"The benefit of this therapy increased with the scope of the heart attack," said Gregg W. Stone, M.D., lead author and professor of medicine at Columbia University College of Physicians and Surgeons and director of cardiovascular research and education in the Center for Interventional Vascular Therapy at NewYork-Presbyterian Hospital/Columbia University Medical Center. Dr. Stone is also the immediate past chairman of the Cardiovascular Research Foundation in New York. "The data show that heart muscle can be saved even after severe heart attack."
The AMIHOT-II study focused on patients having the most serious types of heart attacks - those with anterior ST-segment elevation myocardial infarctions (STEMIs) - and on patients treated within 6 hours. Of the 733,000 Americans who suffer acute coronary syndromes (i.e. heart attack or chest pain) each year, 361,000 (almost half) have a STEMI, according to the American Heart Association. When a large area of the heart is damaged, heart failure is more likely, and catheter-based percutaneous coronary intervention is a procedure that can effectively open blocked arteries in STEMI patients, Dr. Stone said.
In the trial, the "supersaturated" oxygen was delivered via catheter directly to the area of the heart muscle affected by the heart attack. The size of the "infarct zone," or the amount of damaged tissue, was significantly reduced in the patients that received the "supersaturated" oxygen.
Data from the study show that the median size of the "infarct zone" was 20 percent in the patients that received the "supersaturated" blood and 26.5 percent in the control group.
In addition, at 30 days after the treatment a key safety measure -- the rates of major adverse cardiac events - were not statistically different between the two groups.
