International Normalized Ratio Control Research Articles

Bilateral Acute Limb Ischemia due to Severe Rheumatic Mitral Stenosis and Atrial Fibrillation with Neglected International Normalized Ratio Control

Bilateral Acute Limb Ischemia due to Severe Rheumatic Mitral Stenosis and Atrial Fibrillation with Neglected International Normalized Ratio Control

Patient-reported treatment burden: comparison between vitamin-K antagonist and non-vitamin K antagonist oral anticoagulants

Abstract Introduction Treatment burden (TB) is defined as the overall workload that maintenance or improvement of their functioning and well-being poses on patients with chronic medical conditions. A high patient-reported TB has been associated with lower adherence to treatment and increased risk of major adverse events including death. We explored the differences in patient-reported TB value and prevalence of unacceptably high TB score (≥59 points) between patients receiving vitamin K antagonist oral anticoagulants (VKA) and non-vitamin K antagonist oral anticoagulants (NOAC). Furthermore, we explored contributory factors associated with TB and the relationship between TB and quality of life (QoL) in these patients. Methods A single-centre study included consecutive adult in- and outpatients on long-term oral anticoagulation, seen at a university clinical centre a from April to June 2019, who were willing to complete the Treatment Burden Questionnaire encompassing 13 items assessing the TB associated with taking medicine, self-monitoring, laboratory assessments, medical consultations, organisational and administrative requirements, adherence to dietary and physical activity recommendations, as well as the social repercussions of the treatment. Results Of 320 enroled patients, 206 (64.4%) were taking a VKA. Atrial fibrillation was the most common indication for long-term oral anticoagulation (n=299, 93.4%). The mean TB score was significantly higher in patients on VKA versus those taking a NOAC (48.8 ±26.5 vs. 41.8 ±19.7, P= 0.014), mostly owing to significantly higher TB values for questions related to self-monitoring, including the International Normalized Ratio (INR) control (3.85±3.32 vs. 1.62±1.38, P<0.001) and diet restrictions (3.98±3.43 vs. 2.48±2.49, P<0.001) in patients taking VKA (Figure 1). In addition, these patients significantly more often reported an unacceptably high TB of ≥59 points compared with those taking NOAC (30.1% vs 18.4%, P= 0.024). Multivariable regression analysis of predictors of TB in patients taking a VKA or NOAC are presented in Table 1. Conclusion In our study, patients receiving a VKA reported significantly higher TB compared to those using NOAC, especially regarding the questions about self-monitoring (including INR control) and diet restrictions. An unacceptably high TB was also more prevalent among patients receiving a VKA. Our findings suggest that prescribing NOACs in preference to VKAs could help in decreasing the self-reported TB in patients who need oral anticoagulant therapy.

Mechanical valve replacement for patients with rheumatic heart disease: the reality of INR control in Africa and beyond.

The majority of patients requiring heart valve replacement in low- to middle-income countries (LMICs) need it for rheumatic heart disease (RHD). While the young age of such patients largely prescribes replacement with mechanical prostheses, reliable anticoagulation management is often unattainable under the prevailing socioeconomic circumstances. Cases of patients with clotted valves presenting for emergency surgery as a consequence of poor adherence to anticoagulation control are frequent. The operative mortality rates of reoperations for thrombosed mechanical valves are several times higher than those for tissue valves, and long-term results are also disappointing. Under-anticoagulation prevails in these regions that has clearly been linked to poor international normalised ratio (INR) monitoring. In industrialised countries, safe anticoagulation is defined as >60%-70% of the time in the therapeutic range (TTR). In LMICs, the TTR has been found to be in the range of twenty to forty percent. In this study, we analysed >20,000 INR test results of 552 consecutive patients receiving a mechanical valve for RHD. Only 27% of these test results were in the therapeutic range, with the vast majority (61%) being sub-therapeutic. Interestingly, the post-operative frequency of INR tests of one every 3-4 weeks in year 1 had dropped to less than 1 per year by year 7. LMICs need to use clinical judgement and assess the probability of insufficient INR monitoring prior to uncritically applying Western guidelines predominantly based on chronological age. The process of identification of high-risk subgroups in terms of non-adherence to anticoagulation control should take into account both the adherence history of >50% of patients with RHD who were in chronic atrial fibrillation prior to surgery as well as geographic and socioeconomic circumstances.

Directions for optimizing the organization of long-term anticoagulant treatment

Background: In this study the organization of long-term anticoagulant treatment has been evaluated to estimate whether clinical practice is in accordance with current recommendations for optimal use and effective control of oral anticoagulant (OAC) treatment. Material and methods: Mixed (quantitative and qualitative), transversal, descriptive, selective study. Samples: quantitative study – 394 adult patients, eligible for anticoagulant treatment; qualitative study – 39 family doctors. Results: The rate of use of OAC treatment is 68%. The period from the diagnosis of the disease to the initiation of OAC treatment lasted one month or more in 59.1% of patients. 60.6% of patients do not have sufficient knowledge regarding the treatment of OAC. The high price is the most important barrier to direct oral anticoagulant administration (91.1%). Patients’ satisfaction with OAC treatment control is low, mainly for vitamin K antagonists (59.8%). 75.5% of respondents claim that OAC treatment control and management is poor. 40.3% do not perform safe therapeutic International Normalized Ratio control, and 54.7% are not in the optimal therapeutic range. Conclusions: The main barriers to adherence to OAC treatment: the burden of regular monitoring of blood parameters, perceived concern about complications, limited access to laboratory tests and specialist doctors, insufficient information about anticoagulation, and deficiencies in communication with medical staff. There is limited conviction, and uncertainty persists in the initiation and monitoring of OAC treatment by family doctors.

Effect of Previous INR Control during VKA Therapy on Subsequent DOAC Adherence and Persistence, in Patients Switched from VKA to DOAC.

Current guideline suggests a switch from vitamin K antagonist (VKA) to direct oral anticoagulant (DOAC) in patients with low time in therapeutic range (TTR < 70%). Poor international normalized ratio (INR) control may be the result of poor compliance, and might therefore be associated with subsequent DOAC intake. Therefore, this study evaluates the effect of previous TTR and other measures of INR control on DOAC nonadherence and nonpersistence, in patients who switched from VKA to DOAC. A total of 437 patients who switched from VKA to DOAC between 2012 and 2019 were included using data from Certe Thrombosis Service, IADB.nl pharmacy community database University Groningen, and Statistics Netherlands. DOAC prescriptions were used to determine nonadherence and nonpersistence. INR control (i.e., TTR, time under therapeutic range [TUR], and INR variability) was assessed during the last 180 days of VKA use. Multivariable regression models were applied to determine the association between INR control and DOAC nonpersistence/nonadherence. On VKA, 67.7% of the patients had a TTR below 70%. DOAC nonpersistence was 39.8% (95% confidence interval [CI]: 33.4-45.5%) during a median follow-up of 34.4 months (interquartile range: 19.1-49.2). Approximately 80% of persistent patients were DOAC-adherent. Low TTR was not associated with DOAC nonpersistence (hazard ratio: 1.14, 95% CI: 0.69-1.87) and DOAC nonadherence (odds ratio: 1.38, 95% CI: 0.67-2.84), nor were TUR and INR variability. Previous INR control during VKA therapy is not associated with subsequent DOAC nonadherence and nonpersistence. This study suggests that INR control on VKA cannot, and therefore should not, be used for predicting DOAC adherence or persistence.

Reasons for low adherence to anticoagulant therapy with warfarin

Objective. To assess patients' adherence to therapy with warfarin, to identify main reasons for its discontinuation or lack of timely the international normalized ratio (INR) monitoring. Material and methods. The database of anticoagulant rooms controlling the intake of warfarin was analyzed. Adherence to warfarin therapy was assessed by interviewing patients. The data were statistically processed using the computational program Statistica v10.0. Results. Only 20.6% of the patients who were prescribed warfarin to prevent thromboembolic events in the presence of non-valvular atrial fibrillation (AF) continue to take it. Of them, 69.2% regularly monitored INR. In the subgroup using warfarin after artificial heart valves had been installed; 32.4% of the patients continued its outpatient use; in 24.5% of them had an INR within the therapeutic range of ≥70%. There were main reasons for the termination of INR control: the fear of visiting polyclinics and anticoagulant rooms due to the epidemiological situation in 2021-2022; the presence of queues in the polyclinics; residence change and the inability to control INR within walking distance; movement difficulties experienced by patients with limited mobility; most patients stopped INR control because they were not properly informed about its necessity and the possible consequences of uncontrolled intake of warfarin. Conclusion. Among the patients with non-valvular AF and prosthetic heart valves who were prescribed warfarin, 74.9% stopped taking it after discharging from the hospital. The patients receiving warfarin in an outpatient setting controlled INR in ≤83.3% of cases.

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.

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.

SAIL study of stroke, systemic embolism and bleeding outcomes with warfarin anticoagulation in non-valvular atrial fibrillation (S4-BOW-AF).

In patients with non-valvular atrial fibrillation (NVAF) prescribed warfarin, the association between guideline defined international normalised ratio (INR) control and adverse outcomes in unknown. We aimed to (i) determine stroke and systemic embolism (SSE) and bleeding events in NVAF patients prescribed warfarin; and (ii) estimate the increased risk of these adverse events associated with poor INR control in this population. Individual-level population-scale linked patient data were used to investigate the association between INR control and both SSE and bleeding events using (i) the National Institute for Health and Care Excellence (NICE) criteria of poor INR control [time in therapeutic range (TTR) <65%, two INRs <1.5 or two INRs >5 in a 6-month period or any INR >8]. A total of 35 891 patients were included for SSE and 35 035 for bleeding outcome analyses. Mean CHA2DS2-VASc score was 3.5 (SD = 1.7), and the mean follow up was 4.3 years for both analyses. Mean TTR was 71.9%, with 34% of time spent in poor INR control according to NICE criteria.SSE and bleeding event rates (per 100 patient years) were 1.01 (95%CI 0.95-1.08) and 3.4 (95%CI 3.3-3.5), respectively, during adequate INR control, rising to 1.82 (95%CI 1.70-1.94) and 4.8 (95% CI 4.6-5.0) during poor INR control.Poor INR control was independently associated with increased risk of both SSE [HR = 1.69 (95%CI = 1.54-1.86), P < 0.001] and bleeding [HR = 1.40 (95%CI 1.33-1.48), P < 0.001] in Cox-multivariable models. Guideline-defined poor INR control is associated with significantly higher SSE and bleeding event rates, independent of recognised risk factors for stroke or bleeding.

Prevalence of oral anticoagulant therapy in clinical practice in patients hospitalized with acute ischemic stroke

Aim. To evaluate the prevalence of oral anticoagulant therapy at the outpatient and inpatient stages in patients hospitalized with ischemic stroke.Material and methods. This open observational prospective real-world study included 114 patients with atrial fibrillation (AF) hospitalized with confirmed stroke.Results. Only 26,3% of patients with AF hospitalized with a confirmed diagnosis of ischemic stroke took anticoagulants (70% — direct oral anticoagulants (DOACs), 30% — warfarin). At the same time, among those taking warfarin, only one patient had normal international normalized ratio (INR) at the time of hospitalization (INR 2,6). In all other cases, the INR was &lt;2. Of the 105 patients discharged at the outpatient stage, 93 (88,6%) patients were prescribed anticoagulants, and in most cases — DOACs (89 (84,8%)). 4 (3,8%) patients insisted on continuing warfarin therapy. There were following reasons for not prescribing DOACs: 4 (33,3%) patients were diagnosed with acute peptic ulcer during hospitalization, 2 (16,7%) — hemorrhagic transformation of the ischemic focus.Conclusion. One of the common reasons for stroke in outpatients with AF is the refusal to take oral anticoagulants or insufficient INR control when taking warfarin.

Vitamin K antagonist-associated microscopic hematuria.

Vitamin K antagonists (VKA) are the most widely used anticoagulants for the prevention of thrombotic events. Several renal adverse effects have been associated with the use of VKA. The main aim of our study was to explore the association between international normalized ratio (INR) levels and microscopic hematuria in patients with VKA. We performed a cross-sectional study of patients treated with VKA that attended the outpatient clinic for routine INR control. A simple urinalysis was performed on the day of the INR control and the precise number of red cells in the urine sediment was quantified. Demographic data, kidney function tests, comorbidities, anticoagulant dose and concomitant treatment were registered. A total of 337 patients were included with median INR levels of 2.6 (IQR 2.1-3.3). 11.9% of the patients presented microscopic hematuria (≥14 RBCs/µl). There was a significant correlation between INR levels and the number of red blood cells in the urine sediment (r=0.201, p=0.024). In the univariate analysis, microscopic hematuria was associated with having an INR >3.5 (19% vs. 10.2%, p=0.046), bacteriuria (15.2% vs. 3.6%, p=0.015), leukocyturia (14.8% vs. 6.6%, p= 0.026), hypertension (16.2% vs. 9.5%, p=0.053), and the use of renin-angiotensin system (RAS) blockers (6.9% vs. 17.2%, p=0.004). Multivariate logistic regression showed an association between microscopic hematuria and RAS blockade (OR 0.38, CI 95% 0.163-0.886, p=0.025), independent from INR levels, hypertension, leukocyturia or bacteriuria. INR overdose was significantly associated with the presence of microscopic hematuria. RAS blockade is an independent protective factor for the presence of microscopic hematuria in anticoagulated patients.

SARS-CoV-2 infection, hormonal contraception and pulmonary embolism in a 17-year-old female patient

The paper presents the history of a 17-year-old patient admitted to the paediatric cardiology department in a life-threatening condition with dyspnoea, blood desaturation up to 90% and chest pain. The patient contracted COVID-19 (she was not vaccinated), and additionally treated her acne with oestrogen hormonal drugs. Computed tomography of the chest revealed massive embolic changes in the pulmonary artery and its branches. After introduction of heparin under the control of activated partial thromboplastin time and then warfarin under the control of international normalised ratio (INR), regression of changes was achieved; however, the arterial vessel narrowed up to the upper lobe of the right lung. During cardiac catheterisation, the vessel was widened with a balloon and successfully opened. Follow-up echocardiography showed regression of changes, the dimensions of the right heart decreased, and the features of pulmonary hypertension disappeared. During the exercise test, she reached stage 4. After 2 months, to avoid patient exposure to radiation, follow-up magnetic resonance imaging of pulmonary vessels was performed instead of computed tomography, showing partial restoration of the artery. Currently, the patient is still taking warfarin (INR 2.5–3.5), is in good general condition and a lung scan is planned in the future.

Oral anticoagulants, time in therapeutic range and renal function over time in real-life patients with atrial fibrillation and chronic kidney disease

AimsTo describe the use of warfarin and direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) and chronic kidney disease (CKD), to evaluate changes in renal function over time...

Compliance of patients after prosthetics mitral double valve mechanical prostheses

Objective: to study and compare the influence of such factors as: gender, age, family status, level of education and the frequency of determination of the international normalized ratio (INR) on the compliance of patients after mitral valve replacement (MC) with mechanical prostheses in dynamics - after 6 and 12 months. Materials and methods: it were analyzed data of 260 patients after MC prosthetics with mechanical bicuspid prostheses. The Morisky-Green test was used to assess compliance.Results: the most committed to treatment were female, middle-aged persons with secondary specialized and higher education, as well as married persons. Among patients who monitored INR on a monthly basis, the percentage of compliant patients was higher compared to patients where this indicator was determined less than once a month. The dynamics of a decrease in the number of compliant patients after 12 months of follow-up was established. Conclusions: the data obtained indicate the need to carry out more active work on the formation of compliance with «vulnerable» categories of patients: with men, with elderly and young patients, with persons with secondary education, unmarried. The revealed tendency to decrease compliance after 12 months, regardless of the studied factor, indicates the importance of maintaining compliance in the long-term postoperative period. Also, the data obtained indicate the presence of a relationship between the multiplicity of INR control and compliance.

The influence of clinical and genetic factors on the stability of warfarin’s anticoagulant effect in patients with atrial fibrillation

The aim. To investigate the influence of clinical and genetic factors on the stability of warfarin’s anticoagulant effect in patients with atrial fibrillation (AF) during the year. Materials and methods. The study involved 60 patients with AF, age 70.50 (64.25; 76.25) years (32 men and 28 women). Coagulogram indexes with International Normalized Ratio (INR) were determined using Coag Chrome 3003 monthly; the CHA2DS2-VASC, HAS-BLED, SAMe-TT2R2 scales scores were evaluated; the calculation of TTR was performed using the Rosendaal method. CYP2C9, CYP4F2, VKORC1 genes polymorphisms were determined using multiplex real time polymerase chain reaction in CFX-96 thermocycler (BioRad). Results. Median TTR in groups of patients with SAMe-TT2R2 score &lt;2 (n = 33) and ≥2 (n = 27) did not differ significantly (74 % versus 68 % respectively, P &gt; 0.05). There were significantly more patients with TTR &lt;70 % in the group with predicted labile INR (59.36 % versus 30.30 %; χ2 = 5.07, P &lt; 0.05). SAMe-TT2R2 score ≥2 increased the risk of poor INR control by 1.96 times (CI 1.05–3.63). No association of TTR with CYP2C9, CYP4F2 and VKORC1 gene polymorphisms was found. Episodes of excessive hypocoagulation (INR &gt;4) were detected in 21 (40 %) patients during the year. Excessive hypocoagulation was significantly more common in patients carrying the allele A of the VKORC1 gene in comparison with non-carriers (51.43 % versus 24.00 %; χ2 = 4.57, P &lt; 0.05). The presence of mutant allele A was associated with 2.14-fold higher risk of excessive hypocoagulation (RR = 2.14; CI 1.06–4.69). Taking amiodarone (χ2 = 3.13; P &lt; 0.05) had a significant effect on the development of excessive hypocoagulation with a relative risk RR = 1.83 (CI 1.01–3.35). Conclusions. SAMe-TT2R2 score can be useful to predict poor INR control, while VKORC1 genotype estimating – to predict excessive hypocoagulation episodes. An integrated approach using clinical and genetic methods is needed to determine the potential efficacy and safety of warfarin therapy.

Feasibility study of the Fearon Algorithm in anticoagulation service guided warfarin management

BackgroundPatients receiving warfarin who spend a lower proportion of time in therapeutic international normalized ratio (INR) range (TTR) have a higher risk of both bleeding complications and thromboembolic events. Using warfarin dosing algorithms is one intervention associated with improved INR stability. ObjectiveTo determine the feasibility of an individualized warfarin dosing algorithm (Fearon Algorithm) under anticoagulation management service (AMS) care and compare measures of INR control using the algorithm with standard care. MethodsA pre/post intervention feasibility study consisting of the 12 months prior to patient enrollment (pre-study phase) and 6 months in which patients used the Fearon Algorithm under the supervision of an AMS pharmacist (AMS phase). The primary study outcome was the change in individual TTR. ResultsA total of 30 patients were enrolled in the study, 26 (87%) of whom successfully completed the AMS study phase using the Fearon Algorithm. Median corrected individual TTR increased significantly from 53% (IQR: 39%, 64%) during the year prior to enrollment to 63% (IQR: 57%, 73%) during the AMS phase (p < 0.01) The uncorrected TTR also increased significantly from 52% (IQR: 39%, 64%) to 61% (IQR: 57%, 72%) (p < 0.01). The Fearon Algorithm specified a smaller warfarin tablet strength in half the patients. ConclusionThe Fearon Algorithm is feasible for an AMS to implement in patients receiving long-term warfarin therapy and appears to improve TTR.

Anticoagulation Control in Older Atrial Fibrillation Patients Receiving Vitamin K Antagonist Therapy for Stroke Prevention.

Introduction Efficacy and safety of vitamin K antagonists (VKAs) among atrial fibrillation (AF) patients are enhanced when the International Normalised Ratio (INR) is 2.0–3.0. Anticoagulation control among older patients is perceived to be lower and contributes to poorer initiation and uptake. Objective To examine the quality of INR control, adverse clinical outcomes, and factors associated with bleeding in older AF patients (≥80 years). Methods Anticoagulation control assessed by time in therapeutic range (TTR) (Rosendaal method) and percentage INRs in range (PINRR). Among the 205 patients aged ≥80 years, 58.5% were female, with mean (SD) CHA2DS2-VASc 4.4 (1.3) and HAS-BLED 1.8 (0.8) scores. Results Mean (SD) TTR and PINRR were similar for those aged ≥80 vs. <80 years (66.7 (13.8) vs. 66.7 (13.1)) despite significantly lower INR monitoring intensity (51.2 (22.7) vs. 60.7 (25.8)) and shorter follow-up (4.4 (2.6–6.2) vs. 5.7 years (3.3–7.1)) in those ≥80 years of age. Good anticoagulation control (TTR and PINRR ≥70%) of 44% was seen in both age groups. No significant differences in composite major adverse clinical events were evident for those aged ≥80 vs. <80 years (p = 0.55). Cox regression analysis confirmed that age ≥80 years was associated with higher risk of bleeding (HR 1.90 (1.01–3.56); p = 0.047). Conclusions Suboptimal (TTR and PINRR <70%) anticoagulation control was evident in all patients. Risk of bleeding increased, but there was no difference in thromboembolic events and all-cause mortality in those aged ≥80 years. Improving TTR to ≥70% and enhancing anticoagulation monitoring of VKA use remain a clinical priority to prevent bleeding complications, particularly among those aged 80 years and above.

Virtual Education for Patient Self-Testing for Warfarin Therapy Is Effective During the COVID-19 Pandemic.

BackgroundPrior to the COVID-19 pandemic, warfarin users were required to complete in-person training in order to participate in approved international normalized ratio (INR) patient self-testing (PST) programs. To minimize in-person contact during the pandemic, a federal waiver of the in-person training requirement allowed new patients to begin PST after completing virtual training. However, it was uncertain whether such patients achieved comparable levels of INR control to patients receiving in-person training.MethodsINR results for patients receiving virtual training upon PST commencement between April 1, 2020, and December 31, 2020, were compared to those of patients initiating PST with in-person training between April 1, 2019, and December 31, 2019. The primary outcome was the difference in warfarin time in therapeutic range (TTR) between the groups, with secondary outcomes including differences in the percentages of INR values within individually prescribed INR range and of critical INR values.ResultsThe records of 33,683 patients were included in the analysis (13,568 in the “In-Person” sample; 20,115 in the “Virtual” sample). Patients in the Virtual sample achieved a TTR of 66.78%, compared to the In-Person sample (64.19%; absolute difference 2.59; 95% confidence interval [CI] = 2.50–2.68, p < 0.001). The TTR values were also statistically significantly higher in all subgroups evaluated across categories of patient age, gender, geography, and indication. Similarly favorable results were achieved for INR values in range and critical values.ConclusionVirtual education for PST for warfarin therapy is effective and should continue to be an option for patients and providers throughout the pandemic, and possibly beyond.

Antiphospholipid Syndrome (Clinical case)

40-year-old woman, unemployed. She sought Nutrition Consultation for nutritional control, as she was taking oral anticoagulant therapy. No other pathologies requiring nutritional therapy, but she wanted to lose a little weight. She is followed in the Thrombophilia Consultation for Antiphospholipid Syndrome (APS) for mutation of the prothrombin gene in heterozygosity. She takes warfarin as an oral anticoagulant, with INR (International Normalized Ratio) control. Keywords: International Normalized Ratio, nutritional intervention, vitamin K, Antiphospholipid Syndrome, warfarin

Clinical Impact of the Time in Therapeutic Range on Early Hospital Readmission in Patients with Acute Heart Failure Treated with Oral Anticoagulation in Internal Medicine

Patients with heart failure (HF) often present with non-valvular atrial fibrillation and require oral anticoagulation with coumarin anticoagulants such as acenocoumarol. The objective of this study was to evaluate the relationship between time in therapeutic range (TTR) and the risk of early readmission. A retrospective descriptive study was carried out on hospitalized patients with a diagnosis of HF between 2014 and 2018 who had adverse effects due to oral anticoagulation with acenocoumarol (underdosing, overdosing, or hemorrhage). Clinical, analytical, therapeutic, and prognostic variables were collected. TTR is defined as the duration of time in which the patient's International Normalized Ratio (INR) values were within a desired range. Early readmission was defined as readmission within 30 days after hospital discharge. Patients were divided into two groups depending on whether or not they had a TTR less than 60% (TTR < 60%) over the 6 months prior to the adverse event. In the cohort of 304 patients, the mean age was 82 years, 59.9% of the patients were female, and 54.6% had a TTR < 60%. Patients with TTR < 60% had a higher HAS-BLED score (4.04 vs. 2.59; P < 0.001) and INR (6 vs. 5.31; P < 0.05) but lower hemoglobin (11.67 vs. 12.22 g/dL; P < 0.05). TTR < 60% was associated with early readmission after multivariate analysis (OR: 2.05 (CI 95%: 1.16-3.61)). They also had a higher percentage of hemorrhagic events and in-hospital mortality but without reaching statistical significance. Patients with HF and adverse events due to acenocoumarol often have poor INR control, which is independently associated with a higher risk of early readmission.