Assessment of oral anticoagulation control at two pharmacist-managed clinics in Brazil

The First Brazilian Cardiovascular Registry of Atrial Fibrillation: Primary Results of the RECALL Study

BACKGROUND

It is estimated that atrial fibrillation (AF) affects approximately 1.5 million people in Brazil; however, epidemiological data are limited. We sought to evaluate the characteristics, treatment patterns, and clinical outcomes in patients with AF in Brazil by creating the first nationwide prospective registry.

METHODS

RECALL was a multicenter, prospective registry that included and followed for 1 year 4,585 patients with AF at 89 sites across Brazil from April 2012 to August 2019. Patient characteristics, concomitant medication use, and clinical outcomes were analyzed using descriptive statistics and multivariable models.

RESULTS

Of 4,585 patients enrolled, the median age was 70 (61, 78) years, 46% were women, and 53.8% had permanent AF. Only 4.4% of patients had a history of previous AF ablation and 25.2% had a previous cardioversion. The mean (SD) CHA2DS2-VASc score was 3.2 (1.6); median HAS-BLED score was 2 (2, 3). At baseline, 22% were not on anticoagulants. Of those taking anticoagulants, 62.6% were taking vitamin K antagonists and 37.4% were taking direct oral anticoagulants. The primary reasons for not using an oral anticoagulant were physician judgment (24.6%) and difficulty in controlling (14.7%) or performing (9.9%) INR. Mean (SD) TTR for the study period was 49.5% (27.5). During follow-up, the use of anticoagulants and INR in the therapeutic range increased to 87.1% and 59.1%, respectively. The rates/100 patient-years of death, hospitalization due to AF, AF ablation, cardioversion, stroke, systemic embolism, and major bleeding were 5.76 (5.12-6.47), 15.8 (14.6-17.0), 5.0 (4.4-5.7), 1.8 (1.4-2.2), 2.77 (2.32-3.32), 1.01 (0.75-1.36), and 2.21 (1.81-2.70). Older age, permanent AF, New York Heart Association class III/IV, chronic kidney disease, peripheral arterial disease, stroke, chronic obstructive pulmonary disease, and dementia were independently associated with increased mortality while the use of anticoagulant was associated with lower risk of death.

CONCLUSIONS

RECALL represents the largest prospective registry of patients with AF in Latin America. Our findings highlight important gaps in treatment, which can inform clinical practice and guide future interventions to improve the care of these patients.

Assessment of the relationship between the level of patient knowledge on warfarin therapy and the quality of oral anticoagulation: A systematic review and meta-analysis

The present study aimed to investigate the relationship between the level of patient knowledge on warfarin therapy and the quality of oral anticoagulation. This is a systematic review and meta-analysis written on the basis of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Searches at MEDLINE, EMBASE, Scopus and LILACS electronic databases were carried out on February 13, 2023, using the descriptors "Patient Medication Knowledge", "Patient Education as Topic", "Health Education", "Patient Education" and Warfarin. The steps of selection, data extraction and quality analysis of articles were performed independently by two reviewers. The analysis was performed considering patient knowledge as a possible modifier of time in therapeutic range (TTR). The meta-analysis included studies that reported the correlation coefficient (Pearson or Spearman) between patient knowledge and TTR. A subgroup analysis was performed according to questionnaires employed to measure patient knowledge. Twelve studies were selected with an overall sample size of 7634 participants and mean age 58.2 (standard deviation (SD)±12,8) years. Eleven (92.0%) cross-sectional studies. The mean TTR was 57.8% (SD±11,3%) and the average level of knowledge was 60.4%. The meta-analysis indicated that patient level of knowledge on warfarin therapy was moderately associated with TTR (rs = 0.435; 95% confidence interval (CI) = 0.163-0.645; I2 = 96%). Subgroup analysis indicated association between knowledge level and TTR in studies employing the OAK test (rs = 0.617; 95% CI = 0.192-0.847; I2 = 97%) and the AKA (rs = 0.269; 95% CI = 0.002 to 0.501; I2 = 94%). However, the subgroup analysis presented no significant difference between them (p = 0.14). The meta-regression showed a non-significant negative effect of age on the correlation (estimate = -0.028, 95% CI = -0.073 to 0.016, p = 0.207). No publication bias was noted (p = 0.881). To our knowledge, this is the first systematic review and meta-analysis gathering evidence about the relationship between the level of patient knowledge on oral anticoagulation with warfarin and TTR. The implementation of structured and patient-centered educational interventions is essential to effectively increase the level of patient knowledge and, thus, to improve the quality and safety of warfarin therapy. Systematic review registration number: PROSPERO CRD42023398030.

Sex-influence on the time in therapeutic range (TTR) during oral anticoagulation with coumarin derivatives: Systematic review and meta-analysis

AIMS

We sought to investigate the association between sex and oral anticoagulation control employing coumarin derivatives.

METHODS

Electronic sources were MEDLINE, Biblioteca Virtual em Saúde (BVS), The Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMBASE, Cochrane Central and Web of Science. Inclusion criteria were: observational and experimental studies; age ≥18 years; both sexes; treatment with any coumarin derivative for ≥3 months; any indication of long-term use; quality of oral anticoagulation measured by time in therapeutic range (TTR). The meta-analysis was developed with odds ratios (OR) for binary variables and mean differences (MD) for continuous variables, using random-effects models (DerSimonian and Laird) with 95% confidence intervals (CI).

RESULTS

Overall, 22 articles were selected, comprising 16 cohort studies, four cross-sectional studies and two clinical trials. The number of participants ranged from 110 to 104 505 (183 612; women: 45%). The main indication of oral anticoagulation was atrial fibrillation. Most studies reported the use of warfarin. In the meta-analysis, 15 studies were analysed using TTR as a binary variable (OR = 0.87; 95% CI = 0.78, 0.96; z = -2.75; P = .006.; I²  = 67%) and seven studies as a continuous variable (MD = -2.97; 95% CI = -4.80, -1.14; z = -3.19; P = .0014; I²  = 75%). The pooled estimates indicated that women were associated with lower TTR than men.

CONCLUSIONS

Our findings revealed an association between female sex and worse oral anticoagulation control. Further studies are needed with primary design to investigate sex-related factors influencing oral anticoagulation control with coumarin derivatives. Innovative strategies focused on women's health may be useful to improve patient-centred care.

Quality of anticoagulation with warfarin in rural Chhattisgarh, India

Background & objectives

In most of rural India, warfarin is the only oral anticoagulant available. Among patients taking warfarin, there is a strong association between poor control of the international normalized ratio (INR) and adverse events. This study was aimed to quantify INR control in a secondary healthcare system in rural Chhattisgarh, India.

Methods

The INR data were retrospectively obtained from all patients taking warfarin during 2014-2016 at a secondary healthcare system in rural Chhattisgarh, India. Patients attending the clinic had their INR checked at the hospital laboratory and their warfarin dose adjusted by a physician on the same day. The time in therapeutic range (TTR) was calculated for patients who had at least two INR visits.

Results

The 249 patients had 2839 INR visits. Their median age was 46 yr, and the median body mass index was 17.7 kg/m^[2]. They lived a median distance of 78 km (2-3 h of travel) from the hospital. The median INR was 1.7 for a target INR of 2.0-3.0 (n=221) and 2.1 for a target of 2.5-3.5 (n=28). The median TTR was 13.0 per cent, and INR was subtherapeutic 66.0 per cent of the time. Distance from the hospital was not correlated with TTR.

Interpretation & conclusions

INR values were subtherapeutic two-thirds of the time, and TTR values were poor regardless of distance from the health centre. Future studies should be done to identify interventions to improve INR control.

Relationship of health literacy and adherence to oral anticoagulation therapy in patients with atrial fibrillation: a cross-sectional study

Oral anticoagulant therapy (OAT) has increased substantially due to the aging population and prevalence rise of atrial fibrillation (AF). Medication adherence is important to achieve effectiveness and safety of OAT. The study aim was to investigate the relationship between health literary (HL) and the adherence to OAT in patients with atrial fibrillation (AF). This is a cross-sectional study conducted in a public cardiology clinic in Brazil, 2019. Sociodemographic and clinical data were collected by the review of medical records and interviews with patients. The relation between health literacy (HL) and adherence to OAT was investigated by a multiple logistic regression model. Overall, 100 AF patients were included in this study, with average age of 68.8 ± 13.8 years and predominance of women (54 %). Inadequate HL was found in 79 % of the patients and non-adherence was identified in 66 % of the participants. Sex was the only variable with a statistically significant association with non-adherence to OAT. Men presented a 2.54-fold greater chance of non-adherence to OAT, when compared to the women (Odds ratio (OR) = 2.54; 95 % confidence interval (CI): 1.03-6.62; p = 0.047). No statistically significant relationship was found between inadequate HL and non-adherence to OAT (OR 1.48; 95 % CI, 0.47-4.61; p = 0.49). High rates of inadequate HL and non-adherence to OAT were identified in this study; however, this relationship did not prove to be statistically significant. Further studies are needed to investigate factors associated with non-adherence to OAT in large samples of vulnerable populations and strategies for its improvement in public health.

Anticoagulation Therapy in Patients with Non-valvular Atrial Fibrillation in a Private Setting in Brazil: A Real-World Study

Fundamento:

A segurança e a eficácia da varfarina dependem da qualidade do controle da anticoagulação. Estudos observacionais associam controle deficiente com aumento de morbidade, mortalidade e custos com saúde.

Objetivos:

Desenvolver um perfil de pacientes com fibrilação atrial não valvar (FANV) tratados com varfarina em ambiente ambulatorial e hospitalar privado brasileiro, avaliar a qualidade do controle da anticoagulação e sua associação com resultados clínicos e econômicos.

Métodos:

Este estudo retrospectivo, por meio de um conjunto de dados de seguros privados de saúde no Brasil, identificou pacientes com FANV tratados com varfarina entre 01 de maio de 2014 a 30 de abril de 2016, descreveu seu manejo da anticoagulação e quantificou os custos relacionados à doença. Foram recuperados dados demográficos, histórico clínico, medicação concomitante e tempo na faixa terapêutica (TTR) dos valores da razão normalizada internacional (RNI). Os pacientes foram agrupados em quartis de TTR, com um bom controle sendo definido como TTR ≥65% (método de Rosendaal). Sangramentos maiores e custos médicos diretos por todas as causas foram calculados e comparados entre subgrupos de controle bons e ruins. Valores de p < 0,05 foram considerados estatisticamente significantes.

Resultados:

A análise incluiu 1220 pacientes (mediana de seguimento: 1,5 anos; IIQ: 0,5–2,0). Em média, cada paciente recebeu 0,95 medidas mensais de RNI (RNI média: 2,60 ± 0,88, com 26,1% dos valores < 2 e 24,8% > 3), (mediana de TTR: 58%; IIQ: 47-68%), (TTR médio: 56,6% ± 18,9%). Apenas 31% dos pacientes estavam bem controlados (TTR médio: 78% ± 10%), com 1,6% apresentando grandes sangramentos na mediana do seguimento e custos médicos diretos por membro por ano (PMPY) de R$25.352 (± R$37.762). Pacientes com controle abaixo do ideal (69%) foram associados a 3,3 vezes mais sangramentos graves (5,3% vs. 1,6%; p <0,01) e custos 40% maiores (R$35.384 vs. R$25.352; p < 0,01).

Conclusões:

Mais de 60% dos pacientes estavam abaixo da meta desejada e os custos associados foram significativamente maiores nesta população.

Algorithm for predicting low maintenance doses of warfarin using age and polymorphisms in genes CYP2C9 and VKORC1 in Brazilian subjects

Warfarin exhibits a wide variation in dose requirements. We sought to evaluate the association of polymorphisms CYP2C9*2 (rs1799853), CYP2C9*3 (rs1075910), and VKORC1-G1639A (rs9923231) and nongenetic factors with maintenance doses of warfarin <17.5 mg/week and to create an algorithm to predict drug sensitivity. This is a retrospective cohort study including 312 patients assisted at an anticoagulation clinic in Brazil. The mean age of participants was 60.4 ± 13.5 years and 59.9% were female. The logistic regression model included: age [odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.06], genotype VKORC1 AA (OR 31.61, 95% CI 11.20-100.15) and genotype CYP2C9 2/2, 2/3 or 3/3 (OR 16.48, 95% CI 3.37-81.79). The creation of our algorithm involved warfarin-experienced patients on stable doses, identifying factors associated with drug sensitivity. The validation of this algorithm allows its use in future populations to determine the initial dose distinguishing patients with dose requirements <17.5 mg and reducing time to achieve stable doses.

Protocol of a clinical trial study involving educational intervention in patients treated with warfarin

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide. Oral anticoagulation is an effective strategy for primary and secondary prevention of stroke in patients with AF. Warfarin is an oral anticoagulant widely prescribed and, despite its benefits, the achievement of the goals of drug therapy depends on patient involvement, among other factors. Educational interventions can contribute for effectiveness and safety of oral anticoagulation therapy. We sought to describe the protocol of a clinical trial designed to evaluate the effect of a patient-centered educational strategy focused on low-income patients with AF and poor anticoagulation control.

METHODS

Patients ≥18 years with AF, on warfarin for at least 6 months and time in therapeutic range (TTR) <60% will be recruited at 2 anticoagulation clinics (ACs) in Brazil. Patients from 1 AC will be allocated to the intervention group and patients from the other AC will be allocated to the control group. Intervention group will attend educational sessions based on a patient-centered care approach, and the control group will receive usual care. The intervention will be based on Paulo Freire's theory and tailored according to practices involving health empowerment and techniques applied to individuals with limited socioeconomic status. The intervention is estimated to last 5 months. We will consider TTR as the primary outcome and knowledge and self-reported non-adherence to warfarin therapy as secondary outcomes. TTR values and non-adherence will be measured before intervention (T0) and at times immediately after (T1), and 3 (T2), 6 (T3), 9 (T4), and 12 (T5) months after intervention. Knowledge will be measured at times T0, T1 e T5. The calculated sample size indicated 85 patients in each group.

DISCUSSION

The proposed study aims to investigate whether an innovative educational approach to deliver care to a low-income population on warfarin improves anticoagulation control. Once our hypothesis is confirmed, our findings are expected to help improving anticoagulation control, knowledge on warfarin therapy and adherence to drug therapy. Thus, we believe our results may contribute to improve oral anticoagulation effectiveness in a low-income population.

TRIAL REGISTRATION

Registro Brasileiro de Ensaios Clínicos (ReBEC) RBR- 9cy6py and UTN: U1111-1217-0151 (March, 2019).

Alarming lack of knowledge about antithrombotic therapy among patients with atrial fibrillation

ABSTRACT Large population campaigns have been conducted in Brazil to improve knowledge about the signs and symptoms of stroke and the importance of time to care. Objective: Parallel to these important actions, we aimed to evaluate the lay knowledge of patients with atrial fibrillation, a well-recognized etiology of stroke, adequate treatment and management of which can prevent up to 30% of cerebrovascular events. Methods: We questioned 143 patients with atrial fibrillation about the risks associated with the disease. Results: Ninety-one percent were on anticoagulation treatment. Of the total, 63.6% reported having been informed about the risks and benefits of anticoagulants but only 46.9% were able to correctly mention one of these risks. Ischemic stroke was identified as a risk by only 25.9% and hemorrhagic stroke was not mentioned. A CHADS2 ≥ 2 was scored by 84.0% of the patients. Conclusions: Our study showed an alarming knowledge gap in patients with atrial fibrillation. Difficulty in adherence to treatment resulting from the failure of this communication is possibly one of the factors responsible for the high incidence and recurrence of stroke, and should not go unnoticed.

Pharmaceutical Care Increases Time in Therapeutic Range of Patients With Poor Quality of Anticoagulation With Warfarin

Thromboembolic events are associated with high mortality and morbidity indexes. In this context, warfarin is the most widely prescribed oral anticoagulant agent for preventing and treating these events. This medication has a narrow therapeutic range and, consequently, patients usually have difficulty in achieving and maintaining stable target therapeutics. Some studies on the literature about oral anticoagulant management showed that pharmacists could improve the efficiency of anticoagulant therapy. However, the majority of these studies included general patients retrospectively. The aim of this study was to prospectively evaluate a pharmacist’s warfarin management in patients with poor quality of anticoagulation therapy (Time in the Therapeutic Range- TTR < 50%). We included 268 patients with atrial fibrillation (AF) and without stable dose of warfarin (TTR < 50%, based on the last three values of International Normalized Ratio-INR). We followed them up for 12 weeks, INR values were evaluated and, when necessary, the dose adjustments were performed. During the first four visits, patient’s INR was measured every 7 days. Then, if INR was within the target therapeutic range (INR: 2–3), the patient was asked to return in 30 days. However, if INR was out the therapeutic target, the patient was asked to return in 7 days. Adherence evaluation was measured through questionnaires and by counting the pills taken. Comparison between basal TTR (which was calculated based on the three last INR values before prospective phase) and TTR of 4 weeks (calculated by considering the INR tests from visits 0 to 4, in the prospective phase of the study) and basal TTR and TTR of 12 weeks (calculated based on the INR tests from visits 0 to 12, in the prospective phase of the study) revealed significant statistical differences (0.144 ± 0.010 vs. 0.382 ± 0.016; and 0.144 ± 0.010 vs. 0.543 ± 0.014, p < 0.001, respectively). We also observed that the mean TTR of 1 year before (retrospective phase) was lower than TTR value after 12 weeks of pharmacist-driven treatment (prospective phase) (0.320 ± 0.015; 0.540 ± 0.015, p < 0.001). In conclusion, pharmaceutical care was able to improve TTR values in patients with AF and poor quality of anticoagulation with warfarin.

Assessment of patients' warfarin knowledge and anticoagulation control at a joint physician- and pharmacist-managed clinic in China

PURPOSE

Warfarin is a widely used anticoagulant with a narrow therapeutic index, and it requires close monitoring and adequate patient education. We aimed to assess the knowledge level regarding warfarin therapy among its users and to identify the factors that significantly influence anticoagulation control.

PATIENTS AND METHODS

Patients attending the Warfarin Clinic at the Beijing Tiantan Hospital were enrolled in this study. Patients' knowledge on warfarin was assessed using a validated Anticoagulation Knowledge Assessment (AKA) questionnaire. Patients' responses to each question were analyzed to identify areas of improvement in current warfarin education. International normalized ratio (INR) control was defined by the time in therapeutic range (TTR) calculated using the Rosendaal method. Spearman correlation analysis was used to investigate the association between TTR and the independent variables.

RESULTS

A total of 65 patients were enrolled in this study. Eleven questions were answered correctly by <50% of the patients. A total of 858 INR results were recorded; 432 INR values (50.3%) reached the predefined goals, and the mean TTR was 49.8%±24.8%. There were significant associations between TTR and patients' AKA scores (R=0.356, P=0.004) and between TTR and patients' educational levels (R=0.339, P=0.006). No significant association was observed between other factors (age and duration of anticoagulation) and TTR. The INR outcome measure was positively associated with patients' knowledge on warfarin and their educational levels.

CONCLUSION

Areas for improvement in patient education have been identified, and processes for educational modification are currently in development.