Arrhythmias & electrophysiologyMeta-analysis
Systemic Embolic Events in Atrial Fibrillation: An Individual Patient Data Meta-analysis of 71 683 Participants Randomized to NOAC Versus Warfarin
- Individual patient data meta-analysis of randomised trials
Authors' conclusion
In this large individual patient data meta-analysis, non-vitamin K antagonist oral anticoagulants significantly reduced the risk of SEE compared with warfarin. Although SEEs were approximately one-tenth as frequent as IS, they were associated with comparable mortality and substantial morbidity.
Study context
- Population
- Patients with AF in 4 pivotal RCTs enrolling 2005–2010
- Participants
- 71,683 patients · 4 RCTs
- Comparison
- NOAC vs warfarin
- Outcome
- Clinically overt systemic embolic events (SEE): incidence, features, management and outcomes vs IS
Pooled result
SEE · median follow-up 25.2 months (IQR 17.5-32.0)
Hazard ratio
0.71
95% CI 0.51–0.99
P = 0.04
NOAC vs Warfarin
HR 0.71 (95% CI 0.51–0.99); P = 0.04
As reported in the abstract
per patient-year
- Annualized SEE rate (188 patients, 26 with concurrent ischemic stroke (IS))
- 0.13%
- Annualized IS rate (n=1797)
- 1.25%
Further pooled results
| Outcome | HR (95% CI) | |
|---|---|---|
| Mortality after SEE · long-term mortality | 2.85 (2.11–3.85) | |
| 0.20.5125Hazard ratio (log scale) |
- Mortality after SEE — 30-day mortality, SEE vs IS
- 18% versus 17%
Characteristics of SEE (n=171 first event) vs IS
- Peripheral arterial disease (PAD), SEE vs IS
- 16.5% versus 5.4%; P<0.001
- Previous MI, SEE vs IS
- 24% versus 17%; P=0.02
- Previous VKA exposure, SEE vs IS
- 57% versus 46%; P=0.007
- Median creatinine clearance, SEE vs IS
- 58 versus 62 mL/min; P=0.02
- Nonparoxysmal AF, SEE vs IS
- 86% versus 80%; P=0.047
Interventions (surgical or percutaneous) after SEE
- Patients with SEE treated
- 62 patients (31%)
Original publication
Systemic Embolic Events in Atrial Fibrillation: An Individual Patient Data Meta-analysis of 71 683 Participants Randomized to NOAC Versus Warfarin. Circulation. Published 30 January 2026. doi:10.1161/circulationaha.125.075275
Summarised from the published abstract; every number is checked against it