Updated

People who arrive at the hospital with a heart attack during business hours are more likely to survive than those who show up on weeknights, weekends or holidays, according to a new study.

Rates of death in the hospital are very low overall, at just over 4 percent, the researchers found. But some life-saving treatments can take longer to get to patients during off hours, which makes care less than optimal, they write.

It was actually surprising how similar quality of care seemed to be for working hours and after hours in the hospital, and even for balloon angioplasty, there was only a difference of 16 minutes, said study author Dr. Jorge F. Saucedo of the NorthShore University Health System in Evanston, Illinois.

In the most severe heart attacks, a blood vessel in the heart is completely blocked. Using a catheter to thread a balloon into the blocked artery can immediately restore blood flow.

In the new study, which included more than 50,000 severe heart attacks between 2007 and 2010 in the U.S., patients who arrived at the hospital during work hours took an average of 56 minutes to have angioplasty, the balloon procedure. For those who arrived on nights or weekends, the average wait time was 72 minutes.

Both times fall within the American Heart Association’s recommendation of no more than 90 minutes wait for angioplasty. The time to patients getting imaging or medication was the same for both groups, according to the results in Circulation: Cardiovascular Quality and Outcomes.

When the researchers adjusted for a variety of patient characteristics, they found those who arrived at the hospital during off hours were about 13 percent more likely to die from any cause.

The proportion of patients who had angioplasty within the recommended 90 minutes was 89 percent during the weekdays and 79 percent during off hours.

All in all, the numbers are better than in past studies, the authors note in their report, and in most categories there were no differences in treatment based on when patients arrived at the hospital.

Management of these severe heart attacks seems to have improved greatly over the past several years, said Dr. Rodrigo Estévez-Loureiro of the interventional cardiology unit at Complejo Asistencial Universitario de León in Spain.

“Differences observed in (door to balloon) times, although statistically significant, are not clinically relevant between off and on-hours,” Estévez-Loureiro, who was not involved in the new study, told Reuters Health by email.

A 16-minute delay likely will not influence overall mortality from the heart attacks he said.

“Also surprising was the very low in- hospital mortality for both groups,” Saucedo told Reuters Health.

The hospital catheterization laboratory, where angioplasties are performed, is fully staffed during the day but most hospitals in the U.S. do not staff the lab after hours, he said. When a heart attack patient arrives on a night or weekend, staff members are paged and have to drive to the hospital from their homes.

To make angioplasty wait times equal day and night, catheterization labs would have to be fully staffed 24-hours per day, but currently the financial and logistical costs would be too high to recommend that, Saucedo said by email.

Patients may have waited longer to come to the hospital with heart attack symptoms in the middle of the night, which might have contributed to the increased risk of death, he noted. All things considered, the management and outcomes for people with severe heart attacks after hours was very good.

One takeaway message for patients, he said, is to come to the hospital as soon as you have symptoms of a heart attack, including tightness of the chest, excess sweating, weakness and light-headedness.

Estévez-Loureiro recommended calling an ambulance to get to the hospital, since medical personnel may be able to verify if you are having a heart attack on the way and start administering treatment and call the catheterization lab en route.