INCREASED ADHERENCE TO WARFARIN TREATMENT WITH TRAINING PROGRAMS IN PATIENTS WITH ATRIAL FIBRILLATION

SummaryThe ARISTOTLE trial showed a risk reduction of stroke/systemic embolism (SE) and major bleeding in non-valvular atrial fibrillation (NVAF) patients treated with apixaban compared to warfarin. This retrospective study used four large US claims databases (MarketScan, PharMetrics, Optum, and Humana) of NVAF patients newly initiating apixaban or warfarin from January 1, 2013 to September 30, 2015. After 1:1 warfarin-apixaban propensity score matching (PSM) within each database, the resulting patient records were pooled. Kaplan-Meier curves and Cox proportional hazards models were used to estimate the cumulative incidence and hazard ratios (HRs) of stroke/SE and major bleeding (identified using the first listed diagnosis of inpatient claims) within one year of therapy initiation. The study included a total of 76,940 (38,470 warfarin and 38,470 apixaban) patients. Among the 38,470 matched pairs, 14,563 were from MarketScan, 7,683 were from PharMetrics, 7,894 were from Optum, and 8,330 were from Humana. Baseline characteristics were balanced between the two cohorts with a mean (standard deviation [SD]) age of 71 (12) years and a mean (SD) CHA2DS2-VASc score of 3.2 (1.7). Apixaban initiators had a significantly lower risk of stroke/SE (HR: 0.67, 95 % CI: 0.59–0.76) and major bleeding (HR: 0.60, 95 % CI: 0.54–0.65) than warfarin initiators. Different types of stroke/SE and major bleeding – including ischaemic stroke, haemorrhagic stroke, SE, intracranial haemorrhage, gastrointestinal bleeding, and other major bleeding – were all significantly lower for apixaban compared to warfarin treatment. Subgroup analyses (apixaban dosage, age strata, CHA2DS2-VASc or HAS-BLED score strata, or dataset source) all show consistently lower risks of stroke/SE and major bleeding associated with apixaban as compared to warfarin treatment. This is the largest “real-world” study on apixaban effectiveness and safety to date, showing that apixaban initiation was associated with significant risk reductions in stroke/SE and major bleeding compared to warfarin initiation after PSM. These benefits were consistent across various high-risk subgroups and both the standard-and low-dose apixaban dose regimens.Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.Supplementary Material to this article is available online at www.thrombosis-online.com.

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Abstract 171: Warfarin Use And Stroke Risk Among Patients With Nonvalvular Atrial Fibrillation In A Large Managed Care Population

Circulation Cardiovascular Quality and Outcomes ◽

10.1161/circoutcomes.5.suppl_1.a171 ◽

2012 ◽

Vol 5 (suppl_1) ◽

Author(s):

Steven B Deitelzweig ◽

Erin Buysman ◽

Brett Pinsky ◽

Michael Lacey ◽

Yonghua Jing ◽

...

Keyword(s):

Atrial Fibrillation ◽

Managed Care ◽

Treatment Period ◽

Real World ◽

Warfarin Therapy ◽

Stroke Risk ◽

Nonvalvular Atrial Fibrillation ◽

Chads2 Score ◽

Warfarin Treatment

Introduction Warfarin discontinuation among real world nonvalvular atrial fibrillation (NVAF) patients is common. Hypothesis We hypothesized that in a managed care population, warfarin discontinuation is associated with increased stroke risk. Methods Patients who initiated warfarin therapy between Jan 2005 and Jun 2009 and had a healthcare claim related to AF within 30 days prior to the first warfarin claim, but no evidence of valvular disease, were included. Warfarin discontinuation was defined as a supply gap of >60 days without evidence of International Normalized Ratio (INR) measurements. Follow-up was divided into periods of warfarin treatment and discontinuation. Stroke events were identified based on claims for inpatient stays with a primary diagnosis for stroke or transient ischemic attack (TIA). Cox proportional hazards models were constructed to assess the relationship between warfarin discontinuation and incident stroke while adjusting for baseline demographics, stroke and bleeding risk, and comorbidities, as well as time-dependent antiplatelet use, stroke, and bleeding events in the prior warfarin treatment period. Results The mean (SD) age of the study sample (N=16,253) was 67±12 years; 64.8% was male. Mean CHADS2 score was 1.84±1.30; mean HAS-BLED score was 2.00±1.18. Half (51.4%) of patients discontinued warfarin therapy at least once and the overall sample had a mean of 1.87 warfarin treatment periods during a mean of 668 days follow-up. Approximately 1186 patients (7%) had a stroke or TIA at any site of service during follow-up. Risk of stroke significantly increased during warfarin discontinuation periods compared with therapy periods (HR 1.60; 95%CI 1.35-1.90; P<.0001). Stroke risk was significantly increased for patients with baseline CHADS2 score ≥2 (HR 2.69; 95%CI 1.44-5.03; P=.002), HAS-BLED score ≥3 (HR 1.46; 95%CI 1.05-2.05; P=.027), or who had a bleeding (HR 1.29; 95%CI 1.06-1.57; P=.013) or stroke event (HR 3.04; 95%CI 2.47-3.75; P<.0001) in the prior treatment period. Conclusions In the real world, over half of patients on anticoagulation therapy had treatment gaps or permanently discontinued therapy. These usage patterns, as well as prior bleeding, were associated with increased stroke risk.

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Abstract 15396: Atrial Fibrillation Bleeding Risk and Prediction While Treated With Direct Oral Anticoagulants in Warfarin Naïve and Experienced Patients

Circulation ◽

10.1161/circ.142.suppl_3.15396 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Alexander C Perino ◽

Krishna Pundi ◽

Jun Fan ◽

Susan K Schmitt ◽

Mitra Kothari ◽

...

Keyword(s):

Atrial Fibrillation ◽

Warfarin Therapy ◽

Oral Anticoagulants ◽

Direct Oral Anticoagulants ◽

Bleeding Risk ◽

Risk Of Bleeding ◽

Warfarin Treatment ◽

Treatment Analysis ◽

Using Data ◽

Favorable Safety

Introduction: Direct oral anticoagulants (DOAC) are guideline-recommended over warfarin for stroke prevention in atrial fibrillation (AF). However, patients who are DOAC eligible are commonly maintained on warfarin. We sought to evaluate bleeding risk and prediction while on DOAC treatment (both for warfarin-naïve and -experienced patients) as compared to warfarin. Methods: We performed a retrospective cohort study using data from the Veteran Affairs health care system. We included patients with a prescription for warfarin and/or DOAC from 10/1/2010 to 9/30/2017 with an AF encounter in the 90 days prior to 30 days after prescription. We categorized DOAC treated patients as warfarin-naïve or -experienced and performed an on-treatment analysis to determine bleeding incidence and HAS-BLED score discrimination. In adjusted analyses, we compared risk of bleeding while treated with DOAC (both for warfarin-naïve and -experienced patients) to warfarin. Results: The analysis cohort included 99,143 patients treated with warfarin (71±10 years, HAS-BLED 2.6±1.2) and 73,732 and 26,760 patients treated with DOAC who were warfarin-naïve (74±10 years, HAS-BLED 2.4±1.0) and -experienced (71±9 years, HAS-BLED 2.8±1.1), respectively. DOAC patients with warfarin experience had more prior bleeds (DOAC, warfarin-experienced: 11.9%; DOAC, warfarin-naïve: 4.5%; warfarin: 6.2%; p<0.001 for both). Risk of intracranial bleeding was substantially lower while on DOAC treatment (both for warfarin-naïve and -experienced patients) as compared to warfarin ( Table ). HAS-BLED discrimination for bleeding outcomes, intracranial or any bleeding, was modest ( Table ). Conclusion: DOAC treatment had a favorable safety profile compared to warfarin treatment, even for DOAC treated patients with warfarin-experience who had more prior bleeds. These data argue against maintaining DOAC eligible patients on warfarin therapy regardless of HAS-BLED score.

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How effective are dose-adjusted warfarin and aspirin for the prevention of stroke in patients with chronic atrial fibrillation?

Thrombosis and Haemostasis ◽

10.1160/th08-08-0499 ◽

2009 ◽

Vol 101 (03) ◽

pp. 527-534 ◽

Cited By ~ 26

Author(s):

Stephan Rietbrock ◽

Jonathan M. Plumb ◽

Arlene M. Gallagher ◽

Tjeerd P. van Staa

Keyword(s):

Atrial Fibrillation ◽

Clinical Practice ◽

Risk Reduction ◽

Relative Rate ◽

General Practice Research Database ◽

Chronic Atrial Fibrillation ◽

Practice Research ◽

Research Database ◽

Warfarin Treatment ◽

The Uk

SummaryThe objective of this study was to evaluate the rate of stroke associated with aspirin and warfarin in routine clinical practice. The study included patients aged 40+ with chronic atrial fibrillation (cAF) registered in the UK General Practice Research Database. The outcome was the rate of stroke during current, past and no use of aspirin and warfarin. The study included 51,807 cAF patients. There was no difference in the rate of stroke between current and past use of aspirin (relative rate [RR]=1.04 [95% confidence interval (CI) 0.94 – 1.15]), while the rate of stroke was reduced during current warfarin use compared to past use (RR=0.62 [95% CI 0.54 – 0.71]). For warfarin, a pattern of lower rates of stroke during current exposure and higher rates with past exposure was seen only in patients treated for at least 6–12 months. For aspirin, no changes in the rates of stroke were observed with discontinuation of aspirin. The effectiveness of warfarin was dependent on the level of anticoagulation, with optimal risk reduction occurring within the recommended international normalised ratio (INR) range of 2.0 to 3.0. The proportion of patients achieving a stable INR within the target therapeutic range was at its lowest during the first three months of warfarin treatment. In conclusion, the results of this study support the effectiveness of warfarin treatment to reduce the rate of stroke in cAF patients in the general clinical practice setting, however the risk reduction is lower than that reported in clinical trials.

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