Coronary Artery Vasculopathy in Pediatric Heart Transplant Patients
Condition: Orthotopic Heart Transplant
MeSH terms: Vascular Diseases
Intervention: Adenosine
Intervention description: Administration of intravenous adenosine infusion over 3 minutes (0.14 ml/kg, 3mg/ml concentration, total dose).
Intervention MeSH terms: Adenosine
Phase: Phase 3
Study type: Interventional
Primary purpose: Diagnostic
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 22.0
Sex: All
Minimum age: 1 Year
Maximum age: 25 Years
Healthy volunteers: No
Keywords: Orthotopic Heart Transplant

Summary:

      Heart transplantation is a life-sustaining therapy that allows patients with either
      congenital or acquired heart disease and severe cardiac dysfunction to survive. Over time,
      however, the transplanted heart can develop problems. One of the more common and troubling
      problems is the development of stenoses, or narrowings, within the coronary arteries. These
      narrowings, technically referred to as coronary artery vasculopathy (CAV for short), account
      for the single most common cause of death or need for repeat heart transplant in persons more
      than one year post-transplant. Traditionally, CAV has been diagnosed at cardiac
      catheterization using coronary angiography (where dye is directly injected into the coronary
      blood vessels and viewed using special x-ray equipment called fluoroscopy). There is no good
      treatment for CAV aside from treatment of symptoms and listing for repeat heart
      transplantation. The goal of this study is to test several newer methods of diagnosing CAV.
      The first is called coronary flow reserve (catheterization test). The second is called
      Endo-PAT (a finger probe test) and the third is called contrast-enhanced cardiac MRI (MRI
      test, only for patients 12 and older). The older method (coronary angiography) will still be
      used in all cases, in addition to the new tests The goal is, one day, to be able to diagnose
      patients with CAV earlier in the course, prior to a patient's development of abnormal
      angiograms. If this can be done, it is possible that better therapies will be able to be used
      to stop or even reverse the development of CAV, perhaps reducing, or at least delaying, the
      need for repeat heart transplantation.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Patients age 1 - 25 years who are status-post OHT (≤18 years at the time of
             transplantation) and undergoing routine post-transplant surveillance catheterization
             for endomyocardial biopsy and coronary angiography

        Exclusion Criteria:

          -  The presence of sick sinus syndrome or 2nd or 3rd degree atrioventricular block
             (without a functioning implanted pacemaker)

          -  Hemodynamically significant valvular disease

          -  Severe asthma or bronchospasm, known severe CAV

          -  Pulmonary hypertension.

          -  Patients taking digoxin

          -  Verapamil and dipyridamole are also excluded given known interactions with adenosine.