Value of [68Ga]Ga‐FAPI‐04 PET imaging in acute coronary syndrome complicated by suspected gastrointestinal malignancies

Abstract Early diagnosis of gastrointestinal malignancies in patients with acute coronary syndrome (ACS) is often delayed. The present study aims to demonstrate the value of [68Ga]Ga‐FAPI‐04 PET imaging in ACS with suspected gastrointestinal malignancies. Twelve ACS patients with suspected gastrointestinal malignancies were enrolled, including ST‐elevation myocardial infarction (STEMI) (n = 5), non‐ST‐elevation myocardial infarction (NSTEMI) (n = 5), and unstable angina (UA) (n = 2). All patients underwent coronary angiography (CAG) and [68Ga]Ga‐FAPI‐04 PET/MR or PET/CT within 1 week. All five STEMI and five NSTEMI patients had high [68Ga]Ga‐FAPI‐04 uptake in the injured myocardium compared to remote area (TBR: 2.10 ± 0.72 vs. 0.62 ± 013; p < .001), correlated with peak cTnI level (R = .82, p = .004). No [68Ga]Ga‐FAPI‐04 in the myocardium was found in UA patients. NSTEMI displayed a similar myocardial [68Ga]Ga‐FAPI‐04 intensity as STEMI (p = .42). Compared with STEMI, NSTEMI patients had a significantly delayed door‐to‐balloon time for reperfusion treatment (p = .023). High uptake of [68Ga]Ga‐FAPI‐04 in the gastrointestinal tract was detected in three patients. Because of no myocardial [68Ga]Ga‐FAPI‐04 expression, they discontinued antiplatelet therapy and underwent endoscopy. The rectal, colon, and gastric cancer diagnoses were made by biopsy. The other nine patients showed no accumulation of [68Ga]Ga‐FAPI‐04 beyond the heart, and invasive tumor examinations were delayed. During a median 6‐month follow‐up, no tumor formation was observed. [68Ga]Ga‐FAPI‐04 PET imaging is valuable to assess injured myocardium, detect tumors, and guide invasive examinations in ACS patients with suspected gastrointestinal malignancies.