Left ventricular diastolic and systolic functions by cardiac magnetic resonance in beta-thalassemia major: correlation with clinical findings and cardiac complications.

Abstract

This cross-sectional study explored the association of left ventricular (LV) fractional area change (FAC) with demographic characteristics, clinical data, cardiovascular magnetic resonance (CMR) findings, and cardiac complications (heart failure and arrythmias) in patients with beta-thalassemia major (β-TM). We included 292 β-TM patients (151 females, 36.72 ± 11.76 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project and 20 healthy controls (8 females, 36.97 ± 3.54 years). CMR was used to assess FAC and derive LV systolic and diastolic indexes, to quantify myocardial iron overload (MIO) by the T2* technique and LV volumes and ejection fraction, and to detect late gadolinium enhancement (LGE). Healthy subjects and β-TM patients showed comparable LV systolic and diastolic indexes. In β-TM, the LV systolic index was significantly correlated with global heart T2* values, and patients with significant MIO (T2*<20ms) were more likely to have a reduced LV systolic index compared to those without MIO (odds ratio-OR = 3.13; p = 0.013). In multivariate analysis, global heart T2* values and positive LGE emerged as independent determinants of the LV systolic index. The number of segments with LGE inversely correlated with the LV systolic index (p = 0.003). Patients with a reduced LV systolic index were more likely to have cardiac diseases than those with a normal LV systolic index (OR = 5.34; p < 0.0001). No significant correlates were found for the LV diastolic index. In well-treated β-TM patients, MIO and LGE were the strongest determinants of the LV systolic index, and a reduced LV systolic index was associated with an increased risk of cardiac complications.