This study aims to investigate the guiding value of coronary CTA combined with CT-FFR in diagnostic and treatment decision-making for emergency chest pain patients at moderate risk, as well as its impact on clinical outcomes. Through a prospective multicenter randomized controlled trial, this research compares the preventive effects of early application of this technology versus standard care on major adverse cardiovascular and cerebrovascular events (MACCE), with the goal of optimizing the diagnostic and treatment processes for emergency chest pain patients.

This study involves intermediate-risk emergency department patients presenting with chest pain or symptoms suggestive of acute coronary syndrome (ACS) but without acute myocardial infarction (AMI), defined by a HEART score greater than 3. After providing written informed consent, these patients are randomized to one of two strategies: an initial approach incorporating early coronary computed tomographic angiography (CCTA) or a standard care pathway without early CCTA. Patients in the CCTA group receive standard care as determined by their treating physician and undergo CCTA as soon as possible, typically within 24 hours and at most within 21 days. The results of the CCTA, including coronary artery stenosis severity and CT-derived fractional flow reserve (CT-FFR) values, are provided to the physician to inform further management, which may include invasive coronary angiography, medical therapy, or lifestyle interventions.

In contrast, patients randomized to the standard care group without early CCTA proceed with physician-directed evaluations that may include non-invasive functional tests such as exercise electrocardiography, stress echocardiography, or nuclear imaging according to local clinical practices, though CCTA is not part of their initial workup. Both groups receive optimal preventive care in line with current guidelines, and treating physicians are encouraged to initiate secondary prevention measures like antiplatelet therapy or statin use if any diagnostic tests reveal signs of coronary artery disease (CAD).

The primary endpoint of the study is a composite of death, readmission due to myocardial infarction, or hospitalization for unstable angina requiring revascularization. The trial aims to determine whether an early CCTA strategy improves diagnostic and treatment decision-making for intermediate-risk chest pain patients, ultimately influencing clinical outcomes compared to standard care. The study incorporates a prospective, multicenter design to ensure broad applicability and rigor, with careful attention to patient safety and adherence to ethical standards throughout the enrollment and follow-up processes.

Inclusion Criteria:

1. Age≥18 years；
2. Within 24 hours of presenting to the emergency department (ED) with chest pain or other symptoms suggestive of coronary artery disease (CAD)；
3. HEART-score >3 (according to http://www.heartscore.nl/)；
4. Signed written informed consent.

Exclusion Criteria:

1. Inability to obtain informed consent；
2. Acute Coronary Syndromes (ACS) requiring urgent revascularization；
3. Known Obstructive Coronary Artery Disease (CAD) or previous PCI or CABG;
4. Concomitant severe congestive heart failure (New York Heart Association [NYHA] class III-IV or left ventricular ejection fraction [LVEF] < 30%) or acute pulmonary edema;
5. Severe hepatic insufficiency (Child-Pugh score ≥ C, or aspartate aminotransferase [AST] > 5× upper limit of normal); severe renal insufficiency (estimated glomerular filtration rate [eGFR] ≤ 30 mL/min/1.73 m²) or patients receiving continuous renal replacement therapy, hemodialysis, or peritoneal dialysis;
6. History of prior coronary artery bypass grafting (CABG);
7. Severe allergy to iodinated contrast agents;
8. Inability to obtain high-quality imaging;
9. Pregnant or lactating females;
10. Concomitant diseases or limited life expectancy, quality of life, or functional status precluding further CAD evaluation;
11. Any other factors that, in the investigator's judgment, make the patient unsuitable for study enrollment, completion of the study, or follow-up.

Prior to outcome adjudication, all relevant documents will be de-identified to exclude any reference to prior coronary computed tomographic angiography (CCTA) results, ensuring evaluators remain blinded to baseline imaging data that could influence objective assessment.