New heart procedure cuts death risk by 65%
For those who suffer a severe heart attack, a new procedure is now available that greatly increases the chance of survival while avoiding severe complications. It works by unblocking the artery that caused the heart attack, while also removing blockages in other arteries.
Details about the heart procedure and its findings are published online this week in the New England Journal of Medicine. As part of a randomized trial, the interim results of the preventive procedure were so impressive that the study ended early.
What causes a heart attack?
A heart attack occurs when arteries that supply blood to the heart become partly or completely blocked by a clot, causing some of the heart muscle to die.
The most severe type of heart attack (also called STEMI) occurs when the blood clot completely blocks the heart artery.
Researchers hope the results from the trial will help doctors decide when to use the new procedure, called percutaneous coronary intervention (or PCI), to remove blockages after a patient has a severe (STEMI) heart attack.
During a PCI, the doctor performs an angioplasty, a procedure that opens narrow or blocked coronary arteries by inserting a thin tube or stent into the blockage to keep the artery open and allow blood to flow through to the heart. During this part of the procedure, doctors can see if other arteries are blocked too.
For the randomized trial, researchers wanted to see if unblocking these arteries could prevent future heart attacks, complications and deaths.
“When a patient is admitted with an acute myocardial infarction, it is known that PCI to the blocked culprit artery is life-saving, but there is uncertainty as to whether doctors should undertake preventive PCI in vessels that are partially blocked but did not cause the myocardial infarction. This is a common clinical dilemma," points out lead investigator Dr. David Wald.
The committee overseeing the trial ended up stopping it early after the interim results clearly showed that the patients receiving preventive PCI were doing much better than those who only received PCI to remove the arterial blockage that caused their heart attack.
“The results of this trial show that in this situation preventive PCI [...] reduces the risk of cardiac death, a subsequent myocardial infarction or angina resistant to medical therapy, by about two-thirds," Wald explains.
The trial involved 465 patients who were undergoing emergency PCI for serious heart attacks and had blockages in other blood vessels. They patients were randomized just before the procedure to receive either preventative PCI (234 patients) or culprit-only PCI (231).
Over a follow-up period of nearly 2 years, 21 patients in the preventive PCI group and 53 in the culprit-only group, either died or had another heart attack, or they developed refractory angina; thus, representing an absolute risk reduction of 14 per 100 in the preventive PCI group, and a relative risk reduction of 65% compared with the culprit-only group.
According to Wald, the average preventive PCI extends the procedure time by approximately 20 minutes, and that "the initial costs of preventive PCI are higher, but there will be reduced costs thereafter, with a reduced need for subsequent hospital admissions, cardiac investigations and revascularization procedures."
SOURCE: New England Journal of Medicine, Randomized Trial of Preventive Angioplasty in Myocardial Infarction; D.S. Wald and others for the PRAMI Investigators; NEJM published online 1 September 2013; DOI: 10.1056/NEJMoa1305520.