COMPARATIVE CHARACTERISTICS OF THE FUNCTIONAL PARAMETERS IN PATIENTS WITH CHRONIC HEART FAILURE WITH REDUCED LEFT VENTRICULAR EJECTION FRACTION DEPENDING ON IRON DEFICIENCY TYPE

An in-depth study of the combination of iron deficiency (ID) with chronic heart failure (CHF) is resulted from the extremely high prevalence of iron metabolism disorders among patients with cardiovascular pathology. Objective. To compare the functional state and effort tolerance by means of the six-minute walk test in patients with chronic heart failure with reduced left ven-tricular ejection fraction depending on iron deficiency type. Materials. 152 patients with CHF functional class (FC) II-III according to NYHA with reduced left ventricular (LV) ejection fraction (EF) of hypertensive and ischemic etiology with/and without iron deficiency (ID) were examined. All patients were divided into three clinical groups: the first clinical group (which is presented as a comparison group) amounted to 30 (19.7%) patients with CHF with reduced LV EF without ID, the second one amounted to 60 (39.5%) patients with CHF with reduced LV EF and latent ID, which included a number of patients with functional and absolute ID and the third clinical group amounted to 62 (40.79 %) patients with I-II severity degree of concomitant iron deficiency anemia (IDA). In order to assess effort tolerance (ET), all patients underwent the six-minute walk test and the registration frequency of different FC of CHF according to NYHA was analyzed. The comparison of the obtained findings was carried out among groups of patients with CHF with reduced LV EF without iron metabolism disorders, with functional ID and absolute ID, and among groups of patients with CHF with reduced LV EF without iron metabolism disorders, with I degree of IDA and II degree of IDA. Research findings. In patients with I-II severity degree of concomitant IDA as well as in patients with latent functional ID and absolute ID as compared to patients without ID there was a significant predominance by the registration frequency of cases of CHF FC III over CHF FC II. Comparative analysis of the median values of the six-minute walk test distance showed significantly shorter distances in patients with functional ID and abso-lute ID as compared to patients in the group without ID (287, p=0.04; 282.5, p=0.002 vs. 300 m, respectively). The difference between the groups with functional ID and with absolute ID is unreliable (p=0.42). In patients with I severity degree of IDA the covered six-minute walk test distance in meters was significantly lower as opposed to the comparison group – the median value was 250 m (p=0.0001). The median value of the covered distance by patients with II severity degree of IDA was 247 m, which also significantly differed from the group without ID (p<0.0001). Among the indices of iron metabolism cor-relative interconnections between the levels of transferrin saturation with iron (TSI), serum iron (SI) and FC of HF rs=-0.28 (p=0.001) and rs=-0.18 (p=0.03), respectively were detected, and the covered six-minute walk test dis-tance rs=0.45 (P0,000001) and rs=0.34 (p=0.00002), respectively. Conclusions. Patients with CHF with reduced LV EF and concomitant ID, regardless of the presence of anemia, are characterized by a higher frequency of FC III according to NYHA and low ET. Moreover, functional and absolute ID has the same clinical relevance in terms of the functional ability of patients. Taking into account the detected dependence between TSI levels, iron content in blood serum, functional state of patients with CHF, it is TSI and total iron content in blood serum which can be regarded as markers of severe CHF with ID.