Commonplace causes may lead to deadly cath lab delay
NEW YORK (Reuters Health) - Delays that are outside a hospital's control often prevent doctors from unblocking a heart attack patient's arteries right away, according to a new study that also found the delayed patients are more likely to die in the hospital.
So-called non-system delays occurred in about 15 percent of U.S. heart attack cases between 2009 and 2011, researchers found. Causes for the delay in using balloon angioplasty to open coronary arteries ranged from problems obtaining consent to issues involving patients' other complex medical problems.
Of the patients who experienced non-system delays between the time they entered the hospital and when they underwent the artery-opening procedure, just over 15 percent died while in the hospital. That compared to about 3 percent of patients without a delay.
"We found non-system reasons in delay of door-to-balloon time are associated to significantly greater mortality, compared to patients without non-system delays," said Dr. Rajesh Swaminathan, the study's lead author from the Weill Cornell Medical College in New York.
During heart attacks caused by blocked arteries, doctors try to open the blockage using a thin wire with a balloon attached to the end. The ideal is to open the patients' arteries and restore blood flow to the heart within 90 minutes of a patient's arrival at the hospital.
Swaminathan said cardiologists believe "time is muscle," and that patients are worse off as more time elapses between the start of a heart attack and clearing the blockage.
In the Journal of the American College of Cardiology, he and his colleagues write that most studies have focused on so-called system delays - such as operating rooms or doctors not being ready to start the procedure, but few have looked at these non-system delays.
For the new study, Swaminathan's team used a U.S. database of records on 82,678 heart attack patients who had angioplasty between January 2009 and July 2011.
Of those, 12,146 patients experienced non-system delays.
About 37 percent of them were in cardiac arrest and needed breathing tubes inserted before anything else could be done. About 27 percent had physical characteristics that made it difficult for health workers to access veins or break through blockages. Another 4 percent refused consent for doctors to operate and 31 percent had "other" reasons noted in their files.
Despite these obstacles, the researchers found that almost half the delayed patients had their blockages cleared within the recommended 90-minute threshold.
The shortest delays were caused by patients going into cardiac arrest and needing a breathing tube inserted. Yet, that reason for delay was associated with the highest mortality - about 30 percent of those patients died in the hospital.
That finding suggests delays aren't solely responsible for huge differences in mortality, according to Dr. Cindy Grines, of the Detroit Medical Center Cardiovascular Institute, who wrote in an editorial accompanying the new study.
"It is likely a marker for higher risk patients," she pointed out.
Dr. Gregg Fonarow, co-chief of the University of California, Los Angeles Division of Cardiology, told Reuters Health that it's important to get blockages cleared as soon as possible, but the new study shows these other issues are also important.
"Time matters, but there is a lot that goes into outcome and some of those non-system reasons for delays raise the mortality risk," said Fonarow, who was not involved in the new research.
Swaminathan told Reuters Health that although these delays are usually considered outside a hospital's control, there may be ways to improve on the numbers with changes to hospital systems.
For example, he said, there were a high number of Asians who delayed in giving their doctors consent to operate. That suggests there could be a language barrier that easy access to translators would help break down.
"There are some ways that we can provide system solutions to reducing the time (spent on non-system delays)," Swaminathan said.