In a spectacular turnabout, hospitals are treating almost all major heart attack patients within the recommended 90 minutes of arrival, a new study finds. Just five years ago, less than half of them got their clogged arteries opened that fast.

The time it took to treat such patients plunged from a median of 96 minutes in 2005 to only 64 minutes last year, researchers found.

Some hospitals are moving at warp speed: Linda Tisch was treated in a mere 16 minutes after she was stricken while visiting relatives near Yale-New Haven Hospital in Connecticut this month. Emergency responders called ahead to mobilize a team of heart specialists.

Once she arrived, "they had a brief conversation and I went straight into the OR. My family was absolutely flabbergasted," said Tisch, 58, who went home to Westerly, R.I., two days later.

Tisch wasn’t a fluke. The hospital took 26 minutes on another case on Thursday.

"Americans who have heart attacks can now be confident that they’re going to be treated rapidly in virtually every hospital of the country," said Yale cardiologist Dr. Harlan Krumholz. He led the study, published online Monday by an American Heart Association journal, Circulation.

What is remarkable about this improvement, Krumholz said, is that it occurred without money incentives or threat of punishment. Instead, the government and a host of private groups led research on how to shorten treatment times and started campaigns to persuade hospitals that this was the right thing to do.

"It’s amazing and it’s very gratifying. I’m surprised that we were able to achieve that type of dramatic improvement" so quickly, said Dr. John Brush, a cardiologist at Eastern Virginia Medical School in Norfolk, Va., who helped the American College of Cardiology design its campaign, which involved more than 1,000 hospitals.

Heart attacks are caused by clogged arteries that prevent enough oxygen and blood from reaching the heart. Each year, about 250,000 people in the United States and more than 3 million worldwide suffer a major one, where a main artery is completely blocked.

The best remedy is angioplasty, in which doctors push a tube through an artery to the clog, inflate a tiny balloon to flatten it, and place a mesh prop called a stent to keep the artery open.

The period from hospital arrival to angioplasty is called "door-to-balloon" time, and guidelines say this should be 90 minutes or less. Any delay means more heart damage, and the risk of dying goes up 42 percent if care is delayed even half an hour.

Not all hospitals have the capability to do angioplasty around the clock, so part of the effort to speed care involved setting rules for who has to be consulted before deciding to do the procedure.

The study involved more than 300,000 patients who had an emergency angioplasty at hospitals that get Medicare reimbursements. The researchers looked at records from 2005, just before campaigns to shorten treatment times were launched, through September 2010.

Only 44 percent were treated in the recommended time in 2005, but by last year it was 91 percent.

The National Heart, Lung and Blood Institute and the Centers for Medicare and Medicaid Services paid for the study.

"It’s not an exaggeration to say that care of heart attacks in the United States has been transformed by this improvement," said Dr. Christopher Granger, a Duke University Medical Center cardiologist who led a Heart Association program to improve care.

"We’ve made very important progress but there still is a lot of unfinished work in improving heart attack care," such as what happens before people get to a hospital where angioplasty is done, he said.

Patients also need to do their part, by knowing the warning signs of a heart attack:

— Discomfort in the center of the chest lasting more than a few minutes, or that goes away and comes back. It can feel like pressure, squeezing, fullness or pain.
— Pain or discomfort in one or both arms, the back, neck, jaw or stomach.
— Shortness of breath, which might include breaking out in a cold sweat, or feelings of nausea or lightheadedness.

What to do is simple, doctors say: Call 911.