While beta-thalassemia was once a fatal disease, the implementation of iron chelation therapy and other medical advances in the past few decades have reduced mortality. With this change in outlook for childhood patients, medical complications associated with the disease can now be observed and managed as they reach adulthood.
In a new report published in Blood, 2 hematologist-physicians, Ali Taher, MD, PhD, FRCP of the American University of Beirut Medical Center in Lebanon, and Maria Domenica Cappellini, MD, of the University of Milan in Italy, describe how they manage beta-thalassemia and the major complications of the disease that emerge in adults in their mid-30s and beyond: arrhythmia, liver disease, thrombotic disease, and pulmonary hypertension.
The experience of Drs Cappellini and Taher is based on the management of approximately 1000 patients seen at their clinics. “When it comes to older patients, the main challenge is that patients may already have several comorbidities or comedications [that] may increase their susceptibility or decrease their tolerance to side effects [of iron chelators],” Drs Taher and Cappellini said in a joint statement to Hematology Advisor.
Addressing Beta-Thalassemia Complications
Drs Taher and Cappellini classify patients with beta-thalassemia according to the need for transfusion therapy, transfusion-dependent thalassemia, and non-transfusion-dependent thalassemia. Secondary iron overload (serum ferritin >800 ug/L or liver iron concentration >5 mg Fe/g dry weight) is a serious concern for patients receiving transfusion therapy. However, adherence to 1 of the 3 available iron chelators (deferoxamine, deferioprone, and deferasirox), optimal dosing, and side-effect monitoring are critical to managing iron loads and preventing heart failure in both non-transfusion- and transfusion-dependent patients.
The use of cardiac MRI imaging and improved patient adherence to iron chelators have reduced the incidence of heart failure in patients with beta-thalassemia, but other cardiac manifestations are often seen. Approximately 40% of patients over 40 years of age present with atrial fibrillation. Symptomatic arrhythmias may result from fibrosis after clearance of iron deposition and, therefore, may occur even in patients with currently normal iron levels.
Drs Taher and Cappellini recommend that electrocardiograms be conducted annually for all patients, biannually for asymptomatic patients with abnormalities, and at least monthly for symptomatic patients. In the case of cardiac iron overload or if iron status cannot be assessed, patients with transfusion-dependent thalassemia can often control their disease with increased iron chelation therapy.
Some other options for arrhythmia treatment exist. Catheter ablation may be used for chronic symptomatic arrhythmias and beta-blockers can help to control ectopic arrhythmias. Other medications such as amiodarone may be used; however, the authors warn that amiodarone has been associated with liver and thyroid function side effects, which can be problematic for patients with thalassemia. All cardiac care for patients with thalassemia should be supplemented with consultation from a cardiologist.
Excess iron is primarily stored in the liver. With improved patient therapy and reduced heart failure deaths, hematologists are seeing an increase in the rate of liver disease in adult patients. Liver disease is now a common cause of mortality in patients with transfusion-dependent thalassemia and accounts for approximately 10% of deaths in patients with non-transfusion-dependent thalassemia. In both types of patients, chronic hepatic iron deposition may lead to liver fibrosis and cirrhosis.