Loeffler’s Endocarditis due to Idiopathic Hypereosinophilic Syndrome

Introduction Hypereosinophilic syndrome (HES) is a rare disease characterized by persistent eosinophilia (>1,500 eosinophils× 10/L) for at least 6 months that remains unexplained in spite of a comprehensive evaluations and evidence of organ dysfunction primarily attributed to the eosinophilia. Loeffler’s endocarditis is a myocardial disease, thought to be secondary to idiopathic hypereosinophilia and often secondary to infection, medication or clonal disorders such as acute leukemia. It is characterized by fibrous thickening of the endocardium of one or both ventricles, leading to apical obliteration and restrictive cardiomyopathy, resulting in heart failure, thromboembolic event and/or atrial fibrillation. Prognosis is believed to be poor due to high mortality from heart failure, sudden death or thromboembolism. The reported 10-year survival rate is less than 50%, which is especially lower in corticosteroid resistant cases with cardiac involvement. Here, we present a patient who presented with anasarca, peripheral hypereosinophilia, and typical echocardiographic findings consistent with Loeffler’s endocarditis, which disappeared with corticosteroid and anticoagulation therapy. Case A 41-year-old male visited our hospital for recently progressed generalized edema and abdominal distension. He had a history of persistent malaise and fatigue for 3 months. Prior to the this first visit, he had been admitted for ascites control at the other hospital for several days, but he did not have a favorable response to conventional diuretic therapy. On his visit, vital signs were stable; blood pressure, 120/80 mmHg; pulse rate, 78 bpm; respiratory rate, 18/min and body temperature, 36.5。C. Physical examination revealed jugular venous distension in the sitting position, decreased breaths sound in the bilateral lower lung fields, severely distended abdomen with shifting dullness on percussion and pretibial pitting edema. Chest X-ray revealed cardiomegaly and blunting of bilateral costophrenic angles. Electrocardiography demonstrated normal sinus rhythm with low voltage in the limb leads. Laboratory studies showed marked eosinophilia (5,060×10/L), mild elevated cardiac enzyme (troponin-I 0.57 mg/mL), mild elevated liver enzyme (total bilirubin 2.5 mg/dL, alkaline phosphatase 144 U/L) and elevated C-reactive protein (2.43 mg/dL). But serum electrolyte level and thyroid functions were