Cardiac involvement in eosinophilic granulomatosis with polyangiitis: acute eosinophilic myocarditis and chronic inflammatory cardiomyopathy

Abstract Objectives Currently, cardiac involvement is used to describe all eosinophilic granulomatosis with polyangiitis (EGPA) cardiac problems. However, heterogeneity exists among them. We aimed to depict the disease spectrum of EGPA cardiac involvement and identify the high-risk population. Methods We included EGPA patients hospitalized in our centre from 2012 to 2023 and in public databases. Based on the cardiac enzymes, cardiac MRI and endomyocardial biopsy results, the patients were divided into three groups: eosinophilic myocarditis (EGPA-EM), chronic inflammatory cardiomyopathy (EGPA-ICM) and EGPA-Control. Their clinical, laboratory, imaging results and prognoses were collected and compared. Results A total of 193 EGPA patients were included, 118 with cardiac involvement (74 EGPA-EM, 44 EGPA-ICM) and 75 control. Among EGPA-Control, EGPA-ICM and EGPA-EM, eosinophil increased (6.12/8.71/10.42 × 109/l, P < 0.01), ANCA positivity decreased (41.33/31.82/14.86%, P < 0.01) and lung involvement was reduced (73.33/72.73/43.24%, P = 0.02). In EGPA-EM, cardiac troponin was further elevated (0.27 vs 6.00 ng/ml, P < 0.01), ejection fractions decreased (57.79 vs 33.20%, P < 0.01) while more ST-T abnormality was observed (41.89 vs 20.45%, P = 0.02). The prognosis of EGPA-EM was significantly worse, with a 14.86% death rate and 2-year event-free survival rate below 50%. Furthermore, we proposed a LATE-EAST diagnostic score (7 items, 9 points) to discriminate EGPA-EM from EGPA-ICM using 4 points as threshold [area under the receiver operating characteristic curve 0.85 (95% CI 0.78–0.92), sensitivity 0.78, specificity 0.86]. Conclusions We first proposed different subtypes of cardiac involvement in EGPA. Identification and treatment of EGPA-EM needs improvement. LATE-EAST score could recognize the high-risk EGPA-EM effectively. Multi-disciplinary treatment is warranted, immunosuppressive therapy should be given in a timely manner and anti-IL-5 antibodies should be be tested in trials.