Tailoring Use of Platelet Inhibitors.

• Position: Research into super aspirins - Brief Article

Researchers at Duke University Medical Center, Durham, N.C., think they know why glycoprotein IIb/IIIa platelet inhibitor drugs, collectively known as "super aspirins," produce only modest benefits for patients with acute coronary syndromes--they are often being used on patients who only can gain very little benefit. In the process of tabulating results on a trial on lamifiban, one of three intravenous super aspirins that have been tested, they discovered that a simple blood test identified patients who benefited markedly when the drug was used. In those individuals, improvement in the risk of death and a second heart attack was about 50%, compared to patients who received a placebo.

In contrast, data on all patients in the lamifiban trial show just a modest, statistically insignificant improvement, similar to that seen in tests of eptifibatide and tirofiban, two other intravenous-use GP IIb/IIIa receptor inhibitors already on the market.

"This is good news. It shows us that we can potentially refine the use of IIb/IIIa inhibitors and direct them to the patients who can really benefit from them," indicates the study's lead investigator, Robert Harrington of the Duke Clinical Research Institute. He maintains that use of the super aspirins in the U.S. is tepid, with only about 15% of eligible patients put on them. "But with this new information, we may have the ability to target the power of these drugs."

The three super aspirins attempt to prevent platelets circulating in the blood from clumping together and forming a clot at the site of atherosclerotic plaque. The drugs are delivered intravenously over a three-day period to patients who suffer from unstable angina or are at risk for a second heart attack. (They are not used on patients who are receiving thrombolytic therapy to break up existing blood clots.) Oral forms of these super aspirins have not shown any...