Monday seems to be the day of the week when serious heart attacks are most likely to occur.
According to the study, Mondays had a 13% higher than predicted chance of having a heart attack.
Data from 10,528 individuals were analysed by doctors at the Belfast Health and Social Care Trust and the Royal College of Surgeons in Ireland, including 7,112 patients in the Republic and 3,416 in Northern Ireland.
Between 2013 and 2018, they had undergone hospitalisation for the most severe form of heart attack, an ST-segment elevation myocardial infarction (STEMI), which happens when a major coronary artery is totally blocked.
The researchers discovered a rise in STEMI heart attacks at the beginning of the workweek, with rates on Monday being the greatest.
The research was revealed at the British Cardiovascular Society (BCS) meeting in Manchester. There were also higher than anticipated rates on Sundays.
Scientists have been unable to fully explain this “Blue Monday” phenomenon.
Cardiologist Dr Jack Laffan, who led the research at the Belfast Health and Social Care Trust, said: “We’ve found a strong statistical correlation between the start of the working week and the incidence of STEMI.
“This has been described before but remains a curiosity. The cause is likely multifactorial, however, based on what we know from previous studies, it is reasonable to presume a circadian element.”
Previous studies suggesting heart attacks are more likely on a Monday highlighted an association with circadian rhythm – the body’s sleep or wake cycle.
Over 30,000 hospital admissions in the UK are attributed to STEMI each year, according to the British Heart Foundation (BHF).
Emergency angioplasty, a technique to unblock the blocked coronary artery, is typically performed during the attack in order to assess the situation quickly and treat the patient to reduce cardiac damage.
Professor Sir Nilesh Samani, medical director at the BHF, said: “Someone is admitted to hospital due to a life-threatening heart attack every five minutes in the UK, so it’s vital that research continues to shed light on how and why heart attacks happen.
“This study adds to evidence around the timing of particularly serious heart attacks, but we now need to unpick what it is about certain days of the week that makes them more likely.
“Doing so could help doctors better understand this deadly condition so we can save more lives in future.”