Prognostic Value of Transthoracic Impedance Cardiography, Amino-Terminal Pro-B-Type Natriuretic Peptide Levels, The Six-Minute Walk Test, and Chest X-Ray in Elderly Patients with Chronic Heart Failure: A Comparative Study in Lithuania

BACKGROUND Chronic heart failure (CHF) is a complex clinical syndrome associated with frequent, recurrent, and long-term hospitalizations. This study from a single center in Lithuania aimed to evaluate outcomes in 87 elderly patients hospitalized with CHF. The methods used included comparing transthoracic impedance cardiography (ICG), amino-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, the six-minute walk test (6MWT), and dilatation of the right pulmonary artery on chest X-ray (dRPAcXR). MATERIAL AND METHODS The study sample consisted of 87 patients (49 men and 38 women). All subjects underwent 6MWT and ICG in addition to the standard CHF tests. The median duration of the follow-up was 23 months. Data about patient outcomes were gathered from the National Medical Record Database. RESULTS By multivariate Cox proportional analysis, thoracic fluid content (TFC) ≥41.1 1/kΩ (hazard ratio [HR] 32.354, 95% confidence interval [CI] 2.758-379.488), NT-proBNP ≥332.0 pmol/L (HR 4.739, 95% CI 1.656-13.559), 6-minute walk distance (6MWD) ≤203.5 m (HR 3.975, 95% CI 1.002-15.770), and dRPAcXR (HR 5.555, 95% CI 1.714-18.005) were associated with a poor prognosis in CHF patients (all P<0.05). The correlations between ICG and 6MWD and other non-invasive diagnostic tests examined in this study were weak to moderate. CONCLUSIONS TFC ≥41.1 1/kΩ, NT-proBNP ≥332.0 pmol/L, 6MWD ≤203.5 m, and dRPAcXR had a combined prognostic value in predicting cardiovascular death in patients with CHF. Therefore, these parameters may be of value in the assessment of the diagnosis and prognosis in this patient cohort.