The study will use 18F-PBR06/uExplorer to study the activation of macrophages and systemic perfusion in patients with ST-segment elevation myocardial infarction (STEMI) or stable angina (SA). Participants will receive the total-body PET/CT scan on the seventh day (Day 7, D7) and D180 of enrolment.

The aim of our study is to explore the activation of macrophages in patients with ST-segment elevation myocardial infarction (STEMI) or stable angina (SA) using the 18 kDa translocator protein (TSPO) radioligand 18F N-fluoroacetyl-N-(2,5-dimethoxybenzyl)-2-phenoxyaniline (18F-PBR06) in combination with the world's first commercially available total-body PET/CT (uExplorer). The investigators expect to enroll 10 patients diagnosed with STEMI and 10 patients with SA who receive coronary angiography (CAG) and the percutaneous coronary intervention (PCI), and 5-10 healthy individuals diagnosed with SA but presenting negative CAG at Renji Hospital, Shanghai. The activation of macrophages (TSPO uptake) and blood perfusion in different organs will be studied using 18F-PBR06/uExplorer.

With written consent from eligible participants, the investigators will review past medical records and document the medical history for each participant. Patients will undergo PCI on the day of enrolment (12 hours within the symptom onset for STEMI patients). Screen procedures will be performed at the seventh day of enrolment (Day 7, D7) and Day 180 (D180). Participants will receive one dose of the non-therapeutic administration of the radioactive TSPO tracer 18F-PBR06 and receive a whole-body scan by uExplorer. TSPO uptake and blood flow in the heart, kidney, liver, brain, and lung will be recorded. All participants will be followed for 1 year after enrolment. Blood samples will be collected and echocardiography will be performed at D7 and D180. Major adverse cardiovascular events (MACE) will be recorded throughout the follow-up.

Inclusion Criteria:

• Aged 18-75 years old
• Diagnosed with STEMI, NSTEMI or suspected SA (ACC/AHA guidelines)
• Half male and half female
• Undergo CAG and PCI treatment if necessary (primary PCI for STEMI patients within12 hours after symptom onset)
• Written informed consents will be offered and signed by all participants

Exclusion Criteria:

• History of myocardial infarction/vascular disease/heart failure/systemic inflammatory diseases before enrolment
• Patients who are pregnant/breastfeeding, or in a plan to have a baby during the year after CAG/PCI
• People under the age of 18 years old
• Inability to lie or maintain posture during the scanning procedure

half male and half female

Patients aged between 18 and 75 years with the diagnosis of STEMI or SA will be eligible for our study.