The drug regadenoson is safe and poses fewer side effects than the conventional medication used during a cardiac nuclear stress test of heart transplant patients, according to a Henry Ford Hospital study.

Researchers say the 25 patients in the study did not experience adverse side effects such as abnormally low blood pressure or slow heart beat when regadenoson was used during the stress test.

Additionally, patients showed no signs of heart block, a condition in which the signal from the heart's upper chamber is impaired or doesn't transmit.

Adenosine, the conventional drug used during a cardiac nuclear stress test, is known to cause lightheadedness, fainting and heart palpitations in patients, as well as high incidence of heart blocks.

We believe regadenoson to be a safe and well tolerated medication for this specialized group of patients without causing any significant adverse heart issues, says Karthik Ananth, M.D., a Henry Ford cardiologist and the study's senior author.

The Henry Ford study is the first to date to specifically examine the safety profile of regadenoson in heart transplant patients to see whether it would prove to be a better alternative to adenosine, which long has been used during a nuclear stress test to assess a patient's blood vessels for blockages after a heart transplant.

Prior research in the general population has shown regadenoson to be safe and cause few side effects for use in evaluating coronary artery disease, which led to its approval for use in stress testing in 2008.

Henry Ford Hospital is one of the only three hospitals in Michigan that perform heart transplants.