Iron deficiency in patients with a Fontan circulation and its impact on exercise capacity
Rolf M F Berger,
Joost P van Melle,
Peter van der Meer,
Elke S Hoendermis,
Gaston van Hassel,
Sean C S Rivrud,
Frank J Timmerman,
Eryn T Liem
Affiliations
Rolf M F Berger
Center for Congential Heart Diseases, Department of Paediatric Cardiology, Beatrix Children`s Hospital, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Joost P van Melle
Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Peter van der Meer
Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Elke S Hoendermis
Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Gaston van Hassel
Center for Congential Heart Diseases, Department of Paediatric Cardiology, Beatrix Children`s Hospital, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Sean C S Rivrud
Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Frank J Timmerman
Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Eryn T Liem
Center for Congential Heart Diseases, Department of Paediatric Cardiology, Beatrix Children`s Hospital, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
Background Iron deficiency (ID) has been reported in patients with congenital heart disease. There is, however, a scarcity of data on its prevalence in patients with a Fontan circulation. The aim of this study is to investigate the prevalence of ID in Fontan patients and to investigate the association between ID and exercise capacity in this population.Methods and results Blood count and haematological parameters were determined in plasma of 61 Fontan patients (51% female, mean age 29±9 years). ID was defined as transferrin saturation (TSAT) ≤19.8%. The prevalence of ID was 36% (22/61 patients). Especially among women, the diagnosis of ID was highly prevalent (52%) despite normal haemoglobin levels (153.7±18.4 g/L). Mean ferritin levels were 98±80 µg/L and mean TSAT levels were 22%±12%. Cardiopulmonary exercise testing was performed in 46 patients (75%). Patients with ID had a lower peak oxygen uptake (V̇O2peak) (1397±477 vs 1692±530 mL/min; p=0.039), although this relationship was confounded by sex. The presence of ID increased the likelihood of not achieving a respiratory exchange ratio (RER) ≥1.1 by 5-fold (p=0.035).Conclusion ID is highly prevalent among patients with a Fontan circulation. V̇O2peak is lower in patients with ID. Fontan patients with ID are less likely to achieve an RER≥1.1 during cardiopulmonary exercise testing.
