Rivaroxaban Versus Warfarin in the Evaluation of Progression of Coronary Calcium
Condition: Atherosclerosis
MeSH terms: Atherosclerosis
Intervention: rivaroxaban; Warfarin
Intervention MeSH terms: Warfarin; Rivaroxaban
Phase: Phase 4
Study type: Interventional
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: randomized controlled trial, with blinded randomization to one of two groups.
Masking: None (Open Label)
Enrollment: 110.0
Sex: All
Minimum age: 18 Years
Maximum age: 84 Years
Healthy volunteers: No
Keywords: atherosclerosis; coronary artery disease; cardiac CT; computed tomographic angiography

Summary:

      Current oral anti-coagulation for atrial fibrillation is most commonly performed with
      warfarin. Warfarin is a vitamin K antagonist that has been shown in non-randomized trials to
      increase vascular calcification. Increased vascular calcification has been tied to increased
      cardiovascular events (CVE). This study will randomize patients currently taking warfarin to
      either continue on warfarin or be switched to rivaroxaban. Rivaroxaban is an oral
      anti-coagulant that works by inhibiting Factor Xa, and has no interaction with vitamin K.
      This study is a randomized, open label study that will randomize 120 patients and have them
      undergo blood tests and a calcium scan at baseline, and again after 12 months. Patients will
      be seen quarterly for examinations, safety checks and supply of rivaroxaban, as well as
      follow up INR testing for warfarin.
    

Eligibility criteria:

        Key Inclusion Criteria:

          1. Eligible patients with atrial fibrillation at enrollment or two or more episodes of
             atrial fibrillation or flutter, as documented by electrocardiography, at least 2 weeks
             apart in the 12 months before enrollment

          2. Age 18-84

          3. On Warfarin for 6 months prior to enrollment at a stable dose.

          4. Willingness to participate in the study and ability to sign informed consent

          5. Minimum CAC score of 10

        Key Exclusion Criteria:

          1. Atrial fibrillation due to a reversible cause, moderate or severe mitral stenosis, or
             conditions other than atrial fibrillation that require anticoagulation (e.g., a
             prosthetic heart valve)

          2. Prior apixaban, dabigatran, rivaroxaban use.

          3. A need for aspirin at a dose of >165 mg a day or for both aspirin and clopidogrel,

          4. Renal insufficiency (serum creatinine level of 12.5 mg per deciliter or calculated
             creatinine clearance of <50 ml per minute).

          5. 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)

          6. Weight in excess of 325 pounds

          7. Resting hypotension (systolic blood pressure of <90mmHg) or resting hypertension
             (systolic blood pressure of >170mmHg or diastolic blood pressure of >110 mmHg).

          8. History of active malignancy requiring concurrent chemotherapy.

          9. Any unstable medical, psychiatric, or substance abuse disorder that in the opinion of
             the principal investigator is likely to affect the subject's ability to complete the
             study.

         10. Known allergy to iodinated contrast material

         11. Pregnancy or breast feeding