FAPI PET/CT Imaging in Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) (FAPI-ARVC))

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease associated with fibrofatty myocardial replacement, ventricular arrhythmias, and an increased risk of sudden cardiac death. Although current diagnostic approaches, including the 2010 Task Force Criteria and the Padua criteria, improve recognition of the disease, early diagnosis remains challenging, particularly when structural abnormalities are subtle or absent on conventional imaging. Echocardiography and cardiac magnetic resonance imaging are central to evaluation, but their sensitivity for early or active fibrotic remodeling may be limited. This limitation may be particularly relevant in patients who are unable to undergo cardiac magnetic resonance imaging, in whom 68Ga-DOTA-SA-FAPI PET/CT may provide complementary diagnostic information. This prospective single-group diagnostic imaging study aims to investigate the incremental value of protocol-specified 68Ga-DOTA-SA-FAPI PET/CT imaging in patients with ARVC. FAPI PET/CT is a novel molecular imaging method that targets activated fibroblasts and may allow non-invasive detection of active myocardial fibrosis.Fifteen adult patients with an established diagnosis of ARVC will undergo protocol-specified 68Ga-DOTA-SA-FAPI PET/CT imaging in addition to clinical evaluation, electrocardiography, echocardiography, and review of previously obtained cardiac magnetic resonance imaging findings. FAPI PET/CT findings will be compared with conventional diagnostic criteria and other clinical and imaging parameters, including previously available cardiac magnetic resonance imaging findings. Participants will also be followed clinically for 6 months after imaging to explore possible associations between FAPI uptake and short-term clinical outcomes, including arrhythmic events, ventricular function, and laboratory markers. The study is expected to provide preliminary evidence on whether 68Ga-DOTA-SA-FAPI PET/CT may improve the detection of myocardial fibrosis and contribute to diagnostic assessment and risk stratification in ARVC. It may also help clarify the potential role of FAPI PET/CT in patients who are unable to undergo cardiac magnetic resonance imaging. The findings may support future larger prospective studies in this field.