Surviving a heart attack may depend on time of day, study warns

TORONTO – Your chances of surviving a heart attack could be a matter of day or night.

Death rates are higher and emergency treatment takes longer for heart attack patients who come to the hospital during the night or on weekends compared to regular hours, a new study based on Canadian, U.S. and European data suggests.

A team of Mayo Clinic researchers say that the heart attacks themselves aren’t necessarily more severe, it’s access to hospital care that could be at play.

“We all know that hospitals have fewer staff and resources at night,” the study’s lead author, Dr. Atsushi Sorita, a senior fellow in preventive medicine at the Mayo Clinic Rochester, told NBC.

“Patients do not get to choose when they have a heart attack. I believe the health system should be designed so that it provides consistent care 24 hours a day, seven days a week,” he said.

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Sorita’s study even points to a five per cent increase in death – both in hospital and 30 days after discharge – in patients who had heart attacks during off-hours compared to their counterparts who had weekday, daytime heart attacks.

Five per cent may not seem like a lot but Sorita is tying it to an extra 6,000 deaths each year in the U.S. alone.

There are an estimated 70,000 heart attacks in Canada each year, according to the Heart and Stroke Foundation. About 16,000 Canadians die each year as a result.

So far, research has suggested that heart attack patients who arrive at hospital during off-hours may have higher death rates, but there has not been a comprehensive review of all the research.

That’s why Sorita and his team scoured through the findings of 48 studies that looked at nearly 1.9 million heart attack patients.

They found that patients diagnosed with a certain heart attack – known as ST elevation myocardial infarction or STEMI – in off-hours even had a delay of 15 minutes in “door to balloon time.” It’s an emergency procedure that inflates the coronary artery.

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This 15-minute delay could increase the chance of death by 10 to 15 per cent, according to the study authors.

The researchers say they can’t rule out other issues, such as underlying health problems or even how long it took for patients to arrive at hospital. But they suggest their findings are linked to “factors that arise after presentation at hospital.”

They’re calling for further studies that would look at how quality of care differs by time of day, staffing and levels of expertise available during each rotation.

Canadian researchers, including doctors from Mount Sinai, penned an accompanying editorial that warned that the disparity between day and night care may be worsening.

Dr. Chaim Bell, an internal medicine doctor at Toronto’s Mount Sinai Hospital, wrote that patients arriving to hospital after hours “experience delays in urgent care and worse outcomes, and the gap seems to be increasing over time.”

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He and his colleagues are calling for health care managers to focus their efforts on improving off-hour care. Ultimately, high quality hospital care should be provided 24 hours a day and seven days a week, they say.

Read the full study here.

And read the full accompanying editorial here.

carmen.chai@globalnews.ca
Follow @Carmen_Chai