Research at Texas Heart Institute at St. Luke's Episcopal Hospital
Shows Simple Blood Test Is as Effective as Biopsy to Monitor Heart
Lower cost and less inconvenience, discomfort and risk to patients
Houston, Texas (April 28, 2010)
– Researchers at the Texas Heart Institute at St. Luke’s Episcopal Hospital (THI at St. Luke’s) have announced the successful testing of a method to profile genetic markers in the blood as a way to monitor the risk of organ rejection in heart transplant patients. The method, known as AlloMap®, would replace part of a progression of biopsy procedures for transplant patients with a simple, noninvasive blood test.
Dr. Roberta Bogaev
“Instead of having to check into the hospital as an out-patient and undergo an invasive procedure to biopsy the heart, patients undergo a simple blood draw and are on their way,” said Dr. Roberta Bogaev, director of the Heart Failure and Transplant Program at THI at St. Luke’s.
“The balance between preventing rejection with immunosuppressant drugs and avoiding adverse effects of the anti-rejection drugs is always a challenge. The AlloMap allows physicians to have an increased confidence level that patients are not rejecting without subjecting them to an invasive procedure. The patients spend much less time in the hospital and are able to enjoy their life outside the hospital,” said Dr. Bogaev. “The AlloMap test is in keeping with THI’s mission to develop less-invasive methods to diagnose, monitor and treat patients.”
Endomyocardial biopsy has been the primary method of monitoring for rejection. Heart transplant recipients typically undergo 15 to 20 biopsies in the first six months following transplantation, and two to four biopsies per year after that. Biopsies are invasive and associated with discomfort, inconvenience and low but definite risks of complications and death. Each biopsy can cost approximately $4,000 or more.
Dr. Bogaev is one of the principal researchers who helped investigate the Gene Expression Profiling (GEP) test, along with XDx-Inc., a molecular diagnostics company based in Brisbane, Calif.
The AlloMap procedure is designed to analyze the expression of certain genetic markers in a transplant patient’s bloodstream and, with the help of other screening by physicians, identify patients with low risk of organ rejection at the time of the testing.
Since January 2005, there have been more than 600 patients, ranging from six months to five years post-transplant, who have participated in randomized testing at THI at St. Luke’s and other centers around the country, including at Stanford University Medical Center. The testing was designed to compare outcomes for patients undergoing the AlloMap blood test vs. patients subjected to biopsies. The study showed that the AlloMap procedure was “non-inferior” to biopsy testing.
“The findings are important because they demonstrate that AlloMap is as effective as biopsy for monitoring stable post-transplant patients,” said Dr. Bogaev. “Physicians can monitor cardiac transplant patients and identify those with a low probability of organ rejection, while reducing the number of biopsies performed, thereby minimizing patient discomfort, cost and risk.”
Results from the study were presented last week at the International Society for Heart & Lung Transplantation 30th Anniversary Meeting & Scientific Sessions in Chicago. The scientific paper based on the study was published online April 22 in the New England Journal of Medicine, and will be in the print edition in June.
On average, just more than 2,000 heart transplants are performed each year across the United States.
For media inquiries please contact:
Texas Heart Institute
Frank Michel ♦ 713-218-2210 or 832-355-9246
For THI and St. Luke's media profiles, see Public Affairs.