After Heart Attack, Stenting More Than the Blocked Artery May Be Best

SUNDAY, Sept. 1, 2019 (HealthDay News) -- Opening all of a person's clogged arteries after a heart attack can protect their health better than reopening only the one that caused it, a major international clinical trial has concluded.

Opening all blockages and not just the "culprit" behind the attack reduces a patient's risk of dying or having another heart attack by 26%, researchers reported Sept. 1 in the New England Journal of Medicine.

This large-scale trial confirms nearly a decade's worth of research pointing in the same direction, and should lead to this approach becoming standard practice, said lead researcher Dr. Shamir Mehta. He's director of interventional cardiology at Hamilton Health Sciences in Hamilton, Ontario.

"The results were very clear. They weren't borderline," he said. "It will almost certainly have an impact on the guidelines and on clinical practice, not just in the U.S. or Canada, but worldwide."

About half of all heart attack victims have more clogged arteries than the one that caused their heart attack, the researchers said in background notes.

Of those patients with multiple blockages, at least 80% should be able to benefit from having all of their clogged arteries reopened, said Dr. Samin Sharma, director of clinical and interventional cardiology at Mount Sinai Hospital, in New York City.

Importantly, having the additional blockages reopened did not increase a patient's risk of other health problems, Sharma noted.

Mehta said, "This study shows that if you do it correctly, nothing happens. The kidney injuries were identical. The vascular complications were identical. There was no increase in stroke. This approach appears to be a home run in a large number of cases."

Heart attacks happen because a single clogged artery prevents the flow of blood to the heart, damaging the organ.

Initial treatment focuses on reopening that artery and restoring the flow of oxygen to the heart muscle, Mehta said.

But there has been great debate about what to do about other blocked arteries that a patient might have.

"That's where all the controversy has been," Mehta said. "Should we just leave them alone? Have they been there for years, and are they not going to cause any problems in the future? Should we really run the risk of going back in and opening them just after a patient's had a major heart attack?"

The guidelines were "really on the fence about this issue," Mehta said. "The data wasn't there to say 100% go ahead and fix them or don't fix them. It was kind of in the middle."

At least eight years of studies and clinical trials have provided mounting evidence that reopening all of the blockages should improve a person's outcome, said Dr. C. Michael Valentine, president of the American College of Cardiology.

"This is the long-awaited confirmation that most cardiologists have been waiting for," said Valentine, a senior cardiologist at Stroobants Cardiovascular Center of Centra Health in Lynchburg, Va.

To provide this definitive answer, the researchers undertook a clinical trial involving more than 4,000 patients treated at 140 hospitals in 31 countries.

All patients had their blocked "culprit" vessel reopened, Mehta said.

After that initial procedure, about half were randomly chosen for a second procedure days later to reopen the rest of their blocked arteries.

Taking care of the other blockages cut in half a person's combined risk of either death from heart disease, a repeat heart attack, or a need to return and have another clogged artery reopened due to chest pain or other symptoms, the findings showed.

Over a median of three years, about 8% of patients who had everything reopened suffered a second heart attack or cardiovascular death. That compared to about 11% of those who received treatment only for the artery that caused the first heart attack.

"We've shown clearly that putting stents in these clogged arteries and opening them provides a major benefit," Mehta said. "The interesting thing is that the benefit accrues over the long term. The trial followed patients for up to three years, and the benefit continued to accrue over that period."

Mehta and Sharma expect fully opening all blockages also would save money over the long run, compared with people returning to the hospital with future problems caused by untreated clogged arteries.

"You can't really send a patient with a full-blown heart attack home anyway. You have to keep them in hospital for 48 hours, at minimum," Mehta said. "They're sitting around anyway in the hospital. To bring them down the next day and fix the other blockages is not that huge an increase in cost."

However, the results also show there's no rush. Patients benefitted from having all blockages reopened even if the follow-up procedure took place weeks later, Mehta said.

"The nice thing about the trial is if a person is frail or elderly, or if they have kidney disease, it's OK to delay it and let the patient recover from the initial heart attack," he said. "Then when they're strong enough, you can bring them back and do the other vessels."

It's important for physicians to understand there are options, he said. "You don't have to do it right away."

Still, Sharma suggested, it might be even more cost-effective to clear all the blockages during the initial procedure.

"If you know it's a simple blockage, why do you need to wait until the next day? Why don't you do it at the same time? That's the only question that's not answered by this study," Sharma said.

The results of the clinical trial were also presented Sunday at the European Society of Cardiology's annual meeting, in Paris.

More information

The American Heart Association has more on the warning signs of a heart attack.

SOURCES: Shamir Mehta, M.D., M.Sc., director of interventional cardiology, Hamilton Health Sciences, and professor of medicine, McMaster University, Hamilton, Ontario, Canada; Samin Sharma, M.D., director of clinical and interventional cardiology, Mount Sinai Hospital, New York City; C. Michael Valentine, M.D., president, American College of Cardiology, and senior cardiologist, Stroobants Cardiovascular Center of Centra Health, Lynchburg, Va.; Sept. 1, 2019, New England Journal of Medicine, online