Anticoagulation Control In Patients Research Articles

A "Bundle of Care" to Improve Anticoagulation Control in Patients Receiving Warfarin in Uganda and South Africa: Protocol for an Implementation Study.

The quality of warfarin anticoagulation among Sub-Saharan African patients is suboptimal. This is due to several factors, including a lack of standardized dosing algorithms, difficulty in providing timely international normalized ratio (INR) results, a lack of patient feedback on their experiences with treatment, a lack of education on adherence, and inadequate knowledge and training of health care workers. Low quality of warfarin anticoagulation, expressed as time in therapeutic range (TTR), is associated with higher adverse event rates, including bleeding and thrombosis, and ultimately, increased morbidity and mortality. Processes and interventions that improve this situation are urgently needed. This study aims to evaluate the implementation of the "warfarin bundle," a package of interventions to improve the quality of anticoagulation and thereby clinical outcomes. The primary outcome for this study is TTR over the initial 3 months of warfarin therapy. Patients aged 18 years or older who are newly initiated on warfarin for venous thromboembolism, atrial fibrillation, or valvular heart disease will be enrolled and followed up for 3 months at clinics in Cape Town, South Africa, and Kampala, Uganda, where the warfarin bundle is implemented. A retrospective review of the clinical records of patients on warfarin treatment before implementation (controls) will be used for comparison. This study uses a mixed methods approach of the implementation of patient- and process-centered activities to improve the quality of anticoagulation. Patient-centered activities include the use of clinical dosing algorithms, adherence support, and root cause analysis, whereas process-centered activities include point-of-care INR testing, staff training, and patient education and training. We will assess the impact of these interventions by comparing the TTR and safety outcomes across the 2 groups, as well as the cost-effectiveness and acceptability of the package. We started recruitment in June 2021 and stopped in August 2022, having recruited 167 participants. We obtained ethics approval from the University of Cape Town Faculty of Health Sciences Human Research Ethics Committee, the Provincial Health Research Committees in South Africa, the Joint Clinical Research Centre Institutional Review Board, Kampala, and the University of Liverpool Research Ethics Committee. As of February 2023, data cleaning and formal analysis are underway. We expect to publish the full results by December 2023. We anticipate that the "bundle of care," which includes a clinical algorithm to guide individualized dosing of warfarin, will improve INR control and TTR of patients in Uganda and South Africa. We will use these findings to design a larger, multisite clinical trial across several Sub-Saharan African countries. DERR1-10.2196/46710.

Anticoagulation Control and Major Adverse Clinical Events in Patients with Operated Valvular Heart Disease with and without Atrial Fibrillation Receiving Vitamin K Antagonists.

Good quality anticoagulation among patients with operated valvular heart disease is needed to reduce ischaemic and thromboembolic complications. There is limited evidence regarding factors that affect anticoagulation control in patients implanted with mechanical or tissue prosthetic valve(s). To examine the quality of and factors that affect anticoagulation control, major adverse clinical events and all-cause death in operated valvular heart disease patients with and without atrial fibrillation who are receiving a vitamin K antagonist. Quality of anticoagulation were retrospectively assessed among 456 operated valvular heart disease patients [164 (36%) with AF and 290 (64%) without AF] via time in therapeutic range (TTR) (Rosendaal method) and percentage of INRs in range (PINRR) over a median of 6.2 (3.3-8.5) years. VHD was defined by the presence of a mechanical or tissue prosthetic valve at the mitral, aortic, or both sites. Mean age 51 (14.7), 64.5% men. Most (96.1%) had a mechanical prosthesis and 64% had aortic valve replacement. Overall, mean TTR was 58.5% (14.6) and PINRR was 50.1% (13.8). Operated valvular heart disease patients with AF had significantly lower mean TTR and PINRR (TTR: 55.7% (14.2) vs. 60.1% (14.6); p = 0.002, respectively, PINRR: 47.4% (13.5) vs. 51.6% (13.7); p = 0.002, respectively), and a lower proportion of TTR ≥ 70%, despite a similar number of INR tests compared to those without AF. Predictors of TTR < 70% were female sex, AF and anaemia/bleeding history. Significantly higher proportions of operated valvular heart disease patients with AF died (20.7% vs. 5.8%; p < 0.001), but ≥1 MACE rates were similar between the two groups. Operated valvular heart disease patients with AF at baseline have poorer anticoagulation control compared to those without AF. The presence of concomitant AF, anaemia/bleeding history and female sex independently predicted poor TTR. Stringent INR monitoring is needed to improve anticoagulation control and prevent major adverse clinical events in patients with operated valvular heart disease.

The Immediate Effect of COVID-19 Vaccination on Anticoagulation Control in Patients Using Vitamin K Antagonists.

Background In January 2021, the Dutch vaccination program against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was started. Clinical studies have shown that systemic reactions occur in up to 50% of vaccine recipients. Therefore, COVID-19 vaccination could affect anticoagulation control, potentially leading to an increased risk of thrombotic events and bleeding complications. Aims This article investigates whether the BNT162b2 vaccine affects anticoagulation control in outpatients using vitamin K antagonists (VKAs). Methods A case-crossover study was performed in a cohort of outpatient VKA users from four Dutch anticoagulation clinics who received a BNT162b2 vaccine. International normalized ratio (INR) results and VKA dosages before the first vaccination, the reference period, were compared with those after the first and second vaccination. Results A total of 3,148 outpatient VKA users were included, with a mean age (standard deviation) of 86.7 (8.7) years, of whom 43.8% were male, 67.0% used acenocoumarol, and 33.0% phenprocoumon. We observed a decrease of 8.9% of INRs within range in the standard intensity group (target INR 2.0–3.0). There was both an increased risk of supratherapeutic (odds ratio [OR] = 1.34 [95% confidence interval [CI] 1.08–1.67]) and subtherapeutic levels (OR = 1.40 [95% CI 1.08–1.83]) after first vaccination. In the high-intensity group (target INR 2.5–3.5), the risk of a supratherapeutic INR was 2.3 times higher after first vaccination (OR = 2.29 [95% CI 1.22–4.28]) and 3.3 times higher after second vaccination (OR = 3.25 [95% CI 1.06–9.97]). Conclusion BNT162b2 was associated with an immediate negative effect on anticoagulation control in patients treated with VKAs, so it is advisable to monitor the INR shortly after vaccination, even in stable patients.

Warfarin adherence and anticoagulation control in atrial fibrillation patients: a systematic review.

This paper aims to review the literature systematically on warfarin adherence in patients with atrial fibrillation and to assess the anticoagulation control focused on patient clinical outcomes. Atrial Fibrillation (AF) is a cardiac disease defined by abnormal heart rhythm, which significantly impacts a patient's health status, quality of life, and heart output, and thus a greater risk of stroke and hospitalization. Most AF patients should be managed with long-term anticoagulation, either with vitamin K antagonists such as warfarin or new oral anticoagulants (NOACs). Anticoagulants have been a core in treating AF and weighing the consequences of thrombosis with the risk of bleeding. This systematic review aimed to assess the impact of warfarin adherence on AF patients. A systematic search of the literature was conducted on electronic databases of PubMed/MEDLINE, EBSCO, Cochrane library, Google, and Google Scholar from January 2011 to April 2021 to determine studies that reported warfarin adherence on patients with atrial fibrillation. Out of 1429 titles and abstracts were retrieved, 12 studies fulfilled and met the inclusion criteria. From the included studies, two were carried out in Brazil and one from the following nations: Libya, Jordan, Iran, KSA, Canada, Malaysia, Bahrain, UAE, Singapore, and the USA. The study designs identified were cross-section, retrospective, and prospective studies. Warfarin adherence was influenced by multiple causes, including pharmaceutical services, the number of medications, and warfarin knowledge regarding anticoagulation control. Warfarin adherence illustrates its positive association with TTR and INR as a measure of anticoagulation control. While the available evidence is limited, this systematic review demonstrated a positive finding of the association between warfarin adherence and anticoagulation control in patients with AF.

The Immediate Effect of COVID-19 Vaccination on Anticoagulation Control in Patients Using Vitamin K Antagonists

Background: In January 2021, the Dutch vaccination programme against SARS-CoV-2 was started. Clinical studies have shown that systemic reactions occur in up to 50% of vaccine recipients. Therefore, COVID-19 vaccination could affect anticoagulation control, potentially leading to an increased risk of thrombotic events and bleeding complications.Aims: To investigate whether the BNT162b2 vaccine affects anticoagulation control in outpatients using Vitamin K antagonists (VKAs).Methods: A case-crossover study was performed in a cohort of outpatient VKA users from four Dutch anticoagulation clinics who received a BNT162b2 vaccine. INR results and VKA dosages before the first vaccination, the reference period, were compared with those after the first and second vaccination.Results: A total of 3148 outpatient VKA users were included, with a mean age (standard deviation (SD)) of 86.7 (8.7) years, of whom 43.8% were male, 67.0% used acenocoumarol and 33.0% phenprocoumon. We observed a decrease of 8.9% of INRs within range in the standard intensity group (target INR 2.0-3.0). There was both an increased risk of supratherapeutic [OR=1.34 (95% CI 1.08-1.67)] and subtherapeutic levels [OR=1.40 (95% CI 1.08-1.83)] after first vaccination. In the high-intensity group (target INR 2.5-3.5), the risk of a supratherapeutic INR was 2.3 times higher after first vaccination [OR=2.29 (95% CI 1.22-4.28)] and 3.3 times higher after second vaccination [OR 3.25 (95% CI 1.06-9.97).Conclusion: BNT162b2 was associated with an immediate negative effect on anticoagulation control in patients treated with vitamin K antagonists, so it is advisable to monitor the INR short after vaccination, even in stable patients. [Display omitted] DisclosuresKruip: Daiichi Sankyo: Research Funding; Bayer: Honoraria, Research Funding.

Анализ антитромботической терапии у пожилых людей во врачебной клинической практике центров семейной медицины Кыргызской Республики

Введение. Риски тромбоза и кровотечения с возрастом увеличиваются одновременно, при этом пожилой контингент извлекает больше пользы от антитромботической терапии, чем лица молодого возраста. Цель исследования: изучить ситуацию с назначением антикоагулянтной терапии у пациентов пожилого и старческого возраста с фибрилляцией предсердий (ФП) при центрах семейной медицины южных регионов Кыргызской Республики. Материалы и методы. Из 2000 амбулаторных карт медицинского наблюдения отобрано 470 пациентов с неклапанной ФП, которые имели показания для назначения антитромботической терапии: 187 (39,8%) мужчин, 283 (60,2%) женщины, из них 212 (45,1%) городских жителей и 258 (54,9%) сельских жителей. Средний возраст обследованных составил 69,5 ± 10,2 лет. Результаты. Из 377 (80,2%) пациентов должная антикоагулянтная терапия была назначена 162 (42,9%), антиагрегантная терапия — 191 (50,6%), и терапия не была назначена 24 (6,4%) больным при наличии абсолютных показаний. В качестве антикоагулянтной терапии 148 больным был назначен варфарин, адекватная антикоагуляция к концу года составила всего 12,2%. Новый оральный антикоагулянт — ривароксабан был назначен 14 (8,6%) пациентам. Врачами-терапевтами сельской местности 50% больным при необходимости антикоагулянтов была назначена антиагрегантная терапия. Заключение. В южных регионах республики наблюдается неблагоприятная ситуация с назначением антикоагулянтной терапии и ведением пациентов пожилого и старческого возраста. Необходимо продолжить исследования по другим регионам страны для получения полноценной и реальной картины по проблеме и выработки единой и соответствующей рекомендации. Background. The risks of thrombosis and bleeding increase simultaneously with age. At the same time, the elderly population derives more benefit from antithrombotic therapy than young individuals. Objectives: to study the current state of the anticoagulant therapy prescription for elderly and senile patients with atrial fibrillation (AF) at the centers of family medicine in the southern regions of the Kyrgyz Republic. Patients/Methods. From 2000 outpatient medical records, 470 patients with nonvulvar AF were selected who had indications for prescribing antithrombotic therapy: 187 (39.8%) men, 283 (60.2%) women; 212 (45.1%) were urban residents and 258 (54.9%) were village residents. The average age was 69.5 ± 10.2 years. Results. From among 377 (80.2%) patients, needful anticoagulant therapy was prescribed to 162 (42.9%), 191 (50.6%) patients received antiplatelet therapy and therapy was not prescribed to 24 (6.4%) patients in the presence of absolute indications. Warfarin as anticoagulant therapy was prescribed to 148 patients; adequate anticoagulation by the end of the year was only 12.2%. A new oral anticoagulant — rivaroxaban was prescribed to 14 (8.6%) patients. In non-urban area primary care physicians prescribed antiplatelet therapy to 50% of patients who needed anticoagulants. Conclusions. An unfavorable situation is observed with the prescription of anticoagulant therapy and management of elderly and senile patients in the southern regions of the republic. It is necessary to continue study in other regions of the country in order to obtain a complete and real picture of the problem, and to develop a unified and relevant recommendation.

Gut Microbiota and the Quality of Oral Anticoagulation in Vitamin K Antagonists Users: A Review of Potential Implications.

The efficacy and safety of vitamin K antagonists (VKAs) as oral anticoagulants (OACs) depend on the quality of anticoagulation control, as reflected by the mean time in therapeutic range (TTR). Several factors may be involved in poor TTR such as comorbidities, high inter-individual variability, interacting drugs, and non-adherence. Recent studies suggest that gut microbiota (GM) plays an important role in the pathogenesis of cardiovascular diseases, but the effect of the GM on anticoagulation control with VKAs is unknown. In the present review article, we propose different mechanisms by which the GM could have an impact on the quality of anticoagulation control in patients taking VKA therapy. We suggest that the potential effects of GM may be mediated first, by an indirect effect of metabolites produced by GM in the availability of VKAs drugs; second, by an effect of vitamin K-producing bacteria; and finally, by the structural modification of the molecules of VKAs. Future research will help confirm these hypotheses and may suggest profiles of bacterial signatures or microbial metabolites, to be used as biomarkers to predict the quality of anticoagulation. This could lead to the design of intervention strategies modulating gut microbiota, for example, by using probiotics.

Using machine learning to predict anticoagulation control in atrial fibrillation: A UK Clinical Practice Research Datalink study

Abstract Objective To investigate the predictive performance of machine learning (ML) algorithms for estimating anticoagulation control in patients with atrial fibrillation (AF) who are treated with warfarin. Methods This was a retrospective cohort study of adult patients (≥18 years) between 2007 and 2016 using linked primary and secondary care data (Clinical Practice Research Datalink GOLD and Hospital Episode Statistics). Various ML techniques were explored to predict suboptimal anticoagulation control, defined as time in therapeutic range (TTR) Results 35,479 patients were eligible for inclusion, of whom 24,684 and 10,795 were assigned to the training (32,683 unique LOTs) and holdout sets (14,218 unique LOTs). Across all models, depression (diagnosis and/or prescription of antidepressant medication) was a significant driver in predicting anticoagulation control. At baseline, XGBoost was the best-performing model (area under the curve [AUC]: 0.624) due to its ability to identify non-linear associations such as age and weight (greater probability of suboptimal control: 80 years and Conclusion ML algorithms displayed clinically useful ability to predict patients who are at greater risk of suboptimal control. The addition of time-varying data to the algorithm, especially prior INR measurements, improved predictive performance. These algorithms provide improved predictive tools for identifying patients who may benefit from more frequent INR monitoring or switching to alternative therapies.

A new index to predict quality of anticoagulation control in patients on vitamin K antagonists: the DAFNE score.

Aim: To derive a new clinical score to improve the prediction of those at risk of poor International Normalized Ratiocontrol among patients with atrial fibrillationtaking vitamin K antagonists. Materials & methods: The score was calculated using PAULA database and validated in the FANTASIIA population. Results: The DAFNE score (cardiovascular Disease, concomitant treatment with Amiodarone, Food/dietary transgressionand taking ≥7 pills daily, fEemale sex) score was related to a higher probability of poor International Normalized Ratio control. C-indexes were 0.611 and 0.576 (De Long test, p=0.007) for the DAFNE and SAMe-TT2R2 scores, respectively. Conclusion: The DAFNE score is a new clinical score which may potentially help determine those patients with atrial fibrillation who are at high risk of poor anticoagulation control with vitamin K antagonists.

Influence of sex-based differences on oral anticoagulation control in patients taking coumarin derivatives: a systematic review protocol.

This review will aim to assess the influence of sex-based differences on oral anticoagulation control in patients taking coumarin derivatives. Coumarin derivatives, such as warfarin, have a narrow therapeutic index, requiring frequent monitoring to achieve adequate anticoagulation control, which can be assessed by the time in therapeutic range. Differences in the quality of oral anticoagulation control between men and women have been reported, although the current evidence is controversial. A systematic review on this topic would provide results that could be incorporated into clinical practice to enhance oral anticoagulation control and treatment outcomes. Observational and experimental studies were assessed for eligibility, with participants aged ≥18 years of either sex taking oral anticoagulation or other coumarin derivatives for ≥3 months, for any indication of chronic use, who had oral anticoagulation control evaluated by time in therapeutic range. Electronic databases to be searched include MEDLINE, BVS, CINAHL, Embase, Cochrane CENTRAL, and Web of Science. Two reviewers will independently perform title/abstract selection and screening, and then full text retrieval and screening of articles that meet the inclusion criteria. The evaluation of methodological quality and data extraction will also be performed by two independent reviewers. Data will be synthesized in tables and then the compiled results will be meta-analyzed. In the presence of subgroup differences, meta-regression methods will be used to investigate the effects of categorical or continuous covariates. If statistical pooling is not possible, a narrative synthesis will be presented. PROSPERO (CRD42019128329).

Determinants of Anticoagulation Control in Patients Receiving Warfarin Therapy

Background: Warfarin, nowadays is considered one of the most prescribed anticoagulant medications. In England for example, there is at least 1% of the whole population being prescribed warfarin. Despite the emergence of new agents of anticoagulants like NOACS, warfarin still prevail in most prescriptions knowing that it can’t be substituted in certain indications. Objectives: To assess different factors associated with International Normalized Ratio (INR) control in patients who are on warfarin therapy for different indications. Methods: A retrospective cohort study conducted in National Heart Institute Outpatient Anticoagulation Clinic over six-month period. It included 250 patients on warfarin therapy for different indications. Results: After calculating Time in Therapeutic Range (TTR) of each patient the level of anticoagulation control was determined using the following cut off values: a) Good control: TTR>70%, b) Intermediate control: TTR 50 -70 %, c) Poor control: TTR <50%. Majority of patients in our study 62% had poor control with TTR less than 50%. Conclusion: Majority of patients have poor anticoagulation control by means of TTR. Male gender, higher education and employment status are associated with higher mean TTR and better anticoagulation control. Male gender and employment were significant predictors for good INR control.

Determinants of Anticoagulation Control in Patients Receiving Warfarin Therapy

Background: Warfarin, nowadays is considered one of the most prescribed anticoagulant medications. In England for example, there is at least 1% of the whole population being prescribed warfarin. Despite the emergence of new agents of anticoagulants like NOACS, warfarin still prevail in most prescriptions knowing that it can’t be substituted in certain indications. Objectives: To assess different factors associated with International Normalized Ratio (INR) control in patients who are on warfarin therapy for different indications. Methods: A retrospective cohort study conducted in National Heart Institute Outpatient Anticoagulation Clinic over six-month period. It included 250 patients on warfarin therapy for different indications. Results: After calculating Time in Therapeutic Range (TTR) of each patient the level of anticoagulation control was determined using the following cut off values: a) Good control: TTR>70%, b) Intermediate control: TTR 50 -70 %, c) Poor control: TTR <50%. Majority of patients in our study 62% had poor control with TTR less than 50%. Conclusion: Majority of patients have poor anticoagulation control by means of TTR. Male gender, higher education and employment status are associated with higher mean TTR and better anticoagulation control. Male gender and employment were significant predictors for good INR control.

Cost and burden of poor anticoagulation control with vitamin K antagonists in patients with nonvalvular atrial fibrillation in Spain

Introduction and objectivesThe aim of this analysis was to evaluate the burden and cost of complications due to poor anticoagulation control in patients with nonvalvular atrial fibrillation (NVAF) treated with vitamin K antagonists (VKA) in Spain. MethodsAn analytical model was used to estimate annual differences in ischemic stroke, major bleeding, deaths, costs, and potential years of life lost between patients with poor anticoagulation control (time in therapeutic range <65%) and adequate control (time in therapeutic range ≥ 65%) with a 1-year time horizon. Information on the target population (patients ≥ 65 years), event rates, and costs were obtained from national sources. Direct costs in euros (2018) were included from the perspective of the national health system (NHS) and direct and indirect costs from the societal perspective. A sensitivity analysis was performed with post-hoc data from the SPORTIF III/V trials. ResultsWe analyzed a hypothetical cohort of 594 855 patients, 48.3% with poor anticoagulation control, with an increase of 2321 ischemic strokes, 2236 major bleeding events and 14 463 deaths, and an annual incremental cost between €29 578 306 from the NHS perspective and €75 737 451 from the societal perspective. The annual impact of mortality was 170 502 potential years of life lost. The results of the sensitivity analysis showed that the annual cost would reach €97 787 873 from the societal perspective. ConclusionsPoor anticoagulation control with AVK has a strong impact on loss of health and on increased spending for the NHS.

Carga y coste del mal control de la anticoagulación con antagonistas de la vitamina K en pacientes con fibrilación auricular no valvular en España

Introduction and objectivesThe aim of this analysis was to evaluate the burden and cost of complications due to poor anticoagulation control in patients with nonvalvular atrial fibrillation (NVAF) treated with vitamin K antagonists (VKA) in Spain. MethodsAn analytical model was used to estimate annual differences in ischemic stroke, major bleeding, deaths, costs, and potential years of life lost between patients with poor anticoagulation control (time in therapeutic range <65%) and adequate control (time in therapeutic range ≥ 65%) with a 1-year time horizon. Information on the target population (patients ≥ 65 years), event rates, and costs were obtained from national sources. Direct costs in euros (2018) were included from the perspective of the national health system (NHS) and direct and indirect costs from the societal perspective. A sensitivity analysis was performed with post-hoc data from the SPORTIF III/V trials. ResultsWe analyzed a hypothetical cohort of 594 855 patients, 48.3% with poor anticoagulation control, with an increase of 2321 ischemic strokes, 2236 major bleeding events and 14 463 deaths, and an annual incremental cost between €29 578 306 from the NHS perspective and €75 737 451 from the societal perspective. The annual impact of mortality was 170 502 potential years of life lost. The results of the sensitivity analysis showed that the annual cost would reach €97 787 873 from the societal perspective. ConclusionsPoor anticoagulation control with AVK has a strong impact on loss of health and on increased spending for the NHS.

Use of SAMe-TT₂R₂ Score to Predict the Quality of Anticoagulation Control in Patients with Atrial Fibrillation Receiving Warfarin in Thailand

Objective: To predict the quality of anticoagulation control in patients with atrial fibrillation (AF) receiving warfarin in Thailand. Materials and Methods: The present study retrospectively recruited Thai AF patients receiving warfarin for three months or longer between June 2012 and December 2017 in Central Chest Institute of Thailand. The patients were classified into those with SAMe-TT₂R₂ of 2 or less, and 3 or more. The Chi-square test or Fisher’s exact test was used to compare the proportion of the patients with poor time in therapeutic range (TTR) between the two groups of SAMe-TT₂R₂ score. The discrimination performance of SAMe-TT₂R₂ score was demonstrated with c-statistics. Results: Ninety AF patients were enrolled. An average age was 69.89±10.04 years. Most patients were persistent AF. An average CHA₂DS₂-VASc, SAMe-TT₂R₂, and HAS-BLED score were 3.68±1.51, 3.26±0.88, and 1.98±0.85, respectively. The present study showed the increased proportion of AF patients with poor TTR with higher SAMe-TT₂R₂ score. The AF patients with SAMe-TT₂R₂ score of 3 or more had a larger proportion of patients with poor TTR than those with SAMe-TT₂R₂ score of 2 or less with statistical significance when TTR was below 70% (p=0.03) and 65% (p=0.04), respectively. The discrimination performance of SAMe-TT₂R₂ score was demonstrated with c-statistics of 0.60, 0.59, and 0.55 when TTR was below 70%, 65% and 60%, respectively. Conclusion: Thai AF patients receiving warfarin had a larger proportion of patients with poor TTR when the SAMe-TT₂R₂ score was higher. The score of 3 or more could predict poor quality of anticoagulation control in those patients. Keywords: Time in therapeutic range, Poor quality of anticoagulation control, Warfarin, SAMe-TT₂R₂, Labile INR

Evaluation of the SAMe-TT2R2 score to predict the quality of anticoagulation control in patients with venous thromboembolism treated with vitamin K antagonists: Findings from the RIETE registry

BackgroundThe time in therapeutic range (TTR) of patients with venous thromboembolism (VTE) treated with vitamin K antagonists (VKA) is usually below recommended, leading to higher frequency of vascular events, bleeding and mortality. The SAMe-TT2R2 prediction score discriminates those patients with high or low probability of obtaining poor INR control and its use is recommended in patients with atrial fibrillation. Its usefulness has been evaluated in patients with VTE, with conflicting results. MethodWe included consecutive patients enrolled in Registro Informatizado Enfermedad TromboEmbolica (RIETE), a prospective multicenter VTE registry, treated with VKA for >90 days and a minimum of 3 INR determinations. We analyzed the relationship between the SAMe-TT2R2 score and TTR, determined by the Rosendaal method and by the percentage of INR determinations (after excluding the first month). A ROC curve was calculated considering a cut-off point of TTR ≥65% for good anticoagulation control. Results3893 patients were included and classified in high (1411 patients) or low (2482 patients) probability of obtaining poor INR control according to the total score obtained (0–1 points versus 2 points, respectively). TTR, calculated by direct method and Rosendaal method, was 51.2 (±23.4) and 55.4 (±25.9) in the high probability group; and 54.4 (±23.0) and 58.2 (±25.6) in the low probability group, respectively (p < 0.001 for both comparisons). The outcomes were similar between groups. The predictive capacity of the SAMe-TT2R2 score showed an area under the ROC curve of 0.54 (CI 95% 0.52–0.56) and 0.53 (CI 95% 0.51–0.55). ConclusionsIn patients with VTE treated with VKA, the SAMe-TT2R2 score discriminated those patients with high probability of obtaining poor INR control, but with a low predictive capacity. Further studies are required to assess the usefulness of the score in clinical decision-making.

Influence of renal function on vitamin K antagonist oral anticoagulation quality in non-valvular atrial fibrillation patients

Chronic kidney disease (CKD) has been related to poor quality of anticoagulation and an increased risk of bleeding. This study aims to evaluate the association between impaired renal function (eGFR < 60 mL/min/1.73 m 2 ) and anticoagulation control in patients with non-valvular atrial fibrillation (AF) on vitamin K antagonists (VKA) therapy. This is an ancillary analysis of the prospective NATURE AF registry (NAtionalTUnisianREgistry of Atrial Fibrillation). Between March and June 2017, we prospectively registered information of 912 patients with a recently diagnosed AF and they were followed for one year. Patients with CKD were in turn categorized according to their eGFR level (Stage 3A: 59–45 mL/min, Stage 3B: 44–30 mL/min, Stage 4:29-15 mL/min and Stage 5: < 15 mL/min). The calculations for the time in therapeutic range (TTR) were made for the 12 months in each group and compared with the TTR of patients without CKD. A total of 103 patients (11.4%) had eGFR < 60 mL/min/1.73 m 2 . Anticoagulation control levels progressively worsened across each stage of CKD till the stage 3B then it progressively improved in stages 4 and 5. In the subgroup of patients with preserved renal function (75.5%), the concomitant use of anti-platelet agents was associated with better TTR ( Table 1 ). Early stages of CKD seem to be associated with poorer anticoagulation control in patients with non-valvular AF taking VKA but without statistically significant difference. Larger studies with longer follow-up are necessary.

Factors associated with sub-optimal control of anticoagulation in patients with prosthetic heart valves taking oral anticoagulants in a sub-Saharan African setting.

Replacement of diseased valves reduces the morbidity and mortality rate associated with native valvular disease but comes at the expense of risking complications related to the implanted prosthetic device. Establishing the desired anticoagulation level in a sub-Saharan African setting may be a challenge. This study was conducted to determine the challenges of maintaining a desired level of anticoagulation and factors associated with sub-optimal anticoagulation in patients with prosthetic heart valves on chronic anticoagulation. We reviewed 73 patients who had undergone prosthetic valve replacement for chronic rheumatic valvular heart disease and were taking warfarin. The follow up ranged from one to 13 years. We studied international normalised ratio (INR) profiles of the patients for the six months preceding the study and defined optimal control as an INR of 2.5-3.5. We aimed to determine if there were factors associated with sub-optimal control of INR. Forty-two patients (57.5%) were female. Mean age of the participants was 21.5 ± 3.1 years (range 14-25 years). Warfarin was the anticoagulant in 55 (75.3%) of the patients and 18 (24.7%) were on combined warfarin and aspirin anticoagulation. Thirty-five (47.9%) patients had optimal control of their INR. Educational level of primary school or less, distance from follow-up medical facility of more than 300 km, quarterly or less-frequent check-up visit, and public health institution as a source of free warfarin supply were found to be significantly associated with sub-optimal control of INR. Educational level, distance from follow-up facility, number of follow-up visits and source of warfarin supply were found to be significantly associated with sub-optimal control of INR.

P2753Anticoagulation control and all-cause death in patients with operated valvular heart disease with and without atrial fibrillation receiving vitamin K antagonists

Abstract Introduction Good quality of anticoagulation in patients with valvular heart disease (VHD) is needed to reduce ischaemic complications. There is limited evidence on factors affecting anticoagulation control in patients implanted with mechanical or tissue prosthetic valve(s). Objective To examine quality, factors affecting anticoagulation control and all-cause death in VHD patients with and without atrial fibrillation (AF) receiving a vitamin K antagonist (VKA) oral anticoagulant. The relationship between INR control with all-cause death and ≥1 adverse clinical events (ACE) [thromboembolism, bleeding, cardiovascular hospitalisation and all-cause death] were explored. Methods Anticoagulation control of 456 VHD patients [164 (36%) with AF and 290 (64%) without AF] referred to a hospital-based anticoagulation clinic were assessed retrospectively by time in therapeutic range (TTR) (Rosendaal) and percentage of INRs in range (PINRR) for a median of (IQR) 6.2 years (3.3–8.5). VHD was defined by the presence of mechanical or tissue prosthetic valve at either the mitral or aortic site or both. Results Mean (SD) age 51 (14.7), 64.5% male, mean (SD) CHA2DS2-VASc score 2.0 (1.4), 96.1% mechanical prosthesis and 64% aortic valve replacement. VHD patients with AF had lower mean TTR and PINRR, lower proportion of optimal TTR (i.e.≥70%) despite similar number of INR tests compared to VHD patients without AF [Table 1]. Predictors of poor TTR on multivariate logistic regression analysis were female sex, AF and anaemia/bleeding history. Significantly higher proportions of VHD patients with AF died [Table 1]. More deaths (13.1% vs. 4.1%; p=0.011) and ≥1 ACE (42.7% vs. 27.6%; p=0.006) were seen in VHD patients with TTR &lt;70% vs. TTR≥70%, respectively. Table 1 N (%) Total (N=456) AF (N=164) No AF (N=290) p-value Mean (SD) TTR 58.5 (14.6) 55.7 (14.2) 60.1 (14.6) 0.002 TTR ≥70% 98 (21.5) 23 (14.0) 75 (25.7) 0.004 Mean (SD) PINRR 50.1 (13.8) 47.4 (13.5) 51.6 (13.7) 0.002 Mean (SD) INR tests 96.2 (55.3) 100.7 (58.8) 93.7 (53.1) 0.19 All-cause death 51 (11.2) 34 (20.7) 17 (5.8) &lt;0.001 AF: Atrial fibrillation; IQR: interquartile range; PINRR: percentage of INRs in range; SD: standard deviation; TTR: Time in therapeutic range. Conclusion The quality of anticoagulation in VHD patients with AF was low. The presence of AF, anaemia/bleeding history and female sex independently predicted poor TTR. All-cause death was more common in VHD patients with AF and poor TTR. Closer INR monitoring is needed especially in VHD patients with AF to improve anticoagulation control and prevent adverse clinical outcomes. Acknowledgement/Funding Kementerian Pendidikan Malaysia and Universiti Teknologi MARA for PhD study but not directly for work under consideration

Quality of Chronic Anticoagulation Control in Patients with Intracranial Haemorrhage due to Vitamin K Antagonists.

Introduction Patients treated with vitamin K antagonists (VKA) are at increased risk of intracranial haemorrhage (ICH). The purpose of our study was to determine the quality of previous anticoagulation control in patients with VKA-associated ICH. Materials and Methods We prospectively assessed every consecutive patient admitted to our stroke unit with VKA-associated ICH between 2013 and 2016. Demographic, clinical, and radiological variables, as well as consecutive international normalized ratios (INR) during 7 previous months, were extracted. Time in therapeutic range (TTR), time over range (TOR), time below range (TBR), and percentage of INR within range (PINRR) were calculated. Results and Discussion The study population comprised 53 patients. Mean age was 79 years; 42% were women. Forty-eight patients had atrial fibrillation (AF) and 5 mechanical prosthetic valves. Therapeutic or infratherapeutic INR on arrival was detected in 64.4% of patients (95% CI 2.7 to 3.2). TTR was 67.8% (95% CI: 60.2 to 75.6 %) and PINRR was 75% (95% CI: 49.9-100). TOR was 17.2% (95% CI: 10.4 to 23.9% ) and TBR was 17% (95% CI: 10.6 to 23.9%). ConclusionVKA-associated ICH happens usually in the context of good chronic anticoagulation control. Newer risk assessment methods are required.