Abstract Body (Do not enter title and authors here): Background: Hypereosinophilic syndrome (HES) is a rare disease that causes organ damage and thrombosis due to sustained eosinophilia of the blood or tissues. Loeffler endocarditis (LE) is defined as cardiac involvement in the setting of HES. There are limited data on the diagnostic and prognostic impact of strain imaging on LE.
Methods: A single-center retrospective cohort study was performed. Patients with eosinophilia between January 2000 and January 2023 were identified. We included patients who met the current diagnostic criteria for HES and underwent echocardiography prior to treatment. LE was defined as the presence of eosinophils in the myocardium by an endomyocardial biopsy, endocardial thickening, or left ventricular thrombus due to HES. We evaluated the composite events defined as CV death and stroke at diagnosis and during follow-up.
Results: Of 1,664 patients with eosinophilia, 34 patients with HES were included (10 with LE and 24 without LE). In the entire cohort, the mean age was 57 ± 16 years and 41% were male. The median follow-up duration was 85 months (25th -75th percentile: 41-145 months). The composite events occurred in 6 patients. Left ventricular ejection fraction (LVEF) was similar in both groups (60% vs. 61%, p = 0.691). Patients with LE had significantly lower left ventricular global longitudinal strain (LV-GLS) (-9.7% vs. -15.5%, p = 0.001), left atrial (LA) reservoir strain (21.0% vs. 32.1%, p = 0.021) and LA conduit strain (-9.7% vs. -19.2%, p <0.001), compared to patients without LE. There were no significant differences in LA booster strain (-11.3% vs. -12.8%, p = 0.606) and right ventricular free wall strain (-17.5% vs. -23.4%, p = 0.083). All LE patients and half of non-LE patients had LV-GLS worse than -16 %. There was a significant difference in the compsoite events for patients with LV-GLS worse than -16% (28.6% vs. 0.0%, p = 0.049).
Conclusions: LE was associated with significantly worse LV-GLS and left atrial strain compared to patients without LE. Worse LV-GLS was associated with a higher frequency of the composite events.