Hypereosinophilia and Löffler's Endocarditis: A Systematic Review.

Löffler endocarditis is an uncommon, but known complication of hypereosinophilic syndrome (HES). It is a relatively rare entity, and remains poorly understood. To this point in time, the compendium of knowledge about this disease consists of various case reports, prospective studies and review articles. We aim to present a scoping study about this disease. Our goals are to identify the characteristic features found in case reports to identify characteristic features found in patients with Löffler endocarditis as a result of hypereosinophilic syndrome. An analysis of the 26 case reports showed a mean age of 41.6 years with a standard deviation of 17.1 years. Dyspnea was the most common presenting complaint (64%) followed by fatigue (23%), cough (19%), fever (19%), orthopnea/paroxysmal nocturnal dyspnea (19%), stroke related symptoms (15%), chest pain (15%) and lower extremity edema (15%). The most common cardiac structure affected was the mitral valve (65%), followed by the tricuspid valve (42%), left ventricle (23%), with 35% of cases having involvement of two valves. The most common therapeutic modality was immunosuppression (85%), followed by anticoagulation (73%) and mitral valve replacement (23%). Death was reported in 19% of the cases. Löffler's endocarditis continues to be associated with high morbidity and mortality. Further research must aim to develop guidelines for management of this uncommon manifestation of hypereosinophilic syndrome.