CT Scans of Heart Arteries After Emergency Chest Pain: What the TARGET-CTCA Trial Found

Table of Contents

• Key Points
• Why This Research Matters
• How the Trial Was Designed
• Who Took Part in the Trial
• What the CT Scans Found
• Key Findings: Heart Attacks and Cardiac Deaths
• Treatment Changes: Medications and Procedures
• What These Results Mean for Patients
• Study Limitations
• Recommendations for Patients
• Source Information
• Frequently Asked Questions

Key Points

• In the TARGET-CTCA trial of 3,170 patients with suspected acute coronary syndrome and a ruled-out heart attack, CT coronary angiography-guided care did not reduce heart attacks or cardiac deaths compared with standard care.
• Over a median follow-up of 3 years, the primary outcome occurred in 7.1% of the CT group and 7.3% of the standard-care group, a difference that was not statistically significant.
• CT-guided care led to more preventive medications, more cardiology visits, and more procedures, but these did not translate into fewer heart attacks or cardiac deaths.
• Among 1,462 patients who had CT coronary angiography, 22.6% had obstructive disease and 10.7% had clinically significant noncardiac findings that might otherwise have gone unnoticed.
• The trial enrolled adults with intermediate-risk troponin levels after a ruled-out heart attack; results do not apply to confirmed heart attacks, very low troponin levels, or high-risk features needing immediate intervention.

Why This Research Matters

Chest pain is one of the most common reasons people visit an emergency department. In fact, patients with acute chest pain account for 5 to 10% of all emergency department visits.

Assessing these patients puts a heavy burden on hospitals and healthcare resources. In recent years, accelerated diagnostic pathways using high-sensitivity cardiac troponin testing — a blood test that measures a protein released into the bloodstream when heart muscle is injured or stressed — have helped doctors safely rule out myocardial infarction (heart attack) at the time of presentation. This has allowed many patients to be discharged from the emergency department rather than admitted to the hospital.

However, being told you have not had a heart attack is not the end of the story. For patients in whom a heart attack has been ruled out, the troponin level still provides important information. It can identify people who remain at risk for future problems and might benefit from further testing, preventive therapies, or coronary revascularization (procedures that restore blood flow to the heart).

Patients with very low troponin concentrations have a low risk of myocardial infarction or death from a cardiac cause for up to 5 years. But patients at intermediate risk are twice as likely to have coronary artery disease visible on CT coronary angiography compared with those who have very low troponin levels. They are also 10 times as likely to have a subsequent heart attack or die from a cardiac cause within 1 year.

Clinical practice guidelines suggest considering CT coronary angiography or noninvasive stress imaging in patients with suspected acute coronary syndrome (a condition that includes heart attack and unstable angina) who are at intermediate risk. Yet there has been no clear evidence that performing additional investigation actually changes long-term outcomes. The TARGET-CTCA trial was designed to answer this question directly.

How the Trial Was Designed

The full name of the study was the Troponin in Acute Chest Pain to Risk Stratify and Guide Effective Use of Computed Tomography Coronary Angiography trial. It was a multicenter, open-label, event-driven, randomized, controlled trial. "Open-label" means that both patients and their doctors knew which group each patient was assigned to.

The trial had blinded end-point assessment. That means the doctors who reviewed and classified the outcomes did not know which treatment group each patient was in. This design helps make sure the results are judged fairly and without bias.

A total of 14 hospitals across the United Kingdom took part. Enrollment ran from September 18, 2019, to May 11, 2023. Participants were randomly assigned in a 1:1 ratio to one of two groups:

1. CT coronary angiography-guided care plus standard care (the CT group), or
2. Standard care alone (the standard-care group).

Randomization was performed with a web-based computer-generated system to ensure the group assignment was properly concealed. The assignment was stratified (balanced) according to the hospital site, age (under 70 or 70 and older), sex, and whether the patient had known coronary artery disease.

The trial was originally designed to include 2,270 participants. This would have given the study 90% power to detect a 40% difference in events between groups. At least 97 primary-outcome events in the standard-care group were required for the trial to be conclusive.

Because of interruptions in recruitment caused by the COVID-19 pandemic, a blinded review of the first 1,925 participants on April 25, 2022, showed that the trial would not reach this number of events by the planned date. The data monitoring committee therefore recommended continuing recruitment until 3,170 participants were enrolled. Patients were followed until at least 97 primary-outcome events had accumulated in the standard-care group. That milestone was reached on December 4, 2025, and the trial concluded on May 25, 2026.

Who Took Part in the Trial

The trial enrolled adult patients aged 18 years or older who came to an emergency department or acute medical assessment center with suspected acute coronary syndrome. Patients were eligible if a heart attack had been ruled out, but they were judged to be at intermediate risk. Intermediate risk was defined as a maximum high-sensitivity cardiac troponin I or T concentration between the low-risk threshold of 5 ng per liter and the sex-specific 99th percentile of the upper reference limit.

To make the study inclusive, researchers also used electronic medical records to identify patients who had not been approached while in the hospital and contacted them by telephone. In total, 3,170 participants were enrolled:

• 1,587 patients were assigned to the CT coronary angiography group.
• 1,583 patients were assigned to the standard-care group.

The median age was 61 years (interquartile range, 53 to 70). About 30.2% of participants were women. The characteristics of the two groups were well balanced and representative of patients seen in the UK with suspected acute coronary syndrome.

At presentation, notable features among the patients were:

• 88.7% (2,809 of 3,166) had chest discomfort.
• 17.5% (553 patients) had a previous diagnosis of myocardial infarction.
• 15.1% (478 patients) had a previous diagnosis of angina.
• The average HEART score (a risk scoring tool that stands for History, Electrocardiogram, Age, Risk Factors, and Troponin) was 3.5 ± 1.4.
• Almost half — 49.7% (1,566 of 3,152) — were classified as intermediate or high risk based on a HEART score above 3.

The HEART score ranges from 0 to 10. Scores of 0 to 3 indicate low risk, 4 to 6 intermediate risk, and 7 to 10 high risk. Another tool, the GRACE score, ranges from 0 to 383, with higher scores meaning higher risk.

At the time of randomization, 29.1% of patients (921 of 3,164) were already taking an antiplatelet agent — a medicine such as aspirin or a P2Y12 antagonist that prevents blood clots. And 43.4% (1,373 of 3,165) were already taking a statin, a cholesterol-lowering medication.

How the CT Intervention Worked

Patients assigned to the CT group were invited to undergo outpatient CT coronary angiography. The scan was performed using a 64-slice or higher multidetector scanner, ideally within 4 weeks after randomization. The actual median time from randomization to the scan was 22 days (interquartile range, 13 to 36 days).

Imaging results were reported according to the guidelines of the Society of Cardiovascular Computed Tomography. The coronary arteries were classified as:

• Normal: diameter narrowing (stenosis) of less than 10%
• Mild coronary artery disease: narrowing of 10 to 49%
• Moderate coronary artery disease: narrowing of 50 to 70%
• Obstructive coronary artery disease: narrowing greater than 70%, or greater than 50% in the left main stem

Results were shared with the participant, their primary care doctor, and other clinicians involved in their care. Any clinically significant noncardiac findings outside the heart were also reported. The report included a recommendation to begin secondary preventive therapy. Patients with mild coronary artery disease were advised to start a statin alone. Those with moderate nonobstructive or obstructive disease were advised to start both an antiplatelet agent and a statin. Patients with obstructive disease or important noncardiac findings were offered an outpatient consultation, ideally within 2 weeks of the scan result.

What the CT Scans Found

Among the 1,587 patients assigned to the CT group, 92.1% (1,462 participants) actually underwent CT coronary angiography. By contrast, only 2.2% (35 patients) in the standard-care group received a CT scan within 90 days, and 6.5% (103 patients) received one by the end of the trial. This shows that the two groups were treated quite differently, providing a fair test of the two strategies.

There were 7 participants (0.4%) who had a CT coronary angiography-related adverse event. The results of the scans in the CT group were as follows:

• Normal coronary arteries: 465 patients (31.8%)
• Nonobstructive coronary artery disease: 622 patients (42.5%)
• Obstructive coronary artery disease: 331 patients (22.6%)

Among those with obstructive disease, the location and extent varied. Obstructive plaque was found in the proximal left anterior descending artery in 132 patients (9.0%). It was found in the left main stem in only 11 patients (0.8%). Disease involved one vessel in 201 patients (13.7%), two vessels in 87 (6.0%), and three vessels in 43 (2.9%).

The median CAD-RADS score (a grading system for coronary artery disease on a scale of 0 to 5) was 2.0 (interquartile range, 0.0 to 3.0). The scan was nondiagnostic or data were missing in 44 patients (3.0%).

The CT scan also looked beyond the heart. Noncardiac findings were seen in 617 of 1,462 patients (42.2%). Of these, 157 patients (10.7%) had findings that the investigators considered clinically significant. This means the scans sometimes identified unsuspected health problems in the lungs, chest, or surrounding structures, which is a potential benefit of the test.

Key Findings: Heart Attacks and Cardiac Deaths

The primary outcome of the trial was a composite of myocardial infarction or death from a cardiac cause. A composite outcome combines several meaningful events into a single measure.

After a median follow-up of 3.0 years (interquartile range, 3.0 to 4.0), the results were clear:

• In the CT coronary angiography group, a primary-outcome event occurred in 112 patients (7.1%).
• In the standard-care group, a primary-outcome event occurred in 116 patients (7.3%).

The adjusted hazard ratio was 0.95, with a 95% confidence interval of 0.73 to 1.23 and a P value of 0.71. In plain terms, a hazard ratio below 1 suggests a lower risk, and a ratio above 1 suggests a higher risk. The confidence interval here crosses 1. The P value of 0.71 is far above the standard cutoff of 0.05 for statistical significance. The result means there is no meaningful difference between the two treatment approaches.

The researchers checked this finding in several additional ways. They saw no meaningful difference when assessing results with adjustment for competing risks, when looking at events occurring within 2 years, or in landmark, per-protocol, or post hoc sensitivity analyses. In every analysis, the conclusion was consistent.

Looking at the components of the primary outcome separately, myocardial infarction occurred in 93 patients (5.9%) in the CT group and 100 patients (6.3%) in the standard-care group. The adjusted hazard ratio was 0.92, with a 95% confidence interval of 0.69 to 1.22. Again, this difference was not statistically significant.

Treatment Changes: Medications and Procedures

Although the CT-guided approach did not reduce heart attacks, it did change what happened afterward in the clinic. Doctors who saw the CT results more often prescribed preventive medications.

At 90 days after randomization, medication use in the two groups was as follows:

• Antiplatelet agents: 665 patients (42.4%) in the CT group versus 515 patients (32.8%) in the standard-care group
• Statins: 994 patients (63.4%) in the CT group versus 760 patients (48.5%) in the standard-care group
• Preventive medication (an antiplatelet agent or a statin): 1,046 patients (66.7%) versus 820 patients (52.3%)

By the end of the trial, the gap had widened even further:

• Antiplatelet agents: 619 patients (41.5%) in the CT group versus 462 (31.6%) in the standard-care group
• Statins: 1,024 patients (68.6%) versus 813 (55.6%)
• Preventive medication: 1,070 patients (71.7%) versus 854 (58.4%)

Procedures to restore blood flow in the heart were also more common in the CT group. Percutaneous coronary intervention (PCI, commonly called angioplasty with stenting) or coronary-artery bypass grafting (CABG, open-heart surgery to bypass blockages) were performed at 90 days in 26 patients (1.6%) in the CT group versus 15 patients (0.9%) in the standard-care group. By the end of the trial, these numbers were 98 patients (6.2%) versus 77 patients (4.9%).

More patients in the CT group also underwent invasive coronary angiography, the traditional catheter-based test for blockages. That procedure was performed in 177 patients (11.2%) in the CT group versus 137 patients (8.7%) in the standard-care group. Noninvasive stress testing was slightly more common in the standard-care group: 153 patients (9.7%) versus 133 patients (8.4%).

Cardiology outpatient follow-up was also much more frequent in the CT group. At 90 days, 424 patients (26.7%) in the CT group had a cardiology visit versus 264 patients (16.7%) in the standard-care group. By the end of the trial, those totals had risen to 799 (50.3%) versus 598 (37.8%).

Yet none of these additional visits, medications, or procedures translated into fewer heart attacks or cardiac deaths. This is the central and somewhat surprising message of the trial.

What These Results Mean for Patients

The main conclusion of the study is straightforward. In patients with suspected acute coronary syndrome in whom a heart attack had been ruled out, routine CT coronary angiography-guided management did not result in a lower incidence of subsequent myocardial infarction or death from a cardiac cause compared with standard care.

This finding matters for several reasons. First, it challenges the assumption that more testing automatically means better outcomes. In this trial, more than twice as many patients in the CT group were started on antiplatelet therapy and statins. They also had more revascularization procedures. Still, their cardiac event rate was essentially identical to patients who received standard care.

Second, the results highlight a well-known gap in preventive cardiology. Starting a statin or antiplatelet agent does not instantly erase risk. Preventing future heart attacks depends on long-term adherence, blood pressure control, cholesterol lowering, smoking cessation, and other lifestyle measures. A single diagnostic test, by itself, may simply come too late or be insufficient to change the course of disease that has already developed.

Third, the trial does not suggest that CT scans are useless. More than 22% of patients were found to have obstructive disease that doctors did not know about. Another 10.7% had clinically significant noncardiac findings that otherwise might have gone unnoticed. For individual patients, that information could still be valuable. The finding here is about whether a routine, targeted policy of scanning everyone at intermediate risk improves hard outcomes. It does not.

Study Limitations

Every clinical trial has limits, and this one is no exception. Understanding these caveats helps patients and doctors interpret the results correctly.

The trial was open-label. Both patients and clinicians knew which group they were in. This can influence decisions about other tests and treatments. The researchers protected against bias in the outcome assessment by having two independent clinicians, unaware of treatment assignment, adjudicate all deaths and hospital admissions. Disagreements were resolved by a third clinician.

Not everyone followed their assigned plan. About 7.9% of patients in the CT group did not undergo CT coronary angiography. In addition, 2.2% of the standard-care group had a CT scan within 90 days anyway. If anything, this crossover would tend to dilute any real difference between the groups, but it also reflects the real-world challenge of running such a trial.

The timing of the scan varied. The median time from randomization to the CT scan was 22 days. It is possible that an earlier scan might have led to different results, although the trial design was intended to reflect practical outpatient care.

The study was event-driven. Because of COVID-19 interruptions, the trial needed more participants and a longer follow-up than originally planned. The total number of outcome events was modest, which limits the statistical precision of the estimates.

The study population was specific. Results apply to patients presenting to emergency departments with suspected acute coronary syndrome in whom a heart attack had already been ruled out by troponin testing. The findings do not apply to patients with confirmed heart attacks, very low troponin levels, or those with clear high-risk features such as ongoing chest pain or ECG changes requiring immediate intervention.

The secondary outcomes were exploratory. The researchers did not adjust for multiple testing when analyzing secondary outcomes. Therefore, their confidence intervals should not be used as proof of a treatment effect, and those findings should be considered hypothesis-generating only.

Recommendations for Patients

If you have been to an emergency department with chest pain and a heart attack was ruled out, what should you take away from this study?

1. Understand your risk category. Ask your doctor what your troponin level means and whether you are in a low, intermediate, or high risk group. Your risk category should guide the intensity of follow-up.
2. Do not expect a single test to solve everything. This trial shows that a CT scan, while useful for diagnosis, does not by itself reduce the chance of a future heart attack or cardiac death.
3. Take preventive medications seriously. Statins and antiplatelet agents substantially reduce cardiac risk when taken consistently over time. If your doctor prescribes them, the benefit accumulates over years, not days or weeks.
4. Focus on lifestyle. Stopping smoking, keeping blood pressure under control, eating a heart-healthy diet, and staying physically active remain the foundations of cardiovascular prevention.
5. Ask about the right test for you. If you have persistent symptoms or concerning risk factors, a CT scan, stress test, or invasive angiogram may still be appropriate. The decision should be individualized, not routine.
6. Attend follow-up visits. Patients in the CT group had many more cardiology visits, and yet their outcomes were the same. That does not mean follow-up is useless — it means that what happens during those visits, such as starting and staying on medication, matters more than the visit itself.

The bottom line is hopeful. Overall event rates in this trial were low. About 93 out of every 100 patients in both groups did not have a heart attack or die from a cardiac cause during a median follow-up of 3 years. Modern emergency care and preventive treatment are working. The question going forward is how to deliver the right care to the right patients without unnecessary testing, and how to help patients stay on effective long-term treatment.

Frequently Asked Questions

I went to the emergency department with chest pain and my heart attack test was negative. What does that mean for my risk?

In the TARGET-CTCA trial of 3,170 patients, a negative heart attack result did not mean zero risk. People with intermediate troponin levels were twice as likely to have coronary artery disease visible on a CT scan, and 10 times as likely to have a heart attack or die from a cardiac cause within one year, compared with those with very low troponin levels.

What is intermediate risk after chest pain, and how is it defined?

In the TARGET-CTCA trial, intermediate risk meant a maximum high-sensitivity cardiac troponin I or T level between the low-risk threshold of 5 ng per liter and the sex-specific 99th percentile of the upper reference limit. Patients in this group had a heart attack ruled out but remained at higher risk, so guidelines suggest considering further testing such as CT coronary angiography.

Did having a CT scan of my heart arteries after chest pain reduce my chance of a future heart attack?

In the TARGET-CTCA trial of 3,170 patients followed for about 3 years, CT-guided care did not reduce heart attacks or cardiac deaths. Events occurred in 7.1% of the CT group versus 7.3% of the standard-care group, a difference that was not statistically significant. The scan changed treatment but not the ultimate risk of major cardiac events.

What did the CT scan find in patients who had it?

Among 1,462 patients in the TARGET-CTCA trial who had CT coronary angiography, 31.8% had normal arteries, 42.5% had nonobstructive disease, and 22.6% had obstructive disease. Noncardiac findings were seen in 42.2%, and 10.7% had findings considered clinically significant. The scan sometimes identified unsuspected problems in the lungs, chest, or surrounding structures.

Did the CT scan lead to more medications or procedures?

Yes. In the TARGET-CTCA trial, CT-guided care led to more preventive medications, more cardiology visits, and more procedures. By the end of the trial, 71.7% of the CT group received an antiplatelet agent or statin versus 58.4% of the standard-care group. Revascularization procedures were also more common, yet heart attacks and cardiac deaths were not reduced.

What are the risks or downsides of having a CT coronary angiogram?

In the TARGET-CTCA trial, 7 of 1,462 patients (0.4%) who had CT coronary angiography experienced a scan-related adverse event. The trial also noted that the scan can reveal noncardiac findings, which may be helpful but can lead to further tests. The main finding was that routine scanning did not improve hard outcomes such as heart attack or cardiac death.

What should I do after being sent home from the emergency department with chest pain?

In the TARGET-CTCA trial, overall event rates were low: about 93 of every 100 patients in both groups did not have a heart attack or die from a cardiac cause over a median of 3 years. Ask your doctor about your troponin level and risk category, take prescribed statins and antiplatelet agents consistently, focus on lifestyle, and attend follow-up visits.

If a heart attack was ruled out in the emergency department but I'm at intermediate risk, when should I get a second opinion about whether I need a CT scan of my heart arteries?

A second opinion can help when you are told you are at intermediate risk after a heart attack has been ruled out, since guidelines suggest considering CT coronary angiography or stress imaging for these patients. In a trial of 3,170 patients, CT-guided care led to more statins, antiplatelet agents, cardiology visits, and procedures, yet heart attack or cardiac death rates were similar: 7.1% versus 7.3%. A second opinion can clarify whether testing is individualized for your symptoms and risk factors rather than routine. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

This patient-friendly article is based on peer-reviewed research originally published in the New England Journal of Medicine.

Original article title: Targeted Use of Computed Tomographic Coronary Angiography in Acute Chest Pain

Authors: Kuan Ken Lee, M.D., Ph.D.; Ryan Wereski, M.D.; David Lowe, M.D.; Rachel O'Brien, B.N.; Amy V. Ferry, Ph.D.; Anda Bularga, M.D.; Matthew T.H. Lowry, M.D., Ph.D.; Caelan Taggart, M.D., Ph.D.; Giles Roditi, M.D.; Nick Curzen, Ph.D.; Sarojini David, M.D.; Dirk Felmeden, M.D.; Randeep Hunjan, M.D.; Attila Kardos, M.D.; Liza Keating, M.D.; Dennis Sandeman, B.N.; Jason E. Smith, M.D.; Carl Roobottom, M.D.; Chris Tuck, B.Sc.; Denise Cranley, M.Sc.; Praveen Thokala, Ph.D.; Steve Goodacre, Ph.D.; Titouan Kennel, M.Sc.; Catriona Keerie, M.Sc.; John Norrie, M.Sc.; Michelle C. Williams, M.D., Ph.D.; David E. Newby, M.D.; Alasdair J. Gray, M.D.; and Nicholas L. Mills, M.D., Ph.D., for the TARGET-CTCA Investigators

Publication details: Published August 29, 2026, at NEJM.org. DOI: 10.1056/NEJMoa2608903. © 2026 Massachusetts Medical Society.

Trial registration: ClinicalTrials.gov number NCT03952351.

Funding: British Heart Foundation.