Potential of Ga-FAPI-04 PET/MR to predict worsening renal function after acute ST-elevation myocardial infarction.

Purpose: The fibroblast activation protein inhibitor-04 (FAPI-04) specifically binds to the FAP of activated myocardial fibroblasts, which makes Ga-labelled FAPI-04 (Ga-FAPI-04) positron emission tomography (PET)/magnetic resonance (MR) a new potential imaging technique for the evaluation of myocardial fibrosis. This study aimed to evaluate the potential value of Ga-FAPI-04 PET/MR in assessing and predicting changes in renal function in patients with acute ST-elevation myocardial infarction (STEMI).

Methods: Thirty-three patients with STEMI were included in this study. Ga-FAPI-04 PET/MR and cardiac magnetic resonance were performed before discharge in all patients. Worsening renal function(WRF) was defined as ≥20% decrease in estimated glomerular filtration rate(eGFR) from baseline to 12 months.

Results: The WRF group demonstrated higher Ga-FAPI-04 uptake volume (UV) at baseline than the non-WRF group(P = 0.009). Ga-FAPI-04 UV at baseline was correlated with follow-up eGFR (r = -0.493, P = 0.004). Ga-FAPI-04 UV at baseline was a significant predictor of WRF (OR = 1.014, P = 0.029) at 12 months after STEMI.

Conclusions: As an effective tool to non-invasively quantify myocardial fibroblast activation, Ga-FAPI-04 PET/MR has potential value for assessing and predicting worsening renal function in patients with STEMI.