• Side-effects using the GSRS (Gastrointestinal Symptoms Rating Scale), GI complications and GI adverse events [ Time Frame: 6 month ] [ Designated as safety issue: Yes ]
  

• Incidence of biopsy proven acute rejection, graft loss, and death [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
  

This is an open-labeled, prospective, non-randomized pilot-phase study of the enteric-coated, Myfortic® versus the non enteric-coated, Cellcept® in patients who are within 5 years of having undergone heart transplant surgery who are currently taking Cellcept®. After the initial screening, 20 patients who fulfill the inclusion criteria and report symptoms of gastrointestinal side-effects while taking Cellcept will be switched to Myfortic. All 20 patients will be followed closely over a period of 6 months following enrollment. Concomitant immunosuppressive therapy will continue in all patients per standard treatment protocol.

Inclusion Criteria:

1. Patients of either sex aged 18 and above who have undergone successful orthotopic heart transplant surgery.
2. Patients who are currently taking Cellcept® and experiencing gastrointestinal side-effects from this standard therapy.
3. Individuals on Cellcept® with total dosage of 2 mg a day or less would be eligible to participate.
4. Patients who are able to give written informed consent.

Exclusion Criteria:

1. Patients with an absolute neutrophil count <1500 cells/mm3, and/or leukocytopenia (<2500 cells/mm3), thrombocytopenia (<75,000 cells/mm3) and significant anemia (hemoglobin < 6g/dl) at the time of potential enrollment.
2. Women of childbearing potential not using the contraception method(s), as well as women who are breastfeeding.
3. Known sensitivity to the study drug or class of the study drug.
4. Patients with severe medical condition(s) that in the view of the investigator prohibits participation in the study.
5. Use of any other investigational agent in the last 30 days.