Anticoagulation Control Research Articles

Sex differences in treatment strategy and adverse outcomes among patients 75 and older with atrial fibrillation in the MarketScan database

BackgroundWomen with atrial fibrillation (AF) experience greater symptomatology, worse quality of life, and have a higher risk of stroke as compared to men, but are less likely to receive rhythm control treatment. Whether these differences exist in elderly patients with AF, and whether sex modifies the effectiveness of rhythm versus rate control therapy has not been assessed.MethodsWe studied 135,850 men and 139,767 women aged ≥ 75 years diagnosed with AF in the MarketScan Medicare database between 2007 and 2015. Anticoagulant use was defined as use of warfarin or a direct oral anticoagulant. Rate control was defined as use of rate control medication or atrioventricular node ablation. Rhythm control was defined by use of anti-arrhythmic medication, catheter ablation or cardioversion. We used multivariable Poisson and Cox regression models to estimate the association of sex with treatment strategy and to determine whether the association of treatment strategy with adverse outcomes (bleeding, heart failure and stroke) differed by sex.ResultsAt the time of AF, women were on average (SD) 83.8 (5.6) years old and men 82.5 (5.2) years, respectively. Compared to men, women were less likely to receive an anticoagulant or rhythm control treatment. Rhythm control (vs. rate) was associated with a greater risk for heart failure with a significantly stronger association in women (HR women = 1.41, 95% CI 1.34–1.49; HR men = 1.21, 95% CI 1.15–1.28, p < 0.0001 for interaction). No sex differences were observed for the association of treatment strategy with the risk of bleeding or stroke.ConclusionSex differences exist in the treatment of AF among patients aged 75 years and older. Women are less likely to receive an anticoagulant and rhythm control treatment. Women were also at a greater risk of experiencing heart failure as compared to men, when treated with rhythm control strategies for AF. Efforts are needed to enhance use AF therapies among women. Future studies will need to delve into the mechanisms underlying these differences.

Anticoagulation control in atrial fibrillation patients with chronic kidney disease receiving warfarin for stroke prevention: The west Birmingham AF project

The effectiveness and safety of warfarin is optimised in atrial fibrillation (AF) patients when the International Normalised Ratio (INR) is 2.0–3.0. Anticoagulation control comparing different categories of kidney function has not been well-assessed, although poorer INR control may be more likely in AF patients with chronic kidney disease.

Anticoagulation Control in Different Ethnic Groups Receiving Vitamin K Antagonist for Stroke Prevention in Atrial Fibrillation.

Vitamin K antagonist such as warfarin reduces the risk of stroke in atrial fibrillation (AF) patients. Since warfarin has a narrow therapeutic index, its administration needs to be regularly monitored to avoid any adverse clinical outcomes such as stroke and bleeding. The quality of anticoagulation control with warfarin therapy can be measured by using time in therapeutic range (TTR). This review focuses on the prevalence of AF, quality of anticoagulation control (TTR) and adverse clinical outcome in AF patients within different ethnic groups receiving warfarin therapy for stroke prevention. A literature search was conducted in Embase and PubMed using keywords of “prevalence,” “atrial fibrillation,” “stroke prevention,” “oral anticoagulants,” “warfarin,” “ethnicities,” “race” “time in therapeutic range,” “adverse clinical outcome,” “stroke, bleeding.” Articles published by 1st February 2020 were included. Forty-one studies were included in the final review consisting of AF prevalence (n = 14 studies), time in therapeutic range (n = 18 studies), adverse clinical outcome (n = 9 studies) within different ethnic groups. Findings indicate that higher prevalence of AF but better anticoagulation control among the Whites as compared to other ethnicities. Of note, non-whites had higher risk of strokes and bleeding outcomes while on warfarin therapy. Addressing disparities in prevention and healthcare resource allocation could potentially improve AF-related outcomes in minorities.

Abstract 11404: Disparities in Anticoagulation for Atrial Fibrillation: A Systematic Review of Recent Literature

Atrial fibrillation (AF) causes 1 in 7 strokes as it is the most prevalent arrhythmia in the United States. 1 Previous work has shown that even with significant recurring AF and high CHA 2 DS 2 VASc scores, there are various disparities that occur within the prescription, type, and quality of anticoagulation control. One previous systematic review published in 2018 discusses disparities within anticoagulation for AF. Given the importance of health equity for this highly efficacious intervention, we aimed to review recent data on disparities with respect to anticoagulation for AF published after 12/31/17. This systematic review used the PubMed database to identify 19 articles that discuss disparities within anticoagulation for AF. We limited our search to articles published after 12/31/17. The search string consisted of 7 phrases that combined AF, anticoagulation, and disparities involving sex, race, ethnicity, income, socioeconomic (SE) status, etc. Articles were excluded if they focused on anticoagulation for conditions other than AF, if they did not discuss anticoagulation as a treatment for AF, and/or lack of inclusion of data referring to disparity as defined above. We found 7 articles on race and anticoagulation, 6 articles on anticoagulation and sex/gender, 3 articles that discussed SE status and anticoagulation, and 5 articles that discuss other types of disparity related to anticoagulation. Results showed that black populations were much less likely to be given anticoagulation than other patients. Black patients were more likely to be given warfarin over DOACs. Women were less anticoagulated than men even when their stroke risk was higher. Some studies in this review found that there were not statistically meaningful differences in anticoagulation use in women and men. Lower income and less educated patients were less likely to receive DOAC compared to warfarin. Compared to a prior systematic review, focusing on articles after 2017 revealed much more information about DOAC use. Disparities first noted in the warfarin era have persisted with DOACs. Given that we have identified disparities in anticoagulation with respect to race, sex, and SE status, more work is needed to identify mechanisms of these disparities and identify potential solutions.

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.

Time in Therapeutic Range (TTR) and the Efficacy of Anticoagulant Therapy in Preventing Thromboembolism in Cardiac Patients Receiving Warfarin at Shifa Medical Complex: A Cross-Sectional Study

Background: Anticoagulant control is assessed by Time in Therapeutic Range (TTR). For a given patient, TTR is defined as the duration of time in which the patient’s International Normalized Ratio (INR) values were within a desired range. Aim: To assess TTR in patients receiving anticoagulant treatment and the efficacy of Anticoagulant therapy in preventing Thromboembolism in Cardiac Patients receiving Warfarin for atrial fibrillation and with high CHADS VASC score, valvular and non-valvular heart disease at a referral center for cardiovascular diseases at Gaza Shifa Medical Complex, Palestine. Materials and Method: Over 8 months, we enrolled eligible patients presenting to Shifa Medical Complex in Gaza for regular INR testing. Demographic data, medical history, and current medications were determined for all participants. TTR was assessed by both tradition and cross-sectional methods. Results: A total of 46 patients (mean age 57.15±12.6 years, 50% women) underwent 230 INR measurements. The mean TTR was calculated as 50.86±21.37%. Participants of this study were assessed for their risk of having stroke using CHADS VASC score and risk of bleeding using HAS BLED score. Risk of stroke was significantly higher for females (P= 0.031). Of the sample patients, 47.8% were in the good control category (TTR &gt;60%), and 52.2% were in the poor control category (TTR &lt;60%). The mean TTR of the studied patients (54.9%) was below the good control range.There were 12 participants had thromboembolism of patients with low traditional TTR. This was statistically significant, TTR with occurrence of thromboembolism, (P= 0.001). Conclusion: We found a mean TTR of 50.86% among study patients diagnosed with atrial fibrillation and high CHADS VASC score, valvular and non - valvular heart disease who were receiving warfarin therapy. None of the risk factor was significantly related to low TTR values among study participants. The study showed the low TTR was associated with increased risk of thromboembolism among participants in this study. Moreover, showed the superiority of tradition TTR over cross-sectional TTR in evaluating anticoagulant therapy.

Switching of oral anticoagulants in patients with nonvalvular atrial fibrillation: A narrative review.

Approval of direct-acting oral anticoagulants (DOACs) for stroke prevention in atrial fibrillation (AF) was an important milestone, providing a wider range of treatment options and creating the possibility for drug switching after initiation. In addition to improved utilisation of oral anticoagulants (OACs) for stroke prevention, reports of switching among OACs are growing in the literature; switching may influence clinical outcomes, healthcare costs and patient satisfaction. This review aimed to summarise the current literature on the pattern of OAC switching in patients with AF, including reasons for switching and clinical consequences following switching. A literature search was conducted in PubMed, Scopus and Embase on 27 June 2020. We included 39 articles published after 2013, following the introduction of apixaban. The review found that switching among OACs was common in clinical practice, significantly varying with the type of OAC. Studies reporting the reason for switching and clinical outcomes were comparatively limited. The decision to switch was often related to safety issues (usually bleeding), poor anticoagulation control and ease of use. Patient characteristics, clinical conditions and drug interactions were found to be associated with switching from OACs. Findings regarding bleeding outcomes following switching were inconsistent, possibly confounded by the rationale for switching and the switching protocol. Noting the limited number of studies included and their relatively short follow-up periods, switching did not have a significant impact on the risk of stroke and other thrombotic outcomes. Further prospective studies are needed to understand better potential rationales for switching and the clinical outcomes.

Association of neighbourhood-level poverty with outcomes and clinical care following atrial fibrillation diagnosis in a universal healthcare system

Abstract Background There are limited data on the association of poverty with outcomes and care patterns after an atrial fibrillation (AF) diagnosis in jurisdictions with universal healthcare. The Canadian province of Ontario provides publicly funded healthcare and prohibits private payment for medically necessary physician and in-hospital care. It also covers prescription medications for residents aged &amp;gt;65 years. Purpose Determine the association of neighbourhood-level poverty with outcomes and processes of care after AF diagnosis in older people within a universal healthcare system. Methods Using linked administrative databases, we conducted a population-based cohort study of community-dwelling adults aged ≥66 years who were newly diagnosed with AF in Ontario between April 1, 2007 and March 31, 2019. The primary exposure was material deprivation of patients' neighborhood of residence. This metric is derived using Canadian census data to estimate inability to access and attain basic material needs. Neighborhoods were categorized by quintile of material deprivation from Q1 (wealthiest) to Q5 (poorest). We used cause-specific hazards regression models to study the association of deprivation quintile with time to the following outcomes over one year from AF diagnosis: death, ischemic stroke, bleeding, heart failure (HF) hospitalization, cardiology services, and AF-specific treatments. Models accounted for clustering by region of residence and adjusted for age, sex, diabetes, HF, stroke/transient ischemic attack, vascular disease, hypertension, bleeding history, rural residence, renal function, and setting of AF diagnosis (hospital, emergency department [ED] or outpatient). Results We studied 350,353 patients with AF (median age 78 years, 48.9% female). People from neighborhoods in higher deprivation quintiles (poorer) were more likely to be diagnosed in hospital/ED than outpatient settings. Relative to people from the wealthiest neighbourhoods (Q1), patients in the poorest neighbourhoods (Q5) had higher prevalence of baseline hypertension, diabetes, HF, vascular disease and other comorbidities. In adjusted analyses (Figure), higher quintiles of neighborhood poverty were associated with greater rates of death, ischemic stroke, bleeding, and HF hospitalization, but lower rates of cardiology visits, cardiac testing, anticoagulation, anti-arrhythmic medications, cardioversion, or AF ablation. Conclusions In a setting of universal healthcare and prescription medication coverage, people living in poorer neighbourhoods had worse baseline health and higher rates of adverse outcomes after an AF diagnosis. Despite this, people in poorer neighbourhoods had less cardiology visits and diagnostic tests and were less likely to receive anticoagulation and rhythm control interventions. This shows that universal healthcare and medication coverage are insufficient to achieve equitable health care and outcomes for people with AF. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): This research was funded by a Canadian Institutes of Health Research Foundation grant; and is supported by ICES (formerly the Institute for Clinical Evaluative Sciences), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC).

Association between transportation barriers and anticoagulation control among an inner‐city, low‐income population: A prospective observational cohort study

BackgroundAnticoagulation with warfarin represents a transportation‐sensitive treatment state. Transportation barrier is a common reason for not using health care services. ObjectiveTo assess the association between transportation barriers to anticoagulation clinic and anticoagulation control (AC) among an inner‐city, low‐income population. Patients/MethodsAdults expected to be on chronic warfarin therapy were recruited from an ambulatory anticoagulation clinic. Participants completed a validated questionnaire that assessed transportation barriers to clinic, defined as self‐reported trouble getting transportation to a clinic and a composite score of the presence of transportation barriers. Suboptimal AC was defined as time in therapeutic range (TTR) <60% over 6 months. Prevalence ratios with 95% confidence intervals (CIs), adjusted for age, sex, and annual household income, described the association of transportation trouble and barriers with AC. ResultsOf 133 participants, 42.9% had suboptimal AC. Mean age was 60.4 (SD, 13.6) years, and the majority of participants were women (62.2%). Participants with transportation trouble were more likely to report being disabled/unable to work (63.6%) and annual household income <$15 000 (45.5%). Mean TTR was significantly lower for participants with transportation trouble compared to those without (53.8% [SD, 24.7%] vs 64.7% [SD, 25.0%]; P= .03). Participants reporting transportation trouble or at least one transportation barrier were 1.60 (95% CI, 1.07‐2.39) and 1.68 (95% CI, 1.01‐2.80) times more likely, respectively, to have suboptimal AC compared to those without. ConclusionInner‐city, low‐income individuals with transportation barriers were more likely to have suboptimal AC. Further research is warranted to evaluate the impact of alleviating patient‐specific transportation barriers on anticoagulation outcomes.

Relationship between multimorbidity and outcomes in atrial fibrillation.

Multimorbidity is common in atrial fibrillation (AF) patients. Charlson comorbidity index (CCI) is used to evaluate multimorbidity in the general population. Limited long-term data are available on the relationship between CCI and AF. We examined the association between CCI, anticoagulation control and outcomes in AF patients. We studied 1956 from the FANTASIIA registry, an observational Spanish nationwide study on anticoagulated AF patients. Time in therapeutic range (TTR) was used to evaluate anticoagulation control. Stroke/TIA, major bleeding, cardiovascular (CV) death and all-cause death were study outcomes. Mean±SD CCI was 1.1±1.2. Based on CCI quartiles, patients were categorised in four groups: 676 (34.6%) in Q1 (CCI 0); 683 (34.9%) in Q2 (CCI 1); 345 (17.6%) in Q3 (CCI 2); and 252 (12.9%) in Q4 (CCI ≥3). In vitamin K antagonist treated patients, the highest CCI quartile was inversely associated with TTR >70% (odds ratio:0.67, 95% confidence interval (CI):0.45-0.99). During observation, a progressively higher rate of major bleeding, CV death and all-cause death was found across the quartiles (all p<0.001). The final Cox multivariable regression analysis showed an association with increasing risk for major bleeding occurrence in Q3 and Q4 (hazard ratio (HR):1.69, 95%CI:1.00-2.87 and HR:1.92, 95%CI:1.08-3.41). An increasing risk for all-cause death and CV death was found across CCI quartiles. In a nationwide contemporary cohort of AF anticoagulated patients, multimorbidity was inversely associated with good anticoagulation control. A progressively higher risk for major bleeding, CV death and all-cause death was found across CCI quartiles.

Recurrent bleeding and thrombotic events after resumption of oral anticoagulants following gastrointestinal bleeding: Communication from the ISTH SSC Subcommittee on Control of Anticoagulation

BackgroundGastrointestinal bleeding frequently complicates anticoagulant therapy causing treatment discontinuation. Data to guide the decision regarding whether and when to resume anticoagulation based on the risks of thromboembolism and recurrent bleeding are scarce. ObjectivesWe aimed to retrospectively evaluate the incidence of these events after anticoagulant‐related gastrointestinal bleeding and assess their relationship with timing of anticoagulation resumption. MethodsPatients hospitalized because of gastrointestinal bleeding during oral anticoagulation for any indication were eligible. All patients were followed up to 2 years after the index bleeding for recurrent major or clinically relevant non‐major bleeding, venous or arterial thromboembolism, and mortality. ResultsWe included 948 patients hospitalized for gastrointestinal bleeding occurring during treatment with vitamin K antagonists (n = 531) or direct oral anticoagulants (n = 417). In time‐dependent analysis, anticoagulant treatment was associated with a higher risk of recurrent clinically relevant bleeding (hazard ratio [HR] 1.55; 95% confidence interval [CI] 1.08–2.22), but lower risk of thromboembolism (HR 0.34; 95% CI 0.21–0.55), and death (HR 0.50; 95% CI 0.36–0.68). Previous bleeding, index major bleeding, and lower glomerular filtration rate were associated with a higher risk of recurrent bleeding. The incidence of recurrent bleeding increased after anticoagulation restart independently of timing of resumption. ConclusionsAnticoagulant treatment after gastrointestinal bleeding is associated with a lower risk of thromboembolism and death, but higher risk of recurrent bleeding. The latter seemed to be influenced by patient characteristics and less impacted by time of anticoagulation resumption.

Tele-pharmacy Anticoagulation Clinic During COVID-19 Pandemic: Patient Outcomes.

Introduction: It is well-established that clinical pharmacist-managed anticoagulation services achieve superior anticoagulation control, with a positive impact. At King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia, the structure of anticoagulation management is a pharmacist-managed specialty service. With the current COVID-19 situation, measures were taken to assure the continuity of patient care by establishing tele-pharmacy anticoagulation clinics.Materials and Methods: This was a prospective study with patients prescribed anticoagulation and followed up for 3 months. Since establishing the anticoagulation virtual clinic in March 2020, 270 patients were recruited in the study. The data collected included age, gender, comorbidities, indication for anticoagulation, intended duration of treatment, warfarin dose, testing of International Normalized Ratio (INR), INR target, range of INR values, time INR that was within the therapeutic range (TTR), and complications of therapy (bleeding and/or bruises). The patients were asked to complete the pharmacist satisfaction survey (PSS) after their consultation to assess patient satisfaction with the new virtual consultation system. Linguistic and cultural validation was conducted for the questionnaire.Results: A total of 270 patients were included in the study. The mean percentage of overall INR values in the range was 59.39% ± 32.84, and the mean time with the overall INR was within the therapeutic range 57.81% ± 32.08. Thirty-one percent of the sample had good anticoagulation control (time in therapeutic range >70%). The median satisfaction score was 32 (IQR 28–36) with a maximum score of 40.Conclusion: This is the first study to assess the tele-pharmacy anticoagulation clinic’s efficiency and patient satisfaction in Saudi Arabia during the COVID-19 pandemic. This type of consultation was as effective as face-to-face consultations. The study also highlighted that though the reduction in the cost of care was not substantial, there was a significant increase in resource (clinical pharmacist) utilization as a result of this model. The adoption of tele-pharmacy resulted in time savings for the clinical pharmacists who can be utilized in many other improvement projects in adult ambulatory clinics to ensure the delivery of better quality and safe patient care.

Addendum to British Society for Haematology guideline on the investigation, management and prevention of venous thrombosis in children (Br. J. Haematol. 2011; 154: 196-207).

Addendum to British Society for Haematology guideline on the investigation, management and prevention of venous thrombosis in children (Br. J. Haematol. 2011; 154: 196-207).

Assessment of Anticoagulation Control Association with Warfarin Knowledge and Demographic Features of Iranian Population

Background: Warfarin is the most commonly used oral anticoagulant for patients with atrial fibrillation, prosthetic heart valves, and deep vein thrombosis with a narrow therapeutic index. Due to the importance of patients’ adherence to treatment and also regular measurements of International normalized ratio (INR), this can have a significant impact on the quality of anticoagulation control. Objectives: The primary aim of this study was to assess the association between warfarin knowledge and time in therapeutic range (TTR) in patients on warfarin anticoagulation for at least 6 months who were referred to anticoagulation clinic in Rajaie Heart Center during 2016 - 2017. Methods: In this cross-sectional study, 620 patients who had been referred to the outpatient Rajaie Hospital anticoagulant clinic and had been taking warfarin for over six months were asked to fill two questionnaires named anticoagulation knowledge assessment (AKA) during a 12-week period. After obtaining the necessary permits, TTR (by Rosendal method) was calculated using the INR results of patients. Results: A total of 620 patients completed the questionnaire. The relation between warfarin knowledge and anticoagulation control was not significant. The mean age of the study population was 52.45 SD ± 14.01 years. This study showed a significant relationship between TTR, duration of warfarin usage (PV = 0.03) and the underlying cause of this usage (PV = 0.016). Conclusions: Prevention of chronic diseases is one of the most important priorities of the health care systems. Reduction in complications such as thrombosis and bleeding can be achieved by efforts to promote patient’s knowledge. By recognition of relation between warfarin knowledge and social and demographic indicators, patient’s education gap can be detected and also planned for dissolving. This study showed that although many of the patients visited in anticoagulation clinic have poor anticoagulation control, but a major part of them have good knowledge of warfarin usage.

Relative risk of thrombo-embolisms and major bleedings is high in left ventricular assist device patients with unstable anticoagulation control

Background and Aims: Left ventricular assist device (LVAD) patients are at increased risk of thrombo-embolisms and major bleedings, making anticoagulation therapy challenging. Unstable anticoagulant control expressed as high international normalized ratio (INR) variability, is associated with clinical events in atrial fibrillation patients. However, data on this association in LVAD patients are unavailable. We therefore aimed to study the association between anticoagulant control and clinical events in patients with an LVAD.

Relationship between Chronic Kidney Disease, Time-in-Therapeutic Range, and Adverse Outcomes in Atrial Fibrillation: A post hoc Analysis from the AMADEUS Trial

Background: The benefit of anticoagulation therapy in atrial fibrillation (AF) and chronic kidney disease (CKD) remains controversial. We aimed to evaluate the impact of renal function on the quality of anticoagulation control, and the effects of both these factors on outcomes in AF. Methods: Post hoc analysis of the AMADEUS trial. Trial-related outcomes were adjudicated and we studied the composite of first stroke/major bleeding/all-cause mortality, ischaemic stroke, major bleeding, all-cause mortality, and cardiovascular mortality. Results: We included 2,282 vitamin K antagonist (VKA)-treated patients {n = 787 (34.5%) females; median age 72 (interquartile ranges [IQR] 64–77) years}. Median follow-up was 365 (IQR 189–460) days. There were 1,922 (84.2%) non-CKD and 360 (15.8%) CKD patients. Renal function was inversely correlated with time-in-therapeutic range (r = −0.047, p = 0.025). There was no statistical difference in terms of crude study outcomes based on renal function. Multivariable regression analysis demonstrated that moderate renal failure with estimated glomerular filtration rate of less than 60 mL/min/1.73 m² (p = 0.032) and percentage of time-in-therapeutic range (p = 0.011) were independent predictors for the composite outcome of stroke, major bleeding, and all-cause mortality. Conclusion: Deteriorated renal function has a small negative impact on the quality of anticoagulation control with VKA which is linked to poor outcomes in AF. However, moderate renal failure itself was an independent risk factor for increased risk of stroke, major bleeding, and all-cause mortality amongst patients with AF.

Patient-related factors associated with oral anticoagulation control: a population-based cohort study.

Time in therapeutic range (TTR) of ≥70% is a commonly used indicator of optimal anticoagulation control. This study aimed to determine the patterns and predictors of anticoagulation control in a population-based cohort of new users of warfarin. This was a retrospective cohort study. All adults (age ≥18 years) who had been newly initiated on warfarin therapy between January 2006 and March 2011were selected from administrative health databases. TTR was calculated using the Rosendaal method. Multivariable logistic regression models were used to identify patient-related factors associated with optimal TTR. Predictors of patients spending >30% of time above and below the therapeutic international normalised ratio (INR) range were also examined. A total of 6032 patients were included in this study. The mean TTR was 54.1 ± 18.8%, and 82.3% of patients had subthreshold TTR (<70%). Compared with New Zealand Europeans, Māori and Pacific people had decreased odds of achieving optimal TTR and increased odds of spending >30% of time below the therapeutic INR range. Patients aged 65-74 years and 75 years or older had increased odds of achieving optimal TTR but decreased odds of spending >30% of time below the therapeutic INR range than those <65 years. Compared with those living in the least socioeconomically deprived areas, those living in the most deprived areas had decreased odds of achieving optimal TTR. Anticoagulation control with warfarin is suboptimal in routine care in New Zealand. Age, ethnicity and deprivation index were significant predictors of TTR. It is important to ensure equitable access to appropriate, high-quality care for those living in deprived areas and those from ethnic minority groups.

Warfarin: time in therapeutic range, a single centre study on patients using warfarin for stroke prevention in non-valvular atrial fibrillation and prosthetic heart valves

Background: Two common indications for oral anticoagulants are patients with non-valvular atrial fibrillation (AF) or prosthetic heart valves (PHV). The degree of anticoagulation is monitored by evaluating the international normalised ratio (INR); however, the quality of anticoagulation, determined by the time in therapeutic range (TTR), is less often evaluated. TTR has significant clinical implications in patient outcomes. Objectives: We sought to identify the indications for anticoagulation and determine its quality via the TTR at a single centre, community-based and district level hospital in the setting of usual care. We documented the prevalence of thrombo-embolic and haemorrhagic adverse events and we also collected data on factors that may contribute to a poor TTR or increased risk of adverse events. Methods: We conducted a retrospective, descriptive and observational study with chart audits evaluating the anticoagulation indication and control for the preceding 1 year for each patient. Descriptive statistics included mean and standard deviation for quantitative data and frequencies for categorical data. Chi-square tests were used to analyse comparisons of categorical data and the student’s t-test for continuous variables. Two-tailed p-values less than 0.05 were considered significant. Results: TTR was poor for patients with AF and PHV (44.5% and 13.7% respectively). We identified older age, less frequent testing and high target ranges as significant factors associated with poorer outcomes. We demonstrated a high prevalence of adverse events (25.4%). Conclusion: Patients in this setting demonstrated poor quality of anticoagulation and had a high prevalence of adverse events.

Evaluation of Time in Therapeutic Range of Patients with Non-Valvular Atrial Fibrillation on Oral Anticoagulation with Vitamin K Antagonist in Delta Region

Background: Non-valvular atrial fibrillation (AF) is the most common cardiac arrhythmia with a prevalence as high as 1.5±2.0% in the general population. This arrhythmia remains one of the major causes of stroke, heart failure, sudden death, and cardiovascular morbidity in the world. The aim of study was to evaluation of the patients in delta region who have non-valvular AF and on oral anticoagulation with Vitamin K antagonist as regard the time they spend within therapeutic range.&#x0D; Patients and Methods: A total of 100 patients were included in this study for evaluation of the patients in delta region who have non-valvular AF and on oral anticoagulation with Vitamin K antagonist as regard the time they spend within therapeutic range.&#x0D; Results: Our study showed that only 35% achieved the recommended TTR (percent time in therapeutic range) above 60% from studied risk factors, none showed statistical significance.&#x0D; Conclusions: The quality of anticoagulant control was lower that reported in European countries with a significant proportion of patients had TTR below 60%.

Can clinical pharmacists utilize telehealth to double the safety and efficacy of oral anticoagulation while reducing health care costs and improving patient satisfaction in patients with atrial fibrillation?

AbstractBackgroundPublished reports from the United States and New Zealand have described excellent control of the international normalized ratio (INR) and improved patient satisfaction in warfarin‐treated patients whose therapy was managed by clinically trained pharmacists using point of care (POC, or “fingerstick”) blood testing and online technology. This report examines the projected impact of such management on clinical outcomes and health care costs by using previously published information which quantified the relationships between anticoagulation control and rates of thromboembolism, major hemorrhage, and death.MethodsAnticoagulation control was defined as the percent of time that the INR was within the target range (TTR). Published regression equations and adjusted relative risks were used to calculate the rate of thromboembolism, major bleeding, and death associated with various TTR values. The rates of ischemic stroke, myocardial infarction, intracranial hemorrhage, gastrointestinal bleed, and death, and the cost for each type of event, were used to determine a key composite end point rate and associated costs at various TTR values and as reported in the four direct‐acting oral anticoagulant (DOAC) studies.ResultsBoth the US and New Zealand online systems achieved comparable TTR values of approximately 75% (or better). Cost avoidance per 1000 patients per year based on projected key composite end point rates at a TTR of 75% ranged from $10.4 million compared with a TTR of 30% to $2.2 million compared with a TTR of 65%,. Cost avoidance compared with the rates reported in the DOAC trials ranged from $1.4 to $4.5 million. Patient satisfaction scores exceeded 90% with both systems as reported previously.ConclusionClinically‐trained pharmacists using POC INR testing and online management may reduce major clinical events by more than 50%, substantially reduce health care costs, and improve patient satisfaction. Data from Europe confirm that these low projected event rates are achievable.