Diagnosing and Managing Diastolic Dysfunction with Iron Deficiency

Introduction to Diastolic Dysfunction

The American College of Cardiology recommends that iron deficiency without overt anemia should be treated, as it causes lethargy, reduced performance, and impaired cardiac function, particularly in patients with diastolic dysfunction 1, 3
Iron deficiency can independently cause severely reduced stroke volume index through multiple mechanisms, including decreased oxygen delivery, impaired oxidative metabolism in cardiac myocytes, and reduced exercise capacity, even with normal hemoglobin 1, 2, 3

The European Society of Cardiology diagnostic criteria for heart failure with preserved ejection fraction (which includes diastolic dysfunction) require an E/e' ratio via tissue Doppler, with E/e' >15 confirming diastolic dysfunction, E/e' 8-15 requiring additional testing, and E/e' <8 suggesting normal diastolic function 4
Left atrial volume index (LAVI) >34 ml/m² indicates chronically elevated filling pressures, which is a key parameter in diagnosing and grading diastolic dysfunction 4

The European Society of Cardiology recommends IV iron (specifically ferric carboxymaltose) for symptomatic heart failure patients with iron deficiency (ferritin <100 μg/L or ferritin 100-300 μg/L with TSAT <20%), as it improves NYHA functional class, 6-minute walk test, quality of life, and reduces hospitalizations 7
Oral iron is inadequate for cardiac dysfunction, and IV iron therapy has proven cardiac benefit independent of anemia correction, with expected improvement in exercise tolerance and functional status within weeks of treatment 2, 7

Intravenous iron therapy is indicated for iron deficiency, particularly given cardiac symptoms and severely reduced stroke volume index, with a recommended total iron need based on hemoglobin and body weight 1, 2, 7
The American College of Cardiology and the European Society of Cardiology emphasize the importance of treating iron deficiency in patients with heart failure, including those with diastolic dysfunction, to improve cardiac function and reduce morbidity 1, 7