KANSAS CITY, Mo. — There’s the pressure in the chest, the pain radiating through arms and shoulders, the queasiness, sweating, shortness of breath.

Warning signs of a heart attack should be hard to ignore. But that’s just what many people try to do if they have little or no health insurance, a new study finds.

Uninsured people — and even people who have insurance but have trouble paying medical bills — wait significantly longer to go to a hospital for heart attacks than insured people who don’t have major financial concerns about their health care.

“Even for those with the security blanket of insurance, it wasn’t always enough,” said researcher Paul Chan, a heart specialist at St. Luke’s Hospital in Kansas City, Mo. “They knew they could get care, but there was no guarantee they could afford it. You can just imagine what it was like for the uninsured.”

Or you can ask patients such as Larry Scott, who waited weeks after his symptoms appeared before seeing a doctor.

“I was more worried about creating a medical bill than about my health,” Scott said.

His heart is now permanently damaged.

In a study being published Wednesday in the Journal of the American Medical Association, Chan, St. Luke’s heart specialist John Spertus and researchers at Yale New Haven Hospital, the Mayo Clinic and several other medical centers looked at data on 3,721 patients from across the country who had survived heart attacks. The patients went to 24 hospitals from 2005 through 2008.

The researchers found that 48.6 percent of uninsured patients waited more than six hours after their symptoms started to get to a hospital. That compared to 39.3 percent of patients who were insured and did not have significant problems paying for care.

And among insured patients who had financial concerns about getting health care, 44.6 percent waited more than six hours. After about six hours, emergency heart attack treatments become less effective.

Previous studies have found that uninsured patients are less likely than the insured to get checkups or preventive care. They are more likely to end up in the hospital with avoidable conditions such as pneumonia or uncontrolled diabetes. When they develop cancer, it is more often diagnosed at later stages.

But there has been little research on how insurance affects decisions to seek care in life-threatening medical emergencies.

Nearly 1 million people suffer heart attacks each year in the United States.

“For the large majority of patients, the symptoms of a heart attack are very noticeable. It’s a sudden and acute change,” Chan said.

Denial accounts for some of the delays getting to the hospital, Chan said. So does a lack of knowledge about the urgency of a heart attack.

But for the uninsured and underinsured, costs can be the overriding concern.

Medicare pays hospitals on average about $20,000 to treat a heart attack, Chan said. But hospitals may charge private insurance plans and people without insurance considerably more, he said.

“People weigh risks and benefits,” Chan said. “You’ll have to pay something, but you won’t know what it is until you leave the hospital.”

Even when a heart attack isn’t fatal, delaying treatment can have devastating consequences. When patients arrive at the hospital in time, doctors can use stents or clot-busting drugs to restore blood flow to the heart muscle.

“If the patient delays, the heart muscle will die,” Chan said.

One of his patients is Scott, 59, of Kansas City. He works part time for the Park Hill School District and doesn’t have health coverage.

When his chest pains started last December, Scott ignored them at first. He’d take some aspirin, and the pain would go away. But on Dec. 28, the pain wouldn’t quit. He had a hard time catching his breath.

Scott called his brother for help. The phone dropped from his hand. His brother dialed 911.

When the test results came in, Scott learned his heart had lost much of its ability to pump blood.

Scott is taking heart medications now. The heart damage hasn’t slow him down. But he is at risk of developing heart failure.

“If I had medical insurance, this would never have happened,” Scott said. “I would have gotten in (to the doctor) sooner.”

Chan and the other researchers are continuing to follow the patients in the heart attack study. They will be looking at whether the patients’ insurance status affected their health or quality of life a year after treatment, or their odds of survival.

The research is sponsored by the National Institutes of Health.