Imaging of cardiac fibroblast activation in a patient after acute myocardial infarction using 68Ga-FAPI-04

Abstract

Our previous study has demonstrated the feasibility of noninvasive imaging of fibroblast activation protein (FAP)-expression after myocardial infarction (MI) in MI-territory in a rat model with 68Ga-FAPI-04-PET. In the current extended clinical case, we sought to delineate cardiac uptake of 68Ga-FAPI-04 in a patient after MI with clinical indication for the evidence of fibroblast activation. Carcinoma patients without cardiac disease underwent 68Ga-FAPI-04-PET/CT as control. The patient with one-vessel disease underwent dynamic 68Ga-FAPI-04-cardiac-PET/CMR for 60 minutes. Correlation of cardiac 68Ga-FAPI-04 uptake with clinical findings, ECG, echocardiography, coronary-arteriography and enhanced cardiac-MRI with T1 MOLLI and ECV mapping were performed. No uptake was found in normal myocardium and in mature scar. A focal intense 68Ga-FAPI-04 uptake with continuous wash-out in the infarct territory of coronary occlusion correlating with T1 and ECV mapping was observed. The uptake of 68Ga-FAPI-04 extends beyond the actual infarcted area and overestimates the infarct size as confirmed by follow-up CMR.

Fibroblast activation protein imaging in reperfused ST-elevation myocardial infarction: comparison with cardiac magnetic resonance imaging

“…Reperfused MI induced an extending FAPI uptake over the infarct region Previous reports [12,14] demonstrated an extended broblasts activation over the perfusion defect and LGE area. In the current study, by comparing with multiple CMR sequences, we further identi ed that the FAPI uptake extent was even larger than the edematous area.…”

“…Using gallium-68 ( 68 Ga)-labeled FAPI, Varasteh and coworkers demonstrated excellent in vivo imaging quality for the detection of post-MI broblast activation in a MI rat model [11]. More recently, the feasibility of 68 Ga-FAPI imaging in MI patients was reported by Notohamiprodjo [12], Kessler [13], and Diekmann [14], which identi ed intense FAPI uptake in the infarcted territory. These data suggest that FAPI imaging is a reliable technique in delineating the temporospatial status of activated broblasts and may help to better explain post-MI pathophysiologic evolution and monitoring of the e cacy of anti brotic therapies.…”

“…These tracers have been widely used for positron emission tomography/computed tomography (PET/CT) imaging in various diseases especially cancer, and recently in cardiac diseases [9,10]. Several pre-clinical and clinical studies reported that MI would induce enhanced FAPI uptake, which extended over the culprit territory and the LGE area [11][12][13][14], these ndings suggested FAPI imaging may have unique advantage in detecting the affected myocardium.…”

FAP and FAPI-PET/CT in Malignant and Non-Malignant Diseases: A Perfect Symbiosis?

“…This study also revealed that most of the uptake was in the border-ischemic area [61]. FAPI accumulated beyond the extent of the infarcted zone, thereby revealing a tendency to overestimate the infarct size [62]. However, this may be caused by a remodeling in the peri-infarct zone as a result of perfusion deficits also in this area.…”

Nuclear Molecular Imaging of Cardiac Remodeling after Myocardial Infarction

“…FAP inhibitor (FAPI) tracers were initially developed as theranostic ligands for metastasized cancer. Recently, they have been used to study cardiac remodeling following MI in small-animal models [59] and in humans (Figure 3) [60,61]. The tracers were also used to investigate cardiac remodeling in patients who underwent FAPI PET imaging for cancer staging [62][63][64], in patients with a checkpoint inhibitor (ICI)-associated myocarditis [65], with nonischemic dilated cardiomyopathy [66], and to image cardiotoxicity in patients after receiving systemic cancer therapy [67].…”