Efficacy and safety of calcium channel blockers in preventing cardiac siderosis in thalassemia patients: An updated meta-analysis with trial sequential analysis.

Abstract

Iron overload in patients with thalassemia represents a serious complication by affecting numerous organ systems. This meta-analysis aims to establish an evidence regarding the effect of amlodipine on cardiac iron overload in thalassemia patients. We searched PubMed, Scopus, Web of Science, Cochrane Central, and EMBASE for all relevant randomized controlled trials (RCTs). The primary outcomes were cardiac T2* and myocardial iron concentration (MIC). Secondary outcomes were liver iron concentration (LIC), risk of Gastrointestinal (G.I.) upset and risk of lower limb edema. We used Hedges' g to pool continuous outcomes, while odds ratio was used for dichotomous outcomes. Seven RCTs were eligible for this systematic review and meta-analysis, comprising of 233 patients included in the analysis. Amlodipine had a statistically significant lower MIC (Hedges' g= -0.82, 95% confidence interval [CI] [-1.40, -0.24], p< .001) and higher cardiac T2* (Hedges' g= 0.36, 95% CI [0.10, 0.62], p= .03). Amlodipine was comparable to standard chelation therapy in terms of the risk of lower limb edema and GI upset. Our meta-analysis found that amlodipine significantly increases cardiac T2* and decreases MIC, hence decreasing the incidence of cardiomyopathy-related iron overload in thalassemia patients.