Comparison of the effects of calcium channel blockers plus iron chelation therapy versus chelation therapy only on iron overload in children and young adults with transfusion-dependent thalassemia: A randomized double-blind placebo-controlled trial.

BACKGROUND: Myocardial iron deposition is a significant cause of morbidity and mortality in patients with transfusion-dependent thalassemia (TDT). Amlodipine, L-type calcium channel blocker with regular chelation therapy may reduce myocardial iron overload. Lack of randomized trials prompted this study to assess the effect of calcium channel blocker (amlodipine) in combination with iron chelation therapy on iron overload in patients with TDT.

METHODS: Sixty-four eligible patients were randomized to receive either amlodipine and chelation (group A) or chelation alone (group B) in double-blind placebo-controlled trial. Myocardial iron concentration (MIC) using T2* magnetic resonance imaging (MRI), liver iron concentration (LIC), left ventricular ejection fraction (LVEF), and serum ferritin were measured at baseline and 12 months.

RESULTS: In the amlodipine group, mean cardiac T2* value significantly increased from 18.11 ± 8.47 to 22.15 ± 7.61 (p = .002) at 12 months, whereas in control group, there was a nonsignificant increase (p = .62) in cardiac T2* value from 19.50 ± 8.84 to 20.03 ± 9.07. There was a significant decrease in MRI-derived MIC in the amlodipine group compared to control group (1.93 ± 1.61 to 1.29 ± 0.90, p = .01). Changes in the LVEF (p = .45), MRI-derived LIC (p = .09), and serum ferritin (p = .81) were not significant between the two groups.

CONCLUSION: Amlodipine is safe and when combined with chelation therapy appears to be more effective in reducing cardiac iron overload than chelation only in children and young adults with TDT.