Simbaqueba, C et al. - Researchers assessed if myocardial structure, performance, and long-term clinical outcomes are impacted by a decrease of hemoglobin content in the erythrocytes as approximated by mean corpuscular hemoglobin concentration (MCHC). A total of 197 ambulatory patients with chronic systolic and symptomatic heart failure with a comprehensive echocardiographic evaluation were evaluated hematologic data and long-term outcomes. Reduced MCHC levels were linked with higher risk of death, transplant, or heart failure hospitalization after adjusting for age, LVEF, eGFR, and New York Heart Association class after a 5-year follow up, especially in conjunction with above-median hemoglobin. Relative hypochromia, defined as low MCHC, correlated with higher natriuretic peptide levels and lower estimated glomerular filtration rate and was modestly associated with indices of left and right ventricular diastolic dysfunction, but not left ventricular ejection fraction. In the setting of chronic systolic heart failure, relative hypochromia, especially without anemia, could indicate poor outcomes.