Clinical, demographic and instrumental characteristics of patients with chronic heart failure and reduced left ventricular ejection fraction depending on iron deficiency

Abstract

The aim  — to establish clinical and other factors associated with iron deficiency (ID) in patients with chronic heart failure (CHF) and reduced left ventricular (LV) ejection fraction (EF). Materials and methods. 134 stable patients with CHF (113 (84.3 %) men and 21 (15.7 %) women), 18 — 75 years old, NYHA class II — IV, with left ventricular ejection fraction < 40 % were screened on a basis of the Heart Failure Department of the National Scientific Center «M. D. Strazhesko Institute of Cardiology» of NAMS of Ukraine in the period from January 13, 2016 till February 28, 2018. Patients were included in a clinical compensation phase. Quality of life was assessed by the Minnesota living with heart failure questionnaire (MLHFQ), physical activity was estimated by the Duke University index, functional status — by assessing the 6­minute walking test (6MWT) and a standardized lower limb extension test. Results and discussion. ID was found in 83 (61.9 %) of 134 patients with CHF and reduced LVEF. They did not differ in regard of presence of coronary artery disease, arterial hypertension, dilated cardiomyopathy, myocardial infarction, persistent/long standing form of atrial fibrillation, chronic obstructive pulmonary disease and diabetes mellitus. There were no significant differences in demographic, clinical and instrumental indices such as gender, age, heart rate, end­diastolic volume index, brachial artery flow­dependent vasodilation in groups with and without ID. However, patients with ID were in more severe (III — IV) NYHA class and inclined to have anemia and worse renal dysfunction. The ID group was characterized by a slightly lower body mass index (BMI) and level of systolic blood pressure (SBP), a higher N­terminal prohormone of brain natriuretic peptide (NTproBNP) level, a lower hemoglobin, lower MCV, MCH, a higher interleukin­6 (IL­6) level, and a lower glomerular filtration rate, as well as a worse quality of life by MLHFQ, worse 6MWT and lower limb extension test results. Ferritin has shown a significant direct correlation with serum iron levels, MCV, MCH, hemoglobin and BMI levels. Transferrin saturation (TSAT) level directly correlated with a serum iron level, hemoglobin, MCV and MCH levels, limb muscles endurance, 6­minute walking test result, SBP, BMI, physical activity index and reversely correlated with citrulline, NTproBNP, IL­6 levels in blood plasma and MLHFQ score. Conclusions. Iron deficiency was observed in 62 % of patients with CHF and reduced LVEF. CHF patients with reduced LVEF and ID versus CHF patients with reduced LVEF without ID had a higher NYHA III — IV class patients percentage, a greater proportion of patients with anemia and greater renal dysfunction, lower BMI, SBP, lower hemoglobin, MCV, MCH; higher NTproBNP, IL­6, citrulline levels; worse quality of life, lower physical activity index, lesser 6MWT distance and lesser quadriceps femoris muscle endurance. Unlike the ferritin plasma level, that correlates only with hemoglobin level and iron metabolism indices, TSAT showed the connection not only with the indicated parameters, but also with the BMI, SBP, physical activity index, 6MWT, quadriceps femoris muscle endurance (direct correlation) and with citrulline, IL­6, NTproBNP plasma levels and quality of life by MLHFQ (reverse correlation).