Tissue-level evidence of fibroblast activation protein inhibitor imaging in hypertrophic obstructive cardiomyopathy: a case series.

Background: Myocardial fibrosis is a key pathological factor for the occurrence of ventricular arrhythmias in hypertrophic obstructive cardiomyopathy (HOCM).

Case Summary: This case series reports on two patients diagnosed with HOCM who underwent F-fibroblast activation protein inhibitor (FAPI) positron-emission tomography/computed tomography imaging and Morrow myotomy procedure. The collected myocardial tissue was examined histopathologically.

Functional significance of myocardial activity at F-FAPI PET/CT in hypertrophic cardiomyopathy identified by cardiac magnetic resonance feature-tracking strain analysis.

Purpose: This study aimed to evaluate the functional significance of F-labeled fibroblast activation protein inhibitor (F-FAPI) activity in hypertrophic cardiomyopathy (HCM) by comparison with cardiac magnetic resonance feature-tracking (CMR-FT) strain analysis.

Methods: A total of 49 HCM patients were included in this study. Two independent control groups of healthy participants with a matched age and sex to the HCM patients were also enrolled.

Fibroblast activation protein imaging in atrial fibrillation: a proof-of-concept study.

Background: To evaluate the feasibility of using radiolabeled fibroblast activation protein inhibitor (FAPI) PET/CT imaging to assess activated fibroblasts in the atria of individuals with AF and to identify factors contributing to enhanced atrial activity.

Methods: We constructed left atrial appendage (LAA) pacing beagle dog AF models (n = 5) and conducted F-FAPI PET/CT imaging at baseline and eight weeks after pacing. Right atrial (RA) specimens were collected from these models.

Myocardial Activity at F-FAPI PET/CT and Risk for Sudden Cardiac Death in Hypertrophic Cardiomyopathy.

Background Myocardial fibrosis contributes to adverse cardiovascular events in hypertrophic cardiomyopathy (HCM). Purpose To explore the characteristics of cardiac fibroblast activation protein inhibitor (FAPI) PET/CT imaging and its relationship with the risk of sudden cardiac death (SCD) in HCM. Materials and Methods In this prospective study from July 2021 to January 2022, participants with HCM and healthy control participants underwent cardiac fluorine 18 (F)-labeled FAPI PET/CT imaging.

Pulmonary artery imaging with Ga-FAPI-04 in patients with chronic thromboembolic pulmonary hypertension.

Background: The feasibility and significance of imaging pulmonary artery (PA) remodeling with  Ga-fibroblast activating protein inhibitor (FAPI) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) have not yet been addressed.

Methods:  Ga-FAPI-04 uptake in the PA and ascending artery was evaluated in 13 patients with CTEPH and 13 matched non-CTEPH controls. The correlations of PA  Ga-FAPI-04 uptake and remodeling parameters derived from right heart catheterization (RHC) were analyzed.

Association of atrial F-fluorodeoxyglucose uptake and prior ischemic stroke in non-atrial fibrillation patients.

Background: Atrial cardiomyopathy has gained increasing attention in the field of ischemic stroke due to its prothrombotic substrate. Timely identification of high-risk individuals without atrial fibrillation (AF) is essential in secondary prevention. We sought to explore the feasibility of atrial F-fluorodeoxyglucose (FDG) imaging in detecting diseased atrial substrate and in identifying ischemic stroke in a non-AF population.

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

Purpose: The aim of this study was to explore the correlation of F-labeled fibroblast activation protein inhibitor (FAPI) and cardiovascular magnetic resonance (CMR) parameters in ST-elevation myocardial infarction (STEMI) patients with successful primary percutaneous coronary intervention (PPCI) and to investigate the value of FAPI imaging in predicting cardiac functional recovery, as well as the correlation between FAPI activity and circulating fibroblast activation protein (FAP) and inflammatory biomarkers.

Methods: Fourteen first-time STEMI patients (11 men, mean age: 62 ± 11 years) after PPCI and 14 gender-matched healthy volunteers (10 men, mean age: 50 ± 14 years) who had completed FAPI imaging and blood sample collection were prospectively recruited. All patients underwent baseline FAPI imaging (6 ± 2 days post-MI) and CMR (8 ± 2 days post-MI).

Association of Serum Biomarkers and Cardiac Inflammation in Patients With Atrial Fibrillation: Identification by Positron Emission Tomography.

Peripheral biomarkers may be affected by various factors, their reliability in reflecting local cardiac inflammatory status in patients with atrial fibrillation (AF) needs further exploration. This prospective study was aimed to investigate the relationship between circulating biomarkers and local cardiac inflammation measured by epicardial adipose tissue (EAT) activity F-fluorodeoxyglucose (FDG) imaging in AF patients. From 2017 to 2018, 83 AF patients [43 persistent AF (PsAF) and 40 paroxysmal AF (PAF)] referred for radiofrequency catheter ablation (RFCA) were recruited.

Imaging of cardiac fibroblast activation in patients with chronic thromboembolic pulmonary hypertension.

Purpose: The aim of this study was to explore the association of cardiac fibroblast activation with clinical parameters and cardiovascular magnetic resonance (CMR) imaging parameters in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Methods: Thirteen CTEPH patients were prospectively enrolled. All of the patients underwent cardiac Gallium-labelled fibroblast activation protein inhibitor ( Ga-FAPI-04)-positron emission tomography/computed tomography (PET/CT), right heart catheterisation, and echocardiography, and 11 of them additionally underwent CMR.

18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging in atrial fibrillation: a pilot prospective study.

Aims: This prospective study explored relevant factors and clinical significance of atrial 18F-fluorodeoxyglucose (FDG) uptake in patients with atrial fibrillation (AF).

Methods And Results: One hundred AF patients underwent baseline FDG imaging prior to radiofrequency catheter ablation (RFCA). Of those, 30 subjects underwent additional FDG imaging at 3 months post-RFCA.

Factors relevant to atrial F-fluorodeoxyglucose uptake in atrial fibrillation.

Background: This retrospective study was designed to explore the factors relevant to increased atrial F-fluorodeoxyglucose (FDG) uptake in patients with atrial fibrillation (AF) who had undergone routine whole-body positron emission tomography/computed tomography (PET/CT) imaging.

Methods And Results: Forty-eight consecutive AF patients (32 persistent, 16 paroxysmal) were identified from our routine FDG PET/CT database. Twenty-two control subjects were selected to establish the normal range of FDG uptake (maximum standardized uptake value, SUV) in target tissues.