New evidence has revealed that iron deficiency is associated with unfavourable haemodynamics and worsening of New York Heart Assocation (NYHA) functional class in patients with idiopathic pulmonary arterial hypertension (IPAH), indicating that treatment of iron deficiency should be considered in these patients.
IPAH is a life-threatening disease, characterised by the proliferation of the small pulmonary arteries, and subsequent development of vascular lesions. Patients present with nonspecific symptoms including fatigue, dizziness and dysponea during exertion. Previous studies have shown that iron deficiency is common in IPAH patients; however, it is unclear whether the condition reduces exercise capacity or influences the natural progression of IPAH directly. This study aimed to investigate whether iron deficiency is related to cardiac performance, pulmonary artery pressure and pulmonary vascular response to hypoxia in IPAH patients.
Haemodynamic, echocardiographic and exercise parameters were evaluated in 29 IPAH patients. Iron deficiency was present in 44.8% (n=13) of IPAH patients. Despite having a similar exercise capacity (6-minute walk test: 421 ± 193 vs. 446 ± 141 m, respectively; p=0.719), 46.2% of iron deficient patients reported NYHA functional class 3 or higher, compared to only 12.5% of iron replete patients (p=0.044). Iron deficient patients also demonstrated an increased mean pulmonary arterial pressure (63.3 ± 12.2 vs 38.8 ± 16.7 mmHg; p=0.037), reduced cardiac index (1.4 ± 0.2 vs 2.5 ± 0.4 L/min/m2; p=0.001) and increased pulmonary vascular resistance (19.9 ± 6.9 vs 7.2 WU; p=0.010). Left ventricular systolic and diastolic function, and right ventricular function was similar between groups.
Iron deficiency is prevalent in IPAH patients and is associated with worse cardiac performance. While the exact mechanism causing iron deficiency in IPAH patients is still unclear, the authors concluded that treatment of iron deficiency should be considered in IPAH patients.
The full article is available in the March 2014 issue of Heart, Lung and Circulation. For information on iron deficiency in cardiology, please click here.