[Iron deficiency in cardiovascular disease]

Iron deficiency is worldwide the most frequently occurring deficiency of a trace element. Meanwhile, the indications are increasing that iron deficiency plays a relevant role in many cardiovascular diseases and that treatment is accessible with intravenous administration of iron.

The aim of this article is to elucidate the clinical comorbidities, diagnostic dilemmas and treatment possibilities of iron deficiency in cardiovascular diseases. The study situation on iron deficiency and iron substitution in heart failure, aortic valve stenosis, atrial fibrillation and pulmonary hypertension (PH) is summarized.

The diagnostic criteria of iron deficiency in cardiovascular diseases are not finally decided. The guidelines of the European Society of Cardiology recommend either ferritin below 100 ng/ml alone or ferritin between 100 and 299 ng/ml with a transferrin saturation (TSAT) < 20 %. Some authors consider the determination of TSAT as sufficient as the only diagnostic criterion for iron deficiency in heart failure. Most studies on iron substitution in heart failure showed an improvement in the physical capacity and a reduction of the probability of a heart failure-related hospitalization by the substitution of an existing iron deficiency; however, it has been determined that a relevant proportion of patients show no response to iron substitution and that the cause for this is ultimately unclear. Whether the diagnostic criteria for iron deficiency in heart failure can be transferred to other cardiovascular symptoms, cannot be clearly answered due to the lack of data from prospective interventional studies.

The substitution of iron deficiency is one of very few possibilities to improve the physical capability in heart failure. The pivotal point of the discussion on iron deficiency and substitution in cardiovascular diseases is the correct identification of patients who benefit from treatment.