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Long-Term Anticoagulation Discontinuation After Catheter Ablation for Atrial Fibrillation: The ALONE-AF Randomized Clinical Trial

Author/s: 
Daehoon Kim, MD, Jaemin Shim, MD, Eue-Keun Choi, MD

Importance: Data from randomized clinical trials on a long-term anticoagulation strategy for patients after catheter-based ablation for atrial fibrillation (AF) are lacking.

Objective: To evaluate whether discontinuing oral anticoagulant therapy provides superior clinical outcomes compared with continuing oral anticoagulant therapy in patients without documented atrial arrhythmia recurrence after catheter ablation for AF.

Design, setting, and participants: A randomized clinical trial including 840 adult patients (aged 19-80 years) who were enrolled and randomized from July 28, 2020, to March 9, 2023, at 18 hospitals in South Korea. Enrolled patients had at least 1 non-sex-related stroke risk factor (determined using the CHA2DS2-VASc score [range, 0-9]) and no documented recurrence of atrial arrhythmia for at least 1 year after catheter ablation for AF. The CHA2DS2-VASc score is used as an assessment of stroke risk among patients with AF (calculated using point values for congestive heart failure, hypertension, ≥75 years of age, diabetes, stroke or transient ischemic attack, vascular disease, between 65 and 74 years of age, and sex category). The date of final follow-up was June 4, 2025.

Interventions: The patients were randomly assigned in a 1:1 ratio to discontinue oral anticoagulant therapy (n = 417) or continue oral anticoagulant therapy (with direct oral anticoagulants; n = 423).

Main outcomes and measures: The primary outcome was the first occurrence of a composite of stroke, systemic embolism, and major bleeding at 2 years. Individual components of the primary outcome (such as ischemic stroke and major bleeding) were assessed as secondary outcomes.

Results: Of the 840 adults randomized, the mean age was 64 (SD, 8) years, 24.9% were women, the mean CHA2DS2-VASc score was 2.1 (SD, 1.0), and 67.6% had paroxysmal AF. At 2 years, the primary outcome occurred in 1 patient (0.3%) in the discontinue oral anticoagulant therapy group vs 8 patients (2.2%) in the continue oral anticoagulant therapy group (absolute difference, -1.9 percentage points [95% CI, -3.5 to -0.3]; P = .02). The 2-year cumulative incidence of ischemic stroke was 0.3% in the discontinue oral anticoagulant therapy group vs 0.8% in the continue oral anticoagulant therapy group (absolute difference, -0.5 percentage points [95% CI, -1.6 to 0.6]). Major bleeding occurred in 0 patients in the discontinue oral anticoagulant therapy group vs 5 patients (1.4%) in the continue oral anticoagulant therapy group (absolute difference, -1.4 percentage points [95% CI, -2.6 to -0.2]).

Conclusions and relevance: Among patients without documented atrial arrhythmia recurrence after catheter ablation for AF, discontinuing oral anticoagulant therapy resulted in a lower risk for the composite outcome of stroke, systemic embolism, and major bleeding vs continuing direct oral anticoagulant therapy.

Trial registration: ClinicalTrials.gov Identifier: NCT04432220.

Keywords 
clinical pharmacy and pharmacology Oral Anticoagulation Cardiology atrial fibrillation Rhythm Disorders

Patent Foramen Ovale and Stroke A Review

Author/s: 
David M. Kent, Andy Y. Wang

Importance: A patent foramen ovale (PFO), an opening between the right and left atria during normal fetal development that fails to close after birth, is present in approximately 25% of all adults. Paradoxical embolism, a venous thromboembolism that travels to the systemic circulation typically through a PFO, accounts for about 5% of all strokes and 10% of strokes in younger patients.

Observations: Approximately 50% of patients 60 years or younger with an embolic stroke of undetermined source (cryptogenic stroke) have a PFO, compared with 25% of the general population. The Risk of Paradoxical Embolism (RoPE) score incorporates clinical characteristics (age, history of stroke or transient ischemic attack, diabetes, hypertension, smoking, cortical infarct on imaging) to predict the likelihood that embolic stroke of undetermined source was caused by a PFO. Among patients in the lowest RoPE score category (score <3), PFO prevalence was similar to that in the general population (23%), while PFO prevalence was 77% in patients with a RoPE score of 9 or 10. The PFO-Associated Stroke Causal Likelihood (PASCAL) classification system combines the RoPE score and anatomical criteria from echocardiography (large shunt, atrial septal aneurysm) to classify PFO as the “probable,” “possible,” or “unlikely” cause of otherwise cryptogenic stroke. PFO closure reduces recurrent ischemic stroke in patients 60 years or younger with cryptogenic stroke. In a pooled analysis of 6 trials (3740 patients), the annualized incidence of stroke over a median follow-up of 57 months was 0.47% (95% CI, 0.35%-0.65%) with PFO closure vs 1.09% (95% CI, 0.88%-1.36%) with medical therapy (adjusted hazard ratio, 0.41 [95% CI, 0.28-0.60]). However, the benefits and harms of closure were highly heterogeneous across the trial populations. In patients categorized as PASCAL “probable” (ie, younger patients without vascular risk factors and high-risk PFO anatomical features), there was a 90% decreased relative rate of recurrent ischemic stroke after PFO closure at 2 years (hazard ratio, 0.10 [95% CI, 0.03-0.35]; absolute risk reduction, 2.1% [95% CI, 0.9%-3.4%]). PASCAL “unlikely” patients (eg, older patients with vascular risk factors and no high-risk PFO anatomical features) did not have a lower recurrent stroke rate with PFO closure but had higher risk of procedure- and device-related adverse events, such as atrial fibrillation.

Conclusions and Relevance: Patent foramen ovale is present in approximately 25% of all adults and is a common cause of stroke in young and middle-aged patients. The PASCAL classification system can help guide patient selection for PFO closure. Percutaneous PFO closure substantially reduces the risk of stroke recurrence in well-selected patients younger than 60 years after cryptogenic stroke.

Keywords 
Congenital Defects pediatrics female
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