Deadly heart attacks more common on Mondays in Ireland, study finds

The research examined data from more than 10,000 patients across the country

Deadly heart attacks more common on Mondays across Ireland, new research has indicated.

Patient data from across Ireland was examined in the study around heart attacks.

The research conducted by doctors at the Belfast Health and Social Care Trust and the Royal College of Surgeons in Ireland is set to be presented on Monday at the British Cardiovascular Society (BCS) conference in Manchester.

They analysed data of 10,528 patients across the island, including 7,112 in the Republic of Ireland, 3,416 in Northern Ireland, who were admitted to hospital between 2013 and 2018 with the most serious type of heart attack.


This is known as an ST-segment elevation myocardial infarction (STEMI) and occurs when a major coronary artery is completely blocked.

They found a spike in rates of STEMI heart attacks at the start of the working week, with rates highest on a Monday.

There were also higher rates of STEMI than expected on a Sunday.

Previous studies suggesting that heart attacks are more likely on a Monday have highlighted an association with circadian rhythm – the body’s sleep or wake cycle.

Hundreds of people are admitted to hospital with a STEMI each year in Northern Ireland.

It requires emergency assessment and treatment to minimise damage to the heart, and this is normally performed with emergency angioplasty – a procedure to reopen the blocked coronary artery.

Cardiologist Dr Jack Laffan, who led the research at the Belfast Health and Social Care Trust, said the cause is likely to be multifactorial.

“We’ve found a strong statistical correlation between the start of the working week and the incidence of STEMI,” he said.

“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.”

Prof Nilesh Samani, medical director at the British Heart Foundation (BHF), described the research as vital.

“Someone is admitted to hospital due to a life-threatening heart attack every 135 minutes in Northern Ireland, so it’s vital that research continues to shed light on how and why heart attacks happen,” he said.

“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.” – PA