Thursday, February 7, 2008

New drug could minimize damage from heart attack treatment
By Kelly Winget

In a first-in-human trial, DCRI researchers have found a new drug to be safe and effective at minimizing some of the damage the heart sustains during angioplasty following a heart attack.

Results of the study are available online and are scheduled to be published in the February 19 issue of Circulation .

When a person has a heart attack, one of the most common treatments is for cardiologists to perform percutaneous coronary intervention (PCI). This involves opening up blocked arteries with angioplasty and placing a stent in the artery, which restores normal blood flow to the heart. However, a particular enzyme called delta protein kinase C triggers cell and tissue death following PCI.

DCRI cardiologist Matthew Roe, MD, led the international, first-in-human trial (DELTA-MI) to test a new drug that had shown promising results of minimizing heart damage and quickly restoring heart function in animals. The drug, KAI-9803, blocks the effects of delta protein kinase C.

The heart is damaged the most at two major points during a heart attack. The first is when coronary arteries become blocked and prevent oxygen from reaching the heart, and the second is when normal blood flow is restored, called reperfusion.

“We may not be able to intervene in the first stage of a heart attack, but we think there may be ways to limit damage caused by reperfusion injury,” said Roe.

The trial was intended to test if the drug was safe for people, and researchers did not note any serious side effects. But they also found that patients who received the drug sustained less damage to their hearts and had improved cardiovascular electrical conductivity.

For the trial, 154 patients who had suffered heart attacks and were good candidates for PCI were randomized to receive one of four dosing levels of KAI-9803 or a placebo. Patients then had PCI and physicians injected the drug directly into their coronary blood vessels during the procedure.

“The goal of the treatment is to flood the heart damaged by the heart attack with the drug immediately before blood flow is restored and then again, immediately afterwards,” said Roe. “We believe that bathing the area with this novel compound may block the damaging cascade of events that are triggered specifically by delta protein kinase C when blood is restored to the heart muscle.”