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Atrial FibrillationPhase 4OCEANNCT02168829

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

A Phase 4 study testing Rivaroxaban and Acetylsalicylic acid in people with Atrial Fibrillation and Stroke, run by Ottawa Heart Institute Research Corporation at 55 sites in 6 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

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. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Atrial Fibrillation, Stroke
What is being tested?
Rivaroxaban and Acetylsalicylic acid
Could I receive a placebo?
No, everyone receives an active treatment
How many people
1,284 participants
Where
55 sitesin 6 countries
Study dates
Jan 2016to 14 Aug 2025
Phase
Phase 4
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patient must be at least one year post-successful catheter ablation(s) for atrial fibrillation without evidence of any clinically apparent arrhythmia recurrence defined as all of the following: No AF/AT/AFL on at least 24 hour Holter and an ECG (or equivalent) from 2-6 months after the last ablation, AND no AF/AT/AFL on at least 24 hour Holter and an ECG any time after 6 months after the last ablation AND no AF/AT/AFL on at least 24 hour Holter and ECG 2 months before enrolment in the study. The Holter/ECG within 2 months of enrolment may also serve as the Holter performed 6 months or later after the last ablation - see section 2.3.1 for details.
  • Patient must have a CHA2DS2-VASc risk score of 1 or more. Patients in whom female sex or vascular disease are their sole risk factor may not be enrolled.
  • Patient must be >18 years of age.
  • Patient must have non-valvular AF.

Who cannot join

  • Patient does not meet all of the above listed inclusion criteria.
  • Patient is unable or unwilling to provide informed consent.
  • Patient is included in another randomized clinical trial or a clinical trial requiring an insurance.
  • Patient has been on an investigational drug within 30 days of enrolment.
  • Patient has been on strong CYP3A inducers (such as rifampicin, phenytoin, phenobarbital, or carbamazepine) or strong CYP3A inhibitors (such as ketoconazole or protease inhibitors) within 4 days of enrolment.
  • Patient has creatinine clearance < 30 mL/min.
Show all 19Show fewer
  • Patient has bleeding contra-indication to oral anticoagulation (such as bleeding diathesis, hemorrhagic disorder, significant gastrointestinal bleeding within 6 months, intracranial/intraocular/ atraumatic bleeding history, fibrinolysis within 48 hours of enrollment).
  • Patient has other contraindication to oral anticoagulation or treatment with antiplatelet agent (such as allergy).
  • Patient has a contraindication to magnetic resonance imaging (MRI) or is unlikely to tolerate due to severe claustrophobia.
  • Patients with a contraindication to implantation of an implantable loop recorder if the patient opts for a loop recorder as part of the study (such as limited immunocompetence or a wound healing disorder).
  • Patient has valvular atrial fibrillation [reference AHA guidelines].
  • Patient has a non-arrhythmic condition necessitating long-term oral anticoagulation.
  • Patient had a severe, disabling stroke within one year prior to enrollment or any stroke within 14 days of enrollment.
  • Patient with special risk factors for stroke unrelated to AF, specifically known thrombophilia/ hypercoagulability, uncontrolled hypertension (systolic blood pressure >180 mmHg and/or diastolic blood pressure >100 mmHg within 4 days of enrollment), untreated familial hyperlipidemia, known vascular anomaly (intracranial aneurysm/ arteriovenous malformation or chronic vascular dissection), or known severe carotid disease.
  • Pregnancy or breastfeeding.
  • Women of childbearing age who refuse to use a highly effective and medically acceptable form of contraception throughout the study.
  • Patients who are > 85 years of age.
  • Patients who are critically ill or who have a life expectancy <3 years.
  • Patients for whom the investigator believes that the trial is not in the interest of the patient.

Trial locations and contacts

55 sites in 6 countries.

55 sites in 6 countries

Canada22 sites

  • Foothills Medical Centre

    Calgary, Alberta

  • Sherbrooke- Grandby site

    Granby, Quebec

  • Queen Elizabeth II Health Sciences Centre

    Halifax, Nova Scotia

  • Hamilton Health Sciences Centre

    Hamilton, Ontario

  • Kelowna Interior Health

    Kelowna

  • Kingston General Hospital

    Kingston, Ontario

  • St. Mary's General Hospital

    Kitchener, Ontario

  • London Health Sciences Centre

    London, Ontario

  • Centre Hospitalier de L'Universite de Montreal (CHUM)

    Montreal, Quebec

  • Hôpital du Sacré-Coeur de Montreal

    Montreal, Quebec

  • McGill University Health Centre

    Montreal, Quebec

  • Montreal Health Institute

    Montreal, Quebec

  • Royal Columbian/Fraser Clinical Trials

    New Westminster, British Columbia, V3L 3W4

  • Southlake Regional Health Centre

    Newmarket, Ontario

  • University of Ottawa Heart Institute

    Ottawa, Ontario, K1Y 4W7

  • Institut Universitarie de Cardiologie et de Pneumologie de Quebec

    Québec, Quebec

  • Centre Hospitalier Universitaire de Sherbrooke

    Sherbrooke, Quebec

  • Scarborough Health Network- Rougevalley

    Toronto, Ontario

  • St. Michael's Hospital

    Toronto, Ontario

  • Sunnybrook Health Sciences Centre

    Toronto, Ontario

  • St. Paul's Hospital

    Vancouver, British Columbia

  • Victoria Cardiac Arrhythmia Trials Inc.

    Victoria, British Columbia

Other trials in Canada

Belgium16 sites

  • Algemeen Stedelijk Ziekenhuis - campus Aalst

    Aalst

  • Onze Lieve Vrouw Ziekenhuis

    Aalst

  • ZNA Middelheim

    Antwerp

  • Arlon - Clinique du Sud-Luxembourg

    Arlon

  • Imeldaziekenhuis

    Bonheiden

  • AZ Sint-Jan (Brugge)

    Bruges

  • Europa Ziekenhuizen - ST-ELISABETH

    Brussels

  • Sint-Jean - Kliniek Sint-Jan (Brussels)

    Brussels

  • Universitair Ziekenhuis Antwerpen (UZA)

    Edegem

  • Middelares Gent - AZ Maria Middelares

    Ghent

  • Universitair Ziekenhuis Gent

    Ghent

  • Jessa Ziekenhuis

    Hasselt

  • Ziekenhuis Oost-Limburg , campus St Jan

    Lanaken

  • Universitair Ziekenhuis Leuven, campus Gasthuisberg

    Leuven

  • Centre Hospitalier Universitaire de Liège

    Liège

  • AZ Delta campus Wilgenstraat

    Roeselare

Other trials in Belgium

Germany10 sites

  • Kerckhoff Klinik

    Bad Nauheim, Hesse, 61231

  • Herz- und Diabeteszentrum NRW Ruhr-Universitat Bochum

    Bad Oeynhausen, North Rhine-Westphalia, 32545

  • Segeberger Liniken

    Bad Segeberg, Schleswig-Holstein, 23795

  • Elektrophysiologie GFO-Kliniken Bonn

    Bonn, North Rhine-Westphalia, 53225

  • Klinikum Coburg

    Coburg, Bavaria, 96450

  • Herzzentrum der Universitat Koln

    Cologne, North Rhine-Westphalia, 50937

  • Universitares Herzzentrum Hamburg

    Hamburg, 20246

  • ASklepios

    Hamburg

  • Herzzentrum Leipzig

    Leipzig, Leipzig, 04289

  • UKSH Lubeck

    Lübeck, Schleswig-Holstein, 23538

Other trials in Germany

Australia5 sites

  • Royal Adelaide Hospital

    Adelaide, South Australia, 5000

  • Canberra Hospital

    Canberra, Australian Capital Territory, 2605

  • The Alfred Melbourne

    Melbourne, Victoria, 3004

  • Melbourne Health

    Melbourne, Victoria, 3050

  • Heart Rhythm Clinic

    Nedlands, Western Australia, 6009

Other trials in Australia

China1 site

  • Sir Run Run Shaw Hospital

    Hangzhou, Zhejiang

Other trials in China

Israel1 site

  • Galilee Medical Centre

    Nahariya, 22100

Other trials in Israel

About this study

Official title: The Optimal Anticoagulation for Enhanced Risk Patients Post-Catheter Ablation for Atrial Fibrillation Trial

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.

Read the 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 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.

Being tested
Rivaroxaban, Acetylsalicylic acid
Keywords
AF ablation, Anticoagulation AF ablation, Stroke prevention
Medical subject headings
Atrial Fibrillation, Stroke

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • RivaroxabanDrug

    Also called Xarelto

  • Acetylsalicylic acidDrug

    Also called Aspirin, ASA

Study groups in NCT02168829
Study groupRoleWhat they receive
RivaroxabanActive comparatorRivaroxaban 15 mg daily
Receives: Drug: Rivaroxaban
Acetylsalicylic acid (ASA)Active comparatorASA 75-160 mg daily (if intolerant to ASA, no antiplatelet therapy will be prescribed)
Receives: Drug: Acetylsalicylic acid

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Composite of stroke, systemic embolism and covert embolic stroke as detected by cerebral MRI

    Composite of stroke, systemic embolism and covert embolic stroke as detected by cerebral MRI. A patient will be considered to have a covert stroke if one or more lesions > 15 mm has been detected between the baseline, and final (3 year) MRI on T2 weighted and/or FLAIR imaging protocols.

    Measured: 3 years

Secondary outcomes (13)

  1. Clinical, overt stroke

    Clinical, Overt stroke

    Measured: Up to 3 years

  2. Incidence of one or more covert MRI stroke(s) >15 mm

    Incidence of one or more covert MRI stroke(s) >15 mm

    Measured: Up to 3 years

  3. Composite of all major and minor bleeding

    Composite of all major and minor bleeding

    Measured: Up to 3 years

  4. Major bleeding only

    Major bleeding only

    Measured: Up to 3 years

  5. Minor bleeding only

    Minor bleeding only

    Measured: Up to 3 years

  6. Intracranial hemorrhage

    Intracranial hemorrhage (clinical and covert on MRI alone)

    Measured: Up to 3 years

  7. Transient ischemic attack

    Transient ischemic attack defined as presence of a new focal neurologic deficit thought to be vascular in origin, with signs or symptoms lasting <24 hours

    Measured: Up to 3 years

  8. All-cause mortality

    All-cause mortality

    Measured: Up to 3 years

  9. Net clinical benefit based on reduction in stroke/TIA rate compared to major bleeding events.

    Net clinical benefit based on reduction in stroke/TIA rate compared to major bleeding events.

    Measured: Up to 3 years

  10. Occurrence of non-primary endpoint MRI changes from baseline to final scan

    Occurrence of non-primary endpoint MRI changes from baseline to final scan including: quantification of cerebral atrophy, quantification of cerebral white matter changes, number of all new MRI lesions > 3mm, >5 mm, > 15 mm, and > 20 mm, and number of lesions detected exclusively on DW-MRI

    Measured: 3 years

  11. Neuropsychological testing

    Neuropsychological testing - performed at baseline and repeated at 3 years.

    Measured: 3 years

  12. Health economics

    Cost utilization and cost effectiveness analysis

    Measured: 3 years

  13. Quality of life Assessment

    Quality of life Assessment measured with the Quality of life scale, EQ-5D-5L

    Measured: Quality of Life is measured at Baseline and 36 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Jun 2014 (estimated)
  2. Study startJan 2016
  3. Primary completion14 Aug 2025
  4. Study completion14 Aug 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
1,284 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02168829
Sponsor's protocol ID
327494
Acronym
OCEAN
Status last verified
Sep 2025
First submitted
18 Jun 2014
Last updated
6 Oct 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Publications

  • Verma A, Birnie DH, Jiang C, Heidbuchel H, Hindricks G, Kirchhof P, Healey JS, Wang Y, Dagres N, Deyell MW, Sanders P, Pathak RK, Koopman P, Nuyens D, Novak P, Amit G, Dussault C, Makanjee B, Quinn FR, Jolly U, Iden L, Kuniss M, Sharma M, Ha A, Essebag V, Champagne J, Hill MD, Smith EE, Wells GA; OCEAN Investigators. Antithrombotic Therapy after Successful Catheter Ablation for Atrial Fibrillation. N Engl J Med. 2026 Jan 22;394(4):323-332. doi: 10.1056/NEJMoa2509688. Epub 2025 Nov 8.

    PubMed 41211931

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Rivaroxaban and Acetylsalicylic acid in people with Atrial Fibrillation and Stroke, run by Ottawa Heart Institute Research Corporation at 55 sites in 6 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 6 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 55 sites in Canada, Belgium, Germany, Australia, China and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Composite of stroke, systemic embolism and covert embolic stroke as detected by cerebral MRI (time frame: 3 years). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02168829, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Oct 2025.

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