For certain heart attack victims, "there is no benefit to opening the artery late," says researcher Judith Hochman, MD, clinical chief of cardiology at New York University School of Medicine in New York City.
The findings were posted online by The New England Journal of Medicine to coincide with Hochman's presentation at the annual meeting of the American Heart Association (AHA).
Angioplasty vs. Drug Therapy
Opening blocked arteries with angioplasty plus stenting in the first 12 hours after a major heart attack is known to reduce further damage and improve the chance of survival.
But many U.S. doctors perform the procedure outside the recommended time frame, despite the lack of evidence from large, well-designed studies, says Gervasio Lamas, MD, director of Cardiovascular Research and Academic Affairs at Mount Sinai Medical Center in Miami and moderator of the session.
To find out whether this is good medicine, Hochman and colleagues studied 2,166 people who had 100% blockage in one of the three major heart arteries and were stable three to 28 days after their heart attack.
The participants were randomly assigned to receive either angioplasty plus stenting with medication, or medication alone.
By an average of three years later, 17.2% of people in the angioplasty group had another heart attack, developed heart failure, or died, compared with 15.6% of those in the medication group, a difference so small it could have been due to chance.
When each of those events was looked at separately, there was "a concerning trend" toward more repeat nonfatal heart attacks in the angioplasty group: 6.9% vs. 5% in the medication-only group, Hochman says. But the numbers were small, so this again could have been due to chance.
"Death rates and heart failure rates were exactly the same between the two groups," she adds.
New Time Frame Recommended
The findings surprised the researchers, who went into the study thinking that opening up a blocked artery three to 28 days after the heart attack would cut the risk of death, development of severe heart failure, or another heart attack by 25%.
"It was logical that an open artery would be better than a closed one," Hochman says. "But sometimes logical doesn't prevail. And until this study was done, we didn't know this was an unnecessary procedure for the type of patient we studied."
Hochman says she hopes the findings will dissuade doctors from performing angioplasty outside the recommended time frame.
"It's certainly reason to rethink late angioplasty in stable patients after an acute heart attack," agrees Timothy Gardner, MD, medical director of the Center for Heart and Vascular Health at Christiana Care Health Services in Wilmington, Del., and chairman of the AHA committee that chose which studies to highlight at the meeting.
Angioplasty or Bypass Still Useful
The researchers emphasize that the findings only apply to the type of person studied: those whose heart attacks are caused by a blockage in one major artery and who are stable, with no chest pain when the angioplasty is performed three to 28 days later.
"If you have continuing chest pain or you have blockages in multiple arteries, you still need an intervention -- either angioplasty or bypass surgery," Gardner tells WebMD.
Additionally, angioplasty can still be lifesaving and relieve chest pain and other symptoms when performed within the 12-hour window, Hochman stresses. "That's why it is so critical to seek medical care very early after symptoms that could be a heart attack: chest discomfort, chest pressure or tightness, or even arm discomfort.
"Don't deny something is happening and sit home and take antacids," she says.