This study, known as Donor-derived cell-free DNA Outcomes AlloMap Registry (D-OAR), will examine the heart transplant patient’s blood for circulating DNA from the donor to determine whether the presence of this biomarker can assist in diagnosing rejection. The study is based on the premise that donor derived cell-free DNA is released from the heart cells in response to injury from rejection.

The D-OAR trial is a sub-study of the long-term Outcomes AlloMap Registry (OAR), a multi-center, multi-year outcomes study correlating serial AlloMap(R) scores with cardiac dysfunction and biopsy proven rejection in heart transplant recipients. The AlloMap test has been shown to aid physicians in determining a transplant patient’s risk of acute cellular rejection without requiring the use of invasive endomyocardial biopsy.

"This is the first time that clinicians will prospectively observe in patients cell-free DNA research test results together with commercially available AlloMap scores," said James Yee, MD, PhD, Chief Medical Officer at CareDx, Inc. "These two solutions are anticipated to provide complementary useful knowledge. Donor derived cell-free DNA is expected to reflect the status of the transplanted heart while AlloMap gene-expression profiling reflects the activation of the recipient’s immune system."

"Circulating donor-derived DNA in the blood may serve as an important biomarker for immune surveillance and significantly improve the way we diagnose rejection in heart transplant patients," said Manreet Kanwar, MD, a cardiologist with Allegheny General’s Advanced Heart Failure and Transplantation program, and the principal investigator of the study.

Allegheny General is one of three initial transplant centers in the United States participating in the D-OAR study. About 20 heart transplants are performed at AGH annually and the institution plans to enroll 16 patients in the study each year.

One of the leading enrollment centers in the U.S. for the OAR trial, AGH has 34 patients in the AlloMap registry and has already enrolled eight patients in the D-OAR sub-study.

"Better, reliable, non-invasive solutions are needed to diagnose rejection in heart transplant patients," said Srinivas Murali, MD, Director of the Cardiovascular Institute at Allegheny Health Network, and co-investigator of the study. "Combining analysis of cell-free DNA with AlloMap test results can potentially not only improve our diagnostic capabilities, but also facilitate early treatment for patients who develop rejection in their transplanted heart."

There are approximately 2,000 new heart transplants recipients annually in the United States, and over 20,000 living heart transplant recipients with a mean life expectancy of more than 10 years.