A person is more likely to die of a heart attack if they arrive at hospital during the night or at the weekend, a new study has found.

According to US researchers, heart attacks remain one of the leading causes of death worldwide. While previous studies have suggested that people who are treated outside of regular hours may have a higher mortality rate, until now, there have been no reviews of the evidence.

They decided to look into this further. They analysed the results of almost 50 studies involving over 1.8 million people living in the US, Canada and Europe.

The study found that patients who presented to hospital outside of regular hours had a 5% increased risk of dying - both while they were in hospital and 30 days after being discharged - compared to people who attended during regular hours.

In the US alone, this resulted in an extra 6,000 deaths per year.

The study also found that patients diagnosed with a certain type of heart attack (ST elevation myocardial infarction or STEMI) were more likely to experience a delay in a specific procedure they needed if they attended hospital outside of regular hours.

The emergency procedure is known as ‘door to balloon time' and refers to the coronary artery being inflated. Patients with STEMI who required this were left waiting almost 15 minutes longer if they attended hospital outside of regular hours, compared to those who attended during regular hours.

According to the researchers, this ‘could increase mortality by as much as 10-15%'.

They acknowledged that patient characteristics may play a role in mortality figures, however they believe that the findings indicate that ‘increased mortality during off-hours is associated with factors that arise after presentation at hospital'.

They called for more studies into the quality of care available to heart attack patients in hospitals depending on the time of day.

Details of these findings are published in the British Medical Journal.

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