Abstract
BACKGROUND: Hypereosinophilic syndrome (HES) is a rare disease characterized by persistent eosinophilia associated with organ damage, and may be complicated by eosinophilic myocarditis (EM). However, the utility of strain imaging in these conditions remains unclear. We aimed to evaluate the value of strain imaging in HES. METHODS: We performed a cross-sectional study of all patients aged >18 years diagnosed with HES at Cleveland Clinic between September 1986 and January 2023. Left ventricular global longitudinal strain (LVGLS), left atrial (LA) strain, and right ventricular (RV) free wall strain were measured. The primary endpoint was a composite of stroke at diagnosis and major adverse cardiovascular events during the follow-up period. Outcomes were compared using chi-square tests. RESULTS: Of 1,664 patients with eosinophilia, 34 patients with confirmed HES were included in the final cohort. The mean age was 57±16 years, and 58.8% were female. The median follow-up duration was 85 months. Among them, ten patients (29.4%) were diagnosed with EM and twelve patients (35.3%) developed the primary endpoint. EM patients had significantly worse LVGLS (-9.7% vs. -15.5%, P<0.001), LA reservoir strain (21.0% vs. 32.1%, P=0.02) and LA contraction strain (-9.7% vs. -19.2%, P<0.001) compared to non-EM patients, but there was no significant difference in RV free wall strain (-17.5% vs. -23.4%, P=0.08). All EM patients and half of non-EM patients had LVGLS worse than -16%. Patients with worse LVGLS had significantly higher incidence of primary endpoint compared to patients with normal LVGLS (47.6% vs. 9.1%, P=0.03). CONCLUSIONS: LVGLS is frequently impaired in patients with EM, and is associated with increased risk of stroke and major cardiovascular events. These findings suggest its potential as a marker of cardiac involvement and prognosis in HES.