Managing oral anticoagulation therapy: improving clinical outcomes. A review

Impact of Clinical Pharmacist Running Anticoagulation Clinic in Saudi Arabia

Despite the effectiveness of warfarin in extended anticoagulation, its narrow therapeutic index requires frequent dose adjustments and careful patient monitoring. Thus, we aimed to evaluate the outcomes of clinical pharmacists' intervention in warfarin therapy management in terms of International Normalized Ratio (INR) control, reduction of bleeding, and hospitalization in a tertiary care hospital. An observational retrospective cohort study was conducted on 96 patients taking warfarin therapy in a clinical pharmacist-led anticoagulation clinic. We observed that 39.6% of patients required dose adjustments at their first and second visits. However, dose adjustments during the third, fourth, and fifth weeks were required at 31.1%, 20.8%, and 4.2%, respectively, to achieve INR levels. We also observed that 36.46% of the patients attained the target INR at baseline, which was increased over the first week to the fifth week to 57.29%, 61.46%, 61.46%, 68.75%, and 85.42%, respectively. No one reported the ADR between the third and fifth weeks. Based on our findings, the study strongly suggests that pharmacists' interventions can improve the health-related quality of life of patients undergoing warfarin therapy. Thus, competent pharmacy personnel must be a priority in both usual patient care and critical care among primary care networks.

Cost-Utility and Budget Impact Analysis of Implementing Anticoagulation Clinics and Point-of-Care Monitoring Devices in Anticoagulated Patients in Argentina

BACKGROUND

Worldwide, 1 % of the population receives anticoagulation therapy, with prevalence higher in older adults. Difficulties in the adequate management of these patients have led to the development of strategies focused on achieving therapeutic control and reducing adverse events with efficient use of resources.

OBJECTIVE

To estimate the cost utility and budget impact on the Argentinean health system of implementation of anticoagulation clinics (ACs) (with and without use of point-of-care [POC] CoaguChek^® devices [Roche Diagnostics International Ltd]) compared with the traditional laboratory method (non-AC settings) for the management of anticoagulated patients.

METHODS

For the cost-utility analysis, a cohort-based state transition model was designed to compare costs and health outcomes of implementing ACs for outpatient management of anticoagulated patients. The budget impact analysis used an analytical model to estimate the differential costs of implementing an AC and the expected adverse events avoided, and the differential costs of an international normalized ratio (INR) determination using a POC device rather than a conventional laboratory.

RESULTS

We calculated the study outcomes for a cohort of 1000 patients. Considering a 5 % discount rate, the use of ACs generated 13.9 additional quality-adjusted life-years (0.014 per patient) and 12.5 additional life-years (0.013 per patient). Incremental cost-effectiveness ratios of AC implementation with and without the use of POC devices compared with the scenario without ACs were dominant in both cases. In the probabilistic sensitivity analysis, nearly all simulated results were cost effective (i.e., below the 1 or 3 gross domestic product per capita thresholds). Budget impact analysis results showed AC implementation generated savings from the first year of implementation, with savings of AR $265,325 by year 5. The addition of POC devices in the ACs also generated savings as early as the first year of implementation, with savings of AR $488,072 by year 5 (AR $488 per patient).

CONCLUSIONS

Anticoagulation clinics are estimated to be cost effective and generate notable savings in the treatment of patients on long-term oral anticoagulant therapy when compared with non-AC settings. These savings are considerably higher when POC devices are added as part of the patient management, due to lower laboratory technician costs per INR determination.

Enoxaparin versus Unfractionated Heparin for the Perioperative Anticoagulant Therapy in Patients with Mechanical Prosthetic Heart Valve Undergoing Non-Cardiac Surgery

Background and Objectives: Immediate postoperative anticoagulation regimens in patients with mechanical prosthetic valves undergoing non-cardiac surgery are clear only for unfractionated heparin (UH), whereas the few low-molecular-weight heparin (LMWH) trials available to date concern the use of Enoxaparin in general/orthopedic surgery. We performed a single-center real-world data study comparing the efficacy and safety of LMWH—Enoxaparin (E)— and UH during the perioperative period in non-cardiac surgical procedures in patients with mechanical prosthetic valve replacement in the mitral, aortic, or tricuspid positions. Materials and Methods: We enrolled 380 patients, who received E or UH together with oral anticoagulation with antivitamin K (acenocoumarol) until they achieved an optimal International Normalized Ratio (INR). Objective assessment of E efficacy included the following: normal value for all the parameters of ultrasound prosthetic functioning, no early thrombosis of the prosthesis, and rapid achievement of target INR with a decreased period of subcutaneous anticoagulation. Subjective assessment included the following: clinical improvement with decreased immobilization and in-hospital stay, fewer gluteal ulcerations, and fewer postoperative depression and anxiety episodes. Results: Comparing with UH, anticoagulation with E was more effective (p < 0.0001 and p = 0.02). The probability of death was smaller in the E group compared with the UH group. No major hemorrhagic event was reported. Mild bleeding episodes and thrombocytopenia were more common in the UH group. Patient’s compliance and quality of life were better with E due to shortened hospitalization, decreased need for testing of coagulation (every 6 h for UH), better dosing (SC every 12 h for E versus continuous infusion for UH), shortened immobilization during the immediate postoperative period with subsequent improvement in the psychological status, as well as due to lack of significant side effects. Conclusions: Taking into consideration the improved efficiency and safety, as well as all the supplementary advantages, such as no need for anticoagulation monitoring, the ease of administration, and reduced duration of hospitalization, E should be seen as an attractive alternative for anticoagulation which deserves further investigation.

Individualized versus Standardized Risk Assessment in Patients at High Risk for Adverse Drug Reactions (The IDrug Randomized Controlled Trial)-Never Change a Running System?

The aim of this study was to compare effects of an individualized with a standardized risk assessment for adverse drug reactions to improve drug treatment with antithrombotic drugs in older adults. A randomized controlled trial was conducted in general practitioner (GP) offices. Patients aged 60 years and older, multi-morbid, taking antithrombotic drugs and at least one additional drug continuously were randomized to individualized and standardized risk assessment groups. Patients were followed up for nine months. A composite endpoint defined as at least one bleeding, thromboembolic event or death reported via a trigger list was used. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. In total, N = 340 patients were enrolled from 43 GP offices. Patients in the individualized risk assessment group met the composite endpoint more often than in the standardized group (OR 1.63 [95%CI 1.02-2.63]) with multiple adjustments. The OR was higher in patients on phenprocoumon treatment (OR 1.99 [95%CI 1.05-3.76]), and not significant on DOAC treatment (OR 1.52 [95%CI 0.63-3.69]). Pharmacogenenetic variants of CYP2C9, 2C19 and VKORC1 were not observed to be associated with the composite endpoint. The results of this study may indicate that the time point for implementing individualized risk assessments is of importance.

Physicians' Perceptions of Their Patients' Attitude and Knowledge of Long-Term Oral Anticoagulant Therapy in Bulgaria

Background and Objectives: Oral anticoagulation (OAC) is widely used in daily clinical practice worldwide for various indications. We aimed to explore the perception of Bulgarian clinicians about their patients' attitude and knowledge of long-term OAC, prescribed for atrial fibrillation (AF) and/or known deep venous thrombosis (DVT)/pulmonary embolism (PE). Materials and Methods: We performed a cross-sectional study that involved 226 specialists: 187 (82.7%) cardiologists, 23 (10.2%) neurologists, and 16 (7.1%) vascular surgeons. They filled in a questionnaire, specially designed for our study, answering various questions regarding OAC treatment in their daily clinical practice. Results: The mean prescription rate of OACs in AF patients was 80.3% and in DVT/PE-88.6%. One hundred and eighty-seven (82.7%) of the participants stated they see their patients on OAC at least once per month. According to more than one-third of the inquired clinicians, the patients did not understand well enough the provided information concerning net clinical benefit of OAC treatment. About 68% of the clinicians declared that their patients would prefer a "mutual" approach, discussing with the physician the OAC options and taking together the final decision, whereas according to 43 (19.0%), the patients preferred the physician to take a decision for them. Patients' OAC treatment had been interrupted at least once within the last year due to a physician's decision by 178 (78.8%) of the participants and the most common reason was elective surgery. The most influential factors for a patient's choice of OAC were the need of a specific diet to be kept, intake frequency, and possible adverse reactions. Conclusions: Our results suggest that a clinician's continuous medical education, shared decision-making, and appropriate local strategies for improved awareness of AF/DVT/PE patients are key factors for improvement of OAC management.

Pharmacist-led medicine use review in community pharmacy for patients on warfarin

Background Medicine use review by pharmacists has the potential to improve anticoagulation therapy management in patients on warfarin. Objective To develop, implement and evaluate a pharmacist-led medication use review service for patients on warfarin. Setting Six community pharmacies in Malta. Method Patients (N = 100) aged 18 or older and on warfarin were recruited through pre-selected community-pharmacies. These patients were then invited to attend two sessions: a review session (t₁) and a follow-up session after 2 months (t₂). During the medication use review session, medication reconciliation was performed (a) to detect drug-related problems using the DOCUMENT classification system, (b) to develop an individualised care plan for each patient and (c) to recommend an action for each identified problem for physician, pharmacist or patient consideration. At t₂, the degree of acceptance of the recommendations was determined by assessing the number of drug-related problems for which action was taken to address the problem. International normalisation ration (INR) control was evaluated by calculating the percentage Time in Therapeutic Range (TTR) at t₁ and t₂ using the Rosendaal linear interpolation method. Main outcome measures Frequency and type of drug-related problems detected; percentage of accepted recommendations; and INR control. Results A total of 481 drug-related problems were identified; 40% (n = 190) were related to warfarin treatment. Need for monitoring (30%; n = 145), lack of compliance (20%; n = 97) and need for patient education (19%; n = 90) were the top three problems identified. There was a significant correlation between frequency of the problems and number of chronic medications (Spearman Correlation 0.583, p < 0.001), number of comorbidities (Spearman Correlation 0.327, p = 0.001) and older age (Spearman Correlation 0.285, p = 0.04). A total of 475 recommendations were followed-up; 49% (n = 234) were referred for consideration by the physician. The percentage of recommendations accepted (84%; n = 397) was significantly higher than the percentage of recommendations not accepted (16%; n = 78) (p < 0.001). The time in therapeutic range improved significantly from 68.7% at t₁ to 79.8% at t₂ (p = 0.01). Conclusions The high percentage of accepted recommendations and the improvement in INR control indicate that a pharmacist-led medication use review service in community pharmacy contributes to improving anticoagulation therapy management in patients on warfarin.

Impact of clinical pharmacist intervention in anticoagulation clinic in Sudan

Background Many trials have compared anticoagulation management provided by a pharmacist led anticoagulation clinic versus usual physician care showing the role for clinical pharmacist in the management of anticoagulant therapy, and demonstrating excellent outcomes. In Sudan, there is no published research evaluating the role of pharmacist in providing pharmaceutical care for patients taking warfarin. Objective The objective of the study is to assess the role of clinical pharmacist intervention in warfarin patients compared to usual medical care. Setting This study was conducted in Ahmed Gasim cardiac surgery and renal transplant center warfarin clinic. Methods One hundred thirty-five patients were randomly selected from adult patients on warfarin therapy The history of INR records, and adverse effects for the past year, were recorded. Then patients' warfarin dose adjustments according to INR, was done by the clinical pharmacist for one year. Patients received continuous verbal education and written information about warfarin. Main outcome measure The primary outcome for this study was the INR control, while the secondary outcomes were the bleeding events and hospitalization due to warfarin. Results After the clinical pharmacist intervention there was significant (P < 0.01) improvement in INR control and a significant (P < 0.05) reduction in incidence of bleeding after clinical pharmacist intervention. Hospitalization due to warfarin related complications (bleeding, high INR, low INR) was also significantly (P < 0.001) reduced. Conclusion Clinical pharmacists intervention in warfarin therapy improve INR control, reduce bleeding and hospitalization due to warfarin complications.

Utility of a dedicated pediatric cardiac anticoagulation program: the Boston Children's Hospital experience

Congenital heart disease is the leading cause of stroke in children. Warfarin therapy can be difficult to manage safely in this population because of its narrow therapeutic index, multiple drug and dietary interactions, small patient size, high-risk cardiac indications, and lack of data to support anticoagulation recommendations. We sought to describe our institution's effort to develop a dedicated cardiac anticoagulation service to address the special needs of this population and to review the literature. In 2009, in response to Joint Commission National Patient Safety Goals for Anticoagulation, Boston Children's Hospital created a dedicated pediatric Cardiac Anticoagulation Monitoring Program (CAMP). The primary purpose was to provide centralized management of outpatient anticoagulation to cardiac patients, to serve as a disease-specific resource to families and providers, and to devise strategies to evolve clinical care with rapidly emerging trends in anticoagulation care. Over 5 years the CAMP Service, staffed by a primary pediatric cardiology attending, a full-time nurse practitioner, and administrative assistant with dedicated support from pharmacy and nutrition, has enrolled over 240 patients ranging in age from 5 months to 55 years. The most common indications include a prosthetic valve (34 %), Fontan prophylaxis (20 %), atrial arrhythmias (11 %), cardiomyopathy (10 %), Kawasaki disease (7 %), and a ventricular assist device (2 %). A patient-centered multi-disciplinary cardiac anticoagulation clinic was created in 2012. Overall program international normalized ratio (INR) time in therapeutic range (TTR) is favorable at 67 % (81 % with a 0.2 margin) and has improved steadily over 5 years. Pediatric-specific guidelines for VKOR1 and CYP2C9 pharmacogenomics testing, procedural bridging with enoxaparin, novel anticoagulant use, and quality metrics have been developed. Program satisfaction is rated highly among families and providers. A dedicated pediatric cardiac anticoagulation program offers a safe and effective strategy to standardize anticoagulation care for pediatric cardiology patients, is associated with high patient and provider satisfaction, and is capable of evolving care strategies with emerging trends in anticoagulation.

Implementing evidence-based patient and family education on oral anticoagulation therapy: a community-based participatory project

AIMS AND OBJECTIVES

This study aimed at developing and implementing evidence-based patient and family education on oral anticoagulation therapy.

BACKGROUND

The number of persons with chronic diseases who live at home is increasing. They have to manage multiple diseases and complex treatments. One such treatment is oral anticoagulation therapy, a high risk variable dose medication. Adherence to oral anticoagulation therapy is jeopardised by limited information about the medications, their risk and complications, the impact of individual daily routine and the limited inclusion of family members in education. Hence, improved and tailored education is essential for patients and families to manage oral anticoagulation therapy at home.

DESIGN AND METHODS

A community-based participatory research design combined with the Precede-Proceed model was used including a systematic literature review, posteducation analysis, an online nurse survey, a documentation analysis and patient/family interviews. The study was conducted between April 2010-December 2012 at a department of general internal medicine in a teaching hospital in Switzerland. Participants were the department's nursing and medical professionals including the patients and their families.

RESULTS

The evidence-based patient and family education on oral anticoagulation therapy emerged comprising a learning assessment, teaching units, clarification of responsibilities of nurse professionals and documentation guidelines.

CONCLUSION AND CLINICAL RELEVANCE

The inclusion of the whole department has contributed to the development and implementation of this evidence-based patient family education on oral anticoagulation therapy, which encompasses local characteristics and patient preferences. This education is now being used throughout the department.

Physician's fear of anticoagulant therapy in nonvalvular atrial fibrillation

Despite the availability of predictive tools and treatment guidelines, anticoagulant therapies are underprescribed and many patients are undertreated for conditions that predispose to thromboembolic complications, including stroke. This review explores reasons for which physicians fear that the risks of anticoagulation may be greater than the potential benefit. The results of numerous clinical trials confirm that patients benefit from judiciously managed anticoagulation and that physicians can take various approaches to minimize risk. Use of stratification scores for patient selection and accurate estimation of stroke risk may improve outcomes; bleeding risk is less important than stroke risk. Adoption of newer anticoagulants with simpler regimens may help physicians allay their fears of anticoagulant use in patients with atrial fibrillation. These fears, although not groundless, should not overtake caution and hinder the delivery of appropriate evidence-based care.

Interaction of vitamin K antagonists and trimethoprim-sulfamethoxazole: ignore at your patient's risk

The aim of the study was to summarize available literature regarding the interaction between vitamin K antagonists (VKAs) and trimethoprim-sulfamethoxazole (co-trimoxazole, TMP-SMX), and to provide recommendations for managing patient risk from this interaction. Data sources were English-language publications in the medical literature and Internet databases. Relevant publications that directly or indirectly addressed the VKA-TMP-SMX interaction were selected and reviewed. The mechanism of the VKA-TMP-SMX interaction, frequency of concurrent use, effect on international normalized ratio (INR), increased risk of bleeding, and strategies for risk reduction are summarized. The concurrent use of VKA and TMP/SMX rapidly and consistently raises INR and is associated with a two- to five-fold increase in bleeding. Concurrent use of VKA and TMP-SMX should be avoided when possible. When VKA and TMP-SMX are co-prescribed, VKA dose reduction is usually required. Patient education as well as early and frequent INR monitoring is recommended to reduce risk from this interaction.

Warfarin Interactions with Medicinal Herbs

Recognition of the adverse effects of medicinal herbs is not routine and the reports on such effects are even less frequent in clinical practice. Potential herb-drug interactions are of a major safety concern, especially for drugs with narrow therapeutic indices like warfarin, which can lead to severe adverse reactions that are sometimes life-threatening. The interactions between warfarin and medicinal herbs described in the literature have been summarized in this paper relying on Medline database (via PubMed) using the key words: warfarin, herbal supplements and interactions. The references on the analyzed literature have been investigated in order to collect the existing data. The case reports with severe adverse effects such as spontaneous postoperative bleeding, formation of hematomas, hematemesis, melena, thrombosis, subarachnoid hemorrhage and/or subdural hematomas after concomitant use of warfarin and the medicinal herbs: Panax ginseng, Hypericum perforatum, Salvia milthiorizza, Gingko biloba, Serenoa repens, Angelica sinensis, Vaccinium species, Allium sativum, Zingiber officinale, Tanacetum parthenium, Lucium barbarum, Matricaria chamomilla, Boswellia serrata and Camellia sinensis have been estimated. Some of the interactions between warfarin and medicinal herbs have been well assessed proving that they are closely-dependent.

The interactions between warfarin and medicinal herbs, not generally reported in previous reviews, are presented in our review. The health professionals who are involved in treating the patients are expected to be fully informed about the interactions between warfarin and medicinal herbs in order to minimize the health risks of the patients.

Vitamin K antagonists--current concepts and challenges

Vitamin K antagtonists (VKAs) have, for decades, been the corner-stone of anticoagulation in the outpatient setting. While the long half life makes once daily administration practical, close monitoring of VKA effect is necessary because these medicines have a narrow therapeutic index. Despite inter-individual variations in response to VKA doses, the increasing availability of specialized anticoagulation monitoring systems, along with a better understanding of potential drug and dietary interactions, has made the use of VKAs safer and less burdensome. In the future, newer classes of oral anticoagulants and genomic-based dosing strategies may further expand or improve the management options for many patients at risk for thromboembolism.

Does satisfaction with information equate to better anticoagulant control?

OBJECTIVES

This study examined how satisfaction with information about warfarin related to demographic and clinical factors including therapeutic outcome.

SETTING

This study took place in the Outpatient clinic of the Mercy University Hospital, Cork, Rep. of Ireland.

METHOD

Patients attending an anticoagulation clinic completed the Satisfaction with Information about Medicines (SIMS) Scale. This was examined in line with clinical and demographic information including: age, gender, diagnosis, number of weeks taking warfarin, and INR control.

MAIN OUTCOME MEASURE

The level of satisfaction with information was measured and in addition the association between anticoagulation control and satisfaction level was examined.

RESULTS

One hundred and nineteen patients (61.3% male), participated in the study. The majority of patients were prescribed warfarin for atrial fibrillation (53.8%). Satisfaction with information about warfarin was inversely related to age (ρ = -0.33, P < 0.01). Patient-reported satisfaction with information pertaining to the question "what is your medicine for?" was significantly associated with anticoagulation control (χ(2) = 7.27, P < 0.01).

Conhecimento sobre anticoagulantes orais e seu manejo por médicos de pronto atendimento

Contexto: Desde sua descoberta, os anticoagulantes orais (AO) têm sido cada vez mais estudados e aplicados em diferentes doenças. No entanto, eles apresentam reações medicamentosas com fármacos que trazem riscos ao paciente. Objetivo: Identificar o nível de conhecimento dos médicos plantonistas de pronto atendimento sobre os AO e suas interações, medicamentosas ou não, e verificar se o médico frentista está preparado para integrar o conteúdo teórico com a rotina de urgências. Método: Aplicou-se um questionário a 100 médicos atuantes em pronto atendimentos de dois hospitais públicos e três privados em Curitiba. Visou-se saber se o médico frentista questiona ao paciente sobre o uso de AO. Também, avaliou-se o conhecimento do profissional e seu interesse em saber mais sobre: AO (quais deles conhecia); exames para controle; sinergismo com AO; e manejo das complicações. Resultados: Dos 100 entrevistados, 60% declararam perguntar ao paciente sobre o uso de AO, 81% tinham conhecimento insuficiente a respeito do sinergismo de algumas substâncias apresentadas e os AO, 15% desconheciam qual exame é utilizado para acompanhamento dos pacientes anticoagulados, 50,7% não sabiam os nomes comercias dos AO, 4% desconheciam seu antídoto, e 92% manifestaram interesse em melhorar seus conhecimentos sobre os AO. Conclusão: É BAIXo o número de médicos que atende em pronto atendimentos que conhece sobre os AO e que sabe manejar pacientes anticoagulados. É alta a porcentagem de médicos que não perguntam aos pacientes sobre o uso de AO e que desconhecem princípios do sinergismo medicamentoso, sendo que a maioria se interessou em melhorar seus conhecimentos sobre os anticoagulantes.