Until recently, cardiologists had assumed that opening a closed artery with angioplasty to keep the artery open even three days or longer after a heart attack would be beneficial. But a new study published in the New England Journal of Medicine shows that it is not.
The Occluded Artery Trial of 2,166 patients, conducted at the New York University School of Medicine, showed that having an angioplasty within 12 hours of a heart attack improves long-term survival and reduces the risk of a second heart attack. But doing the procedure more from three to 28 days after an attack does no good.
Angioplasty involves using a small balloon at the tip of a long catheter to open an artery as an alternative to open heart surgery. Usually a mesh coil called a stent is inserted into the newly-opened area of the artery to help keep the artery open.
Dr. Michael Winniford, director of cardiology at University of Mississippi Medical Center in Jackson, said the finding was a surprise.
“I think most cardiologists had assumed that opening up a closed artery even three or more days after a heart attack would be beneficial,” Dr. Winniford said. “The study showed that it was not. I think it will change what physicians do. It will result in a less aggressive approach to opening up closed arteries in the days or weeks following a heart attack. In the past when we found a closed artery three or more days after a heart attack, we would usually make an effort to open the artery with a balloon or stent. This article indicates that is not beneficial, and so I think we will see fewer attempts to open up closed arteries.”
Still a life saver
However, he wanted to make sure the public understands that using angioplasty during a heart attack or within the first 12 hours of a heart attack is unequivocally effective — the most beneficial way to treat heart attack.
“I think it would be a mistake for the public or patients to take away the notion that this procedure is not effective,” Winniford said. “It is a life saver if done early. It doesn’t help when it is done late.”
He speculated there may be a couple of reasons why angioplasty apparently doesn’t help when it is done late. First, the body can compensate for closed arteries by growing collaterals, which are new blood vessels that grow from adjacent arteries to help supply the heart muscle that was previously dependent on the blocked artery.
“I think the other explanation is that the medications that we use today are very effective at preventing some of the complications that we might expect in a patient with an occluded artery,” Winniford said. “Perhaps the most important medication in that regard is a beta blocker. Almost all of the patients in this study were taking a beta blocker, and this may have provided protection against some of the complications you might expect in a patient with a plugged or occluded artery.”
Early recognition, immediate treatment
The study underscores the critical need to recognize a heart attack and get immediate treatment. If you wait too late, you will no longer been able to benefit from opening a closed artery.
“It is vitally important patients recognize symptoms of a heart attack and seek treatment as early as possible,” Winniford said. “By far and away the most effective treatment for heart attacks is opening the artery quickly. You can do that in two ways, a stent or with clog buster drugs. The stent is preferable for patients who can make it to a hospital where that procedure is available on an emergency basis. Using either a clot buster drug or stent, it is important to get the artery open as quickly as possible. After 12 hours or so, there appears to be relatively little benefit to opening a closed artery in patients who are stable and have relatively normal heart function.
“This study didn’t look at patients who are very sick. This study didn’t study patients with severe angina, for example. If you are very sick after heart attack, there may be benefits.”
Dr. Alfredo Figueroa, a cardiologist with Pines Cardiology Associates who practices at the Central Mississippi Medical Center, said prior to the recent study there was an “open artery hypothesis.” Even though the acute event had passed, doctors assumed there would be long-term benefits to keeping the artery open in terms of the healing process in heart and preventing arrhythmias and things of that sort.
“To this point we would be inclined to try to keep arteries open,” Figueroa said. “This is not the first kind of this study that indicates that isn’t helpful, but it is the most recent one. What the study has shown is at least within the three-year follow up, there doesn’t seem to be any benefits.”
There may even be some detriment. Figueroa said that may be because when they intervene on chronically occluded arteries, they may be pushing some of that clot downstream. That could result in increased blood levels of enzymes, some categorized as small heart attacks.
What it means
While decisions will still have to be individualized for different patients, Figueroa said it will be much less likely to do the procedure when someone comes in late in the course of their heart attack with arteries totally occluded.
“As a message to the public, that just means to act quicker,” he said. “The public has to come in quicker so we won’t find ourselves in such a situation with an occluded artery three days down the road. For the general population, that just means if you suspect something, the sooner you come to the emergency room, the better. We shouldn’t have to find ourselves too often having to make a decision to open up an artery too late in the course of a heart attack.”
Women often don’t have the classic symptoms of heart attack, such as chest tightness and sweating. Figueroa said frequently women will have symptoms that mimic indigestion. Under those circumstances, women are less likely to seek medical attention immediately.
“We look for typical symptoms, but are aware many patients don’t get typical symptoms,” he said. “So the real challenge in an office or emergency room evaluation is because of the atypical symptoms.”
Contact MBJ contributing writer Becky Gillette at firstname.lastname@example.org.