Evaluation of carotid artery dynamics & correlation with cardiac & hepatic iron in β-thalassaemia patients

Abstract

Background & objectives: Early atherosclerosis and vascular complication have been described in thalassaemia patients. There is lack of data or guidelines regarding monitoring of vascular health in thalassaemia. This study was conducted to compare carotid artery structural and functional indices such as carotid artery intima-media thickness (CIMT), stiffness index (SI) and Young's elastic modulus (YEM) in β-thalassemia patients with age and sex matched controls, and to correlate these parameters with serum ferritin, cardiac iron, and hepatic iron. Methods: This cross-sectional study included 53 β-thalassaemia patients receiving regular blood transfusions. Carotid artery indices such as CIMT, SI, and YEM were calculated by duplex ultrasound and colour Doppler. Serum ferritin levels were measured by chemiluminescence. Cardiac and hepatic iron estimation were done using MRI T2* sequences analyzed by a special thalassaemia software. Results: Mean CIMT of cases and controls were 0.48 ± 0.04 and 0.44±0.02 mm, respectively and these were significantly different (P<0.001). Similarly significant differences were noted in SI and YEM of cases (2.45±0.79 and 96.12±34.85, respectively) as compared to controls (1.98±0.54 and 68.60±24.29, respectively) (p<0.001). There was significant inverse correlation between stiffness index and cardiac iron overload assessed by MRI cardiac T2* (p=0.03). Mean SI and YEM of cases were (2.1736 ± 0.2986 and 107.3± 41.6, respectively) significantly higher among non-splenectomized patients compared to splenectomized patients (2.0136 ± 0.263 and 86.9 ± 25.2, respectively) (p<0.05). Interpretation & conclusions: CIMT and arterial stiffness indices were significantly increased in β-thalassaemia patients compared to controls which was indicative of early atherogenic changes. This study supports the hypothesis that iron overload is a risk factor for early atherosclerosis and cardiovascular disease.

Keywords

• Atherosclerosis - β-thalassaemia - carotid duplex ultrasound - carotid intima-media thickness - Cardiac T2* - stiffness index - Young's elastic modulus (YEM)