NEW YORK (Reuters Health) – Cardiac allografts might function better when brain-dead organ donors are treated with low-dose dopamine, researchers report.

They say the approach — already known to improve renal graft function — is worthy of testing in heart donors too.

The effect “is related to antioxidant properties of the dopamine molecule,” according to an October 18th paper in the Journal of the American College of Cardiology by Dr. Peter Schnuelle of University Medical Center Mannheim in Germany and colleagues.

Dopamine protects the donor’s renal endothelial cells and cardiomyocytes against damage from cold ischemia, Dr. Schnuelle told Reuters Health by email. Because it’s used in the donor, “dopamine’s protective properties can be achieved without any known side effects in the recipients,” he said.

His group’s data on heart grafts comes from a post-hoc analysis of 93 hearts from brain-dead donors in the kidney transplantation study. Donors were randomly assigned to receive dopamine 4 g/kg/min or no dopamine.

Hearts from dopamine-treated donors had significantly better three-year survival rates (87.0% vs. 67.8%), and significantly fewer recipients of those hearts needed hemofiltration after transplant (21.7% vs. 40.4%).

Recipients of dopamine-treated hearts also showed trends toward fewer problems with left ventricular function (LVF), less need for a left ventricular assist device, and less biopsy-proven rejection.

Patients who developed any of those were at higher risk for death, with hazard ratios of 4.95 for LVF impairment, 2.83 for hemofiltration, and 6.65 for a left ventricular assist device.

After adjustment for a variety of factors including pre-transplant need for a left ventricular or biventricular assist device and impaired kidney function, a survival advantage for dopamine pretreatment was maintained (hazard ratio 0.33).

In an editorial, Dr. Robert P. Frantz of the Mayo Clinic in Rochester, Minnesota, agrees with the recommendation of “a prospective trial of donor dopamine administration on outcome of cardiac transplants.”

“These intriguing results must be viewed as exploratory, given limitations in the study design,” he told Reuters Health by email. “Nonetheless it appears reasonable to place dopamine high on the list of agents to be administered to donors requiring hemodynamic support. Additional research in this area would be most welcome.”

Reference:Effects of Donor Pre-Treatment With Dopamine on Survival After Heart Transplantation

J Am Coll Cardiol 2011;58:1768-1777.