Data were analyzed from 10,528 patients across Ireland who had been admitted to hospitals between 2013- 2018 with St-segment elevation myocardial infarctions (STEMI), which is the most serious type of heart attack that occurs when a major coronary artery is completely blocked. Working in collaboration with doctors from the Belfast Health and Social Care Trust and the Royal College of Surgeons the team found a spike in the rates of STEMI heart attacks at the beginning of the working week, with the highest rates being observed on Mondays and higher rates than expected on Sundays.
While thus far the team is not able to fully explain why the “Blue Monday” phenomenon is occurring, previous research suggests that the increased rate is more likely to be observed on Mondays because of an association with the body’s sleep/wake cycle (circadian rhythm).
In the UK alone there are over an estimated 30,000 hospital admissions due to STEMI heart attacks annually, which require emergency assessment and treatment to minimize damage to the heart that is normally performed with emergency angioplasty to re-open the blocked coronary artery. In America, an estimated 750,000 people experience STEMI, according to a study published in the AHA’s Journal of the American Heart Association.
“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,” said Cardiologist Dr. Jack Laffan, who led the research at the Belfast Health and Social Care Trust. “The cause is likely multifactorial, however, based on what we know from previous studies, it is reasonable to presume a circadian element.”
Professor Sir Nilesh Samani, the British Heart Foundation (BHF) Medical Director, 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.”