Delayed treatment initiation of oral anticoagulants among Medicare patients with atrial fibrillation.

Study objective: This study aimed to identify factors associated with delayed oral anticoagulant (OAC) treatment initiation among atrial fibrillation (AF) patients in United States (US) clinical practice. Participants: Medicare beneficiaries newly diagnosed with AF without moderate-to-severe mitral stenosis or a mechanical heart valve, were aged ≥65 years and prescribed OAC on or after 10/1/2015 through 2019 were included. Delayed and early OAC initiation were defined as >3 months and 0-3 months initiation from first AF diagnosis, respectively. Main outcome measures: Association between delayed OAC initiation and patient demographics, clinical and index OAC coverage and formulary characteristics was examined using multivariable logistic regression. Results: A total of 446,441 patients met the inclusion criteria; 30.0 % (N = 131,969) were identified as delayed and 70.0 % (N = 314,472) as early OAC initiation. Median age for both cohorts was 78 years. In the early and delayed OAC cohorts, 47.1 % and 47.6 % were male and 88.8 % and 86.6 %, were White, respectively. Factors associated with delayed OAC initiation (odds ratio; 95 % confidence interval) included Black race (1.29; 1.25 to 1.33), west region (1.29; 1.26 to 1.32), comorbidities such as dementia (1.27; 1.23 to 1.30), recent bleeding hospitalization (1.22; 1.18 to 1.27), prior authorization (1.69; 1.66 to 1.71), tier 4 formulary for index OAC at AF diagnosis (1.26; 1.22 to 1.30). Conclusion: Our study revealed that nearly one-third of Medicare patients with AF experienced delayed OAC initiation. Key patient characteristics found to be associated with delayed OAC initiation included race and ethnicity, comorbidities, and formulary restrictions.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and active cancer who also had prior bleed or prior renal disease.

OBJECTIVE: Patients with active cancer and venous thromboembolism (VTE) have elevated risk of recurrent VTE (rVTE) and major bleeding (MB). The risk is even higher within those with a prior bleeding event or renal disease. There is a need to understand the risk of rVTE and MB of commonly used anticoagulants among these high-risk patients. METHODS: VTE patients with active cancer and treated with apixaban, warfarin, or low molecular weight heparin (LMWH) within 30 days of VTE were identified from five claims databases in the United States. Inverse probability of treatment weighting (IPTW) was used to balance patient characteristics. The post-IPTW population was stratified by prior bleed or renal disease status. Cox proportional hazards models were used to evaluate interactions between treatment and prior bleed or renal disease on risk of rVTE and MB, with p value <.1 considered significant. RESULTS: Study criteria were met by 30,586 VTE cancer patients: 35.0% had prior bleed and 29.0% had renal disease. For apixaban, LMWH, and warfarin cohorts, the incidence (events per 100 person-years) of MB was higher in patients with prior bleed (17.48 vs 7.58, 25.61 vs 13.11, and 20.38 vs 8.97) or renal disease (15.79 vs 8.71, 22.11 vs 15.90, and 18.49 vs 10.39) vs those without the conditions. Generally, there were no significant interactions between anticoagulant use and prior bleed or renal disease on rVTE and MB (p for interaction >.1). CONCLUSION: The incidence of MB was higher among those with prior bleed or renal disease. Effects of apixaban, warfarin, or LMWH were generally consistent regardless of prior bleed or renal disease status.

Risk of Venous Thromboembolism by Cancer Type: A Network Meta-Analysis.

Patients with cancer have an increased risk of venous thromboembolism (VTE). Comparing tumor-specific VTE risk is complicated by factors such as surgery, disease stage, and chemotherapy. Network meta-analysis (NMA) using cancer types as network nodes enabled us to estimate VTE rates by leveraging comparisons across cancer types while adjusting for baseline VTE risk in individual studies. This study was conducted to estimate the risk of VTE by cancer type and factors influencing VTE risk. The Embase, MEDLINE, and Cochrane Library repositories were systematically searched to identify clinical trials and observational studies published from 2005 to 2022 that assessed the risk of primary cancer-related VTE among two or more distinct cancer types. Studies with similar cancer populations and study methods reporting VTE occurring within 1 year of diagnosis were included in the NMA. Relative VTE rates across cancer types were estimated with random-effects Bayesian NMAs. Absolute VTE rates were calculated from these estimates using the average VTE incidence in lung cancer (the most frequently reported type) as the "anchor." From 2,603 records reviewed, 30 studies were included in this NMA. The general network described 3,948,752 patients and 18 cancer types: 3.1% experienced VTE within 1 year of diagnosis, with cancer-specific rates ranging from 0.7 to 7.4%. Consistent with existing VTE risk prediction tools, pancreatic cancer was associated with higher-than-average VTE risk. Other cancer types with high VTE risk were brain and ovarian cancers. The relative rankings of VTE risk for certain cancers changed based on disease stage and/or receipt of chemotherapy or surgery.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and common cancers or cancers with high venous thromboembolism risk.

Aim: Treatment effects among anticoagulant-treated patients with venous thromboembolism (VTE) and cancer across tumor types were evaluated. Methods: Patients initiating an anticoagulant within 30 days after VTE were identified. After inverse probability treatment weighting, patients were stratified by tumor type. Interactions between treatment and tumor type on recurrent VTE, major bleeding and clinically relevant non-major bleeding were assessed using Cox proportional hazard models. Results: Treatment effects were generally not significantly different among patients with or without the following cancer types: prostate, breast, lung, pancreatic or multiple myeloma. Few significant interactions were observed for lung and pancreatic cancer. Conclusion: Anticoagulant treatment effects were generally consistent across tumor types. The significant interactions may indicate tumor-specific effects of anticoagulants, but further research is needed.

Payer formulary tier increases of apixaban: how patients respond and potential implications.

OBJECTIVE: To assess potential impacts of formulary tier increases of apixaban-an efficacious oral anticoagulant (OAC) for preventing stroke in patients with atrial fibrillation (AF)-on patients' prescription drug plan (PDP) switching and OAC treatment patterns. METHODS: Nationwide claims data for Medicare beneficiaries with Parts A, B, and D (100% sample) were used to assess apixaban-treated AF patients who faced a formulary tier increase for apixaban in 2017 by their Part D PDP. Patients' out-of-pocket (OOP) costs for apixaban were described, along with PDP switching and OAC treatment patterns. RESULTS: Among 1845 included patients, 97.7% had apixaban on tier 3 of their plan's formulary in 2016 and faced its increase to tier 4 for 2017. Approximately 4% (N = 81) of patients pre-emptively switched to a different PDP for 2017 with almost all switching to plans with apixaban on a lower formulary tier and 85.2% continuing apixaban treatment. Among the 96% (N = 1764) of patients who remained on the same PDP for 2017, over half (57.5%) continued apixaban treatment, despite increased OOP costs ($54 vs. $135 for a 30-day supply in 2016 vs. 2017). Only 12.4% of those who remained on the same plan for 2017 switched to another OAC, while as much as 30.1% discontinued OACs. These discontinuers exhibited higher comorbidity burdens than patients continuing on any OAC. CONCLUSION: The majority of patients continued on apixaban despite higher OOP cost, suggesting patients' reluctance to change treatment for non-medical reasons; however, 30% of patients discontinued OAC treatment after higher apixaban tier placement.

Trends and factors associated with outpatient anticoagulant treatment initiation among VTE patients with active cancer.

BACKGROUND: Patients with venous thromboembolism (VTE) and cancer are at higher risk of recurrent VTE and mortality. Clinical guidelines recommend anticoagulant treatment for these patients. This study assessed trends in outpatient anticoagulant treatment and factors associated with this treatment initiation in outpatient setting among this high-risk patient population. OBJECTIVE: To study trends and factors associated with anticoagulant treatment initiation among patients with VTE and cancer. METHODS: VTE cancer patients age ≥65 were identified from the SEER-Medicare database from 01JAN2014-31DEC2019. Patients were enrolled for ≥6 months prior to their first VTE (i.e. index event) and without evidence of other reasons for anticoagulation (i.e., atrial fibrillation). Patients were also required to be enrolled for ≥30 days after index. Cancer status was identified from SEER or Medicare database in the 6 months pre- through 30 days post-VTE. Patients were classified into treated or untreated cohorts depending on whether they initiated outpatient anticoagulant treatment within 30 days post-index. The trends of treated vs. untreated were evaluated by quarter. Logistic regression was used to identify demographic-, VTE-, cancer- and comorbid-related factors associated with anticoagulant treatment initiation. RESULTS: A total of 28,468 VTE-cancer patients met all study criteria. Of these, ~46 % initiated outpatient anticoagulant treatment within 30 days, and ~54 % did not. The above rates were stable from 2014 to 2019. Factors such as VTE diagnosis in inpatient setting, pulmonary embolism (PE) diagnosis, and pancreatic cancer were associated with increased odds whereas bleeding history and some comorbid factors were associated with decreased odds of initiating anticoagulant treatment. CONCLUSION: Over half of VTE patients with cancer did not initiate outpatient anticoagulant treatment within the first 30-days after VTE diagnosis. This trend was stable from 2014 to 2019. A range of cancer-, VTE-, and comorbid-related factors were associated with the likelihood of the treatment initiation.

Effectiveness and Safety of Apixaban vs Warfarin in Patients with Venous Thromboembolism with Risk Factors for Bleeding or for Recurrences.

INTRODUCTION: Patients at increased risk of bleeding and recurrent VTE who develop venous thromboembolism (VTE) present challenges for clinical management. This study evaluated the effectiveness and safety of apixaban vs warfarin in patients with VTE who have risk factors for bleeding or recurrences. METHODS: Adult patients with VTE initiating apixaban or warfarin were identified from five claims databases. Stabilized inverse probability treatment weighting (IPTW) was used to balance characteristics between cohorts for the main analysis. Subgroup interaction analyses were conducted to evaluate treatment effects among patients with and without each of the conditions that increased the risk of bleeding (thrombocytopenia and history of bleed) or recurrent VTE (thrombophilia, chronic liver disease, and immune-mediated disorders). RESULTS: A total of 94,333 warfarin and 60,786 apixaban patients with VTE met selection criteria. After IPTW, all patient characteristics were balanced between cohorts. Apixaban (vs warfarin) patients were at lower risk of recurrent VTE (HR [95% confidence interval (CI) 0.72 [0.67-0.78]), major bleeding (MB) (HR [95% CI] 0.70 [0.64-0.76]), and clinically relevant non-major (CRNM) bleeding (HR [95% CI] 0.83 [0.80-0.86]). Subgroup analyses showed generally consistent findings with the overall analysis. For most subgroup analyses, there were no significant interactions between treatment and subgroup strata on VTE, MB and CRNM bleeding. CONCLUSION: Patients with prescription fills for apixaban had lower risk of recurrent VTE, MB, and CRNM bleeding compared with warfarin patients. Treatment effects of apixaban vs warfarin were generally consistent across subgroups of patients at increased risk of bleeding/recurrences.

Effectiveness and Safety of Direct Oral Anticoagulants Among Patients with Non-valvular Atrial Fibrillation and Multimorbidity.

INTRODUCTION: In the USA, there is a steady rise of atrial fibrillation due to the aging population with increased morbidity. This study evaluated the risk of stroke/systemic embolism (S/SE) and major bleeding (MB) among elderly patients with non-valvular atrial fibrillation (NVAF) and multimorbidity prescribed direct oral anticoagulants (DOACs). METHODS: Using the CMS Medicare database, a retrospective observational study of adult patients with NVAF and multimorbidity who initiated apixaban, dabigatran, or rivaroxaban from January 1, 2012 to December 31, 2017 was conducted. High multimorbidity was classified as having ≥ 6 comorbidities. Cox proportional hazard models were used to evaluate the hazard ratios of S/SE and MB among three 1:1 propensity score matched DOAC cohorts. All-cause healthcare costs were estimated using generalized linear models. RESULTS: Overall 36% of the NVAF study population had high multimorbidity, forming three propensity score matched (PSM) cohorts: 12,511 apixaban-dabigatran, 60,287 apixaban-rivaroxaban, and 12,567 dabigatran-rivaroxaban patients. Apixaban was associated with a lower risk of stroke/SE and MB when compared with dabigatran and rivaroxaban. Dabigatran had a lower risk of stroke/SE and a similar risk of MB when compared with rivaroxaban. Compared to rivaroxaban, apixaban patients incurred lower all-cause healthcare costs, and dabigatran patients incurred similar all-cause healthcare costs. Compared to dabigatran, apixaban patients incurred similar all-cause healthcare costs. CONCLUSION: Patients with NVAF and ≥ 6 comorbid conditions had significantly different risks for stroke/SE and MB when comparing DOACs to DOACs, and different healthcare expenses. This study's results may be useful for evaluating the risk-benefit ratio of DOAC use in patients with NVAF and multimorbidity.

Effectiveness and safety of apixaban vs warfarin among venous thromboembolism patients at high-risk of bleeding.

This study evaluated effectiveness and safety of apixaban versus warfarin among venous thromboembolism patients at high-risk of bleeding (defined as having at least one of the following bleeding risk factors: ≥75 years; used antiplatelet, NSAIDs, or corticosteroids; had prior gastrointestinal bleeding or gastrointestinal-related conditions; late stage chronic kidney disease). Adult venous thromboembolism patients initiating apixaban or warfarin with ≥1 bleeding risk factor were identified from Medicare and four commercial claims databases in the United States. To balance characteristics between apixaban and warfarin patients, stabilized inverse probability treatment weighting was conducted. Cox proportional hazards models were used to estimate the risk of recurrent venous thromboembolism, major bleeding, and clinically relevant non-major bleeding. In total, 88,281 patients were identified. After inverse probability treatment weighting, the baseline patient characteristics were well-balanced between the two cohorts. Among venous thromboembolism patients at high-risk of bleeding, apixaban was associated with significantly lower risk of recurrent venous thromboembolism, major bleeding and clinically relevant non-major bleeding. No significant interactions were observed between treatment and number of risk factors on major bleeding and clinically relevant non-major bleeding or between treatment and type of bleeding risk factors on any of the outcomes. In conclusion, apixaban was associated with significantly lower risk of recurrent venous thromboembolism and bleeding among venous thromboembolism patients at high-risk of bleeding. Effects were generally consistent across subgroups of patients with different number or type of bleeding risk factors.

Risk Levels and Adverse Clinical Outcomes Among Patients With Nonvalvular Atrial Fibrillation Receiving Oral Anticoagulants.

Importance: The CHA2DS2-VASc score (calculated as congestive heart failure, hypertension, age 75 years and older, diabetes, stroke or TIA, vascular disease, age 65 to 74 years, and sex category) is the standard for assessing risk of stroke and systemic embolism and includes age and thromboembolic history. To our knowledge, no studies have comprehensively evaluated safety and effectiveness outcomes among patients with nonvalvular atrial fibrillation receiving oral anticoagulants according to independent, categorical risk strata. Objective: To evaluate the incidence of key adverse outcomes among patients with nonvalvular atrial fibrillation receiving oral anticoagulants by CHA2DS2-VASc risk score range, thromboembolic event history, and age group. Design, Setting, and Participants: This cohort study was a retrospective claims data analysis using combined data sets from 5 large health claims databases. Eligible participants were adult patients with nonvalvular atrial fibrillation who initiated oral anticoagulants. Data were analyzed between January 2012 and June 2019. Exposure: Initiation of oral anticoagulants. Main Outcomes and Measures: We observed clinical outcomes (including stroke or systemic embolism, major bleeding, and a composite outcome) on treatment through study end, censoring for discontinuation of oral anticoagulants, death, and insurance disenrollment. The population was stratified by CHA2DS2-VASc risk score; history of stroke, systemic embolism, or transient ischemic attack; and age groups. We calculated time to event, incidence rates, and cumulative incidence for outcomes. Results: We identified 1 141 097 patients with nonvalvular atrial fibrillation; the mean (SD) age was 75.0 (10.5) years, 608 127 patients (53.3%) were men, and over 1 million were placed in the 2 highest risk categories (high risk 1, 327 766 participants; high risk 2, 688 449 participants). Deyo-Charlson Comorbidity Index scores ranged progressively alongside CHA2DS2-VASc risk score strata (mean [SD] scores: low risk, 0.4 [1.0]; high risk 2, 4.1 [2.9]). The crude incidence of stroke and systemic embolism generally progressed alongside risk score strata (low risk, 0.25 events per 100 person-years [95% CI, 0.18-0.34 events]; high risk 2, 3.43 events per 100 person-years [95% CI, 3.06-4.20 events]); patients at the second-highest risk strata with thromboembolic event history had higher stroke incidence vs patients at the highest risk score strata without event history (2.06 events per 100 person-years [95% CI, 2.00-3.12 events] vs 1.18 events per 100 person-years [95% CI, 1.14-1.30 events]). Major bleeding and composite incidence also increased progressively alongside risk score strata (major bleeding: low risk, 0.68 events per 100 person-years [95% CI, 0.56-0.82 events]; high risk 2, 6.29 events per 100 person-years [95% CI, 6.21-6.62 events]; composite incidence: 1.22 events per 100 person-years [95% CI, 1.06-1.41 events]; high risk 2, 10.67 events per 100 person-years [95% CI, 10.26-11.48 events]). The 12-month cumulative incidence proportions for stroke and systemic embolism, major bleeding, and composite outcomes progressed alongside risk score strata (stroke or systemic embolism, 0.30%-1.85%; major bleeding, 0.55%-5.55%; composite, 1.05%-8.23%). Age subgroup analysis followed similar trends. Conclusions and Relevance: The observed incidence of stroke or systemic embolism and major bleeding events generally conformed to an expected increasing incidence by risk score, adding insight into the importance of specific risk score range, thromboembolic event history, and age group strata. These results can help inform clinical decision-making, research, and policy.

Impact of apixaban treatment discontinuation on the risk of hospitalization among patients with nonvalvular atrial fibrillation and COVID-19.

INTRODUCTION: This study evaluated the risk of hospitalization among nonvalvular atrial fibrillation (NVAF) patients with an outpatient COVID-19 diagnosis who discontinued vs continued apixaban treatment. METHODS: Adult patients with NVAF with an apixaban prescription prior to an outpatient COVID-19 diagnosis were identified from Optum Clinformatics claims database (1 April 2020-31 March 2021). Continuers were those who continued apixaban as of the index date (date of initial outpatient COVID-19 diagnosis) and discontinuers were those who had the last day of apixaban supply on or before index. Patients were followed from COVID-19 diagnosis to change of continuation/discontinuation status, switch, death, end of continuous coverage or study end, whichever occurred first. Inverse probability treatment weighting (IPTW) was performed to balance cohorts. Cox proportional hazard models were used to compare the risk of all-cause hospitalization and hospitalization for ischemic stroke (IS), venous thromboembolism (VTE), myocardial infarction (MI), bleeding and mortality. RESULTS: A total of 7869 apixaban patients with COVID-19 were included: 6676 continuers (84.8%) and 1193 discontinuers (15.2%). Compared with continuers, discontinuers had a higher risk of all-cause hospitalization (hazard ratio [HR]: 1.23; 95% confidence interval [CI]: 1.08-1.40), IS (HR: 2.00; 95% CI: 1.03-3.87), VTE (HR: 2.37; 95% CI: 1.06-5.27) and mortality (HR: 2.28; 95% CI: 1.85-2.80). There were no significant differences in the risk of MI (HR: 1.01; 95% CI: 0.54-1.90) or bleeding-related hospitalization (HR: 1.13; 95% CI: 0.73-1.76). CONCLUSION: NVAF patients with COVID-19 who discontinued apixaban had a higher risk of hospitalization and thrombotic events vs those who continued apixaban, with no significant difference in bleeding-related hospitalization.

Non-persistence to Oral Anticoagulation Treatment in Patients with Non-valvular Atrial Fibrillation in the USA.

BACKGROUND: Studies have shown that patients with non-valvular atrial fibrillation (NVAF) who discontinue oral anticoagulants (OACs) are at higher risk of complications such as stroke. OBJECTIVE: This analysis compared the risk of non-persistence with OACs among patients with NVAF. METHODS: Adult patients with NVAF who initiated apixaban, dabigatran, rivaroxaban, or warfarin were identified using 01JAN2013-30JUN2019 data from Centers for Medicare and Medicaid Services and four US commercial claims databases. Non-persistence was defined as discontinuation (no evidence of index OAC use for ≥ 60 days from the last days' supply) or switch to another OAC. Kaplan-Meier curves were generated to illustrate time to non-persistence along with cumulative incidences of non-persistence. Baseline and time-varying covariates were evaluated, and adjusted Cox proportional hazards models were used to evaluate non-persistence risk. RESULTS: In total, 363,823 patients receiving apixaban, 57,121 receiving dabigatran, 282,831 receiving rivaroxaban, and 317,337 receiving warfarin were included. Of these, 47-72% discontinued/switched OAC therapy within an average 9-month follow-up. Apixaban was associated with a lower risk of non-persistence than were dabigatran (hazard ratio [HR] 0.62; 95% confidence interval [CI] 0.61-0.62), rivaroxaban (HR 0.76; 95% CI 0.75-0.76), and warfarin (HR 0.74; 95% CI 0.74-0.75). Dabigatran was associated with a higher risk of non-persistence than were warfarin (HR 1.21; 95% CI 1.19-1.22) and rivaroxaban (HR 1.23; 95% CI 1.22-1.25), and rivaroxaban was associated with a lower risk of non-persistence than was warfarin (HR 0.98; 95% CI 0.97-0.98). Clinical events (stroke/systemic embolism and major bleeding [MB]) during follow-up were predictors of non-persistence (stroke HR 1.57; 95% CI 1.53-1.61; MB HR 2.96; 95% CI 2.92-3.00). CONCLUSION: In over one million patients with NVAF, our results suggest differences in anticoagulation treatment persistence across OAC agents, even after accounting for clinical events after OAC initiation. It is important for clinicians and patients to take these differences into consideration, especially as non-persistence to OAC therapy is associated with thromboembolic complications.

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.

Effectiveness and Safety of Apixaban versus Warfarin in Venous Thromboembolism Patients with Chronic Kidney Disease.

There has been limited evidence reported about the outcomes of oral anticoagulants among patients with venous thromboembolism (VTE) and chronic kidney disease (CKD), especially those with stage V/end-stage renal disease (ESRD). This retrospective cohort analysis of five U.S. claims databases evaluated the risk of recurrent VTE, major bleeding (MB), and clinically relevant nonmajor bleeding (CRNMB) for apixaban versus warfarin among VTE patients diagnosed with CKD, including ESRD. Inverse probability treatment weighting (IPTW) was used to balance patient characteristics between treatment cohorts. Hazard ratios (HRs) were calculated for recurrent VTE, MB, and CRNMB among patients with CKD who experienced an index VTE. An interaction analysis was conducted to evaluate treatment effects across different stages of CKD. A total of 29,790 VTE patients with CKD were selected for analyses, of whom 10,669 (35.8%) initiated apixaban and 19,121 (64.2%) initiated warfarin. Among IPTW-balanced patient cohorts, the apixaban group had significantly lower risk of recurrent VTE (HR: 0.78; 95% confidence interval [CI]: 0.66-0.92), MB (HR: 0.76; 95% CI: 0.65-0.88), and CRNMB (HR: 0.86; 95% CI: 0.80-0.93) than the warfarin group. When stratified by CKD stage (stage I/II: 8.2%; stage III: 49.4%; stage IV: 12.8%; stage V/ESRD: 12.0%; stage unspecified: 17.6%), no significant interaction was observed for effects of apixaban versus warfarin on recurrent VTE or MB. In summary, apixaban was associated with a significantly lower risk of recurrent VTE and MB than warfarin among VTE patients with CKD. CKD stages did not have significant impact on treatment effects for recurrent VTE and MB.

Effectiveness and Safety of Oral Anticoagulants Among Nonvalvular Atrial Fibrillation Patients With Active Cancer.

BACKGROUND: Patients with cancer are more likely to develop nonvalvular atrial fibrillation (NVAF). Currently there are no definitive clinical trials or treatment guidelines for NVAF patients with concurrent cancer. OBJECTIVES: This subgroup analysis of the ARISTOPHANES study compared the risk of stroke/systemic embolism (stroke/SE) and major bleeding (MB) among NVAF patients with active cancer who were prescribed non-vitamin K antagonist oral anticoagulants (NOACs) or warfarin. METHODS: A retrospective observational study was conducted in NVAF patients with active cancer who newly initiated apixaban, dabigatran, rivaroxaban, or warfarin from January 1, 2013, through September 30, 2015, with the use of Medicare and 4 U.S. commercial claims databases. Cox models were used to estimate the risk of stroke/SE and MB in the pooled propensity score-matched cohorts. RESULTS: A total of 40,271 patients were included, with main cancer types of prostate (29%), female breast (17%), genitourinary (14%), and lung (13%). Compared with warfarin, apixaban was associated with a lower risk of stroke/SE (hazard ratio [HR]: 0.59; 95% confidence interval [CI]: 0.45-0.78) and MB (HR: 0.58; 95% CI: 0.50-0.68); dabigatran and rivaroxaban had similar risks of stroke/SE (dabigatran: HR: 0.88 [95% CI: 0.54-1.41]; rivaroxaban: HR: 0.82 [95% CI: 0.62-1.08]) and MB (dabigatran: HR: 0.76 [95% CI: 0.57-1.01]; rivaroxaban: HR: 0.95 [95% CI: 0.85-1.06]). Risks of stroke/SE and MB varied among NOAC-NOAC comparisons, while consistent treatment effects were seen for all treatment comparisons across key cancer types. CONCLUSIONS: Among this cohort of NVAF patients with active cancer, the risk of stroke/SE and MB varied among oral anticoagulants and were consistent across cancer types.

Effectiveness and Safety of Apixaban Versus Warfarin Among Older Patients with Venous Thromboembolism with Different Demographics and Socioeconomic Status.

INTRODUCTION: Impact of demographics and socioeconomic status (SES) on anticoagulant treatment outcomes among patients with venous thromboembolism (VTE) is not well understood. This study evaluated risks of recurrent VTE, major bleeding (MB), and clinically relevant non-major bleeding (CRNMB) among older patients with VTE initiating apixaban or warfarin stratified by demographics and SES. METHODS: Adult patients (≥ 65 years) who initiated apixaban or warfarin after a VTE event were selected from the US CMS Medicare database (September 2014-December 2017). Stabilized inverse probability treatment weighting (IPTW) was used to balance patient characteristics between treatment cohorts. Patients were stratified by age, gender, race, and SES. For each subgroup, Cox proportional hazard models were used to evaluate if there was a significant interaction (p < 0.10) between treatment and subgroup for recurrent VTE, MB, and CRNMB. RESULTS: In total, 22,135 apixaban and 45,840 warfarin patients with VTE were included. Post-IPTW, patient characteristics were balanced between treatment cohorts. In older patients, apixaban treatment was associated with significantly lower risks of recurrent VTE (hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.52-0.79), MB (HR 0.65; 95% CI 0.57-0.75), and CRNMB (HR 0.79; 95% CI 0.75-0.85) versus warfarin. When stratified by demographics and SES, higher incidence rates of recurrent VTE, MB, and CRNMB were observed for black vs white patients and patients with lower vs higher SES. Comparison of apixaban with warfarin by different demographic and SES subgroups showed generally consistent results as the overall analysis. For most subgroups, no significant interaction was observed between treatment and subgroup strata for recurrent VTE, MB, and CRNMB. CONCLUSION: Among older patients with VTE initiating apixaban or warfarin, higher rates of recurrent VTE and bleeding were observed in black patients and patients with lower SES. Apixaban had a lower risk of recurrent VTE, MB, and CRNMB compared to warfarin. Analyses of demographic and SES subgroups showed consistent findings.

Oral Anticoagulants for Nonvalvular Atrial Fibrillation in Patients With High Risk of Gastrointestinal Bleeding.

Importance: Many patients with nonvalvular atrial fibrillation (NVAF) are at a high risk of gastrointestinal (GI) bleeding due to conditions including older age; stage III to V chronic kidney disease (CKD); HAS-BLED (hypertension, kidney or liver disease, stroke history, prior bleeding, unstable international normalized ratio, age >65, drug or alcohol use) score of 3 or greater; corticosteroid, antiplatelet or nonsteroidal anti-inflammatory drug (NSAID) use; or GI conditions. Objective: To compare the risk of stroke and/or systemic embolism (SE) and major bleeding (MB) among patients with NVAF and high risk of GI bleeding who received non-vitamin K antagonist oral anticoagulants (NOACs) vs those who received warfarin. Design, Setting, and Participants: This retrospective cohort study included patients with NVAF who were 75 years and older; had stage III to V CKD; had an HAS-BLED score of 3 or greater; used corticosteroids, antiplatelets, or NSAIDs; or had GI conditions. Data were collected from the Centers for Medicare & Medicaid Services and 4 commercial insurance databases between January 1, 2012, and September 30, 2015. Data analysis was conducted from January 2012 to September 2015. Exposures: New prescription for apixaban, dabigatran, rivaroxaban, or warfarin between January 1, 2013, and September 30, 2015 (identification period). Main Outcomes and Measures: Six propensity score-matched cohorts were created to compare between study drugs. For the primary objective, Cox models were used to estimate stroke and/or SE and MB hazard ratios (HRs). Results: A total of 381 054 patients (187 489 [49.2%] women) with NVAF and at least 1 high-risk GI bleeding factor were identified (HAS-BLED score ≥3: 284 527 [74.7%]; aged ≥75 years: 252 835 [66.4%]; corticosteroid, antiplatelet, or NSAID therapy: 107 675 [28.3%]; prior GI bleeding conditions: 74 818 [19.6%]; and stage III-V CKD: 56 892 [14.9%]). All NOACs were associated with a lower risk of stroke and/or SE vs warfarin (apixaban: HR, 0.60; 95% CI, 0.52-0.68; dabigatran: HR, 0.75; 95% CI, 0.64-0.88; rivaroxaban: HR, 0.79; 95% CI, 0.73-0.86). Compared with warfarin, apixaban and dabigatran were associated with a lower risk of MB (apixaban: HR, 0.59; 95% CI, 0.56-0.63; dabigatran: HR, 0.78; 95% CI, 0.70-0.86), while rivaroxaban was associated with a higher risk (HR, 1.11; 95% CI, 1.05-1.16). Conclusions and Relevance: In this study of patients with NVAF and high risk of GI bleed, NOACs were associated with lower rates of stroke and/or SE, but NOACs had varying risks of MB compared with warfarin. These results may help inform treatment options in this patient population.

Use of Non-Vitamin K Antagonist Oral Anticoagulants Among Patients with Nonvalvular Atrial Fibrillation and Multimorbidity.

INTRODUCTION: Non-valvular atrial fibrillation (NVAF) is often accompanied by multiple comorbid conditions, which increase the associated risks and complexity of patient management. This study evaluated the risk of stroke/systemic embolism (SE) and major bleeding (MB) among multimorbid patients with NVAF who were prescribed non-vitamin K antagonist oral anticoagulants (NOACs) or warfarin. METHODS: A retrospective study of patients with NVAF and high multimorbidity who initiated apixaban, dabigatran, rivaroxaban, or warfarin from 1 January 2013 to 30 September 2015 was conducted using five insurance claims databases. Multimorbidity was defined as six or more comorbid conditions, and 1:1 propensity score matching (PSM) was conducted between the NOAC-warfarin and NOAC-NOAC cohorts. Cox proportional hazard models were used to evaluate the hazard ratios of stroke/SE and MB. RESULTS: Of the NVAF population (n = 466,991), 33.4% (n = 155,959) had multimorbidity, including 36,921 apixaban, 10,248 dabigatran, 45,509 rivaroxaban, and 63,281 warfarin patients. Compared to warfarin, apixaban and rivaroxaban were associated with a lower risk of stroke/SE (hazard ratio [HR] 0.63, 95% CI 0.54-0.74; HR 0.70, 95% CI 0.64-0.77, respectively). Apixaban and dabigatran were associated with a lower risk of MB (HR 0.61, 95% CI 0.56-0.67; HR 0.75, 95% CI 0.66-0.86, respectively) and rivaroxaban was associated with a higher risk of MB (HR 1.06, 95% CI 1.01-1.12) compared to warfarin. CONCLUSIONS: Among patients with NVAF and six or more comorbid conditions, NOACs were associated with varying risk of stroke/SE and MB compared to warfarin and to each other. Rather than a "one drug fits all" approach, our results may be useful for appropriate OAC treatment for multimorbid patients.

Burden of major gastrointestinal bleeding among oral anticoagulant-treated non-valvular atrial fibrillation patients.

BACKGROUND: Gastrointestinal (GI) bleeding is the most common type of major bleeding associated with oral anticoagulant (OAC) treatment. Patients with major bleeding are at an increased risk of a stroke if an OAC is not reinitiated. METHODS: Non-valvular atrial fibrillation (NVAF) patients initiating OACs were identified from the Centers for Medicare and Medicaid Services (CMS) Medicare data and four US commercial claims databases. Patients who had a major GI bleeding event (hospitalization with primary diagnosis of GI bleeding) while on an OAC were selected. A control cohort of patients without a major GI bleed during OAC treatment was matched to major GI bleeding patients using propensity scores. Stroke/systemic embolism (SE), major bleeding, and mortality (in the CMS population) were examined using Cox proportional hazards models with robust sandwich estimates. RESULTS: A total of 15,888 patients with major GI bleeding and 833,052 patients without major GI bleeding were included in the study. Within 90 days of the major GI bleed, 58% of patients discontinued the initial OAC treatment. Patients with a major GI bleed had a higher risk of stroke/SE [hazard ratio (HR): 1.57, 95% confidence interval (CI): 1.42-1.74], major bleeding (HR: 2.79, 95% CI: 2.64-2.95), and all-cause mortality (HR: 1.29, 95% CI: 1.23-1.36) than patients without a major GI bleed. CONCLUSION: Patients with a major GI bleed on OAC had a high rate of OAC discontinuation and significantly higher risk of stroke/SE, major bleeding, and mortality after hospital discharge than those without. Effective management strategies are needed for patients with risk factors for major GI bleeding.

Effectiveness and safety of oral anticoagulants among non-valvular atrial fibrillation patients with polypharmacy.

AIMS: Polypharmacy is prevalent among non-valvular atrial fibrillation (NVAF) patients and presents a potential issue for the effective management of NVAF. This study compared the risk of stroke/systemic embolism (SE) and major bleeding (MB) among NVAF patients with polypharmacy newly prescribed oral anticoagulants (OACs). METHODS AND RESULTS: A retrospective study of NVAF patients with polypharmacy who initiated OACs from 01 January 2013 to 30 September 2015 was conducted using US CMS Medicare and four commercial databases. Polypharmacy was defined as ≥6 concomitant medications on the index date. Propensity score matching was conducted to compare non-vitamin K antagonists OACs (NOACs) to warfarin as well as between NOACs. Cox proportional hazard models were used to evaluate the risk of stroke/SE and MB. A total of 188 893 patients with polypharmacy were included, with an average of 8 concomitant medications (interquartile range 6-9). Compared to warfarin, apixaban [hazard ratio (HR): 0.59, 95% confidence interval (CI): 0.52-0.68], and rivaroxaban (HR: 0.75, 95% CI: 0.69-0.83) were associated with a lower risk of stroke/SE. Apixaban (HR: 0.57, 95% CI: 0.54-0.61) and dabigatran (HR: 0.76, 95% CI: 0.66-0.88) were associated with a decreased risk of MB compared with warfarin. Compared with dabigatran and rivaroxaban, apixaban was associated with a lower risk of stroke/SE and MB. Dabigatran was associated with lower risk of MB compared with rivaroxaban. CONCLUSIONS: In this observational study of anticoagulated NVAF patients with polypharmacy, effectiveness and safety profiles are more favourable for NOACs vs. warfarin. Our observations are hypothesis generating and may help inform future clinical trials regarding appropriate OAC treatment selection in polypharmacy patients.