Evaluation of the clinical value of CCTA as the preferred screening method in patients with chronic coronary syndrome
Authors: Luo Huan , Zhu Wei , Fan Rui-juan , Duan Li-xiong , Jing Rui 
Published: July 2024

Background: The advantages and disadvantages of direct invasive coronary angiography (ICA) and coronary computed tomographic angiography (CCTA)+ICA were compared in patients with suspected chronic coronary syndrome (CCS) who presented with angina symptoms or who had nonangina chest pain with abnormal electrocardiogram results.
Methods: A total of 1200 patients who met the inclusion criteria at TEDA International Cardiovascular Hospital from January 2021 to December 2022 were randomly divided into two groups at a 1:1 ratio: CCTA+ICA strategy (CCTA group) and direct ICA strategy (ICA group). All patients in the CCTA group underwent CCTA examination first. If these results showed positive obstructive coronary artery disease (CAD), then typical angina with coronary artery stenosis ranging from 50% to 70% or vascular segments could not be analysed due to severe calcification, so ICA was further performed for definitive diagnosis, and ICA results were taken as the final diagnosis. All patients in ICA group underwent ICA examination directly. Demographic data, cardiovascular risk factors, biochemical criteria, chest pain classification, coronary vessel lesion severity and drug use in the two groups were compared. All patients were followed for 1 year after discharge to observe major adverse cardiovascular events (MACE). The differences in unnecessary ICA rate, 1-year MACE, allergic reaction to contrast agent and hospitalization cost between the two groups were analysed. Based on the baseline clinical data of patients included in this study, a risk prediction model for obstructive CAD was established by logistic regression.
Results: (1) There were 592 patients in the CCTA group and 594 patients in ICA group. The percentage of unnecessary ICA procedures was 7.5% in the CCTA group and 55.2% in ICA group (P< 0.001). (2) Fifty-one patients in the CCTA group were readmitted for severe angina, 4 of whom underwent unplanned percutaneous coronary intervention (PCI). Eight patients in the ICA group were readmitted for severe angina, 2 of whom underwent unplanned PCI. There were no cardiac deaths, nonfatal myocardial infarctions or strokes in either group over 1-year follow-up. There was no statistically significant difference in the rates of MACE-free survival between the two groups (97.0% vs. 98.7%, log-rankc²=1.996, P=0.158). (3) Allergic reaction to cotrast was observed in 28 patients in the CCTA group and 16 in the ICA group (P＝0.190). (4) The median hospitalization cost in the CCTA group was 9194.61 yuan, and that in the ICA group was 10215.67 yuan, a significant difference. (5) Based on the combination of the logistic regression forward selection method and backward elimination method, variables with P<0.05 were selected from the baseline data of patients to predict obstructive CAD, including creatinine, age, physical activity or emotionally induced symptoms, hyperlipidaemia, diabetes and smoking history. The above variables were used to establish a risk prediction model for obstructive CAD. The area under the ROC curve (AUC) of this model was 0.721, indicating good predictive ability.
Conclusion: In patients with suspected CCS, including typical angina, atypical angina and nonangina chest pain with abnormal electrocardiogram results, the use of CCTA as a first-line diagnostic test can reduce the unnecessary incidence of ICA and hospitalization costs without increasing the incidence of MACE. A risk prediction model of obstructive CAD was established based on the baseline data of the patients enrolled in this study, providing a clinical basis for the decision to use CCTA or ICA. Patients with a low probability of obstructive CAD can be given priority for CCTA, while patients with a high probability can be given priority for ICA.