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

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 high-risk population. METHODS:We included EGPA patients hospitalized in our center from 2012 to 2023 and in public databases. Based on the cardiac enzymes, cardiac magnetic resonance imaging, and endomyocardial biopsy results, the patients were divided into 3 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 reduced (73.33/72.73/43.24%, p= 0.02). In EGPA-EM, cardiac troponin 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 14.86% death rate, and 2-year event-free survival rate below 50%. Further, we proposed a LATE-EAST diagnostic score (7 items, 9 points) to discriminate EGPA-EM from EGPA-ICM using 4 points as threshold [AUC 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 timely and anti-IL-5 antibodies be tested in trials.