Warfarin In Patients Research Articles

Contemporary clinical and economic outcomes among oral anticoagulant treated and untreated elderly patients with atrial fibrillation: Insights from the United States Medicare database

BackgroundOral anticoagulants (OACs) mitigate the risk of stroke in atrial fibrillation (AF) patients.ObjectiveElderly AF patients who were treated with OACs (apixaban, dabigatran, edoxaban, rivaroxaban, or warfarin) were compared against AF patients who were not treated with OACs with respect to their clinical and economic outcomes.MethodsNewly diagnosed AF patients were identified between January 2013 and December 2017 in the Medicare database. Evidence of an OAC treatment claim on or after the first AF diagnosis was used to classify patients into treatment-defined cohorts, and these cohorts were further stratified based on the initial OAC prescribed. The risks of stroke/systemic embolism (SE), major bleeding (MB), and death were analyzed using inverse probability treatment weighted time-dependent Cox regression models, and costs were compared with marginal structural models.ResultsThe two treatment groups were composed of 1,421,187 AF patients: OAC treated (N = 583,350, 41.0% [36.4% apixaban, 4.9% dabigatran, 0.1% edoxaban, 26.7% rivaroxaban, and 31.9% warfarin patients]) and untreated (N = 837,837, 59.0%). OAC-treated patients had a lower adjusted risk of stroke/SE compared to untreated patients (hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.68–0.72). Additionally patients receiving OACs had a lower adjusted risk of death (HR: 0.56; 95% CI: 0.55–0.56) and a higher risk of MB (HR: 1.57; 95% CI: 1.54–1.59) and this trend was consistent across each OAC sub-group. The OAC-treated cohort had lower adjusted total healthcare costs per patient per month ($4,381 vs $7,172; p < .0001).ConclusionFor the OAC-treated cohort in this elderly US population, stroke/SE and all-cause death were lower, while risk of MB was higher. Among OAC treated patients, total healthcare costs were lower than those of the untreated cohort.

Keeping warfarin patients safe during the COVID-19 pandemic: review of an INR self-testing programme.

Anticoagulation clinics faced an unprecedented challenge during the COVID-19 pandemic to safely manage patients on warfarin therapy. A London teaching hospital trust received INR point-of-care (POC) testing devices from its clinical commissioning group. The Trust distributed the devices to patients who were cognitively and physically able to self-test and evaluated clinical outcomes and patient experience. A significant improvement in warfarin control (mean time in therapeutic range (TTR) before POC 52%, standard deviation (SD) 24.8, vs mean after 60.7%, SD 19.7; P>0.009) and a 39% reduction in missed appointments were seen in self-testing patients. Positive patient satisfaction and lifestyle outcomes were identified through a telephone survey. A minority of patients struggled with the technique, leading to frustration. Some patients used many test strips through unsuccessful and additional tests. POC testing in a carefully selected group of patients on warfarin therapy resulted in positive clinical and patient satisfaction outcomes. Appropriate governance processes are needed, and clinical expertise is required to support patients. Cost-effectiveness of POC testing needs careful monitoring.

A RIVA-DM Subanalysis Investigating Patients With Nonvalvular Atrial Fibrillation and Type 2 Diabetes Aged Under Versus Over 80 Years.

Advanced age and type 2 diabetes (T2D) are common in patients with nonvalvular atrial fibrillation (NVAF). We evaluated the impact of age on the effectiveness and safety of rivaroxaban versus warfarin in this population. We analyzed electronic health record data from November 2010, to December 2019 including adults with NVAF and T2D, newly started on rivaroxaban or warfarin. Propensity score-overlap weighted hazard ratios (HRs) for stroke/systemic embolism (SSE), hospitalization for major or clinically relevant nonmajor bleeding (CRNMB), vascular death, major adverse limb events (MALE), major bleeding, and intracranial hemorrhage (ICH) were calculated for older (≥80 years) and younger (<80 years) cohorts. We included 32 078 rivaroxaban and 83 971 warfarin users (6606 rivaroxaban and 25,335 warfarin patients were aged ≥80 years). No significant interaction for rivaroxaban versus warfarin by age was observed for any outcome, including SSE (HR = 1.05 vs 0.95), hospitalization for major or CRNMB (HR = 1.06 vs 0.90), vascular death (HR = 0.92 vs 0.90), MALE (HR = 0.80 vs 0.76), major bleeding or ICH. The effectiveness and safety of rivaroxaban versus warfarin remained consistent across patient age subgroups.

Predictors of Health-related Quality of Life among Warfarin Patients

Objective: Warfarin is amongst the most frequently used oral anticoagulant, that is often prescribed to control and prevent various thromboembolic diseases like venous thromboembolism, stroke, atrial fibrillation, and valvular heart disease. This study aimed to determine various predictors and their impact on overall HRQoL among warfarin patients.&#x0D; Methods: A cross-sectional study using WHOQOL-BREF research tool was conducted among warfarin patients. Data was collected by convenience sampling method. Descriptive, comparative, and inferential statistics were used by Statistical Package for the Social Sciences (SPSS) ver. 24 to determine the predictors of HRQoL among warfarin patients.&#x0D; Results: The majority of the studied warfarin patients were females than males (n=221, 69.3%, and n=98, 30.7% respectively). In univariate analysis, statistically non-significant differences (p &gt;0.05) were observed in gender, age, marital status and work. In multivariate analysis, significant differences (p &lt;0.05) were observed in education, warfarin usage, and warfarin therapy duration.&#x0D; Conclusion: These results indicated that education, warfarin usage, and warfarin therapy duration were the pure predictors of HRQoL among the studied cohort of the warfarin patients.

Sociodemographic Correlates of Warfarin Knowledge in Warfarin Patients

Objective: This study aimed to determine sociodemographic correlates of warfarin knowledge in warfarin patients.&#x0D; Methods: A cross-sectional study using a newly developed and validated research tool was conducted in warfarin patients. Data was collected by convenience sampling method. Descriptive, comparative, and inferential statistics were used by Statistical Package for the Social Sciences (SPSS) ver. 24 to determine the sociodemographic correlates of warfarin knowledge in warfarin patients.&#x0D; Results: From total 295 participants, the majority of the studied warfarin patients were females than males (n=184, 62.4%, and n=111, 37.6% respectively). In univariate analysis, statistically non-significant differences (p &gt;0.05) were observed in gender, age, marital status and work. In multivariate analysis, significant differences (p &lt;0.05) were observed in education, comorbidities, warfarin usage, and warfarin therapy duration.&#x0D; Conclusion: These results confirmed that education and warfarin therapy duration were the sociodemographic correlates of warfarin knowledge in the warfarin patients.

Sociodemographic Determinants of Therapy Adherence among Warfarin Patients

Objective: This study aimed to explore sociodemographic determinants of therapy adherence in warfarin patients.&#x0D; Methods: A cross-sectional study using a newly developed and validated research tool was conducted in warfarin patients. Data was collected by convenience sampling method. Descriptive, comparative, and inferential statistics were used by Statistical Package for the Social Sciences (SPSS) ver. 24 to determine the sociodemographic determinants of warfarin knowledge in warfarin patients.&#x0D; Results: Out of the total 319 warfarin patients, the majority of the studied warfarin patients were females than males (n=221, 69.3%, and n=98, 30.7% respectively). In univariate analysis, statistically non-significant differences (p &gt;0.05) in age, work, comorbidities and warfarin usage in different diseases. In multivariate analysis, significant differences (p &lt;0.05) were observed in gender and marital status of the studied warfarin patients.&#x0D; Conclusion: These results indicated that education, warfarin usage, and warfarin therapy duration were the pure determinants of HRQoL among the studied cohort of the warfarin patients.

Reliability and Validity of PSS-10 among Warfarin Patients

Objective: The objective of the current study was to assess the reliability and validity of Perceived Stress Scale 10 (PSS-10) among warfarin patients.&#x0D; Methodology: A cross-sectional study was performed among warfarin patients using the PSS-10. Sociodemographic and patients reported clinical data were collected. Descriptive and inferential statistics were applied using the Statistical Package for Social Sciences (SPSS) version 24.0. A p-value &lt; 0.05 was considered statistically significant.&#x0D; Results: There were more female patients (n=238, 65.9%) than the male patients (n=123, 34.1%) in total of 361 studied patients. No major issues regarding internal consistency, factorial validity, convergent validity and floor and ceiling effect were observed.&#x0D; Conclusion: The present study confirmed the reliability and validity of PSS-10 among warfarin patients.

Effect of General Heath State, Therapy Satisfaction, INR Control on Quality of Life in Warfarin Patients

Objective: This study aimed to assess effect of general heath state, therapy satisfaction and INR control on quality of life in warfarin patients.&#x0D; Methods: A cross-sectional study using a newly developed and validated research tool was conducted in patients on warfarin. Data was collected by convenience sampling method. Descriptive, comparative, and inferential statistics were used by Statistical Package for the Social Sciences (SPSS) ver. 24 to determine the sociodemographic correlates of warfarin knowledge in warfarin patients.&#x0D; Results: Among total 275 studied warfarin patients, the majority of the studied warfarin patients were females than males (n=184, 62.4%, and n=111, 37.6% respectively). A total of 188 (63.7%) patients were satisfied from their healthcare providers while 107 (36.3%) were not satisfied from healthcare providers. Around 128 (43.4%) of the patients were actively managing their disease while 167 (56.6%) of the patients were not able to actively manage their disease.&#x0D; Conclusion: These results confirmed that overall study participants had moderate effect of QoL on general heath state, therapy satisfaction, and INR control among patients on warfarin.

Psychometric Validation of Cohen’s Perceived Stress Scale among Warfarin Patients: A Cross-sectional Study

Objective: This study aimed to perform the psychometric validation of Perceived Stress Scale 10 among warfarin patients.&#x0D; Methodology: A cross-sectional study was performed among warfarin patients using the Perceived Stress Scale 10. Sociodemographic and patients reported clinical data were collected. Descriptive and inferential statistics were applied using the Statistical Package for Social Sciences (SPSS) version 24.0. A p-value &lt; 0.05 was considered statistically significant.&#x0D; Results: Out of total 409 study participants, there were more male patients (n=280, 68.5%) than the female patients (n=129, 31.5%). No major issues regarding internal consistency, factorial validity, convergent validity and floor and ceiling effect were observed.&#x0D; Conclusion: The present study confirmed the psychometric properties of Perceived Stress Scale 10 among the studied cohort of the warfarin patients.

Anticoagulation Changes Following Major and Clinically Relevant Nonmajor Bleeding Events in Non-valvular Atrial Fibrillation Patients

Background: Bleeding events are common complications of oral anticoagulant drugs, including both warfarin and the direct oral anticoagulants (DOACs). Some patients have their anticoagulant changed or discontinued after experiencing a bleeding event, while others continue the same treatment. Differences in anticoagulation management between warfarin- and DOAC-treated patients following a bleeding event are unknown. Methods: Patients with non-valvular atrial fibrillation from six anticoagulation clinics taking warfarin or DOAC therapy who experienced an International Society of Thrombosis and Haemostasis (ISTH)-defined major or clinically relevant non-major (CRNM) bleeding event were identified between 2016 and 2020. The primary outcome was management of the anticoagulant following bleeding (discontinuation, change in drug class, and restarting of same drug class). DOAC- and warfarin-treated patients were propensity matched based on the individual elements of the CHA2DS2-VASc and HAS-BLED scores as well as the severity of the bleeding event. Results: Of the 509 patients on warfarin therapy and 246 on DOAC therapy who experienced a major or CRNM bleeding event, the majority of patients continued anticoagulation therapy. The majority of warfarin (231, 62.6%) and DOAC patients (201, 81.7%) restarted their previous anticoagulation. Conclusion: Following a bleeding event, most patients restarted anticoagulation therapy, most often with the same type of anticoagulant that they previously had been taking.

Effectiveness and Safety of Apixaban Versus Warfarin in Obese Patients with Nonvalvular Atrial Fibrillation Enrolled in Medicare and Veteran Affairs

Real-world studies have evaluated the use of anticoagulants in obese patients with nonvalvular atrial fibrillation (NVAF), but they have been limited by sample size or the use of diagnosis codes on claims to define obesity. This retrospective study used body weight data of ≥100 kg or a body mass index of ≥30 kg/m2 to identify elderly (aged ≥65 years) NVAF patients with obesity in dually enrolled Veterans Affairs and fee-for-service Medicare patients. It evaluated the risk of stroke/systemic embolism (SE) and major bleeding (MB) in patients that initiated apixaban versus warfarin. Stabilized inverse probability treatment weighting was used to balance the baseline characteristics between patients prescribed apixaban and warfarin in obese patients. Cox models were used to evaluate the relative risk of stroke/SE and MB. Overall, 35.9% (n = 26,522) of the NVAF population were obese, of which 13,604 apixaban and 12,918 warfarin patients were included. After inverse probability treatment weighting, patient characteristics were balanced. The mean age was 75 years, the mean CHA2DS2-VASc score (Congestive Heart Failure, Hypertension, Age ≥75 [Doubled], Diabetes Mellitus, Prior Stroke or Transient Ischemic Attack [Doubled], Vascular Disease, Age 65-74, Female) was 3.8, the mean HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) Score was ∼2.6, and >98% of patients were males. Obese apixaban patients were associated with a similar risk of stroke/SE (hazard ratio: 0.82; 95% confidence interval: 0.66 to 1.03) and a significantly lower risk of MB (hazard ratio: 0.62; 95% confidence interval: 0.54 to 0.70) versus warfarin. No significant interaction was observed between treatment and obesity status (nonobese, obese/nonmorbid, obese/morbid) for stroke/SE (interaction p = 0.602) or MB (interaction p = 0.385). In obese patients with NVAF, apixaban was associated with a similar risk of stroke/SE and a significantly lower risk of MB versus warfarin.

Thromboembolism, Bleeding, and Vascular Death Among Older and Younger Nonvalvular Atrial Fibrillation Patients with Type 2 Diabetes Receiving Rivaroxaban or Warfarin

Background: Advancing age and diabetes are common comorbidities among patients diagnosed with nonvalvular atrial fibrillation (NVAF). In separate subanalyses of the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF), the relative efficacy and safety of rivaroxaban versus warfarin did not vary with by older (≥75 years old) or younger age (<75 years old) or with the presence or absence of diabetes. We sought to evaluate the impact of age on the comparative effectiveness and safety of rivaroxaban compared to warfarin in NVAF patients with comorbid diabetes treated in routine practiceMethods: We performed an analysis using Optum® De-Identified electronic health record (EHR) data from November 2010 to December 2019. This study included adults with NVAF and type 2 diabetes, newly started on either rivaroxaban or warfarin and who had ≥12-months of EHR activity. Patients who were pregnant, had alternative indications for oral anticoagulation or valvular heart disease were excluded. To allow for the assessment of statistical interaction in outcome rates across age groups, we propensity score-overlap weighted patients after stratification of eligible patients into older (≥80 years old) and younger (<80 years old) cohorts. Weighted incidence rates (%/year) of developing stroke or systemic embolism, or vascular death; hospitalization for major or clinically relevant nonmajor (CRNM) bleeding; and major adverse limb events (need for revascularization or major amputation of the lower limbs) for rivaroxaban and warfarin users with type 2 diabetes patients either ≥80 or <80 years old were reported. Propensity score-overlap weighted hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox regression employing a robust sandwich estimator. Patients were followed in the Cox regression models until time of outcome occurrence, end-of-EHR activity or end-of-data availability. P-values for interaction across age subgroups were adjusted to control for false discovery rates due to multiple hypothesis testing. A p-value <0.05 was considered statistically significant in all cases.Results: A total of 32,078 rivaroxaban (31% initiated on 15 mg dose) and 83,971 warfarin users (time-in-therapeutic range = 47±28%) with NVAF and comorbid type 2 diabetes were included in the present study. Mean follow-up time was 2.9±1.9 years for rivaroxaban and 2.9±2.0 years for warfarin patients. There were 31,941 patients (28%) aged ≥80 years who were initiated on either rivaroxaban (n=6,606) or warfarin (n=25,335). Older patients had a higher mean CHA 2DS 2VASc (4.4±1.2 versus 3.8±1.3) and modified HASBLED (1.7±0.7 versus 1.4±0.8) score compared to younger patients. Propensity score-overlap weighted analyses found no statistically significant interaction for the relative effectiveness or safety of rivaroxaban versus warfarin across the older or younger age groups for the outcomes of stroke, systemic embolism, or vascular death (HR=0.93; 95%CI, 0.87-1.00 versus HR=0.91; 95%CI, 0.86-0.96), hospitalization for major or CRNM bleeding (HR=1.06; 95%CI, 0.96-1.18 versus HR=0.90; 95%CI, 0.84-0.96) or major adverse limb events (HR=0.79; 95%CI, 0.68-0.94 versus HR=0.76; 95%CI, 0.70-0.83) (Table). Major and intracranial bleeding were also observed significantly less frequently with rivaroxaban compared to warfarin regardless of patient age.Conclusions: The effectiveness and safety of rivaroxaban relative to warfarin remained consistent across older and younger patient subgroups, supporting rivaroxaban as an alternative for elderly NVAF patients with concomitant type 2 diabetes (NCT04509193). [Display omitted] DisclosuresColeman: Alexion Pharmaceuticals: Research Funding; Janssen Scientific Affairs LLC: Consultancy, Honoraria, Research Funding; Bayer AG: Consultancy, Honoraria, Research Funding. Vardar: Bayer AG: Current Employment. Abdelgawwad: Bayer AG: Current Employment.

OpenSAFELY: impact of national guidance on switching anticoagulant therapy during COVID-19 pandemic

BackgroundEarly in the COVID-19 pandemic, the National Health Service (NHS) recommended that appropriate patients anticoagulated with warfarin should be switched to direct-acting oral anticoagulants (DOACs), requiring less frequent blood testing....

Pharmacist monitoring of direct oral anticoagulants for American Indians and Alaska Natives in the outpatient setting

BackgroundDirect oral anticoagulants (DOACs) call into question the role of traditional pharmacist-run clinics, and few studies have described the incorporation of DOAC’s into traditional anticoagulation management services (AMS) ObjectiveTo describe the incorporation of DOACs into a pharmacist-run AMS for American Indian and Alaska Native (AI/AN) patients and determine outcomes related to adherence, follow-up, and pharmacist interventions. Practice descriptionTraditional AMS embedded in ambulatory clinic. Warfarin managed by pharmacists under a collaborative practice agreement with supervising physician. Practice innovationDOACs incorporated into AMS by transitioning warfarin patients to rivaroxaban and apixaban and managing new patients with DOAC. Follow-up occurred via phone call and at longer intervals. Evaluation methodsSingle-center, retrospective, observational analysis of AI/AN patients who were followed up by pharmacy AMS. The outcomes measured include adherence to DOAC therapy, number of telephonic encounters versus face-to-face visits, frequency of follow-up, types of interventions made at each visit, and an estimate of face-to-face clinic time savings. ResultsA total of 50 patients were included for analysis. The average medication possession ratio was 91%. The majority of visits occurred over the phone (59%), and most follow-up visits occurred every 3 months (62%). The top 3 most frequent interventions were adherence education, initial DOAC education, and education on use of nonsteroidal anti-inflammatory drugs. Practice implicationsTraditional AMS can evolve by incorporating DOACs and maintaining follow-up. ConclusionPharmacist monitoring of DOACs may promote high levels of adherence and lead to time savings by reducing the amount of time spent in traditional AMS.

Effectiveness and safety of apixaban vs warfarin among venous thromboembolism patients using five US databases: a subgroup analysis of chronic liver disease

Abstract Background Venous thromboembolism (VTE) is a serious disease in the United States affecting approximately 1 in 1000 patients each year. Patients with chronic liver disease (CLD) are at an increased risk of VTE and major bleeding (MB). Currently, insufficient clinical and real-world evidence exists on the efficacy/effectiveness and safety of apixaban or warfarin in VTE patients with CLD. Purpose To evaluate the risk of recurrent VTE, MB, and clinically relevant non-major (CRNM) bleeding among VTE patients initiating apixaban or warfarin stratified by CLD status. Methods VTE patients ≥18 years of age (≥65 years for Medicare) initiating apixaban or warfarin were identified from CMS Medicare and four commercial claims databases. To balance the characteristics between apixaban and warfarin patients, stabilized inverse probability treatment weighting (IPTW) was conducted. Post-IPTW, subgroup interaction analysis was conducted to evaluate whether treatment effects of apixaban vs. warfarin were consistent across patients with and without a diagnosis of CLD. Cox proportional hazard models were used to evaluate the interaction of the treatment (apixaban vs. warfarin) and CLD on recurrent VTE, MB, and CRNM bleeding. The statistical significance of the interaction was set to p-value &amp;lt;0.10. Results A total of 60,786 apixaban and 94,333 warfarin patients with VTE were eligible for analysis. Post-IPTW, all patient characteristics were balanced between the apixaban and warfarin treatment cohorts. Apixaban treated patients had significantly lower risk of recurrent VTE, MB, and CRNM bleeding compared to warfarin patients (Figure). In the IPTW weighted population, 4,766 (7.8%) apixaban patients and 6,320 (6.7%) warfarin patients had a diagnosis of CLD. For the apixaban or warfarin patients, those with a diagnosis of CLD were generally younger (mean 64.0–65.2 vs 66.9 years), had higher Charlson comorbidity index scores (mean 3.8–3.9 vs 2.1) and were more likely to have an inpatient VTE event (67.8–69.5% vs 53.0–53.2%) or provoked VTE events (66.2–67.8% vs 55.4–55.5%) compared to patients without a diagnosis of CLD. The incidence rate of recurrent VTE, MB, and CRNM bleeding was higher among VTE patients with CLD than without CLD and was also higher for patients treated with warfarin compared to those treated with apixaban regardless of CLD status (Figure). There were no significant interactions observed between treatment and CLD status for recurrent VTE, MB or CRNM (Figure). Conclusion Treatment with apixaban had a lower risk of recurrent VTE, MB, and CRNM bleeding compared to treatment with warfarin. The benefits of apixaban were consistently observed among subgroups of VTE patients with and without CLD. Additional studies are needed to evaluate VTE patients with CLD. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer, Inc.

Effectiveness and safety of apixaban vs warfarin among older venous thromboembolism patients: a subgroup analysis of age

Abstract Background Venous thromboembolism (VTE) is the third most common cardiovascular condition in adult patients. Older patients are at an increased risk of VTE. However, they have been underrepresented in clinical trials and evidence on the safety and effectiveness of anticoagulants in older VTE patients, especially very elderly patients (≥80 years), is sparse. Purpose To evaluate the risk of recurrent VTE, major bleeding (MB), and clinically relevant non-major (CRNM) bleeding among older VTE patients initiating apixaban or warfarin according to two age sub-groups: 65–79 and ≥80 years. Methods Older VTE patients (aged ≥65 years) who initiated apixaban or warfarin were identified from the CMS Medicare database (September 2014–December 2017). To balance the characteristics between apixaban and warfarin patients, stabilized inverse probability treatment weighting (IPTW) was conducted. Post IPTW, a subgroup interaction analysis was conducted to evaluate if there was any difference in treatment effects between the two age subgroups (65–79 vs. ≥80) on recurrent VTE, MB, and CRNM bleeding. Cox proportional hazard models were used to conduct the interaction analysis, and the statistical significance of the interaction was set to p-value &amp;lt;0.10. Results A total of 22,135 apixaban and 45,840 warfarin patients with VTE aged ≥65 years were eligible for analysis. Post IPTW, patient characteristics were balanced between the apixaban and warfarin treatment cohorts. Apixaban patients had significantly lower risk of recurrent VTE, MB, and CRNM bleeding compared to warfarin patients (Figure). 42,551 (62.6%) were aged 65–79 years and 25,424 (37.4%) were aged ≥80 years. Among apixaban or warfarin patients, those aged 65–79 years had lower Charlson comorbidity index scores (mean 2.7 vs 3.2) and were less likely to have a diagnosis of anemia (34.7–34.9% vs 42.3–42.5%), cerebrovascular disease (14.7–15.7% vs 20.3–20.5%), or dementia (5.0–6.9% vs 20.4–24.6%) compared to patients aged ≥80 years. Across both age subgroups, incidence rates of recurrent VTE, MB and CRNM bleeding were lower for apixaban vs. warfarin. No significant interaction was observed between the treatment and age on recurrent VTE and MB (Figure). There was a significant interaction between treatment and age on CRNM bleeding. Apixaban trended towards a lower risk of CRNM bleeding across both age groups but the treatment effect on CRNM bleeding was larger for patients aged 65–79 years. Conclusion The treatment effects of apixaban vs. warfarin on recurrent VTE and MB were consistently observed across both older age groups in this analysis. More studies are needed to evaluate management of VTE in an older and especially the very elderly population. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer Inc.

Time at home among nonvalvular atrial fibrillation patients treated with non-vitamin K antagonist oral anticoagulants versus warfarin

Abstract Background Clinical trials and real-world database studies have shown the benefits of non-vitamin K antagonist oral anticoagulants (NOACs) compared to warfarin; however, measures of functional outcomes are critical in evaluating a patient's quality of life. Previous measures of time spent out of hospital in a home setting and time spent receiving disease-related care among non-valvular atrial fibrillation (NVAF) patients are lacking in the current literature. Purpose This analysis was based on the previously published ARISTOPHANES study, and used multiple data sources to evaluate the amount of time spent at a patient's home among NVAF patients who were prescribed NOACs versus warfarin. Methods This retrospective observational study used US data from CMS Medicare and four commercial databases to select adult NVAF patients who initiated apixaban, dabigatran, rivaroxaban, or warfarin (01JAN2013–30SEP2015). Time at home and time at home without external AF-related care were measured during the 180 days after the index date (OAC prescription). Time at home was defined as days from index date without any of the following: an inpatient, skilled nursing facility or nursing facility, hospice, or inpatient rehabilitation facility admission. Time at home and without external AF-related care was defined as days away from home and days with a claim for bleeding, stroke/systemic embolism, AF, or an INR test. Each day a claim was observed was counted as one day. In each database, three 1:1 NOAC-warfarin propensity-score-matched (PSM) cohorts were created before pooling the results. After PSM, a subgroup of patients who were alive and had ≥180 days of follow-up was created. Poisson regression was conducted in each NOAC-warfarin matched cohort to compare time at home and time at home without external AF-related care. Results After matching, a total of 100,977 apixaban-warfarin, 36,990 dabigatran-warfarin, and 125,068 rivaroxaban-warfarin patient pairs were selected. Of those patients, 38–46% had 180 days of follow-up available. Across treatment cohorts, approximately 75% of patients were at home for the 180-day follow-up. Apixaban, dabigatran, and rivaroxaban patients had 1.3, 0.9, and 0.8 more days at home, respectively, compared to warfarin patients. Patients treated with apixaban had 13.4 more days at home without AF-related care compared to warfarin, while dabigatran and rivaroxaban had 11.6 and 11.7 more days at home without AF-related care compared to warfarin. A greater proportion of warfarin patients than NOAC patients had an INR test (81–82% vs 14–21%), and days with INR testing were the main driver for external AF-related care for warfarin patients. Conclusion Among NVAF patients treated with OACs, NOACs were associated with a longer time at home and time at home without external AF-related care compared to warfarin. These results can help inform healthcare providers and patients regarding the impact of NOAC treatment in NVAF patients. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Bristol-Myers Squibb Company and Pfizer Inc.

Effectiveness and safety of apixaban vs warfarin among older venous thromboembolism patients stratified by race

Abstract Background Race has been identified as a risk factor for venous thromboembolism (VTE), with Black individuals having a higher risk of VTE compared to Caucasians. Black patients have been underrepresented in clinical trials evaluating anticoagulants for VTE. There has been limited evidence about the effects of anticoagulants for Black patients with VTE in routine clinical practice. Purpose To evaluate the risk of recurrent VTE, major bleeding (MB), and clinically relevant non-major (CRNM) bleeding among VTE patients initiating apixaban or warfarin stratified by race. Methods Older VTE patients (≥65 years) who initiated apixaban or warfarin were selected from the CMS Medicare database (September 2014–December 2017). Stabilized inverse probability treatment weighting (IPTW) was used to balance the differences between apixaban and warfarin cohorts. After IPTW, subgroup interaction analysis was conducted to evaluate if treatment effects were different between Black and White patients in the Medicare population. Due to small sample size, other races were not included in the interaction analysis. Cox proportional hazard models were used to evaluate if there was significant interaction (p&amp;lt;0.10) between treatment and race on recurrent VTE, MB, or CRNM bleeding. Results A total of 22,135 apixaban and 45,840 warfarin patients with VTE were included in the analysis. Post-IPTW, patient characteristics were balanced between apixaban and warfarin treatment cohorts. Apixaban patients had significantly lower risk of recurrent VTE, MB, and CRNM bleeding compared to warfarin patients (Figure). When stratified by race, 57,008 (83.9%) were White, 7,832 (11.5%) Black, and 3,135 (4.6%) other races. For both treatment cohorts, age was similar between Black (77.0–77.2 years) and White (77.4–77.5 years) patients. However, Black patients were more likely to have an inpatient VTE event (77.3–77.8% vs. 63.1–63.3%), a provoked VTE event (78.6–79.5% vs 69.4–69.6%), and a higher comorbidity index score (mean 4.1 vs. 2.7) compared to White patients with VTE. The incidence rates per 100 person-years of recurrent VTE (2.0–3.3 vs 1.4–2.2) and MB (7.4–10.1 vs 3.5–5.3) were also numerically higher for Black patients compared to White patients. Across both race groups, apixaban patients had a lower incidence rate of recurrent VTE, MB and CRNM bleeding compared to warfarin patients. No significant interaction was observed between treatment and race for recurrent VTE, MB, or CRNM bleeding (Figure). The findings within each race group were consistent with those of the overall VTE population. Conclusion Among older VTE patients, disparities were observed in VTE characteristics and clinical outcomes between Black and White patients. Across both race groups, apixaban had lower risk of recurrent VTE, MB, and CRNM bleeding compared to warfarin patients. Further studies are needed to identify optimal management strategies for Black patients with VTE. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Pfizer IncBristol-Myers Squibb Company

Extending INR testing intervals in warfarin patients at a multi-center anticoagulation clinic.

Warfarin has been used as an anticoagulant by millions of patients due to its effectiveness, availability, and low cost. Evidence on the safe extension of international normalized ratio (INR) testing frequency remains an area of interest, especially during the recent COVID-19 pandemic. The purpose of this study is to safely extend INR testing intervals in patients throughout a multisite, system-wide anticoagulation clinic. Updates were made to the pharmacist’s collaborative practice agreement (CPA) and nurse protocol to optimize practice and allow INR testing interval extension up to a maximum of 8-weeks. The primary outcome was the change in duration between INR tests (INR testing interval) measured before and after providing staff education on clinic updates. The mean duration between INR tests (SD) was 23.69 days (11.29) in the pre-intervention period and 25.58 days (13.91) in the post-intervention period. During the COVID-19 pandemic (post2), intervals were extended further to 27.81 days (14.96), demonstrating a statistically significant increase in INR testing interval from pre-intervention to post-intervention and to post2 (p < 0.001 and p < 0.001, respectively). A secondary outcome indicated the mean time in therapeutic range (SD) showed no significant difference in pre-intervention 70.11% (25.95) versus post-intervention of 69.76% (25.69) with a difference of − 0.35% (29.93) (p = 0.956) or versus the post2 of 68.82% (27.20) with a difference of − 1.29% (33.20) (p = 0.120). This study showed that changes to the CPA and protocol allowed for a significant increase in INR testing interval while simultaneously maintaining a mean time in therapeutic range > 60% for the clinic population.

The burden of undertreatment and non-treatment among patients with non-valvular atrial fibrillation and elevated stroke risk: a systematic review

Objective Global treatment guidelines recommend treatment with oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and an elevated stroke risk. However, not all patients with NVAF and an elevated stroke risk receive guideline-recommended therapy. A literature review and synthesis of observational studies were undertaken to identify the body of evidence on untreated and undertreated NVAF and the association with clinical and economic outcomes. Methods An extensive search (1/2010–4/2020) of MEDLINE, the Cochrane Library, conference proceedings, and health technology assessments (HTAs) was conducted. Studies must have evaluated rates of nontreatment or undertreatment in NVAF. Nontreatment was defined as absence of OACs (but with possible antiplatelet treatment), while undertreatment was defined as treatment with only antiplatelet agents. Results Sixteen studies met our inclusion criteria. Rates of nontreatment for patients with elevated stroke risk ranged from 2.0–51.1%, while rates of undertreatment ranged from 10.0–45.1%. The clinical benefits of anticoagulation were reported in the evaluated studies with reductions in stroke and mortality outcomes observed among patients treated with anticoagulants compared to untreated or undertreated patients. Adverse events associated with all bleeding types (i.e. hemorrhagic stroke, major bleeding or gastrointestinal hemorrhaging) were found to be higher for warfarin patients compared to untreated patients in real-world practice. Healthcare resource utilization was found to be lower among patients highly-adherent to warfarin compared to untreated patients. Conclusions Rates of nontreatment and undertreatment among NVAF patients remain high and are associated with preventable cardiovascular events and death. Strategies to increase rates of treatment may improve clinical outcomes.