According to the results of a study published in Pediatric Blood & Cancer, amlodipine appears to be safe and more effective in reducing cardiac iron overload when combined with chelation therapy than chelation therapy alone in children and young adults with transfusion-dependent thalassemia (TDT).
The investigators hypothesized that amlodipine, an L-type calcium channel blocker, with regular chelation therapy may reduce myocardial iron overload, a major cause of morbidity and mortality in patients with TDT. They conducted randomized, double-blind, placebo-controlled trial to evaluate the efficacy and safety of amlodipine in addition to standard chelation therapy in reducing iron levels in pediatric patients with TDT. The primary outcome of the study was 12-month change in myocardial iron concentration (MIC) from baseline, determined by T2* magnetic resonance imaging (MRI) values. Secondary outcomes included 12-month change in liver iron concentration (LIC), left ventricular ejection fraction (LVEF), and serum ferritin from baseline.
A total of 64 patients (80% male and 20% female) were randomly assigned (1:1) to receive either amlodipine with chelation therapy (n = 32) or chelation therapy alone (control; n = 32). At baseline, the groups had similar patient and clinical characteristics. Most patients (53%) were between 6 to 10 years of age (mean, 10.6 years, for both groups).
At 12 months, the mean cardiac T2* value significantly increased from baseline 18.11 ± 8.47 to 22.15 ± 7.61 (P =.002) in the amlodipine group and showed a nonsignificant increase from 19.50 ± 8.84 to 20.03 ± 9.07 (P =.62) in the control group. The 12-month mean MRI-derived MIC was significantly lower in the amlodipine group compared with control group (1.93 vs 1.29; P =.01). Mean changes in the LVEF (P =.45), MRI-derived LIC (P =.09), and serum ferritin (P =.81) were not significantly different between the groups.
Limitations of the study included that, as a time-saving measure, MRI was not used to calculate the LVEF and that signal-intensity ratios on gradient echo images were used to determine LIC.
Gupta V, Kumar I, Raj V, Aggarwal P, Agrawal V. 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. Pediatr Blood Cancer. Published online January 29, 2022. doi:10.1002/pbc.29564