"The very thing that is the impediment to coming to a facility promptly now becomes compounded, because they come there late and need more care," he said.
Chan said that while patients in the study who came in later had fewer things done to them in the hospital, their stays were longer. Costs were not examined.
"Most people perceive that emergency care is expensive," said Dr. Angela Gardner, president of the American College of Emergency Physicians. "People will take that chance rather than come to the emergency room in order to avoid a costly visit."
But, she said, patients need to remember that they will be taken care of regardless.
"We would hope people come, without regard for the ability to pay, because that is how we treat them," Gardner said.
But while finances may have been a concern, other factors may have played a role in the delay of seeking care.
Patients without health insurance may have been less likely to have a primary care provider, and may have been less likely to know the signs of a heart attack in the first place.
"It may be a lot more than just being aware that you're uninsured or underinsured," Yancy said.
Chan said that in the end, giving everyone health insurance will not change what was observed in this study.
He said rising health care costs, which were not addressed in the legislation, mean that patients will continue to pay more in the form of higher deductibles and coinsurance, so more patients would have insurance but still be concerned about the cost of going to the hospital.
"Patterns of delay will persist ... unless we adequately address those concerns," Chan said. "I don't think we're done, and I think there's a lot more work to be done."
The lead investigator on the study was Kim Smolderen, a psychologist with Tilburg University in the Netherlands.
She said the Dutch press has been having some difficulty in understanding the study, since the uninsured rate in the Netherlands hovers around 1 percent.
"They wouldn't even think it would be possible that someone here would delay their decision to go to the hospital when feeling symptoms of a heart attack," she said.