Azaraksh A1, Ivanov G2, Bulanova N2, Stazhadze L2, Nikolaeva M2, Vostrikov V2.
Treatment of congestive heart failure (CHF) remains one of the challenging problems in cardiology. In recent years, the method of multifrequency bio-impendancemetry is used in patients with CHF for the assessment of water imbalance and determination of its severity. The aim of the study was to determine the diagnostic capabilities of bio-impendancemetry in evaluation of the early manifestations of CHF. The study included 92 healthy individuals, and 335 patients who were hospitalized in the cardiology department with NYHA I-II functional class (FC) of chronic CHF. The echocardiography, rheography and biochemical examination were performed for determination of FC of CHF. Procedures were repeated at day 5 of hospitalization, 6-minute walk test was performed to assess physical tolerance and objectification of the functional status of patients with CHF. 45 patients had signs of CHF FC III-IV, therefore, they were excluded from the study. Analysis of endpoints was conducted by telephone survey in 1 year after discharge from the hospital. The results of the comparison of the predictive value of different methods for diagnosing CHF showed maximum sensitivity for brain natriuretic peptide (BNP) which was 82%, specificity was 88%. The 6-minute walk test showed the lowest values of sensitivity and specificity (sensitivity 67%, specificity 72%) as well as leg impedance at low frequencies (LF) (sensitivity 69%, specificity 74%). The values for the leg impedance at high frequencies (HF) were as follows: sensitivity 68%, specificity 97%. High predictive value of a positive result (PPV) was shown in phase angle (91%) and BNP (91%). Left ventricle ejection fraction(LVEF) measurements had the lowest PPV (72%).