Replacement therapy for iron deficiency improves exercise capacity and quality of life in patients with cyanotic congenital heart disease and/or the Eisenmenger syndrome

Abstract

Introduction: Iron deficiency is common in cyanotic congenital heart disease (CHD) and results in reduced exercise tolerance. Currently, iron replacement is advocated with limited evidence in cyanotic CHD. We investigated the safety and efficacy of iron replacement therapy in this population.

Methods: Twenty-five iron-deficient cyanotic CHD patients were prospectively studied between August 2008 and January 2009. Oral ferrous fumarate was titrated to a maximum dose of 200mg thrice-daily. The CAMPHOR QoL questionnaire, 6 minute walk test (6MWT) and cardiopulmonary exercise testing were conducted at baseline and after 3 months of treatment.

Results: Mean age was 39.9 ± 10.9 years, 80% females. Fourteen had Eisenmenger syndrome, 6 complex cyanotic disease and 5 Fontan circulation. There were no adverse effects necessitating termination of treatment. After 3 months of treatment, hemoglobin (19.0 ± 2.9 g/dL to 20.4 ± 2.7 g/dL, p<0.001), ferritin (13.3 ± 4.7 μg/L to 54.1 ± 24.2 μg/L, p<0.001) and transferrin saturation (17.8 ± 9.6% to 34.8 ± 23.4%, p<0.001) significantly increased. Significant improvements were also detected in the total CAMPHOR score (20.7 ± 10.9 to 16.2 ± 10.4, p=0.001) and 6MWT distance (371.7 ± 84.7 m to 402.8.0±74.9m, p=0.001). Peak VO(2) remained unchanged (40.7 ± 9.2% to 43.8 ± 12.4% of predicted, p=0.15).

Conclusion: Three months of iron replacement therapy in iron-deficient cyanotic CHD patients was safe and resulted in significant improvement in exercise tolerance and quality of life. Identification of iron deficiency and appropriate replacement should be advocated in these patients.