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.

ReducinG stroke by screening for UndiAgnosed atRial fibrillation in elderly inDividuals (GUARD-AF): Rationale and design of the GUARD-AF randomized trial of screening for atrial fibrillation with a 14-day patch-based continuous ECG monitor.

BACKGROUND: Screening for atrial fibrillation (AF) is attractive because AF independently raises the risk of ischemic stroke, this risk is largely reversible by long-term oral anticoagulant therapy (OAC), and many patients with AF remain undiagnosed and untreated. Recent trials of one-time brief screening for AF have not produced a significant increase in the proportion of patients diagnosed with AF. Trials of longer-term screening have demonstrated an increase in AF diagnoses, primarily paroxysmal AF. To date, however, no trials have demonstrated that screening for AF results in lower rates of stroke. Clinical practice guidelines conflict in their level of support for screening for AF. METHODS: The GUARD-AF individually randomized trial is designed to test whether screening for AF in individuals age 70 years or greater using a 2-week single-lead electrocardiographic patch monitor can identify patients with undiagnosed AF and lead to treatment with OAC, resulting in a reduced rate of stroke in the screened population. The trial's efficacy end point is hospitalization for stroke (either ischemic or hemorrhagic) and the trial's safety end point is hospitalization for a bleeding event. End points will be ascertained via Medicare claims or electronic health records at 2.5 years after study start. Enrollment is based in primary care practices and the OAC decision for screen-detected cases is left to the patient and their physician. The initial planned target sample size was 52,000, with 26,000 allocated to either screening or to usual care. RESULTS: Trial enrollment was severely hampered by the novel coronavirus disease 2019 (COVID-19) pandemic and stopped at a total enrollment of 11,931 participants. Of 5,965 randomized to the screening arm, 5,713 patients (96%) returned monitors with analyzable results. Incidence of screen-detected and clinically detected AF and associated stroke and bleeding outcomes will be ascertained. CONCLUSIONS: GUARD-AF is the largest AF screening randomized trial using a longer-term patch-based continuous electrocardiographic monitor. The results will contribute important information on the yield of patch-based AF screening, the "burden" of AF detected (percent time in AF, longest episode), and physicians' OAC decisions as a function of AF burden. GUARD-AF's stroke and bleed results will contribute to pooled trial analyses of AF screening, thereby informing future studies and guidelines.

Systematic Screening for Atrial Fibrillation in Patients at Moderate-to-High Risk of Stroke　- Potential to Increase the Atrial Fibrillation Detection Rate (SCAN-AF).

BACKGROUND: To determine the rate of undiagnosed atrial fibrillation (AF) we screened for AF using an oscillometric blood pressure (BP) monitor device followed by a single-lead handheld electrocardiogram (ECG), with confirmation by 12-lead ECG as the reference standard.Methods and Results: From October 2017 to August 2019, 1,148 patients were enrolled without known AF, who were aged ≥65 years with moderate-to-high stroke risk, at 71 centers in Japan. After exclusion of 7 patients with confirmed AF at the index visit, 1,141 patients were asked to use an oscillometric BP monitor twice daily for 2 weeks (max: 4 weeks) to detect an irregular pulse. The BP monitor detected an irregular pulse in 481 patients, of which 1 patient had confirmed AF. Thereafter, 480 patients were instructed to acquire ECGs twice daily for an additional 2 weeks (max: 4 weeks) using a single-lead handheld ECG device. The handheld ECG device detected irregular rhythm in 41 patients, of which 1 patient had confirmed AF. In total, undiagnosed AF was confirmed in 9 (0.8%) patients of the overall study cohort during the 24-week follow-up period. CONCLUSIONS: Sequential use of a BP monitor and handheld ECG for 4 weeks is a practical strategy for identifying undiagnosed AF in Japanese people at heightened risk of stroke.

Antithrombotic Therapy in Patients With Atrial Fibrillation After Acute Coronary Syndromes or Percutaneous Intervention.

BACKGROUND: The use of apixaban instead of vitamin K antagonists (VKA) as well as dropping aspirin results in less bleeding and comparable ischemic events in patients with atrial fibrillation and acute coronary syndrome and/or percutaneous coronary intervention treated with a P2Y12 inhibitor. OBJECTIVES: The authors assessed the safety and efficacy of antithrombotic regimens according to HAS-BLED and CHA2DS2-VASc scores in AUGUSTUS (The Open-Label, 2 × 2 Factorial, Randomized, Controlled Clinical Trial to Evaluate the Safety of Apixaban vs. Vitamin K Antagonist and Aspirin vs. Placebo in Patients with Atrial Fibrillation and Acute Coronary Syndrome and/or Percutaneous Coronary Intervention). METHODS: In AUGUSTUS, 4,614 patients were randomized in a 2-by-2 factorial design to open-label apixaban or VKA and blinded aspirin or placebo. The primary endpoint was major or clinically relevant nonmajor bleeding over 6 months of follow-up. Cox proportional hazards models were used to assess treatment effects by baseline HAS-BLED (≤2 vs ≥3) and CHA2DS2-VASc (≤2 vs ≥3) scores. RESULTS: Of 4,386 (95.1%) patients with calculable scores, 66.8% had HAS-BLED ≥3 and 81.7% had CHA2DS2-VASc ≥3. Bleeding rates were lower with apixaban than VKA irrespective of baseline risk (HR: 0.57; 95% CI: 0.41-0.78 [HAS-BLED ≤2]; HR: 0.72; 95% CI: 0.59-0.88 [HAS-BLED ≥3]; interaction P = 0.23). Aspirin increased bleeding irrespective of baseline risk (HR: 1.86; 95% CI: 1.36-2.56 [HAS-BLED ≤2]; HR: 1.81; 95% CI: 1.47-2.23 [HAS-BLED ≥3]; interaction P = 0.88). Apixaban resulted in a lower risk of death or hospitalization than VKA without a significant interaction with baseline stroke risk (HR: 0.92; 95% CI: 0.67-1.25 [CHA2DS2-VASc ≤2]; HR: 0.82; 95% CI: 0.73-0.94 [CHA2DS2-VASc ≥3]; interaction P = 0.53). CONCLUSIONS: Our findings support the use of apixaban and a P2Y12 inhibitor without aspirin for most patients with atrial fibrillation and acute coronary syndrome and/or percutaneous coronary intervention, irrespective of a patient's baseline bleeding and stroke risk (NCT02415400).

Impact of prior oral anticoagulant use and outcomes on patients from secondary analysis in the AUGUSTUS trial.

OBJECTIVE: Managing antithrombotic therapy in patients with atrial fibrillation (AF) and an acute coronary syndrome (ACS) and/or percutaneous coronary intervention (PCI) is challenging and can be affected by prior oral anticoagulant (OAC) treatment. We examined the relationship between prior OAC use and outcomes in the AUGUSTUS trial. METHODS: This prespecified secondary analysis is from AUGUSTUS, an open-label, 2-by-2 factorial, RCT to evaluate the safety of apixaban versus vitamin K antagonist (VKA) and aspirin versus placebo in patients with AF and ACS and/or PCI. The primary endpoint, major or clinically relevant non-major bleeding and clinical outcomes were compared in patients receiving (n=2262) or not receiving (n=2352) an OAC prior to enrolment. RESULTS: Patients with prior OAC use had more comorbidities, higher CHA2DS2-VASC and HAS-BLED scores, and were more likely enrolled following elective PCI. There was no difference in major or clinically relevant non-major bleeding with or without prior OAC (30 days: 5.1% vs 5.9% (adjusted HR (aHR) 0.82, 95% CI 0.63 to 1.06); 180 days: 13.5% vs 13.5% (aHR 0.98, 95% CI 0.83 to 1.16)). Patients with prior OAC use had a lower risk of death or ischaemic events (30 days: 1.7% vs 2.8% (aHR 0.61, 95% CI 0.41 to 0.92); 180 days: 5.4% vs 7.6% (aHR 0.70, 95% CI 0.55 to 0.88)). No interactions between randomised treatment (apixaban vs VKA, aspirin vs placebo) and prior OAC status were observed for outcomes, apart from apixaban (vs VKA) being associated with a lower risk of myocardial infarction with prior OAC use (180 days: 2.0% vs 3.7% (aHR 0.56, 95% CI 0.33 to 0.91(). CONCLUSIONS: In AUGUSTUS, prior OAC use was associated with fewer ischaemic events but not more bleeding. In patients with AF and ACS and/or undergoing PCI, clinicians can be assured that the trial results can be applied to patients regardless of their prior OAC status. TRIAL REGISTRATION NUMBER: NCT02415400.

Apixaban or Vitamin K Antagonists and Aspirin or Placebo According to Kidney Function in Patients With Atrial Fibrillation After Acute Coronary Syndrome or Percutaneous Coronary Intervention: Insights From the AUGUSTUS Trial.

BACKGROUND: In the AUGUSTUS trial (An Open-Label, 2×2 Factorial, Randomized Controlled, Clinical Trial to Evaluate the Safety of Apixaban Versus Vitamin K Antagonist and Aspirin Versus Aspirin Placebo in Patients With Atrial Fibrillation and Acute Coronary Syndrome or Percutaneous Coronary Intervention), apixaban resulted in less bleeding and fewer hospitalizations than vitamin K antagonists, and aspirin caused more bleeding than placebo in patients with atrial fibrillation and acute coronary syndrome or percutaneous coronary intervention treated with a P2Y12 inhibitor. We evaluated the risk-benefit balance of antithrombotic therapy according to kidney function. METHODS: In 4456 patients, the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula was used to calculate baseline estimated glomerular filtration rate (eGFR). The effect of apixaban versus vitamin K antagonists and aspirin versus placebo was assessed across kidney function categories by using Cox models. The primary outcome was International Society on Thrombosis and Haemostasis major or clinically relevant nonmajor bleeding. Secondary outcomes included death or hospitalization and ischemic events (death, stroke, myocardial infarction, stent thrombosis [definite or probable], or urgent revascularization). Creatinine clearance <30 mL/min was an exclusion criterion in the AUGUSTUS trial. RESULTS: Overall, 30%, 52%, and 19% had an eGFR of >80, >50 to 80, and 30 to 50 mL·min-1·1.73 m-2, respectively. At the 6-month follow-up, a total of 543 primary outcomes of bleeding, 1125 death or hospitalizations, and 282 ischemic events occurred. Compared with vitamin K antagonists, patients assigned apixaban had lower rates for all 3 outcomes across most eGFR categories without significant interaction. The absolute risk reduction with apixaban was most pronounced in those with an eGFR of 30 to 50 mL·min-1·1.73 m-2 for bleeding events with rates of 13.1% versus 21.3% (hazard ratio, 0.59; 95% CI, 0.41-0.84). Patients assigned aspirin had a higher risk of bleeding in all eGFR categories with an even greater increase among those with eGFR >80 mL·min-1·1.73 m-2: 16.6% versus 5.6% (hazard ratio, 3.22; 95% CI, 2.19-4.74; P for interaction=0.007). The risk of death or hospitalization and ischemic events were comparable to aspirin and placebo across eGFR categories with hazard ratios ranging from 0.97 (95% CI, 0.76-1.23) to 1.28 (95% CI, 1.02-1.59) and from 0.75 (95% CI, 0.48-1.17) to 1.34 (95% CI, 0.81-2.22), respectively. CONCLUSIONS: The safety and efficacy of apixaban was consistent irrespective of kidney function, compared with warfarin, and in accordance with the overall trial results. The risk of bleeding with aspirin was consistently higher across all kidney function categories. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02415400.

Antithrombotic Effects of Combined PAR (Protease-Activated Receptor)-4 Antagonism and Factor Xa Inhibition.

OBJECTIVE: PAR (protease-activated receptor)-4 antagonism has antiplatelet effects under conditions of high shear stress. We aimed to establish whether PAR4 antagonism had additive antithrombotic activity in the presence of factor Xa inhibition in an ex vivo model of acute arterial injury. Approach and Results: Fifteen healthy volunteers (29±6 years, 7 women) completed a phase zero double-blind randomized controlled crossover trial. Ex vivo platelet activation, platelet aggregation, and thrombus formation were measured following blood perfusion of low shear and high shear stress chambers. Upstream of the chambers, extracorporeal blood was admixed with (1) vehicle, (2) low-dose apixaban (20 ng/mL), (3) high-dose apixaban (80 ng/mL), (4) BMS-986141 (400 ng/mL), (5) BMS-968141 and low-dose apixaban, or (6) BMS-968141 and high-dose apixaban in 6 sequential studies performed in random order. Compared with vehicle, BMS-986141 demonstrated selective inhibition of PAR4-AP (agonist peptide)-stimulated platelet aggregation, platelet-monocyte aggregates, and P-selectin expression (P≤0.01 for all). Total thrombus area was reduced under both low shear and high shear stress conditions for all drug infusions (P<0.0001 for all versus vehicle). BMS-968141 reduced total (≤44.4%) and platelet-rich (≤39.3%) thrombus area, whereas apixaban reduced total (≤42.9%) and fibrin-rich (≤31.6%) thrombus area. Combination of BMS-986141 with apixaban caused a further modest reduction in total thrombus area (9.6%-12.4%), especially under conditions of high shear stress (P≤0.027). CONCLUSIONS: In the presence of factor Xa inhibition, PAR4 antagonism with BMS-986141 further reduces thrombus formation, especially under conditions of high shear stress. This suggests the potential for additive efficacy of combination PAR4 antagonism and factor Xa inhibition in the prevention of atherothrombotic events.

Risk/Benefit Tradeoff of Antithrombotic Therapy in Patients With Atrial Fibrillation Early and Late After an Acute Coronary Syndrome or Percutaneous Coronary Intervention: Insights From AUGUSTUS.

BACKGROUND: In AUGUSTUS (Open-Label, 2×2 Factorial, Randomized, Controlled Clinical Trial to Evaluate the Safety of Apixaban vs Vitamin K Antagonist and Aspirin vs Aspirin Placebo in Patients With Atrial Fibrillation and Acute Coronary Syndrome and/or Percutaneous Coronary Intervention), patients with atrial fibrillation and a recent acute coronary syndrome and those undergoing percutaneous coronary intervention had less bleeding with apixaban than vitamin K antagonist (VKA) and with placebo than aspirin. However, the number of ischemic events was numerically higher with placebo. The aim of this analysis is to assess the tradeoff of risk (bleeding) and benefit (ischemic events) over time with apixaban versus VKA and aspirin versus placebo. METHODS: In AUGUSTUS, 4614 patients with atrial fibrillation and recent acute coronary syndrome or percutaneous coronary intervention on a P2Y12 inhibitor were randomized to blinded aspirin or placebo and to open-label apixaban or VKA for 6 months. In a post hoc analysis, we compared the risk of 3 composite bleeding outcomes and 3 composite ischemic outcomes from randomization through 30 days and from 30 days to 6 months with apixaban and VKA and with aspirin and placebo. RESULTS: Compared with VKA, apixaban had either a lower or a similar risk of bleeding and ischemic outcomes from randomization to 30 days and from 30 days to 6 months. From randomization to 30 days, aspirin caused more severe bleeding (absolute risk difference, 0.97% [95% CI, 0.23-1.70]) and fewer severe ischemic events (absolute risk difference, -0.91% [95% CI, -1.74 to -0.08]) than placebo. From 30 days to 6 months, the risk of severe bleeding was higher with aspirin than placebo (absolute risk difference, 1.25% [95% CI, 0.23-2.27]), whereas the risk of severe ischemic events was similar (absolute risk difference, -0.17% [95% CI, -1.33 to 0.98]). CONCLUSIONS: In patients with atrial fibrillation and recent acute coronary syndrome or percutaneous coronary intervention receiving a P2Y12 inhibitor, apixaban is preferred over VKA. Use of aspirin immediately and for up to 30 days results in an equal tradeoff between an increase in severe bleeding and a reduction in severe ischemic events. After 30 days, aspirin continues to increase bleeding without significantly reducing ischemic events. These results inform shared, patient-centric decision making on the ideal duration of the use of aspirin after an acute coronary syndrome or percutaneous coronary intervention in patients with atrial fibrillation receiving oral anticoagulation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02415400.

Antithrombotic Therapy in Patients With Atrial Fibrillation and Acute Coronary Syndrome Treated Medically or With Percutaneous Coronary Intervention or Undergoing Elective Percutaneous Coronary Intervention: Insights From the AUGUSTUS Trial.

BACKGROUND: The safety and efficacy of antithrombotic regimens may differ between patients with atrial fibrillation who have acute coronary syndromes (ACS), treated medically or with percutaneous coronary intervention (PCI), and those undergoing elective PCI. METHODS: Using a 2×2 factorial design, we compared apixaban with vitamin K antagonists and aspirin with placebo in patients with atrial fibrillation who had ACS or were undergoing PCI and were receiving a P2Y12 inhibitor. We explored bleeding, death and hospitalization, as well as death and ischemic events, by antithrombotic strategy in 3 prespecified subgroups: patients with ACS treated medically, patients with ACS treated with PCI, and those undergoing elective PCI. RESULTS: Of 4614 patients enrolled, 1097 (23.9%) had ACS treated medically, 1714 (37.3%) had ACS treated with PCI, and 1784 (38.8%) had elective PCI. Apixaban compared with vitamin K antagonist reduced International Society on Thrombosis and Haemostasis major or clinically relevant nonmajor bleeding in patients with ACS treated medically (hazard ratio [HR], 0.44 [95% CI, 0.28-0.68]), patients with ACS treated with PCI (HR, 0.68 [95% CI, 0.52-0.89]), and patients undergoing elective PCI (HR, 0.82 [95% CI, 0.64-1.04]; Pinteraction=0.052) and reduced death or hospitalization in the ACS treated medically (HR, 0.71 [95% CI, 0.54-0.92]), ACS treated with PCI (HR, 0.88 [95% CI, 0.74-1.06]), and elective PCI (HR, 0.87 [95% CI, 0.72-1.04]; Pinteraction=0.345) groups. Compared with vitamin K antagonists, apixaban resulted in a similar effect on death and ischemic events in the ACS treated medically, ACS treated with PCI, and elective PCI groups (Pinteraction=0.356). Aspirin had a higher rate of bleeding than did placebo in patients with ACS treated medically (HR, 1.49 [95% CI, 0.98-2.26]), those with ACS treated with PCI (HR, 2.02 [95% CI, 1.53-2.67]), and those undergoing elective PCI (HR, 1.91 [95% CI, 1.48-2.47]; Pinteraction=0.479). For the same comparison, there was no difference in outcomes among the 3 groups for the composite of death or hospitalization (Pinteraction=0.787) and death and ischemic events (Pinteraction=0.710). CONCLUSIONS: An antithrombotic regimen consisting of apixaban and a P2Y12 inhibitor without aspirin provides superior safety and similar efficacy in patients with atrial fibrillation who have ACS, whether managed medically or with PCI, and those undergoing elective PCI compared with regimens that include vitamin K antagonists, aspirin, or both. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02415400.

Antithrombotic Therapy after Acute Coronary Syndrome or PCI in Atrial Fibrillation.

BACKGROUND: Appropriate antithrombotic regimens for patients with atrial fibrillation who have an acute coronary syndrome or have undergone percutaneous coronary intervention (PCI) are unclear. METHODS: In an international trial with a two-by-two factorial design, we randomly assigned patients with atrial fibrillation who had an acute coronary syndrome or had undergone PCI and were planning to take a P2Y12 inhibitor to receive apixaban or a vitamin K antagonist and to receive aspirin or matching placebo for 6 months. The primary outcome was major or clinically relevant nonmajor bleeding. Secondary outcomes included death or hospitalization and a composite of ischemic events. RESULTS: Enrollment included 4614 patients from 33 countries. There were no significant interactions between the two randomization factors on the primary or secondary outcomes. Major or clinically relevant nonmajor bleeding was noted in 10.5% of the patients receiving apixaban, as compared with 14.7% of those receiving a vitamin K antagonist (hazard ratio, 0.69; 95% confidence interval [CI], 0.58 to 0.81; P<0.001 for both noninferiority and superiority), and in 16.1% of the patients receiving aspirin, as compared with 9.0% of those receiving placebo (hazard ratio, 1.89; 95% CI, 1.59 to 2.24; P<0.001). Patients in the apixaban group had a lower incidence of death or hospitalization than those in the vitamin K antagonist group (23.5% vs. 27.4%; hazard ratio, 0.83; 95% CI, 0.74 to 0.93; P = 0.002) and a similar incidence of ischemic events. Patients in the aspirin group had an incidence of death or hospitalization and of ischemic events that was similar to that in the placebo group. CONCLUSIONS: In patients with atrial fibrillation and a recent acute coronary syndrome or PCI treated with a P2Y12 inhibitor, an antithrombotic regimen that included apixaban, without aspirin, resulted in less bleeding and fewer hospitalizations without significant differences in the incidence of ischemic events than regimens that included a vitamin K antagonist, aspirin, or both. (Funded by Bristol-Myers Squibb and Pfizer; AUGUSTUS ClinicalTrials.gov number, NCT02415400.).