Cardiovascular Complications Of Thalassemia Patients In The Iron Chelation Therapy Era

Cardiac complications are the most common cause of death in thalassemia, accounting for up to 71% in the past. Iron chelation therapy is given to patients with iron overload to prevent these complications. The cost effectiveness of iron chelation therapy was arguable.

This study aims to evaluate the prevalence of cardiac complication and the correlation between risk factors in iron chelation therapy era.

This is a cross sectional study from June 2011- May 2012. All thalassemia aged > 15 years old were enrolled. Clinical data and hemoglobin typing were reviewed. Echocardiography and CMR T2*, a technique represent cardiac iron deposition used to evaluate cardiac function, were used to evaluate cardiac complications.

Ninety one patients were enrolled, 63.7% were females, median age of 31 years (16-75). There was 49.5 % homozygous β thalassemia, 31.9% β thalassemia/Hb E disease, 18.7% Hb H disease. Half of patients were transfusion dependent and 63.7% underwent splenectomy. Eighty four percent of patients received iron chelation therapy but few of them got their preferable choice in adequate dosage. Patients with serum ferritin levels more than 1,000 ng/ml. received deferoxamine, deferiprone or deferasirox.

Even with the iron chelation therapy, mean serum ferritin level was still high at 3,820 ng/ml for the whole group.

CMR T2* was more sensitive in detecting cardiac function. The CMR T2* showed shorter signal (≤ 20 msec) in 11.1%. Only 8.2% had impaired ejection fraction <55% by echocardiography. The CMR T2*  ≤ 20 msec was significant correlated with higher maximum ferritin 5,739.14 ng/ml compared to 3,614 ng/ml (p=0.001). Pulmonary hypertension was found 7 patients (12.7%) and 71.42% had underwent splenectomy.

From our study, the CMR T2* is the sensitive method for detecting cardiomyopathy and highly correlated with serum ferritin levels. Splenectomy remains the major risk factor for pulmonary hypertension.

The incidence of cardiac complications has decreased with iron chelation therapy for maintaining acceptable serum ferritin levels but the problem with cardiomyopathy and pulmonary hypertension still exist. Early detection, more sensitive implementation and aggressive iron chelation therapy are necessary to prevent these complications.

The majority of the patients in Thailand which are under universal health-care coverage scheme could not get access to more effective and expensive iron chelator. Regular and adequate chelation plays a major role in the prevention of cardiac complications and the achievement of better quality of life.

No relevant conflicts of interest to declare.