An extensive study of heart attack patients in New Jersey finds that those who arrived at hospitals on weekends were less likely to receive aggressive treatment and were slightly more likely to die than those who arrived on weekdays, researchers are reporting today.
The study, based on an analysis of 231,164 heart attack patients admitted to New Jersey hospitals from 1987 to 2002, found a gap of almost 1 percentage point in heart attack death rates over one three-year span, 12.9 percent for weekend patients and 12 percent for weekday patients.
The deaths occurred within a month of admission.
In that period, 1999 to 2002, 10 percent of weekday patients had angioplasty to open blocked arteries on the day they were admitted, compared with 6.7 percent of weekend patients. Angioplasty within a few hours of the start of heart attacks can interrupt the attacks and save lives.
The study, led by William J. Kostis, a fourth-year medical student at the Robert Wood Johnson Medical School in New Brunswick, N.J., who also has a Ph.D. in electrical engineering, is being published today in The New England Journal of Medicine.
Dr. Donald A. Redelmeier, a professor of medicine at the University of Toronto who wrote an accompanying editorial, said the higher death rate on weekends “has everything to do with staffing in hospitals.” It can mean, Dr. Redelmeier said, that not enough expert medical staff members are available on weekends for prompt and aggressive treatment.
“It’s not just that there are fewer people around, but those who are around are often spread thinner,” he added. “And there is a shift in seniority, as well. The most skilled and savvy people don’t work weekends.”
Dr. Kostis said the correlation between more deaths and less angioplasty on weekends was significant.
“One out of every 100 who died,” he said, “died potentially unnecessarily.”
He and others emphasize, however, that people having heart attacks remain much better off going to hospitals on a weekend than waiting until Monday morning.
Although some investigators said the findings gave them pause, not everyone was convinced that there was a cause-and-effect relationship between lower angioplasty rates and higher death rates.
Dr. Eric D. Peterson, a cardiologist at Duke University who led a similar study with a national sample of patients, found that although there was less angioplasty on weekends, there was no difference in mortality rates.
“We couldn’t prove that early catheterization was that key,” Dr. Peterson said, using a term for same-day angioplasty.
He added that the results might reflect findings from New Jersey at a time angioplasty for heart attack patients was being adopted.
Dr. Mark A. Hlatky, a cardiologist and professor of health research and policy at Stanford University, doubted that the sole reason for extra weekend deaths was less aggressive care.
“There is more going on,” Dr. Hlatky said.
The weekend effect shows up in the data as early as 1987 to 1990, when angioplasty was almost never used to save the lives of heart attack patients.
“So this is not as simple as ‘no doctor to do the procedure on weekends,’ ” Dr. Hlatky said, adding that other factors might include staffing in coronary intensive care units.
Dr. Hlatky noted that not just hospitals were different on weekends. Patients are different, too.
Other studies have found that weekend heart attack patients are sicker and waited longer before going to hospitals. The time is limited, a few hours at most, from the beginning of a heart attack to when it is too late for angioplasty to save a life.
The new study did not include data on the severity of the heart attacks, how sick patients were or how long they waited before going to hospitals.
Dr. Hlatky said there were indications that weekend and weekday patients in the study were different.
“More patients per day were admitted on the weekends compared with weekdays,” Dr. Hlatky said. “And they were significantly different in age, sex and rate of complications. There clearly is a difference in the patients admitted to the hospital on the weekend with a heart attack.
“I agree that we need to be ready 24/7 to take care of serious problems like heart attacks. But I don’t think it’s the entire answer, and to say we can fix it with angiography is an oversimplification.”
Dr. Thomas H. Lee, a cardiologist and the network president for Partners Healthcare, a medical care system that includes two Harvard teaching hospitals, said the study indicated that hospitals could do better, making sure that weekend patients received the same level of care as weekday patients.
“We are pretty aggressive in this country,” Dr. Lee said. “Our hospital and other places have worked to make sure these services are available around the clock. But human beings are human beings, and these data really suggest that hospitals may have too high a threshold for calling in their colleagues.”
