Apixaban Versus Warfarin in the Evaluation of Progression of Atherosclerotic Calcification and Vulnerable Plaque
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation; Calcinosis
Intervention: apixaban; warfarin
Intervention description: 5 po or 2.5 po bid.
Intervention MeSH terms: Warfarin; Apixaban
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Enrollment: 66.0
Sex: All
Minimum age: 18 Years
Maximum age: 85 Years
Healthy volunteers: No
Keywords: cardiac Computed tomography; coronary calcification; intervention; warfarin; apixaban

Summary:

      Vitamin K-antagonists (VKA) such as warfarin are the most widely used blood thinners for
      irregular heart beats like atrial fibrillation. Several lines of evidence indicate, however,
      that these agents also cause calcification of vessels (hardening of the vessels). Vascular
      calcification is one of the recently revealed side-effects of warfarin therapy. We will be
      randomizing 66 patients to either take warfarin or a new blood thinner that works without
      affecting vitamin k (apixaban). Patients will undergo blood testing and a CT angiogram
      (non-invasive angiogram) at the beginning of the study, and then be followed for one year
      with quarterly visits including blood tests and given either warfarin or vitamin K. After one
      year, they will undergo another CT angiogram and examination and blood tests and the effect
      of apixaban and warfarin are tested to look at plaque and changes over time. Patients will be
      consented in a private room and the risks and benefits will be explained. The risks include
      the CT angiogram and the possibility of either remaining on warfarin therapy for another year
      (standard of care) or taking a medicine that doesn't require monitoring (apixaban) for one
      year. The CT angiograms will require some contrast and some radiation dose, which will be
      minimized as much as possible. A cardiologist will be present during each CT angiogram to
      minimize risk and ensure patient safety.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Eligible patients with atrial fibrillation or flutter

          -  Age 18-84 years

          -  Willingness to participate in the study and ability to sign informed consent.

        Exclusion Criteria:

          -  Atrial fibrillation due to a reversible cause

          -  moderate or severe mitral stenosis

          -  conditions other than atrial fibrillation that require anticoagulation (e.g., a
             prosthetic heart valve)

          -  A need for aspirin at a dose of >165 mg a day or for both aspirin and P2Y-inhibitor

          -  Serious bleeding event in the previous 6 months or a high risk of bleeding (eg, active
             peptic ulcer disease)

          -  a platelet count of <100,000/mm3 or hemoglobin level of <10 g/dL

          -  stroke within the previous 10 days

          -  documented hemorrhagic tendencies, or blood dyscrasias

          -  Renal insufficiency (serum creatinine level of 12.5 mg per deciliter or calculated
             creatinine clearance of <50 ml per minute)

          -  Weight in excess of 325 pounds

          -  Resting hypotension (systolic blood pressure of <90mmHg) or resting hypertension
             (systolic blood pressure of >170mmHg or diastolic blood pressure of >110 mmHg)

          -  History of active malignancy requiring concurrent chemotherapy

          -  Known allergy to iodinated contrast material

          -  pregnancy, women of childbearing potential unwilling to use adequate contraception.