Deaths from the most common type of heart attack rose by nearly 40 per cent during lockdown, a major study has shown.
The research prompted warnings that the Government's "Stay Home" message may have had a "devastating" impact by deterring thousands of patients in medical crisis from seeking help.
The study, led by the University of Leeds, tracked more than 50,000 patients who had a heart attack and were treated at 99 major hospitals in England before or during lockdown.
It found that, overall, the number being treated for the most common type of heart attack – NSTEMI (Non ST Segment Elevation (NSTEMI) Myocardial Infarction), which is caused by a partial blockage – fell by 49 per cent in the two months from March 23.
Deaths from such attacks rose by 39 per cent in the month after lockdown, with 30-day mortality rates rising from 5.4 per cent to 7.5 per cent. The number of people being seen for the most major type of heart attack fell by 29 per cent, the study found.
Overall, the study suggests that around 2,000 fewer patients received treatment for heart attacks during eight weeks of lockdown. Even by the end of the period studied, the numbers seeking help were far below normal levels, the research found.
Dr Jianhua Wu, associate professor in biostatistics at the University of Leeds and lead author of the study, said: "The study suggests a lot of very ill people were not seeking emergency treatment, and that may have been an unintended consequence of the 'stay at home' messaging."
Chris Gale, professor of cardiovascular medicine at the University of Leeds and senior author of the study, added: "This national picture provides evidence for the devastating impact that the Covid-19 pandemic has had on people's lives.
"Notably, we have not seen a return to the normal rates of admissions with heart attack. This means that people may still be delaying seeking help. The fact that the public delayed seeking help for heart attacks will no doubt be seen in high excess deaths and new diagnoses of heart failure in subsequent weeks and months.
"It was not the case that people were not having heart attacks – they were just deciding not to go to hospital. Some were undoubtedly heeding the message to stay at home, others might have been afraid of picking up the virus in hospital or were trying to shield because they had other conditions.
"A heart attack is a medical emergency and, if people do not seek help, they die or go on to develop heart failure."
The heightened death rate for those with the most common type of heart attack may also have been fuelled by the fact some patients had coronavirus, researchers said.
The study showed that during the crisis, the vast majority of patients attending hospital because of a heart attack received the treatment which they would normally have received. However, around three per cent of those having an NSTEMI heart attack did not have coronary angiography, the normal technique used to pinpoint where blood vessels are obstructed.
The study was published in the European Heart Journal – Quality of Care and Clinical Outcomes.
Dr Sonya Babu-Narayan, associate medical director at the British Heart Foundation, said: "We know that, throughout lockdown, fewer people were treated for a heart attack, risking death or long-term heart damage.
"If you experience chest pain or discomfort, which may feel like squeezing or heaviness or tightness, not necessarily the chest-clutching agony that we see on TV, and which may radiate to your jaw, arm, back or stomach, it's important to understand you could be having a heart attack.
"Prompt treatment for your heart attack could save your life so, if you think you are experiencing symptoms, call 999 immediately."
A Government spokesperson said: "By staying at home and controlling the virus we took the unprecedented yet necessary action to protect the public and ensure that the NHS was not overwhelmed, even at the virus’s peak, ensuring that everyone was always able to get the best possible care.
“Throughout the pandemic the NHS has remained open for urgent care and the clear message has been in a medical emergency, such as those experiencing symptoms of a heart attack, people should call 999 right away.”