Cardiac involvement in sickle β-thalassemia

Abstract

Cardiovascular involvement is a leading cause of mortality and morbidity in patients with inherited hemoglobinopathies, but it has not been adequately assessed in sickle beta-thalassemia. We evaluated 115 sickle beta-thalassemia patients, aged 34 +/- 14 years, along with 50 healthy controls, by resting echocardiography. Patients with systolic left ventricular (LV) dysfunction or severe pulmonary hypertension (PHT) also underwent left and right cardiac catheterization and cardiac magnetic resonance imaging (CMR). Left and right chamber dimensions, LV mass, and cardiac index were significantly higher in patients compared to controls (p < 0.001 in most cases). Three patients (2.9%) had reduced LV ejection fraction (<55%); mean LV ejection fraction was significantly lower in patients (p < 0.001). Left and right ventricular systolic tissue Doppler indices and LV diastolic tissue Doppler indices were also impaired in patients. All three patients with systolic LV dysfunction had normal coronary arteries and mild myocardial iron load (CMR T2* values, 18-25 ms). Systolic pulmonary artery pressure was significantly higher in patients compared to controls (p = 0.002); PHT was present in 28 patients (27%), while severe PHT in three (2.9%). In three patients with severe PHT, only one had impaired LV ejection fraction and increased pulmonary wedge pressure. Overall, three patients (2.9%) had a history of heart failure, two with systolic LV dysfunction, and one with severe PHT. Cardiac involvement in sickle beta-thalassemia concerns biventricular dilatation and dysfunction along with PHT, leading to congestive heart failure.