Antithrombotic Strategies According to Age: Insights from the AUGUSTUS Trial.

OBJECTIVE: We aimed to evaluate the safety and efficacy of antithrombotic strategies by age in patients with atrial fibrillation and acute coronary syndrome and/or percutaneous coronary intervention in AUGUSTUS. METHODS: Patients were stratified into 3 age groups: <65, 65-74, and ≥75 years. Outcomes of interest were major or clinically relevant non-major bleeding, major bleeding, death or rehospitalization, and ischemic events. Treatment effects of apixaban vs. vitamin K antagonist (VKA) and aspirin vs. placebo were assessed across age groups using Cox models. RESULTS: Of 4614 patients, 1267 (27.5%) were <65, 1802 (39.0%) were 65-74, and 1545 (33.5%) were ≥75 years. Apixaban was associated with lower rates of major or clinically relevant non-major bleeding than VKA (<65: HR 0.69 [0.47-1.00]; 65-74: HR 0.57 [0.43-0.75]; ≥75: HR 0.81 [0.63-1.04]). Death or hospitalization occurred less often with apixaban, regardless of age. No differences were observed in rates of ischemic events between apixaban and VKA according to age. Aspirin was associated with higher rates of bleeding than placebo (<65: HR 1.67 [1.15-2.43]; 65-74: HR 2.32 [1.73-3.10]; ≥75: HR 1.69 [1.31-2.19]). Rates of death or rehospitalization and ischemic events were similar among patients receiving aspirin or placebo across age groups. CONCLUSIONS: Apixaban was associated with greater absolute reduction in bleeding than VKA in older age groups, reflecting their higher hemorrhagic risk. Aspirin increased bleeding in all age groups vs. placebo. Our findings support the use of apixaban plus a purinergic receptor P2Y12(P2Y12) inhibitor without aspirin in patients with atrial fibrillation and recent acute coronary syndrome/percutaneous coronary intervention, regardless of age.

Apixaban or Warfarin and Aspirin or Placebo After Acute Coronary Syndrome or Percutaneous Coronary Intervention in Patients With Atrial Fibrillation and Prior Stroke: A Post Hoc Analysis From the AUGUSTUS Trial.

Importance: Data are limited regarding the risk of cerebrovascular ischemic events and major bleeding in patients with atrial fibrillation (AF) and recent acute coronary syndrome (ACS) and/or percutaneous coronary intervention (PCI). Objective: Determine the efficacy and safety of apixaban or vitamin K antagonists (VKA) and aspirin or placebo according to prior stroke, transient ischemic attack (TIA), or thromboembolism (TE). Design, Setting, and Participants: In this prospective, multicenter, 2-by-2 factorial, randomized clinical trial, post hoc parallel analyses were performed to compare randomized treatment regimens according to presence or absence of prior stroke/TIA/TE using Cox proportional hazards models. Patients with AF, recent ACS or PCI, and planned use of P2Y12 inhibitors for 6 months or longer were included; 33 patients with missing data about prior stroke/TIA/TE were excluded. Interventions: Apixaban (5 mg or 2.5 mg twice daily) or VKA and aspirin or placebo. Main Outcomes and Measures: Major or clinically relevant nonmajor (CRNM) bleeding. Results: Of 4581 patients included, 633 (13.8%) had prior stroke/TIA/TE. Patients with vs without prior stroke/TIA/TE were older; had higher CHA2DS2-VASC and HAS-BLED scores; and more frequently had prior bleeding, heart failure, diabetes, and prior oral anticoagulant use. Apixaban was associated with lower rates of major or CRNM bleeding and death or hospitalization than VKA in patients with (hazard ratio [HR], 0.69; 95% CI, 0.46-1.03) and without (HR, 0.68; 95% CI, 0.57-0.82) prior stroke/TIA/TE. Patients without prior stroke/TIA/TE receiving aspirin vs placebo had higher rates of bleeding; this difference appeared less substantial among patients with prior stroke/TIA/TE (P = .01 for interaction). Aspirin was associated with numerically lower rates of death or ischemic events than placebo in patients with (HR, 0.71; 95% CI, 0.42-1.20) and without (HR, 0.93; 95% CI, 0.72-1.21) prior stroke/TIA/TE (not statistically significant). Conclusions and Relevance: The safety and efficacy of apixaban compared with VKA was consistent with the AUGUSTUS findings, irrespective of prior stroke/TIA/TE. Aspirin increased major or CRNM bleeding, particularly in patients without prior stroke/TIA/TE. Although aspirin may have some benefit in patients with prior stroke, our findings support the use of apixaban and a P2Y12 inhibitor without aspirin for the majority of patients with AF and ACS and/or PCI, regardless of prior stroke/TIA/TE status. Trial Registration: ClinicalTrials.gov Identifier: NCT02415400.

Regional variation in clinical characteristics and outcomes in patients with atrial fibrillation: Findings from the ARISTOTLE trial.

BACKGROUND: Variation in patient characteristics and practice patterns may influence outcomes at a regional level. METHODS: We assessed differences in demographics, practice patterns, outcomes, and the effect of apixaban compared with warfarin in ARISTOTLE (n = 18,201) by prespecified regions: North America, Latin America, Europe, and Asia Pacific. The primary outcomes were stroke/systemic embolism and major bleeding. RESULTS: Compared with other regions, patients from Asia Pacific were younger, more women were enrolled in Latin America. Coronary artery disease was more prevalent in Europe and Asia Pacific had the highest rate of prior stroke and renal impairment. Over 50% of patients in North America were taking ≥9 drugs at randomization, compared with 10% in Latin America. North America had the highest rates of temporary study drug discontinuation and procedures. Time in therapeutic range (INR 2.0-3.0) on warfarin was highest in North America and lowest in Asia Pacific. After adjustment and compared with Europe, patients in Asia Pacific had 2-fold higher risk of stroke/systemic embolism and 3-fold higher risk of intracranial hemorrhage. Patients in Latin America had 2-fold increased risk of all-cause death compared with Europe. The benefits of apixaban compared with warfarin were consistent across regions; there was a pronounced reduction in major bleeding in patients from Asia Pacific compared with other regions (p-interaction = 0.03). CONCLUSIONS: Patients with AF enrolled in prespecified regions in ARISTOTLE had differences in clinical baseline characteristics and practice patterns. After adjustment, patients in Asia Pacific and Latin America had worse outcomes than patients from other regions. The relative benefits of apixaban compared with warfarin were consistent across regions with an even greater treatment effect in the reduction of bleeding in patients from Asia Pacific.

Antithrombotic therapy use and clinical outcomes following thrombo-embolic events in patients with atrial fibrillation: insights from ARISTOTLE

METHOD AND RESULTS:Thrombo-embolic events were defined as stroke (ischaemic or unknown cause) or systemic embolism (SE). Clinical outcomes were estimated using the Kaplan­Meier method. All-cause mortality and International Society on Thrombosis and Haemostasis (ISTH) major bleeding after events were analysed using a Cox proportional hazards model with time-dependent covariates. Of 18 201 patients in ARISTOTLE, 365 experienced a thrombo-embolic event [337 strokes (ischaemic or unknown cause), 28 SE]; 46 (12.6%) of which were fatal. In the 30 days before and after a thrombo-embolic event, 11% and 37% of patients, respectively, were not taking an oral anticoagulant. During follow-up (median 1.8 years), 22 patients (7.1%/year) had a recurrent stroke, 97 (30.1%/year) died, and 10 (6.7%/year) had major bleeding. Compared with patients without a thrombo-embolic event, the short- and long-term adjusted hazards of death in patients with a thrombo-embolic event were high [30 days: HR 3.5, 95% CI 2.5­4.8; both P< 0.001]. The adjusted hazards of major bleeding were also high short-term (HR 10.37, 95% CI 3.87­27.78; P< 0.001) but not long-term (HR 1.7, 95% CI: 0.77­3.88; P= 0.18). CONCLUSIONS: Thrombo-embolic events were rare but associated with high short- and long-term morbidity and mortality. Substantial numbers of patients are not receiving oral anticoagulant therapy before and, despite this risk, after a first thrombo-embolic event.

Non-major bleeding with apixaban versus warfarin in patients with atrial fibrillation.

OBJECTIVE: We describe the incidence, location and management of non-major bleeding, and assess the association between non-major bleeding and clinical outcomes in patients with atrial fibrillation (AF) receiving anticoagulation therapy enrolled in Apixaban for Reduction in Stroke and other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE). METHODS: We included patients who received ≥1 dose of study drug (n=18 140). Non-major bleeding was defined as the first bleeding event considered to be clinically relevant non-major (CRNM) or minor bleeding, and not preceded by a major bleeding event. RESULTS: Non-major bleeding was three times more common than major bleeding (12.1% vs 3.8%). Like major bleeding, non-major bleeding was less frequent with apixaban (6.4 per 100 patient-years) than warfarin (9.4 per 100 patient-years) (adjusted HR 0.69, 95% CI 0.63 to 0.75). The most frequent sites of non-major bleeding were haematuria (16.4%), epistaxis (14.8%), gastrointestinal (13.3%), haematoma (11.5%) and bruising/ecchymosis (10.1%). Medical or surgical intervention was similar among patients with non-major bleeding on warfarin versus apixaban (24.7% vs 24.5%). A change in antithrombotic therapy (58.6% vs 50.0%) and permanent study drug discontinuation (5.1% (61) vs 3.6% (30), p=0.10) was numerically higher with warfarin than apixaban. CRNM bleeding was independently associated with an increased risk of overall death (adjusted HR 1.70, 95% CI 1.32 to 2.18) and subsequent major bleeding (adjusted HR 2.18, 95% CI 1.56 to 3.04). CONCLUSIONS: In ARISTOTLE, non-major bleeding was common and substantially less frequent with apixaban than with warfarin. CRNM bleeding was independently associated with a higher risk of death and subsequent major bleeding. Our results highlight the importance of any severity of bleeding in patients with AF treated with anticoagulation therapy and suggest that non-major bleeding, including minor bleeding, might not be minor. TRIAL REGISTRATION NUMBER: NCT00412984; post-results.

Amiodarone, anticoagulation, and clinical events in patients with atrial fibrillation: insights from the ARISTOTLE trial.

BACKGROUND: Amiodarone is an effective medication in preventing atrial fibrillation (AF), but it interferes with the metabolism of warfarin. OBJECTIVES: This study sought to examine the association of major thrombotic clinical events and bleeding with the use of amiodarone in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial. METHODS: Baseline characteristics of patients who received amiodarone at randomization were compared with those who did not receive amiodarone. The interaction between randomized treatment and amiodarone was tested using a Cox model, with main effects for randomized treatment and amiodarone and their interaction. Matching on the basis of a propensity score was used to compare patients who received and who did not receive amiodarone at the time of randomization. RESULTS: In ARISTOTLE, 2,051 (11.4%) patients received amiodarone at randomization. Patients on warfarin and amiodarone had time in the therapeutic range that was lower than patients not on amiodarone (56.5% vs. 63.0%; p < 0.0001). More amiodarone-treated patients had a stroke or a systemic embolism (1.58%/year vs. 1.19%/year; adjusted hazard ratio [HR]: 1.47, 95% confidence interval [CI]: 1.03 to 2.10; p = 0.0322). Overall mortality and major bleeding rates were elevated, but were not significantly different in amiodarone-treated patients and patients not on amiodarone. When comparing apixaban with warfarin, patients who received amiodarone had a stroke or a systemic embolism rate of 1.24%/year versus 1.85%/year (HR: 0.68, 95% CI: 0.40 to 1.15), death of 4.15%/year versus 5.65%/year (HR: 0.74, 95% CI: 0.55 to 0.98), and major bleeding of 1.86%/year versus 3.06%/year (HR: 0.61, 95% CI: 0.39 to 0.96). In patients who did not receive amiodarone, the stroke or systemic embolism rate was 1.29%/year versus 1.57%/year (HR: 0.82, 95% CI: 0.68 to 1.00), death was 3.43%/year versus 3.68%/year (HR: 0.93, 95% CI: 0.83 to 1.05), and major bleeding was 2.18%/year versus 3.03%/year (HR: 0.72, 95% CI: 0.62 to 0.84). The interaction p values for amiodarone use by apixaban treatment effects were not significant. CONCLUSIONS: Amiodarone use was associated with significantly increased stroke and systemic embolism risk and a lower time in the therapeutic range when used with warfarin. Apixaban consistently reduced the rate of stroke and systemic embolism, death, and major bleeding compared with warfarin in amiodarone-treated patients and patients who were not on amiodarone.

Amiodarone, Anticoagulation, and Clinical Events in Patients With Atrial FibrillationInsights From the ARISTOTLE Trial

Amiodarone is an effective medication in preventing atrial fibrillation (AF), but it interferes with the metabolism of warfarin.Objectives This study sought to examine the association of major thrombotic clinical events and bleeding with the use of amiodarone in the ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial.Methods Baseline characteristics of patients who received amiodarone at randomization were compared with those who did not receive amiodarone. The interaction between randomized treatment and amiodarone was tested using a Cox model, with main effects for randomized treatment and amiodarone and their interaction. Matching on the basis of a propensity score was used to compare patients who received and who did not receive amiodarone at the time of randomization.Results In ARISTOTLE, 2,051 (11.4%) patients received amiodarone at randomization. Patients on warfarin and amiodarone had time in the therapeutic range that was lower than patients not on amiodarone (56.5% vs. 63.0%; p < 0.0001). More amiodarone-treated patients had a stroke or a systemic embolism (1.58%/year vs. 1.19%/year; adjusted hazard ratio [HR]: 1.47, 95% confidence interval [CI]: 1.03 to 2.10; p = 0.0322). Overall mortality and major bleeding rates were elevated, but were not significantly different in amiodarone-treated patients and patients not on amiodarone. When comparing apixaban with warfarin, patients who received amiodarone had a stroke or a systemic embolism rate of 1.24%/year versus 1.85%/year (HR: 0.68, 95% CI: 0.40 to 1.15), death of 4.15%/year versus 5.65%/year (HR: 0.74, 95% CI: 0.55 to 0.98)...

Apixaban in patients with atrial fibrillation and prior coronary artery disease: insights from the ARISTOTLE trial.

BACKGROUND: A substantial portion of patients with atrial fibrillation (AF) also have coronary artery disease (CAD) and are at risk for coronary events. Warfarin is known to reduce these events, but increase the risk of bleeding. We assessed the effects of apixaban compared with warfarin in AF patients with and without prior CAD. METHODS AND RESULTS: In ARISTOTLE, 18,201 patients with AF were randomized to apixaban or warfarin. History of CAD was defined as documented CAD, prior myocardial infarction, and/or history of coronary revascularization. We analyzed baseline characteristics and clinical outcomes of patients with and without prior CAD and compared outcomes by randomized treatment using Cox models. A total of 6639 (36.5%) patients had prior CAD. These patients were more often male, more likely to have prior stroke, diabetes, and hypertension, and more often received aspirin at baseline (42.2% vs. 24.5%). The effects of apixaban were similar among patients with and without prior CAD on reducing stroke or systemic embolism and death from any cause (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.71-1.27, P for interaction=0.12; HR 0.96, 95% CI 0.81-1.13, P for interaction=0.28). Rates of myocardial infarction were numerically lower with apixaban than warfarin among patients with and without prior CAD. The effect of apixaban on reducing major bleeding and intracranial hemorrhage was consistent in patients with and without CAD. CONCLUSIONS: In patients with AF, apixaban more often prevented stroke or systemic embolism and death and caused less bleeding than warfarin, regardless of the presence of prior CAD. Given the common occurrence of AF and CAD and the higher rates of cardiovascular events and death, our results indicate that apixaban may be a better treatment option than warfarin for these high-risk patients.