The cardiovascular manifestations of the hypereosinophilic syndrome: Prospective study of 26 patients, with review of the literature

Abstract

The major cause of morbidity and mortality in patients with the hypereosinophilic syndrome is cardiac dysfunction. A review of 65 cases from the literature (historic series) revealed the following cardiovascular manifestations to be most common: dyspnea (60 per cent), signs of congestive heart failure (75 per cent), murmur of mitral regurgitation (49 per cent), cardiomegaly (37 per cent), T wave inversions on electrocardiogram (37 per cent) and pathologic findings of endocardial fibrosis, myocardial inflammation and mural thrombus formation (57 per cent). We have prospectively followed 26 patients with the hypereosinophilic syndrome for up to nine years (average follow-up prospectively was 3.3 years, retrospectively 5.7 years). Common cardiac findings in our 26 patients were dyspnea (42 per cent), chest pain (27 per cent), signs of congestive heart failure (38 per cent), murmur of mitral regurgitation (42 per cent), cardiomegaly (35 per cent) and T wave inversions (35 per cent). Thus, these patients demonstrated cardiovascular manifestations similar to those in the historic series, although the literature review showed a higher incidence of overt congestive heart failure. Of 22 patients having echocardiograms, 55 per cent demonstrated some clinical, roentgenographic or electrocardiographic evidence of cardiac involvement, but 82 per cent had echocardiographic abnormalities. This suggests that the echocardiogram is a sensitive and perhaps early indicator of cardiac involvement in this disease. Common echocardiographic findings included increased left ventricular wall thickness (68 per cent), left ventricular mass (73 per cent) and left atrial size (37 per cent). Prospective echocardiographic follow-up of 18 patients (for up to four and a half years) revealed that seven of eight untreated or inadequately treated patients had increases in left ventricular wall thickness, whereas all 10 adequately treated patients had decreases (eight of 10) or no change (two of 10) in left ventricular wall thickness. This suggests that adequate antihypereosinophilic therapy (with prednisone and/or hydroxyurea) may stabilize and, in some cases, reverse the cardiac manifestations of the hypereosinophilic syndrome. In previous studies, congestive heart failure due to eosinophilic cardiomyopathy has been reported to be very resistant to therapy. In our patients with congestive heart failure, treatment has been almost invariably effective when digitalis and diuretics were combined with adequate antihypereosinophilic therapy.