Assessment of inflammation in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia

PURPOSE: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a myocardial disease that predominantly affects the right ventricle (RV). Its hallmark feature is fibro-fatty replacement of RV myocardium. However, patchy inflammatory infiltrates in the RV are also consistently reported using autopsy and myocardial biopsy. Although the role of inflammation in ARVC/D is unresolved, the ability to assess inflammation non-invasively may aid in the diagnostic process. We aimed to establish whether cardiac inflammation can be assessed non-invasively in ARVC/D patients. METHODS: In eight ARVC/D patients and nine controls (haematology/oncology patients), the level of inflammatory activation was assessed by measuring plasma levels of inflammatory cytokines. Regional myocardial inflammation was assessed with (67)Ga scintigraphy. RESULTS: ARVC/D patients had higher plasma levels than controls of the pro-inflammatory cytokines interleukin (IL)-1β (1.22 ± 0.07 vs 0.08 ± 0.01 pg/ml, p < 0.0001), IL-6 (3.16 ± 0.44 vs 0.38 ± 0.04 pg/ml, p < 0.0001) and tumour necrosis factor (TNF)-α (9.16 ± 0.90 vs 0.40 ± 0.06 pg/ml, p < 0.0001), while levels of the anti-inflammatory cytokine IL-10 were not significantly different (1.36 ± 0.15 vs 1.20 ± 0.30 pg/ml, p = 0.74). (67)Ga uptake in the RV was higher in ARVC/D patients than in controls. In ARVC/D patients, (67)Ga uptake in the RV wall was higher than in the interventricular septum or left ventricular wall. CONCLUSION: Inflammation in the RV wall of ARVC/D patients can be detected non-invasively with the combined analysis of plasma levels of inflammatory cytokines and cardiac (67)Ga scintigraphy.