Complex assessment of patients with decompensated heart failure: The clinical value of impedance cardiography and N-terminal pro-brain natriuretic peptide.

BACKGROUND: Acute decompensated heart failure (ADHF) is a serious clinical problem and a condition requiring immediate diagnostics, supporting the therapeutic decision adequate to the specific ADHF mechanism. N-terminal pro-brain natriuretic peptide (NT-proBNP) is an established biochemical marker of heart failure, strongly related to hemodynamic status. Impedance cardiography (ICG) provides non-invasive hemodynamic assessment that can be performed immediately at the bedside and revealed to be useful diagnostic tool in some clinical settings in cardiology.

OBJECTIVES: The aim of this study was to evaluate the usefulness of ICG in the admission diagnostics and monitoring the effects of treatment in patients hospitalized due to ADHF, with special emphasis on its relation to NT-proBNP.

METHODS: This study enrolled 102 patients, aged over 18 years, hospitalized due to ADHF. The subjects underwent detailed clinical assessment, including ICG and NT-proBNP at admission and at discharge day.

RESULTS: Among all analyzed ICG parameters thoracic fluid content (TFC), a marker of chest overload, was the most significantly correlated with NT-proBNP level (R = 0.46; p = 0.000001). In comparison with patients with low thoracic fluid content (TFC ≤ 35/kΩ), those with higher TFC values (>35/kΩ) exhibited a greater severity of symptoms (NYHA functional class); higher NT-proBNP levels; lower left ventricular ejection fraction (LVEF), stroke index (SI), and cardiac index (CI); as well as significantly higher systemic vascular resistance index (SVRI). These TFC-based subgroups showed no significant differences in terms of heart rate (HR), systolic blood pressure (SBP), or diastolic blood pressure (DBP).

CONCLUSIONS: The evaluation of hemodynamic parameters, especially TFC, seems to be a worthwhile addition to standard diagnostics, both at the stage of hospital admission and while monitoring the effects of treatment. Impedance cardiography is a useful method in evaluating individual hemodynamic profiles in patients with ADHF.