Study finds no benefit of heart CT scan in patients with acute chest pain

Coronary CT angiography (CTCA) scans do not reduce the risk of heart attacks or cardiac death at three years in patients with acute chest pain who have had a heart attack excluded, according to the results of a trial funded by us and presented at the European Society of Cardiology Congress in Munich.

The Troponin in Acute Chest Pain to Risk Stratify and Guide EffecTive Use of Computed Tomography Coronary Angiography (TARGET-CTCA) trial involved 3,170 people with acute chest pain who had a heart attack ruled out in the Emergency Department.

After three years, 7.1 per cent of patients who had a CTCA scan had a heart attack or died due to a heart attack, heart failure or sudden cardiac death, compared to 7.3 per cent in the group who received standard care.

Reduce burden and healthcare costs

With at least 1.5 million people attending emergency departments in the UK each year with chest pain, the researchers say that putting their findings into practice would help to lessen the burden on overstretched radiology and cardiology departments and reduce healthcare costs. The study is published in the New England Journal of Medicine.

Professor Nick Mills, British Heart Foundation Professor of Cardiology at the University of Edinburgh and lead investigator of TARGET-CTCA, said: "Patients with chest pain account for between five and 10 per cent of all emergency department attendances in the UK. Previous research from our group suggests that most patients can be safely discharged once a heart attack is excluded, but it has been unclear whether further cardiac testing after discharge is helpful.

"Our findings provide strong evidence that patients who have had a heart attack excluded do not benefit from early outpatient CTCA scans. Once we are confident that they haven't had a heart attack, we can reassure these patients that their future risk is low and send them home."

Little evidence

When people go to an emergency department with chest pain, doctors use troponin tests – which look for telltale markers of a heart damage in the blood – to rapidly determine if they have had a heart attack. In patients who have a heart attack ruled out, troponin levels are also used to classify their future risk and to decide on the appropriate follow-up tests and treatment.

Patients with a high-sensitivity troponin level over 5 ng/L are deemed to be at 'intermediate' risk, as these levels are associated with an increased risk of further heart problems. European Society of Cardiology guidelines recommend that doctors consider CTCA scans or other non-invasive stress tests in this group to look for blockages in their coronary arteries.

However, the TARGET-CTCA researchers say that there is little evidence to show that this approach reduces subsequent cardiac events and improves outcomes for patients.

Three-year follow up

The trial involved 3,170 people who attended one of 14 UK emergency departments with suspected acute coronary syndrome – unstable angina or a heart attack – over almost four years. The average age of those in the trial was 61 and 30 per cent were women.

Everyone in the study had a heart attack ruled out but had a cardiac troponin level of more than 5 ng/L. Half (1,587) were randomly assigned to have a CTCA scan plus standard care, with the other 1,583 receiving standard care alone, where their GP decided on further treatment based on current guidelines. All study volunteers were followed up for an average of three years.

Among those who underwent a CTCA scan, nearly a third (32 per cent) had normal coronary arteries. Non-obstructive coronary artery disease, and obstructive coronary artery disease were identified in 42 per cent and 23 per cent of the group, respectively.

During follow up, 112 people experienced a heart attack or cardiac death in the CTCA group, compared to 116 in the standard care group. This was despite a higher proportion of people in the CTCA group taking preventative medication.

The findings were consistent in people with no prior diagnosis of heart disease who researchers say may have had more to gain from testing.

Answering important questions

The study suggests that once a heart attack has been ruled out, routine heart scans may not be required. Implementing the findings in practice could reduce costs and simplify care without compromising outcomes for patients.

Dr Sonya Babu-Narayan, our clinical director and consultant cardiologist, said: “These findings demonstrate why high-quality clinical trials are required to answer important questions about patient care. Robust and representative evidence ensures that the right people receive the right tests at the right time, supporting the best possible outcomes for heart patients while making effective use of healthcare resources.

“The results suggest that, for people attending the emergency department with acute chest pain who are not diagnosed with a heart attack, CT coronary angiography (CTCA) scans are not routinely needed.

“Nevertheless, the message for the public remains unchanged. Chest pain is a medical emergency, and you should call for an ambulance if you experience chest pain or discomfort that comes on suddenly and doesn’t go away. Doctors want to see you in the emergency department to ensure you are not having a heart attack and get you on the right path to receive the tests, treatment and follow-up care you need.”