Usefulness of Coronary CT Angiography in Patients With Inconclusive Stress Test Results
Condition: Coronary Angiography; Coronary Disease
MeSH terms: Coronary Disease
Study type: Observational

Summary: 
      The purpose of this study is to evaluate the usefulness of performing a "cat scan" of the
      heart arteries in patients (without a known history of heart disease) seen by their physician
      for chest pain. We plan to evaluate this test in patients who have already undergone stress
      testing. On occasion, stress test results are equivocal or suspected to be inaccurate. In
      these cases, depending on the overall clinical suspicion of coronary artery disease,
      physicians may recommend cardiac catheterization to determine whether or not patients have
      blockages in their heart's arteries. We plan to evaluate whether a Cat Scan of the heart
      arteries will provide your physician with important information to assist in this decision.
      If the results of this test are normal, the patient may not require a heart catheterization;
      alternatively, if the test is abnormal, a physician may proceed with catheterization after
      review of the data. There will 200 patients enrolled into the study. All patients will be
      followed by their usual cardiologist, and all decisions will be made by their cardiologist.

      Computed tomography (CT; "cat scan") is an x-ray test routinely used for diagnostic purposes.
      Cardiac computed tomography using the newer generation multislice CT (MSCT) scanners is an
      improved way of using CT scanning techniques to look at the heart and blood vessels of the
      body. The images of the coronary arteries obtained by MSCT scanners (during a 5-10 minute
      procedure) are highly accurate, when compared to the conventional invasive cardiac
      catheterization procedure. This procedure will provide a calculation of a coronary artery
      calcium score as well as an accurate depiction of the coronary anatomy. The accuracy of this
      test is similar to that achieved with traditional stress test imaging, but has some inherent
      advantages over this traditional stress testing. Therefore, we believe that in patients with
      intermediate, inconclusive, or suspected inaccurate stress tests, MSCT of the coronary
      arteries may provide helpful information to your physician to help guide their decision
      regarding the need (or lack of) for possible invasive cardiac catheterization. This procedure
      is considered an ideal "screening test" to exclude the presence of coronary artery disease in
      patients with suspected coronary artery disease.

      On the day of your procedure, the patient will be given intravenous ("IV dye") contrast
      during their Cat Scan. We will also draw a blood sample to assess your kidney function and/or
      pregnancy status (if necessary). The contrast is what creates the pictures of one's arteries.
      The intravenous contrast used is the same dye as that used for routine cat scans of other
      parts of the body, as well as for cardiac catheterization. Prior to the Scan patients may be
      prescribed a medicine called a beta blocker The beta blocker typically used is called
      Atenolol. This medication slows your heart rate and is one that is commonly used to treat
      high blood pressure. Dosing will be based upon your current medications and vital signs. If a
      patient's heart rate is greater than 60 beats per minute an intravenous beta-blocker may be
      given to optimize their heart images. Patient's will have to hold your breath twice, for up
      to 30 seconds each time. The imaging part of the test takes about 10 minutes. Patient's will
      be observed after the test for about 20 minutes, followed by discharge home. Physicians will
      called with the patient's results of the study, and they will contact their patient's
      regarding the results, as well as the "next step." If a patient is a diabetic (taking
      metformin/glucophage), we will request a follow up (the next day) kidney test. Patient's will
      also will be called at 3 months to asked a few brief questions regarding your health (any
      recent hospitalizations, any new medical illnesses, any follow up heart testing, etc.)
    

Detailed description: 
      The purpose of this observational study is to prospectively evaluate the impact of multi
      detector CT angiography (MDCT) in patients with equivocal/intermediate post exercise stress
      test probability of coronary artery disease.

      The primary objective are to:

        1. Evaluate the diagnostic and prognostic performance of MDCT in patients with equivocal/
           intermediate post test probability of CAD and

        2. Evaluate the accuracy of MDCT in prediction of 30 day major adverse events.
    

Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients with chest pain over the age of 18 years old with symptoms of Coronary Artery
        Disease
      
Keywords: computed tomography; stress test; equivocal; catheterization