables associated with inadequate TTR contributes to identifying weaknesses in the care process and implementing improvement actions in the hospitals studied.

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IJCS

Editorial

Challenging Health Literacy, Patient Knowledge, and Adherence to Oral Anticoagulation in Primary Care Units

Alfredo José Mansur

Care of patients and therapeutics in clinical practice has evolved based on scientific and technological advances, mainly in patients living in societies with appropriate social, educational, and economic conditions, as well as supported facilities that are able to be elicited when needed. However social disparities, whether in social and economic background or in education can vary among population subsets in a way that may hinder the proper care necessary to fulfill expected results. These disparities influence adherence that may be less than optimal. Health literacy is a public concern recognized by different agencies, including the World Health Organization (WHO). Moreover, the healthcare network in different countries may vary.

In Brazil, reports of experiences in primary care facilities, which present interesting opportunities to add to the clinical experience, were evaluated in the city of Divinópolis, in the southeastern region of Brazil, with estimated population of 242,505 inhabitants. Primary care facilities in Divinópolis are organized in 43 primary care units. In the current study, the authors evaluated 162 participants (mean age 64.8±12.7 years-old, 55.6% women) concerning chronic treatments with warfarin, 50% of which were identified due to nonvalvular atrial fibrillation or venous thromboembolism. Participants were evaluated with tests devised to check for oral anticoagulation knowledge, adherence to treatment, health literacy, and the medication complexity index. The relationship of the studied variables with the therapeutic range of INR was unclear; the sample size may well have been a key limitation to estimating associations. The mean follow-up time was 16.5 months after recruitment in March 2020. There were 16 deaths, two of which may have been related to hemorrhage and two possibly related to thromboembolism. The study revealed insufficient knowledge about warfarin therapy and low health literacy in primary care facilities.

[…]

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IJCS

Original Article

Health Literacy, Patient Knowledge and Adherence to Oral Anticoagulation in Primary Care

Milena Soriano Marcolino et al. Thaís Lorenna Souza Sales João Antônio de Oliveira Danyelle Romana Alves Rios … Thaís Marques Pedroso Laura Caetano de Sá Maria Auxiliadora Martins Antonio Luiz Pinho Ribeiro

Abstract

Background

Warfarin is the only oral anticoagulant available in the Brazilian public health system. Health knowledge and treatment are essential to achieving the desirable therapeutic effect. However, data on these aspects among primary care patients are still lacking.

Objective

To assess health literacy, patient knowledge, and adherence to oral anticoagulation with warfarin, as well as the medication regimen complexity in primary health units in the municipality of Divinópolis, Minas Gerais, Brazil.

Methods

This cross-sectional study included patients using warfarin from primary care settings. Sociodemographic and clinical data were collected from medical records. Short Assessment of Health Literacy for Portuguese-Speaking Adults (SAHLPA-18), Oral Anticoagulation Knowledge (OAK), adaptation of the Measure of Adherence to Treatment (MAT-adapted) to oral anticoagulation, and Medication Regimen Complexity Index (MRCI) were applied, and the time in therapeutic range (TTR) was calculated. Patients were stratified in two groups (TTR < 60% and TTR ≥ 60%) and compared using Fisher's exact test at a significance level of p < 0.050.

Results

Analysis included 162 patients (64.8 ± 12.7 years old, 55.6% women). Nonvalvular atrial fibrillation (26.5%) and venous thromboembolism (24.1%) were the main indications for warfarin, and 67.9%, 88.3%, and 16.7% of the patients had inadequate health literacy, insufficient knowledge regarding anticoagulant therapy, and non-adherence to warfarin therapy, respectively. There was no significant association of these parameters in relation to TTR. MRCI showed high pharmacotherapy complexity between the drug prescriptions.

Conclusion

This study showed alarming insufficient knowledge about warfarin therapy and low health literacy in primary care patients.

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IJCS

Original Article

Predictors of Hospitalization in Vitamin K Antagonist Users Presenting with Bleeding at the Emergency Department

Alan Fabiani Chiaparini et al. Paola Stefania Bohrer Rabaioli João Vitor Slaviero Cinthia Scatolin Tem-Pass … Hugo Antonio Fontana Filho Iran Castro Eduardo Dytz Almeida Tiago Luiz Luz Leiria

Abstract

Background

Vitamin K antagonists (VKA) are indicated for the prevention of thromboembolic events and reduction of mortality in patients with atrial fibrillation and patients with valvular prostheses. However, their use is associated with bleeding complications and hospitalizations. Predictors of hospital admission for bleeding in these patients are poorly known.

Objectives

To define the predictors for hospitalization of VKA users who seek emergency care due to bleeding.

Methods

Single-center, cross-sectional study, with retrospective analysis of electronic medical records from 03/01/2012 to 02/27/2017. Clinical and laboratory variables were compared between patients who were hospitalized and those who were not. A logistic regression model as used, in which the variables were included using the Backward stepwise method, with a p value of 0.05 as the input criterion, a removal value of 0.20 and a confidence interval of 95%. The p-value was considered statistically significant when <0.05.

Results

A total of 510 patients with bleeding were included, of whom 158 were hospitalized. Predictors of hospitalization were: INR at supratherapeutic levels (OR 3.45; P <0.01; 95% CI 1.58 – 7.51), gastrointestinal bleeding (OR 2.36; P <0.01; CI 95% 1.24 – 4.50), drop in hemoglobin (OR 6.93; P <0.01; 95% CI 3.67 – 13.07), heart failure (OR 1.96; P 0.01; 95% CI 1.16 – 3.30) and need for blood transfusion (OR 8.03; P <0.01; 95% CI 2.98 – 21.64).

Conclusion

Drop in hemoglobin, heart failure, INR at supratherapeutic levels, gastrointestinal bleeding and need for blood transfusion were associated with hospitalization. Identification of these factors in the initial evaluation would help to define which patients will demand more intensive care.

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IJCS

Original Article

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

Rita Carolina Figueiredo Duarte et al. Priscila Samara Sérgio Moreira Cláudia Natália Ferreira Estevão Lanna Figueiredo … Eduardo Sternick Francisco Rezende Silveira Luan Carlos Vieira Alves Ana Paula Lucas Mota Edna Afonso Reis Maria das Graças Carvalho Helton José dos Reis

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

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IJCS

Original Article

Drug Interactions and Adverse Events in a Cohort of Warfarin Users Attending Public Health Clinics

Christiane de Fátima Colet et al. Tania Alves Amador Isabela Heineck

Abstract

Background:

Warfarin is an oral anticoagulant involved in important interactions with foods and other drugs.

Objectives:

To evaluate the occurrence of adverse events reported by warfarin users and their relationship with drug interactions.

Methods:

This was an open cohort, prospective study conducted in an 18-month period with warfarin users attending public health clinics of the city of Ijuí, Brazil. Data were collected by means of interviews administered at patients’ home every month. Patients’ responses were confirmed by review of medical records when patients sought medical care. Data were analyzed by descriptive statistics. Potential drug interactions were evaluated in a database and vitamin K consumption was quantified using a validated method.

Results:

A total of 68 patients were followed-up; 63 completed the study and 5 died in the study period. Mean number of medications taken by the patients was 9.6 ± 4.5, and mean number of interactions involving warfarin was 2.91 ± 1.52. Most potential interactions increased the risk of bleeding, 61 of them severe interactions and 116 moderate interactions. Eighty-seven episodes of bleeding and 4 episodes of thrombosis were reported by a total of 37 and 4 patients, respectively. At the occurrence of these events, 56.5% of warfarin users were also taking omeprazole, 35.9% were taking simvastatin and 25.0% paracetamol. Most patients had a low vitamin K intake.

Conclusions:

A high frequency of potential interactions between warfarin and other drugs was detected, but a low intake of foods that could possibly affect the effects of warfarin was observed. Based on our results, it seems prudent to follow patients on warfarin therapy for drug-drug interactions, aiming to control adverse effects and to promote a safe and effective therapy.

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ABC

Original Article

Evaluation of the marker of hypercoagulability prothrombin fragment F 1+2 in patients with mechanical or biological heart valve prostheses

Claudia Natália Ferreira et al. Lauro Mello Vieira Luci Maria Sant'Ana Dusse Carlos Faria Santos Amaral … William Antônio de Magalhães Esteves Lúcia Maria Amorim Fenelon Maria das Graças Carvalho

OBJECTIVE: To investigate whether patients with heart valve prostheses and similar International Normalized Ratios (INR) have the same level of protection against thromboembolic events, that is, whether the anticoagulation intensity is related to the intensity of hypercoagulability supression. METHODS: INR and plasma levels of prothrombin fragment 1+2 (F1+2) were assessed in blood samples of 27 patients (7 with mechanical heart valves and 20 with biological heart valves) and 27 blood samples from healthy donors that were not taking any medication. RESULTS: Increased levels of F1+2 were observed in blood samples of 5 patients with heart valve prostheses taking warfarin. These findings reinforce the idea that even though patients may have INRs, within the therapeutic spectrum, they are not free from new thromboembolic events. CONCLUSION: Determination of the hypercoagulability marker F1+2 might result in greater efficacy and safety for the use of oral anticoagulants, resulting in improved quality of life for patients.

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