June 24, 2009 -- Patients who have a heart attack and receive clot-busting drugs do better if they are transferred as soon as possible to a hospital that can perform angioplasty, a procedure to open blocked arteries, according to a new study.
That treatment approach works better than giving clot-busting drugs and then waiting to see if the medications work, transferring them only if the clot-busting drugs fail, says Shaun Goodman, MD, study co-author and co-chair of the Canadian Heart Research Center, Toronto.
Performing angioplasty right after a heart attack "is a great procedure, if it can be done," he says. But in the U.S. and Canada, as well as other locales, angioplasty capabilities aren't available on site at many hospitals. "In the U.S., less than 25% of acute care hospitals have on-site angioplasty," Goodman says. So Goodman's team wanted to see if the timing of angioplasty after clot-busting drugs might improve outcomes. The study is published in The New England Journal of Medicine.
Angioplasty After Heart Attack: Study Details
For the study, Goodman's team compared two angioplasty approaches in heart attack patients initially treated at a facility that does not have angioplasty capabilities:
- Standard treatment, in which clot-busting drugs are given and the patient is transferred later to a facility with angioplasty capabilities only if the clot-busters don't work.
- Routine early angioplasty treatment, in which clot-busting drugs are given and the patient is transferred within six hours to another facility for angioplasty.
They randomly assigned 1,059 patients who went to facilities without angioplasty capability between July 2004 and December 2007 to the two treatment approaches. All had a type of heart attack known as an ST-elevation myocardial infarction (STEMI), a kind of heart attack that occurs when a coronary artery is suddenly and totally blocked. ST elevation refers to a specific finding on an electrocardiogram
"It's the sickest group of patients who come to the hospital," Goodman tells WebMD. STEMIs make up a minority of the heart attacks that occur, he says, but "everyone jumps on them. They have the highest risk of dying early on. Even though they are the minority of all [heart attack] patients, this is a run, don't walk situation" to try to save them, Goodman says.
During angioplasty (also known as PCI or percutaneous coronary intervention), a balloon can be inflated to reopen the artery and restore blood flow. A wire mesh tube known as a stent can be placed inside to prevent the blockage from happening again.
Angioplasty After Heart Attack: Study Results
Those treated with routine angioplasty after the clot busters fared better than those given standard treatment, Goodman's team found.
Angioplasty was eventually performed in more than 67% of patients in the standard treatment group at a median of nearly 22 hours (half longer, half less) after being assigned to the group and in nearly 85% of those in the routine angioplasty group a median of 3.2 hours after being assigned.
The researchers evaluated patients 30 days after the attack, considering complications such as death, repeat heart attack, recurrent heart pain, new or worsening heart failure and cardiogenic shock, in which the heart's pumping ability declines.
When the researchers looked at all those complications together, 17.2% of the standard treatment group had them, compared to only 11% of the routine angioplasty group. "The group that went for the early angioplasty had significantly fewer of those events," Goodman says. There were no differences in rates of bleeding complications.
In an editorial accompanying the study, Freek Verheugt, MD, writes that the newest study agrees with findings of prior smaller studies and "can be considered definitive." He further argues that all patients who have received clot-busting medication during a heart attack should be routinely transferred to a hospital where they can undergo early angioplasty. Given the totality of the published data, Verheugt concludes that pursuing angioplasty between two and 24 hours after the clot buster infusion is best.
"I think it's an important trial and a helpful trial as we try to understand the best strategies for treating patients with heart attack," says Sidney Smith, MD, former president of the American Heart Association and professor of medicine at the University of North Carolina, Chapel Hill.
While it's too early to say whether the study findings will change practice, Smith says, "It will reinforce the idea that patients at high risk will benefit from being transferred to a cardiac catheterization lab soon after the heart attack."
"This is important evidence to support the use of early PCI [angioplasty] in high-risk patients who have STEMIs," he says.
In the recent study, he notes, the major benefits in the group that got clot busters followed quickly by angioplasty were prevention of the vessel from becoming occluded again and prevention of repeat heart attacks.
The take-home message, says Goodman, is that time is of the essence in getting treatment for a loved one you suspect is having a heart attack.
"The most important thing is to call 911 and get an ambulance to take you to the closest emergency department,'' he says. "Don't worry about whether it does or does not have angioplasty capability."
That way, a patient can get the clot buster and be transferred, if necessary, early on, Goodman says.
In the U.S., nearly 80% of the adult population resides within an hour drive of a center that does have angioplasty capabilities.
The study was funded by the Canadian Institutes of Health Research and Roche, Canada.