Patients With Patent Foramen Ovale and Endocardial Device Leads on Apixaban for Prevention of Paradoxical Emboli

Patients with a patent foramen ovale in the setting of endocardially placed cardiac implantable electronic devices such as pacemakers, defibrillators, or resynchronization therapies are likely at higher risk for paradoxical embolic events from device lead thrombus. The investigators are conducting this study to determine if the anticoagulant medication Apixaban is more effective at reducing MRI detected brain lesions compared to placebo.

This is a prospective, double-blinded, placebo-controlled, randomized controlled trial (RCT).

400 patients who meet the study eligibility criteria and consent for enrollment will be randomized in a 1:1 ratio to intervention with apixaban or control group with placebo. The randomization will be performed by a computer generated block randomization protocol. The majority of patients will begin intervention with Apixaban or placebo at the time of cardiac device placement (n approximately 300), and at least a quarter of the randomized patients (n ≥100) will include preexisting CIED (≥6 months) in place. Each patient will undergo a baseline MRI and a comprehensive cognitive screening examination. Repeat MRI and cognitive assessment will be performed at a follow-up period of two years from date of randomization (or less if clinical stroke/TIA occurs prior to this follow-up period). All subjects will receive a phone call at 6 months, 12 months, and 18 months post-randomization to assess for endpoints and adverse events, as well as changes in clinical status, medications, and to assess study medication compliance.

Eligibility Criteria:
Inclusion:

* A clinical indication for a trans venous pacemaker, ICD, or CRT device, or presence of a pre-existing endovascular CIED
* Presence of a PFO (regardless of shunt direction) confirmed with trans-esophageal or trans-thoracic echocardiography with color flow Doppler and/or agitated saline
* Absence of any contraindication for anticoagulation
* Absence of a clinical indication for systemic anticoagulation
* Ability to give informed consent for the trial
* Able to undergo head MRI and consent for MRI study to be performed in presence of CIED

Exclusion:

* Patients with a survival expectancy of less than one year
* Patients who require systemic anticoagulation for any established clinical indication (excluding the presence of PFO with CIED)
* Patients with an atrial or ventricular septal defect that is hemodynamically significant and requires repair as suggested by the ACC/AHA 2008 guidelines on evaluation and treatment of adult congenital heart diseases
* Absence of a CIED or no clinical indication for a trans venous CIED
* Contraindication to undergoing an MRI
* Patients with an active infection that cannot be treated successfully prior to randomization
* Women who are pregnant or breastfeeding, or women of child-bearing potential who do not wish to use an effective method of birth control during the course of study in a manner such that the risk of failure is minimized
* Currently enrolled in another investigational device or drug study, or less than 30 days since ending another investigational device or drug study(s), or receiving other investigational agent(s)
* Known sensitivity to any of the active substances or their excipients to be administered during dosing with study medication