Left ventricular noncompaction in patients with β-thalassemia: uncovering a previously unrecognized abnormality.

Left ventricular noncompaction (LVNC) is a rare cardiomyopathy with potentially serious outcomes. It results in multiple and excessive trabeculations, deep intertrabecular recesses, and a thickened ventricular myocardium with two distinct layers, compacted and noncompacted. The condition is most commonly congenital; however, acquired forms have also been described. A recent report of LVNC detected in a β-thalassemia twin suggested an association with cardiac siderosis. In a cross-sectional study of 135 transfusion-dependent patients with β-thalassemia (130 major and 5 intermedia, mean age 29.6 ± 7.7 years, 49.6% males) presenting for cardiac iron assessment by magnetic resonance imaging (MRI), we evaluated the prevalence and risk factors for LVNC. None of the patients had neuromuscular or congenital heart disease. Eighteen patients (13.3%; 95% confidence interval [CI] = 8.6-20.1) fulfilled the preassigned strict criteria for LVNC on cardiac MRI. There were no statistically significant differences between patients with and without LVNC with respect to demographics; hemoglobin levels; splenectomy status; systemic, hepatic, and cardiac iron overload indices; hepatic disease and infection studies; or iron chelator type. Patients with LVNC were more likely to have heart failure (adjusted odds ratio = 1.77; 95% CI = 0.29-10.89); although with high uncertainty. Patients with β-thalassemia have a higher prevalence of LVNC than normal individuals. As this finding could not be explained by conventional risk factors in this patient population, further investigation of the underlying mechanisms of LVNC is warranted. This remains crucial for an entity with adverse cardiac outcomes, especially in patients with β-thalassemia where cardiac disease remains a primary cause of mortality.