Hypereosinophilic Syndrome Associated with Heterozygous Factor V Gene Mutation: An Unusual Combination Resulting in an Acute Coronary Syndrome and Recurrent Cerebral Stroke

The authors report the first case of a patient with a hypereosinophilic syndrome associated with heterozygous factor V gene mutation, resulting in an acute coronary syndrome and recurrent cerebral stroke despite effective anticoagulation. A 40-year-old man presented with an acute coronary syndrome accompanied by a brachiofacial right-sided hemiparesis and dysarthria. Diagnosis of a hypereosinophilic syndrome was established by blood testing, myocardial biopsy, and bone marrow analysis. Eosinophilic infiltration was present in the myocardium, accompanied by proliferation in the endomyocardium and a pneumonic infiltrate. Although effective anticoagulation with heparin was administered, a recurrent stroke occurred while blood eosinophils were being normalized by corticosteroid treatment. A coexisting heterozygosity of the factor V mutation was demonstrated, and it is hypothesized that this might have contributed to the recurrent thromboembolic episodes. In patients with hypereosinophilic syndrome and recurrent thromboembolic episodes, other thrombophilic diseases, including factor V mutations, should be considered, and long-term coagulation should be contemplated.