Optimal Anticoagulation for Higher Risk Patients Post-Catheter Ablation for Atrial Fibrillation Trial "OCEAN"


Phase 4 Results N/A

Trial Description

This trial is comparing medical approaches for stroke prevention in people who have atrial fibrillation (AF) and have undergone a successful procedure called ablation to eliminate or substantially reduce the arrhythmia. AF is normally associated with an increased risk of stroke which in many patients can be prevented with appropriate blood thinner therapy. This trial will compare a strategy of oral anticoagulant therapy after successful ablation to therapy with an aspirin per day.

Detailed Description

This is a prospective, open-label, randomized trial to investigate whether a strategy of ongoing, long-term oral anticoagulation with rivaroxaban 15 mg daily is superior to a strategy of antiplatelet therapy, ASA 75-160 mg, alone in preventing cerebral embolic events in moderately high risk patients following successful catheter ablation for atrial fibrillation..
At least one year post-successful catheter ablation for AF or left atrial flutter/tachycardia without evidence of any clinically apparent arrhythmia recurrence based on at least one 24 hour Holter and ECG within 6 months after the last ablation procedure and at least one 24 hour Holter and ECG between 6 and 12 months post-ablation or beyond. Patient must have no atrial fibrillation, atrial flutter or atrial tachycardia > 30 seconds detected on a minimum 48 hour Holter monitor within two months prior to enrollment.
Patients will be randomized in a 1:1 fashion to ASA 75-160 mg daily or rivaroxaban 15 mg daily. Patients will be seen at 6 months, one year and every year thereafter for a minimum of 3 years. Blood chemistry tests, ECG, holters and patient quality of life questionnaires will be done annually.
Cerebral MRI scanning at baseline, at year one and at three years will be done for assessment of silent cerebral infarction. MRI imaging will be performed using a specific protocol.
A pre-specified subset of patients will undergo insertion of a implantable loop recorder (ILR) capable of automated AF detection.



  • Rivaroxaban Drug
    ARM 1: Kind: Experimental
    Label: Rivaroxaban
    Description: Rivaroxaban 20 mg daily (15 mg daily if indicated by creatinine clearance)
  • Acetylsalicylic acid Drug
    Other Names: Aspirin 81 mg
    ARM 1: Kind: Experimental
    Label: Acetylsalicylic acid (ASA)
    Description: ASA 81 mg daily (if intolerant to ASA clopidogrel 75 mg daily)

Trial Design

  • Allocation: Randomized
  • Masking: Open Label
  • Purpose: Prevention
  • Endpoint: Safety/Efficacy Study
  • Intervention: Parallel Assignment


Type Measure Time Frame Safety Issue
Primary Composite of stroke, systemic embolism and silent cerebral infarction. 3 years No
Secondary Major and Minor Bleeding Up to 3 years Yes
Primary Composite of stroke, systemic embolism and covert embolic stroke as detected by cerebral MRI 3 years No
Secondary Clinical, overt stroke Up to 3 years Yes
Secondary Incidence of one or more covert MRI stroke(s) >15 mm Up to 3 years Yes
Secondary Composite of all major and minor bleeding Up to 3 years Yes
Secondary Major bleeding only Up to 3 years Yes
Secondary Minor bleeding only Up to 3 years Yes
Secondary Intracranial hemorrhage Up to 3 years Yes
Secondary Transient ischemic attack Up to 3 years Yes
Secondary All-cause mortality Up to 3 years Yes
Secondary Net clinical benefit based on reduction in stroke/TIA rate compared to major bleeding events. Up to 3 years Yes
Secondary Occurrence of non-primary endpoint MRI changes from baseline to final scan 3 years No
Secondary Neuropsychological testing 3 years No
Secondary Health economics 3 years No