Development of an interview-based warfarin nomogram predicting the time spent in the therapeutic INR range: A cost-effective, and non-invasive strategy building from a cross sectional study in a low resource setting

A cross-sectional study was conducted to predict time in therapeutic range (TTR) using clinical history, examination, and socioeconomic data. Study included warfarin-receiving patients from outpatient-clinic. In 203 patients studied, mean warfarin start-dose was 2.55 mg/day and maintenance-dose/week was 30.79 mg. Body mass index (BMI) (p ¼ 0.03), warfarin maintenance dose/day (p ¼ 0.02), and comorbidity presence (p ¼ 0.04) were significantly associated with TTR. Occupation (p ¼ 0.53), income (p ¼ 0.83), education (p ¼ 0.55), and socioeconomic score (p ¼ 0.73) showed non-significant association with TTR. A TTR predicting nomogram was built from clinical history and examination findings.

Análisis de la calidad de la anticoagulación con antagonistas de la vitamina K en tres escenarios clínicos en México / Analysis of the quality of anticoagulation with vitamin K antagonists in three clinical scenarios in Mexico

Resumen Introducción: Los antagonista de la vitamina K (AVK) son una alternativa terapéutica en los pacientes con enfermedad tromboembólica venosa; sin embargo, numerosos factores afectan su farmacología. Objetivo: Evaluar la calidad de la anticoagulación AVK durante tres diferentes periodos en México. Métodos: Estudio prospectivo, anidado en cohortes de pacientes en tres escenarios clínicos entre los años 2013-2019. Se incluyeron pacientes no hospitalizados con indicación para recibir AVK por al menos 12 meses, quienes fueron manejados de acuerdo con el criterio del médico tratante. Resultados: Las características generales de los pacientes fueron similares entre los grupos, excepto por la indicación para usar los AVK. Se analizaron los resultados de 4148 pacientes y 38 548 evaluaciones de INR. Los tiempos en rango terapéutico durante las tres fases del estudio y los datos acumulados fueron significativamente mayores en la clínica de anticoagulación. Solo el número de visitas de control de los pacientes se asoció significativamente con los resultados, a diferencia de la edad, el sexo y el tipo de AVK. Conclusiones: Los AVK se utilizan ampliamente, pero es difícil alcanzar la meta terapéutica, sobre todo en servicios clínicos no especializados. La creación de clínicas de anticoagulación es una necesidad urgente en el sistema mexicano de salud.

Abstract Introduction: Vitamin K antagonists (VKA) are a therapeutic alternative in patients with venous thromboembolic disease; however, numerous factors affect their pharmacology. Objective: To evaluate the quality of VKA anticoagulation at three different time periods in Mexico. Methods: Prospective study, nested in patient cohorts at three different clinical scenarios between 2013 and 2019. Outpatients with indication for treatment with VKAs for at least 12 months were included. Patients were managed according to the criteria of the treating physician. Results: Patient general characteristics were similar between groups, except for the VKA indication. The results of 4,148 patients and 38,548 INR assessments were analyzed. The times in therapeutic range during the three phases of the study and pooled data were significantly higher for the anticoagulation clinic. Only the number of patient visits was significantly associated with the results, unlike age, gender, and type of VKA. Conclusions: VKAs are widely used, but it is difficult for therapeutic goals to be achieved, especially in non-specialized clinical services. Creation of anticoagulation clinics is an urgent need for the Mexican health system.

Study on warfarin dose adjustment strategy at different stages after mechanical valve replacement of mitral valve / 中国胸心血管外科临床杂志

@#Objective    To explore the anticoagulant strategy of adjusting the dose of warfarin at different stages after mechanical valve replacement of mitral valve. Methods    Clinical data of a total of 302 patients, including 76 males and 226 females, with an average age of 50.1±10.1 years, who underwent mechanical mitral valve replacement in the Chinese adult cardiac surgery database from 2013 to 2017 were retrospectively analyzed. According to the dose adjustment strategy of taking warfarin, the patients were divided into a D group (adjusting warfarin dose in days) and a W group (adjusting warfarin dose in weeks) to evaluate the anti-coagulation effect of warfarin. Results    The total follow-up time was 423 277 d (1 159.7 years). There was no significant difference in the overall anticoagulant strength, and the warfarin dose adjusted in days was better in the early postoperative period (P<0.05), especially in patients over 60 years. It was better to adjust warfarin dose in weeks in the middle and long periods (P<0.05), especially in patients ≤40 years. In terms of the stability of anticoagulation, it was better to adjust the dosage of warfarin in weeks (P<0.05). It was better to adjust the dosage of warfarin in weeks for early, middle- and long-term anticoagulant therapy after operation (P<0.05), especially in the females aged >40 and ≤50 years. Conclusion    Within the target range of international normalized ratio (1.5-2.5), the anticoagulant strategy of adjusting warfarin dose in days after mechanical valve replacement of mitral valve can   achieve a better anticoagulant strength, and adjusting the dosage of warfarin in weeks is better in the middle- and long-term after operation. In general, the anticoagulant effect is more stable in the short term when warfarin dose is adjusted on a weekly basis.

SAMe-TT2R2 score for prediction of suboptimal time in therapeutic range in a Thai population with atrial fibrillation

INTRODUCTION@#International normalised ratio (INR) control is an important factor in patients with non-valvular atrial fibrillation (NVAF) being treated with warfarin. INR control was previously reported to be poorer among Asians compared to Westerners. We aimed to validate the SAMe-TT2R2 score for prediction of suboptimal INR control (defined as time in therapeutic range [TTR] < 65% in the Thai population) and to investigate TTR among Thai NVAF patients being treated with warfarin.@*METHODS@#INR data from patients enrolled in a multicentre NVAF registry was analysed. Clinical and laboratory data was prospectively collected. TTR was calculated using the Rosendaal method. Baseline data was compared between patients with and without suboptimal INR control. Univariate and multivariate analyses were performed to identify variables independently associated with suboptimal INR control.@*RESULTS@#A total of 1,669 patients from 22 centres located across Thailand were included. The average age was 69.1 ± 10.7 years, and 921 (55.2%) were male. The mean TTR was 50.5% ± 27.5%; 1,125 (67.4%) had TTR < 65%. Univariate analysis showed hypertension, diabetes mellitus, heart failure, renal disease and SAMe-TT2R2 score to be significantly different between patients with and without optimal TTR. The SAMe-TT2R2 score was the only factor that remained statistically significant in multivariate analysis. The C-statistic for the SAMe-TT2R2 score in the prediction of suboptimal TTR was 0.54.@*CONCLUSION@#SAMe-TT2R2 score was the only independent predictor of suboptimal TTR in NVAF patients being treated with warfarin. However, due to the low C-statistic, the score may have limited discriminative power.

The Impact of Clinical Pharmacy Services on the Quality of Warfarin Anticoagulation Therapy Management / 中国药学杂志

OBJECTIVE: To evaluate the effects of clinical pharmacy services in patients with warfarin and highlight the important role of clinical pharmacists. METHODS: Patients in need of warfarin were enrolled as intervention group during 2016.9-2017.9 to receive standard anticoagulation management and follow-up provided by clinical pharmacists, and clinical data of patients who meet the inclusion criteria during 2013.7-2015.7 as control group was analyzed retrospectively. International normalized ratio(INR) values, maintenance doses, time to achieve therapeutic range, and etc. were recorded and TTRs (time in therapeutic range) were calculated to compare the outcomes of each group. RESULTS: TTRs in intervention group were significantly higher than those in control group, and so was the percentage of patients with the best quality of warfarin therapy(47.89% vs. 20.09%,P<0.001).Time to achieve therapeutic range was shorter and the frequency of INR test was higher in intervention group compared with those in control group. Patients′ cognitive scores of warfarin therapy were substantially increased after pharmacist′s education. CONCLUSION: Anticoagulation therapy management provided by clinical pharmacists could significantly improve the quality of warfarin therapy.

Quality of Anticoagulation with Warfarin in Korean Patients with Atrial Fibrillation and Prior Stroke: A Multicenter Retrospective Observational Study

BACKGROUND AND PURPOSE: The quality of anticoagulation is critical for ensuring the benefit of warfarin, but this has been less well studied in Korean ischemic stroke patients with atrial fibrillation (AF). METHODS: This study retrospectively analyzed the data of patients who had an AF-related ischemic stroke and were treated with long-term warfarin therapy in 16 Korean centers. The quality of warfarin therapy was primarily assessed by the time in therapeutic range [TTR; international normalized ratio (INR), 2.0–3.0] and additionally by the proportion of INR values within the therapeutic range. RESULTS: The long-term warfarin-treated cohort comprised 1,230 patients. They were aged 70.1±9.7 years (mean±SD), 42.5% were female, and their CHA₂DS₂-VASc score was 4.75±1.41. The TTR analysis included 33,941 INR measurements for 27,487 months: per patients, 27.6 (SD, 22.4) INR measurements for 22.4 (SD, 12.9) months. The mean TTR of individual patients was 49.1% (95% confidence interval, 47.9–50.3%), and the TTR quartiles were 64.5%. None of the 16 centers achieved a mean TTR of >60%. Of all INR measurements, 44.6% were within the therapeutic range, 41.7% were 3.0. CONCLUSIONS: In Korean ischemic stroke patients who had AF, the quality of warfarin therapy was low and might be inadequate to effectively prevent recurrent stroke or systemic embolism.

Quality Evaluation of Anticoagulant Therapy in Patients Who Taking Warfarin in Our Hospital / 中国药房

OBJECTIVE:To evaluate the quality of anticoagulant therapy in patients who took warfarin and provide data sup-porting for strengthening the management of these patients. METHODS:A retrospective analysis of related clinical data of 214 pa-tients who meet the inclusion criteria was performed. RESULTS:The average time for patients took warfarin was (321.64 ± 189.50)d,average times for tested INR was(12.01±7.03)times in clinic;when anticoagulant therapy,INR3.0 accounted for 8.91%;patients with target INR≤2.0 accounted for 45.33%,target INR=2.5 accounted for 38.32%,and target INR≥3.0 accounted for 0.93%;the average TTR was (50.80 ± 22.32)%;and there was no statistical significance in the TTR of different ages and diseases(P>0.05). CONCLUSIONS:The anti-coagulant therapy in some patients who took warfarin shows poor quality,it needs strengthening the quality management to make it safe and effective.

Evaluation of Peri-procedural Warfarin Therapy Undergoing Cardioversion in Patients with Atrial fibrillation

OBJECTIVE: Direct current cardioversion for atrial fibrillation could be associated with the risk of thromboembolic events. Anticoagulation therapy with warfarin (INR 2.0-3.0) is recommended 3 weeks before and 4 weeks after cardioversion to reduce the risk of thromboembolism. This study evaluated warfarin therapy in pharmacist-managed anticoagulant services (ACS). METHODS: This retrospective study was performed in 106 patients with atrial fibrillation from 2012 to 2013. The primary efficacy endpoint was the composite of stroke, transient ischemic attack, myocardial infarction, and cardiovascular death. The primary safety measure was major bleeding. To evaluate the peri-procedural effects of warfarin treatment, we studied whether target INR was maintained, as well as the maintenance period of the therapeutic range. Quality of treatment was measured by time in therapeutic range (TTR) by using the Rosendaal method. RESULTS: There were no thromboembolic events, but TEE examination at time of cardioversion showed a left atrial thrombus in three patients (2.8%). Bleeding complications after cardioversion occurred in 2 patients (1.9%). The average INR value at the time of cardioversion was 2.59±0.8, and was within the therapeutic range in 83 patients (78%). Analysis of the patients in whom the value was within the therapeutic range twice consecutively showed that the ratio of TTR was 80% and the therapeutic range was maintained in 67 patients (63%) for an average of 4.90 weeks prior to cardioversion. Similarly, 76 patients (72%) had a stable INR within the therapeutic range for an average of 5.70 weeks and a mean TTR of 83%. CONCLUSION: Pharmacists significantly contributed to appropriate warfarin treatment with close monitoring during cardioversion. Likewise, active pharmacist monitoring and systemic management should be considered to reduce thromboembolism and bleeding complications in the peri-cardioversion period.

Point of care testing for proper use of warfarin in physician-pharmacist cooperative practice : assessment of patient adherence to therapeutic regimens and time in therapeutic range / 日本プライマリ・ケア連合学会誌

<b>Objectives</b> : A pharmacotherapeutic system for safe and proper use of warfarin was developed through physician-pharmacist cooperative practice ; its effects on patient adherence to therapeutic regimens and the therapeutic benefit of warfarin were assessed.<br><b>Methods</b> : Subjects were 12 outpatients or home-care patients receiving warfarin. Patients' level of understanding of warfarin therapy and time in therapeutic range (TTR) were used as indices of adherence and therapeutic benefit, respectively. Before the physician examination, patients were interviewed by pharmacists using point-of-care testing with the CoaguChek ^®XS to check their prothrombin time-international normalized ratio (PT-INR). Pharmacists reported status of warfarin administration, any adverse effects, and medication management status to each patient's physician using the medication record or inter-institute information exchange sheet. Patient adherence was assessed before and after the pre-examination interview and changes in TTR were evaluated.<br><b>Results</b> : Levels of understanding of warfarin therapy were significantly higher after pharmacists provided medication counseling (immediately before 4.8±1.9 vs 24 weeks after 6.8±2.4 ; P=0.0079, Wilcoxon signed-rank test). TTR significantly improved at 24 weeks after the interview (pre-interview 20.9±29.8% vs post-interview 60.5±30.5%, respectively ; P=0.0024, Wilcoxon signed-rank test).<br><b>Conclusion</b> : The results suggest that patients'adherence to warfarin regimens and the therapeutic benefit of warfarin is improved by pharmacists'obtaining information on PT-INR before patients'medical examinations, as well as by utilizing this information to establish a cooperative pharmacotherapeutic system for good TTR management, as supported by a common protocol across pharmacies and medical institutions.