Project description:Background Oral anticoagulant (OAC) therapy reduces the risk of stroke in people with atrial fibrillation (AF), and is considered best practice; however, there is little Australian evidence around the uptake of OACs in this population. Methods and Results We used linked hospital admissions, pharmaceutical dispensing claims, medical services, and mortality data for people in Australia's 2 most populous states (July 2010 to June 2015). Among OAC-naïve people hospitalized with AF, we estimated initiation of OAC therapy within 30 days of discharge, and persistence with therapy in the first year. We analyzed both outcomes using multivariable Cox regression. In 71 184 people with AF (median age 78 years, 49% female), 22.7% initiated OAC therapy. Initiation was lowest in July to December 2011 (17.0%) and highest in July to December 2014 (30.1%) after subsidy of the direct OACs. In adjusted analyses, initiation was most likely in people with a CHA2DS2-VA score ≥7 (versus 0) (hazard ratio=6.25, 95% CI 5.08-7.69), and a history of venous thromboembolism (hazard ratio=2.65, 95% CI 2.49-2.83). Of the people who initiated OAC therapy, 39.9% discontinued within 1 year; a lower risk of discontinuation was associated with a CHA2DS2-VA score ≥7 (versus 0) (hazard ratio=0.22, 95% CI 0.14-0.35), or initiation on a direct OAC (versus warfarin) (hazard ratio=0.55, 95% CI 0.50-0.60). Conclusions We found that OAC therapy was severely underutilized in people hospitalized with AF, even among high-risk individuals. Reasons for this underuse, whether patient, prescriber, or hospital related, should be identified and addressed to reduce stroke-related morbidity and mortality in people with AF.
Project description:BackgroundData are needed on the use of oral anticoagulation in patients with atrial fibrillation (AF) in rural versus urban areas, including the initiation of direct oral anticoagulants (DOACs).ObjectiveWe used Medicare data to examine rural/urban differences in anticoagulation use in patients with AF.MethodsWe identified incident AF in a 20% sample of fee-for-service Medicare beneficiaries (aged ≥ 65 years) from 2011 to 2016 and collected ZIP code and covariates at the time of AF. We identified the first anticoagulant prescription filled, if any, following AF diagnosis. We categorized beneficiaries into four rural/urban areas using rural-urban commuting area codes and used Poisson regression models to compare anticoagulant use.ResultsWe included 447,252 patients with AF (mean age 79 ± 8 years), of which 82% were urban, 9% large rural, 5% small rural, and 4% isolated. The percentage who initiated an anticoagulant rose from 34% in 2011 to 53% in 2016, paralleling the uptake of DOACs. In a multivariable-adjusted analysis, those in rural areas (vs. urban) were more likely to initiate an anticoagulant. However, rural beneficiaries (vs. urban) were less likely to initiate a DOAC; those in isolated areas were 17% less likely (95% confidence interval [CI] 13-20), those in small rural areas were 12% less likely (95% CI 9-15), and those in large rural areas were 10% less likely (95% CI 8-12).ConclusionAmong Medicare beneficiaries with AF, anticoagulation use was low but increased over time with the introduction of DOACs. Rural beneficiaries were less likely to receive a DOAC.
Project description:BackgroundInconsistent evidence suggests that use of certain antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), in patients using oral anticoagulants (OACs) might be associated with an elevated risk of bleeding.ObjectiveThis study aims to investigate the risk of bleeding associated with initiation of different types of antidepressants among atrial fibrillation (AF) patients on OAC therapy.Patients and methodsA total of 30,336 AF patients (mean age 72.2 years; 54% female) on OAC therapy that started antidepressant treatment were identified from the Truven Health Analytics MarketScan Commercial and Medicare Databases for the period 2007-2015. Exposure was defined as filling a prescription for antidepressant, and categorized as SSRI, serotonin/norepinephrine reuptake inhibitors (SNRIs), serotonin reuptake inhibitors (SRIs), tricyclic antidepressants (TCAs), or other antidepressants. The primary outcome was incident hospitalized bleeding. Associations of antidepressant type with bleeding were assessed calculating hazard ratios (HRs) and 95% confidence intervals (CIs) with adjusted Cox models in pairwise propensity score-matched cohorts.ResultsDuring a mean follow-up of 21 months, we identified 1612 bleeding episodes. In pairwise comparisons, SSRI use was associated with an increased risk of bleeding when compared to most other antidepressants (HR 1.22, 95% CI 0.96-1.54 vs SNRI; HR 1.10, 95% CI 0.90-1.35 vs SRI; HR 1.03, 95% CI 0.82-1.30 vs TCA). SNRI use was associated with the lowest bleeding risk. Results did not differ by OAC type, age, and sex.ConclusionsAmong AF patients on OAC initiating antidepressants, risk of bleeding varied across antidepressant type. This information can inform treatment choices among patients receiving OAC.
Project description:Objective: Little is known about initial prescription of currently used oral anticoagulants (OAC), and correlated characteristics in real-world practice. We aimed to assess patterns of initiation of Vitamin K antagonists (VKA) and non-VKA oral anticoagulants (NOAC) in naive patients with non-valvular atrial fibrillation and the factors associated with starting treatment with NOAC. Methods: Population-based retrospective cohort study of all patients with NVAF who had a first prescription of OAC from November 2011 to February 2014 in the Valencia region, Spain (n = 21,881). Temporal trends of OAC initiation are described for the whole population and by type of OAC and therapeutic agent. Factors associated with starting treatment with NOAC (vs. VKA) were identified using logistic multivariate regression models. Results: Among the patients initiating OAC, 25% started with NOAC 2 years after market release. Regarding temporal trends, prescription of NOAC doubled during the study period. VKA prescription also increased (by around 13%), resulting in a 30% rise in total treatment initiation with OAC during 2011-2014. NOAC initiation (vs. VKA) was associated with a lower baseline risk of thromboembolism and higher income. Conclusions: In this Spanish population-based cohort, initiation of OAC therapy saw a rapid increase, mainly but not exclusively, due to a two-fold rise in the use of NOAC. Initiation with NOAC was associated with a lower baseline risk of thromboembolism and higher income, which opposes the indications of NOAC use and reflects disparities in care. Inadequate prescription patterns might threaten the effectiveness and safety of these therapies, thus monitoring OAC prescription is necessary and should be setting-specific.
Project description:OBJECTIVES:Older adult patients are underrepresented in clinical trials comparing non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin. This subgroup analysis of the ARISTOPHANES study used multiple data sources to compare the risk of stroke/systemic embolism (SE) and major bleeding (MB) among very old patients with nonvalvular atrial fibrillation (NVAF) prescribed NOACs or warfarin. DESIGN:Retrospective observational study. SETTING:The Centers for Medicare & Medicaid Services and three US commercial claims databases. PARTICIPANTS:A total of 88 582 very old (aged ≥80 y) NVAF patients newly initiating apixaban, dabigatran, rivaroxaban, or warfarin from January 1, 2013, to September 30, 2015. MEASUREMENTS:In each database, six 1:1 propensity score matched (PSM) cohorts were created for each drug comparison. Patient cohorts were pooled from all four databases after PSM. Cox proportional hazards models were used to estimate hazard ratios (HRs) of stroke/SE and MB. RESULTS:The patients in the six matched cohorts had a mean follow-up time of 7 to 9 months. Compared with warfarin, apixaban (HR = .58; 95% confidence interval [CI] = .49-.69), dabigatran (HR = .77; 95% CI = .60-.99), and rivaroxaban (HR = .74; 95% CI = .65-.85) were associated with lower risks of stroke/SE. For MB, apixaban (HR = .60; 95% CI = .54-.67) was associated with a lower risk; dabigatran (HR = .92; 95% CI = .78-1.07) was associated with a similar risk, and rivaroxaban (HR = 1.16; 95% CI = 1.07-1.24) was associated with a higher risk compared with warfarin. Apixaban was associated with a lower risk of stroke/SE and MB compared with dabigatran (stroke/SE: HR = .65; 95% CI = .47-.89; MB: HR = .60; 95% CI = .49-.73) and rivaroxaban (stroke/SE: HR = .72; 95% CI = .59-.86; MB: HR = .50; 95% CI = .45-.55). Dabigatran was associated with a lower risk of MB (HR = .77; 95% CI = .67-.90) compared with rivaroxaban. CONCLUSION:Among very old NVAF patients, NOACs were associated with lower rates of stroke/SE and varying rates of MB compared with warfarin. J Am Geriatr Soc 67:1662-1671, 2019.
Project description:INTRODUCTION: Oral anticoagulants (OAs) are significantly more effective than Aspirin in the prevention of cerebrovascular accidents among patients with atrial fibrillation (AF). Several studies, however, showed OAs to be widely underused in these patients. OBJECTIVE: To assess the appropriateness of antithrombotic therapy in an Italian population of AF patients. METHODS: Two hundred and fifty-five consecutive patients affected by nonvalvular AF participated in the study. Data were collected on demographic characteristics, risk factors for stroke, current prophylactic therapy, and perceived or actual risk factors for bleeding. INR levels were measured. Patients were stratified by their risk for stroke (214 at high risk, 21 moderate, 20 low), and their prophylactic therapy was analysed in light of international antithrombotic therapy recommendations. After therapy adjustment, 203 of our patients were followed-up for the occurrence of cerebrovascular events for an average of 27 months. RESULTS: Upon admission, 35% (n=75) of patients in the high-risk category were either taking no antithrombotic prophylaxis or were being treated with Aspirin. In addition, 38 of 139 patients receiving OAs had an INR<2. Thus, a total of 113 (52.8%) high-risk subjects were not receiving adequate antithrombotic therapy. Of high-risk patients not treated with OAs, 46.7% reported no perceived or actual risk factors for bleeding. The annual incidence of cerebrovascular accidents was 3.8% among 163 high-risk patients assigned to OA treatment, and 4.5% among 39 patients given Aspirin treatment. Relative to expected annual incidence rates, cerebrovascular risk in anticoagulated patients was reduced by about 70%. CONCLUSIONS: Underuse of OAs is still common in Italy, and much of it cannot be explained by the concern for haemorrhage. Support and training in the complex task of anticoagulation management may help to extend this efficacious prophylactic therapy to all patients who may benefit from it.
Project description:The choice of an oral anticoagulant (OAC) for patients with nonvalvular atrial fibrillation (NVAF) is a major and complex clinical decision taking into account the individual risk-benefit ratio and bearing in mind the chronicity of therapy. This review focuses on the safety and efficacy of new oral anticoagulants (NOACs) compared with conventional vitamin K antagonists (VKA) in patients with NVAF. Current data suggest that NOACs are at least as effective and safe as VKAs for most NVAF subjects. The NOACs do not mandate dietary restrictions and regular pharmacodynamic monitoring, and they seem to have lesser incidence of intracranial or fatal bleeding when compared with VKAs. However, both dabigatran 150 twice daily and rivaroxaban have a slightly higher incidence of gastrointestinal bleeding when compared with VKAs. The article will delineate the current knowledge as well as scientific gaps related to the choice and dosage of anticoagulation regimens for various NVAF subsets and will address certain common clinical scenarios requiring special considerations. The article also addresses the shortcomings of NOACs: lack of therapeutic pharmacokinetic and pharmacodynamic targets, absence of tools to assess compliance and efficacy, rigid and limited dosage options, and absence of effective and inexpensive reversal agents.
Project description:Background and Purpose- This ARISTOPHANES study (Anticoagulants for Reduction in Stroke: Observational Pooled Analysis on Health Outcomes and Experience of Patients) used multiple data sources to compare stroke/systemic embolism (SE) and major bleeding (MB) among a large number of nonvalvular atrial fibrillation patients on non-vitamin K antagonist oral anticoagulants (NOACs) or warfarin. Methods- A retrospective observational study of nonvalvular atrial fibrillation patients initiating apixaban, dabigatran, rivaroxaban, or warfarin from January 1, 2013, to September 30, 2015, was conducted pooling Centers for Medicare and Medicaid Services Medicare data and 4 US commercial claims databases. After 1:1 NOAC-warfarin and NOAC-NOAC propensity score matching in each database, the resulting patient records were pooled. Cox models were used to evaluate the risk of stroke/SE and MB across matched cohorts. Results- A total of 285 292 patients were included in the 6 matched cohorts: 57 929 apixaban-warfarin, 26 838 dabigatran-warfarin, 83 007 rivaroxaban-warfarin, 27 096 apixaban-dabigatran, 62 619 apixaban-rivaroxaban, and 27 538 dabigatran-rivaroxaban patient pairs. Apixaban (hazard ratio [HR], 0.61; 95% CI, 0.54-0.69), dabigatran (HR, 0.80; 95% CI, 0.68-0.94), and rivaroxaban (HR, 0.75; 95% CI, 0.69-0.82) were associated with lower rates of stroke/SE compared with warfarin. Apixaban (HR, 0.58; 95% CI, 0.54-0.62) and dabigatran (HR, 0.73; 95% CI, 0.66-0.81) had lower rates of MB, and rivaroxaban (HR, 1.07; 95% CI, 1.02-1.13) had a higher rate of MB compared with warfarin. Differences exist in rates of stroke/SE and MB across NOACs. Conclusions- In this largest observational study to date on NOACs and warfarin, the NOACs had lower rates of stroke/SE and variable comparative rates of MB versus warfarin. The findings from this study may help inform the discussion on benefit and risk in the shared decision-making process for stroke prevention between healthcare providers and nonvalvular atrial fibrillation patients. Clinical Trial Registration- URL: https://www.clinicaltrials.gov/ . Unique identifier: NCT03087487.
Project description:ObjectiveAn underuse of oral anticoagulants (OAC) in patients with atrial fibrillation (AF) has been suggested, as only 50% of all patients with AF receive OAC treatment. Whether this is due to contraindications, lack of an indication to treat, or an expression of underuse is sparsely investigated. This study therefore aimed to characterize individuals without OAC treatment in a real-life population of patients with AF.DesignRetrospective cross-sectional study. The medical records were scrutinized in order to identify the type of AF, risk factors for embolism and bleeding, and other factors of importance for OAC treatment.SettingThe municipalities of Skellefteå and Norsjö, northern Sweden.SubjectsA total of 2274 living residents with at least one verified episode of AF on or before December 31, 2010.Main outcome measuresPrevalence of treatment with OAC and documented reasons to withhold OAC treatment.ResultsAmong all 2274 patients with AF, 1187 (52%) were not treated with OAC. Of the untreated patients, 19% had no indication or had declined or had experienced adverse effects other than bleeding on warfarin treatment. The most common reason to withhold OAC was presence of risk factors for bleeding, found in 38% of all untreated patients. Furthermore, a documented reason could be identified to withhold OAC in 75%.ConclusionsAmong patients with AF without OAC treatment a reason could be identified to withhold OAC in 75%. The underuse of OAC is estimated to be 25%.
Project description:BackgroundThe effect of type of atrial fibrillation (AF) on adverse outcomes in Chinese patients without oral anticoagulants (OAC) was controversial.HypothesisThe type of AF associated with adverse outcomes in Chinese patients without OAC.MethodsA total of 1358 AF patients without OAC from a multicenter, prospective, observational study was included for analysis. Univariable and multivariable Cox regression models were utilized. Net reclassification improvement analysis was performed for the assessment of risk prediction models.ResultsThere were 896(66%) patients enrolled with non-paroxysmal AF (NPAF) and 462(34%) with paroxysmal AF (PAF). The median age was 70.9 ± 12.6 years, and 682 patients (50.2%) were female. During 1 year of follow-up, 215(16.4%) patients died, and 107 (8.1%) patients experienced thromboembolic events. Compared with the PAF group, NPAF group had a notably higher incidence of all-cause mortality (20.2% vs. 9.4%, p < .001), thromboembolism (10.5% vs. 3.8%, p < .001). After multivariable adjustment, NPAF was a strong predictor of thromboembolism (HR 2.594, 95%CI 1.534-4.386; p < .001), all-cause death (HR 1.648, 95%CI 1.153-2.355; p = .006). Net reclassification improvement analysis indicated that the addition of NPAF to the CHA2 DS2 -VASc score allowed an improvement of 0.37 in risk prediction for thromboembolic events (95% CI 0.21-0.53; p < .001).ConclusionsIn Chinese AF patients who were not on OAC, NPAF was an independent predictor of thromboembolism and mortality. The addition of NPAF to the CHA2 DS2 -VASc score allowed an improvement in the accuracy of the prediction of thromboembolic events.