ASNC: Pharmacologic stress agent well-tolerated for MPI
Lexiscan, the pharmacologic stress agent for radionuclide myocardial perfusion imaging (MPI), is well-tolerated and as effective as the current standard, Adenoscan, according to study results presented this week at the 14th Annual Scientific Sessions of the American Society of Nuclear Cardiology (ASNC) in Minneapolis.

Lexiscan is an A2A adenosine receptor agonist approved for use as a pharmacologic stress agent in radionuclide MPI in patients unable to undergo adequate exercise stress.

“Lexiscan is not only as effective as Adenoscan in detection of perfusion defects by myocardial perfusion imaging, but it also demonstrates that it is well-tolerated and has a side effect profile comparable to Adenoscan,” said Manuel Cerqueira, MD, chairman of nuclear medicine at the Imaging Institute and staff cardiologist at the Heart and Vascular Institute at the Cleveland Clinic.

Aminophylline is administered to ease symptoms in the case of adverse events in patients after receiving a pharmacologic stress agent. The phase III trials included 2,015 patients and the researchers compared patient characteristics, side effects and aminophylline treatment timing and dosage.

The researchers found no significant difference in adverse events in patients randomized to Lexiscan than with Adenoscan. Patients who received aminophylline as well as randomized to Lexiscan, were treated on average of 4.5 minutes later than patients randomized to Adenoscan. Total aminophylline doses ranged from 72 to 300 milligrams (mg) for Lexiscan and from 25 to 240 mg for Adenoscan.

“The low use of aminophylline demonstrates that Lexiscan is similar to the current standard, Adenoscan,” the researchers concluded.

Astellas Pharma US, based in Deerfield, Ill., owns exclusive North American rights to Lexiscan, which was developed in collaboration with the Palo Alto, Calif.-based CV Therapeutics.