Fig. 1

Flowchart of the study design for patient recruitment and inclusion. a A total of 67 patients with coronary artery disease (CAD) in the Department of Cardiology were prospectively enrolled. Overall, 50 patients with acute coronary syndrome (ACS) and 12 patients with stable angina were included in the final analysis. Proven ACS was classified into 3 subgroups, including unstable angina (n = 27), non-ST elevation myocardial infarction (NSTEMI) (n = 8), and ST elevation myocardial infarction (STEMI) (n = 15). CHIPs were observed in 1 (8%) stable angina, 7 (26%) unstable angina, and 3 (38%) NSTEMI, and 10 (67%) STEMI patients, respectively. b Of the 50 ACS patients, 24 patients (including 30 lesions; 8 lesions with CHIPs and 22 lesions with non-CHIPs) were included in the final analysis