Landmark Trials in Atrial Fibrillation
Key clinical trials that shaped the 2023 ACC/AHA/ACCP/HRS AF Guideline across anticoagulation, rhythm control, catheter ablation, and comorbidity management.
RE-LY
2009N Engl J MedAnticoagulationFinding: Dabigatran 150 mg BID reduced stroke/systemic embolism vs warfarin (RR 0.66) with similar major bleeding; 110 mg BID had similar efficacy with lower bleeding.
Impact: Established dabigatran as the first DOAC alternative to warfarin in non-valvular AF, launching the DOAC era.
ROCKET-AF
2011N Engl J MedAnticoagulationFinding: Rivaroxaban 20 mg daily was non-inferior to warfarin for stroke prevention in AF with fewer intracranial hemorrhages.
Impact: Provided a once-daily DOAC option; studied a higher-risk population (mean CHADS₂ 3.5).
ARISTOTLE
2011N Engl J MedAnticoagulationFinding: Apixaban 5 mg BID was superior to warfarin in preventing stroke (HR 0.79), with lower major bleeding (HR 0.69) and lower mortality (HR 0.89).
Impact: Apixaban demonstrated superiority in efficacy, safety, and mortality — the only DOAC to achieve all three endpoints vs warfarin.
ENGAGE AF-TIMI 48
2013N Engl J MedAnticoagulationFinding: Edoxaban 60 mg daily was non-inferior to warfarin for stroke prevention with significantly lower bleeding and CV mortality.
Impact: Completed the evidence base for four DOACs. Edoxaban's reduced efficacy at CrCl >95 mL/min led to a unique contraindication.
EAST-AFNET 4
2020N Engl J MedRhythm ControlFinding: Early rhythm control (within 1 year of AF diagnosis) reduced the composite of CV death, stroke, and HF hospitalization by 21% vs usual care.
Impact: Paradigm shift: demonstrated that early rhythm control improves hard CV outcomes, not just symptoms. Supports early intervention with AADs or ablation.
AFFIRM
2002N Engl J MedRhythm ControlFinding: Rate control was non-inferior to rhythm control for mortality. Rhythm control arm had more hospitalizations and drug adverse effects.
Impact: Historically established rate control as acceptable strategy. EAST-AFNET 4 later showed early rhythm control benefits in recently diagnosed AF.
CASTLE-AF
2018N Engl J MedCatheter AblationFinding: Catheter ablation reduced all-cause mortality (HR 0.53) and HF hospitalization (HR 0.56) vs medical therapy in AF with HFrEF (LVEF ≤35%).
Impact: Landmark trial establishing mortality benefit of ablation in AF + HFrEF. Strongest evidence for ablation in any AF subgroup.
CABANA
2019JAMACatheter AblationFinding: Catheter ablation did not significantly reduce the primary composite endpoint vs drug therapy in intention-to-treat analysis, but per-protocol analysis showed 27% reduction.
Impact: High crossover rate (27.5%) complicated ITT results. Supported ablation as a reasonable alternative to drug therapy.
EARLY-AF
2021N Engl J MedCatheter AblationFinding: Cryoballoon ablation as first-line therapy reduced AF recurrence by 50% vs AADs in treatment-naive paroxysmal AF.
Impact: Supports ablation as a first-line option for paroxysmal AF, not just after AAD failure.
AFIRE
2019N Engl J MedACS/PCIFinding: Rivaroxaban monotherapy was non-inferior for efficacy and superior for safety vs rivaroxaban + antiplatelet in stable CAD with AF (>1 year post-PCI or non-PCI CAD).
Impact: Supports OAC monotherapy (without antiplatelet) in stable CAD + AF beyond 12 months post-PCI.
AUGUSTUS
2019N Engl J MedACS/PCIFinding: In AF patients with ACS or PCI, apixaban + P2Y12 inhibitor (without aspirin) reduced bleeding without increased ischemic events vs VKA-based and aspirin-containing regimens.
Impact: Supports early transition from triple to dual antithrombotic therapy (DOAC + P2Y12i) to minimize bleeding.
RACE II
2010N Engl J MedRate ControlFinding: Lenient rate control (resting HR <110 bpm) was non-inferior to strict rate control (<80 bpm) for the composite of CV events.
Impact: Established lenient rate control as an acceptable and simpler strategy in most AF patients.
LEGACY
2015J Am Coll CardiolLifestyleFinding: Sustained weight loss of ≥10% body weight resulted in six-fold greater probability of AF-free survival compared to <3% weight loss.
Impact: Strongest evidence for weight management as AF therapy. Supports aggressive risk factor modification alongside traditional rate/rhythm control.
PROTECT AF / PREVAIL
2014JAMA / J Am Coll CardiolLAA ClosureFinding: Watchman LAA occlusion device was non-inferior to warfarin for stroke prevention in AF, with lower hemorrhagic stroke and CV mortality at long-term follow-up.
Impact: Established LAA closure as an option for AF patients with contraindications to long-term OAC.
Guideline Reference
Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for Diagnosis and Management of Atrial Fibrillation. Circulation. 2024;149:e1-e156. doi:10.1161/CIR.0000000000001193