Cardiovascular Complications in β-Thalassemia: Getting to the Heart of It

Beta thalassemia is an inherited disorder resulting in abnormal or decreased production of hemoglobin, leading to hemolysis and chronic anemia. The long-term complications can affect multiple organ systems, namely the liver, heart, and endocrine. Myocardial iron overload is a common finding in β-thalassemia. As a result, different cardiovascular complications in the form of cardiomyopathy, pulmonary hypertension, arrhythmias, and vasculopathies can occur, and in extreme cases, sudden cardiac death. Each of these complications pertains to underlying etiologies and risk factors, which highlights the importance of early diagnosis and prevention. In this review, we will discuss different types of cardiovascular complications that can manifest in patients with β-thalassemia, in addition to the current diagnostic modalities, preventive and treatment modalities for these complications.

Myocardial fibrosis by late gadolinium enhancement cardiac magnetic resonance and hepatitis C virus infection in thalassemia major patients

AIMS

Our aim was to evaluate the correlation between myocardial fibrosis detected using the late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) technique and chronic hepatitis C (CHC) in a large, retrospective, multicentre cohort of thalassemia major patients.

METHODS

LGE images were acquired in 434 thalassemia major patients (233 men, 31 ± 9 years) enrolled in the MIOT (Myocardial Iron Overload in Thalassemia) study. Hepatitis C virus (HCV)-RNA tests were sensitive to detect more than 50  copies/ml.

RESULTS

No patient manifested moderate/severe adverse events associated with the use of Gadobutrol. Myocardial fibrosis was detected in 90 (21%) patients. Among the 312 patients tested for HCV-RNA, there was a significant correlation between the presence of myocardial fibrosis and CHC (P = 0.011). Among the 62 patients with myocardial fibrosis tested for HCV-RNA, we found a significantly higher prevalence of diabetes mellitus in CHC patients versus the no-CHC patients (P = 0.049).

CONCLUSION

Our findings support the use of the LGE CMR approach well tolerated in the thalassemia major patients with CHC. HCV infection can be involved in the pathogenesis of myocardial fibrosis through both myocarditis directly and the pancreas and liver damage with the development of diabetes indirectly. These patients could therefore benefit from cardioactive drugs and therapeutic interventions directed towards the eradication of virus.

Multiparametric Cardiac Magnetic Resonance Survey in Children With Thalassemia Major

Background—

Cardiovascular magnetic resonance (CMR) plays a key role in the management of thalassemia major patients, but few data are available in pediatric population. This study aims at a retrospective multiparametric CMR assessment of myocardial iron overload, function, and fibrosis in a cohort of pediatric thalassemia major patients.

Methods and Results—

We studied 107 pediatric thalassemia major patients (61 boys, median age 14.4 years). Myocardial and liver iron overload were measured by T2* multiecho technique. Atrial dimensions and biventricular function were quantified by cine images. Late gadolinium enhancement images were acquired to detect myocardial fibrosis. All scans were performed without sedation. The 21.4% of the patients showed a significant myocardial iron overload correlated with lower compliance to chelation therapy ( P <0.013). Serum ferritin ≥2000 ng/mL and liver iron concentration ≥14 mg/g/dw were detected as the best threshold for predicting cardiac iron overload ( P =0.001 and P <0.0001, respectively). A homogeneous pattern of myocardial iron overload was associated with a negative cardiac remodeling and significant higher liver iron concentration ( P <0.0001). Myocardial fibrosis by late gadolinium enhancement was detected in 15.8% of the patients (youngest children 13 years old). It was correlated with significant lower heart T2* values ( P =0.022) and negative cardiac remodeling indexes. A pathological magnetic resonance imaging liver iron concentration was found in the 77.6% of the patients.

Conclusions—

Cardiac damage detectable by a multiparametric CMR approach can occur early in thalassemia major patients. So, the first T2* CMR assessment should be performed as early as feasible without sedation to tailor the chelation treatment. Conversely, late gadolinium enhancement CMR should be postponed in the teenager age.