Rapid Left Ventricular Thickening and Thrombus Caused by FIP1L1/PDGFRA-Negative Hypereosinophilic Syndrome

Abstract

WEBSITE FEATURE

A 51-year-old man presented with a 3-day history of exertional dyspnea and chills. His total peripheral leukocyte count was 52.5 × 10⁹/L with 77% eosinophils. Serology tests were negative for parasites. Cytogenetic testing of bone marrow confirmed a diagnosis of FIP1L1/PDGFRA-negative hypereosinophilic syndrome (HES). Transthoracic echocardiography (TTE) indicated possible concentric left ventricular (LV) hypertrophy with pseudonormalization of mitral inflow (E/A, 0.8; deceleration time [DT], 172 ms; E/E′, 16) (Fig. 1). Because of worsening dyspnea, the patient was admitted to the hospital. Follow-up TTE 3 days after admission showed severe LV apical thickening with thrombi and decreased LV cavity diameter with restrictive mitral inflow (E/A, 2.2; DT, 121 ms; E/E′, 21) (Fig. 2). Endomyocardial biopsy revealed massive eosinophilic infiltration of the myocardium (Fig. 3). Twelve days after admission, magnetic resonance imaging of the brain showed multiple cerebral infarctions (Fig. 4). The patient was discharged from the hospital 1 month after admission and had no sign of neurologic complication. Three months of imatinib therapy resulted in complete hematologic recovery. Six months after initial presentation, TTE showed persistent thickening of the LV apex with pseudonormalization of mitral inflow (E/A, 1.1; DT, 161 ms; E/E′, 35) (Fig. 5).

Fig. 1 Baseline transthoracic echocardiogram shows possible concentric left ventricular hypertrophy.

Real-time motion image is available at www.texasheart.org/journal.

Fig. 2 Transthoracic echocardiogram 3 days after admission shows severe thickening of the apical left ventricle with thrombi and a smaller left ventricular cavity.

Real-time motion image is available at www.texasheart.org/journal.

Fig. 3 Endomyocardial biopsy results reveal massive eosinophilic infiltration of the myocardium (H & E, orig. ×400).

Fig. 4 Magnetic resonance image of the brain 12 days after admission shows multiple cerebral infarctions.

Fig. 5 Transthoracic echocardiogram 6 months after initial presentation shows persistent thickening of the left ventricular apex.

Real-time motion image is available at www.texasheart.org/journal.

Comment

Cardiac eosinophilic infiltration is reported in more than 60% of patients with HES and promotes cardiac fibrosis, ventricular thickening, and ventricular failure.^1–3 In addition to the regional ventricular wall thickening caused by cardiac involvement of HES, which is commonly revealed by echocardiography or cardiac magnetic resonance (CMR), our images show an unusually rapid progression of LV apical thickening. Kleinfeldt and colleagues⁴ used CMR to record the improvement of cardiac complications after 6 months of medical treatment in a rare case of Loeffler's endocarditis. Although the improvement of cardiac manifestations in HES after early treatment with imatinib has been observed, the response varies.^5,6 In our patient, persistent diastolic dysfunction and LV apical thickening occurred even after early administration of imatinib. We continue to monitor the patient for signs of heart failure, including severe diastolic dysfunction with restrictive filling or atrioventricular valve regurgitation due to involvement of papillary muscles, chords, or valvular leaflets.