Amino-terminal pro-B-type natriuretic peptide, inferior vena cava ultrasound, and biolectrical impedance analysis for the diagnosis of acute decompensated CHF.

BACKGROUND: Both Framingham criteria and natriuretic peptides (NPs) may worsen their diagnostic validity for acute decompensated heart failure (ADHF) in elderly patients with comorbidities, mainly renal failure. Ultrasound of inferior vena cava (IVCu) and bioelectrical impedance analysis (BIA) are useful tools for detecting ADHF, although their utility compared with NP is not fully established.

METHODS AND RESULTS: We conducted a prospective study with 96 patients who presented at the emergency department with dyspnea and were classified as ADHF and non-ADHF groups. Inferior vena cava ultrasonography measured maximum and minimum inferior vena cava diameters and collapsibility index (CIx), whereas BIA calculated resistance (Rz) and reactance (Xc). The primary goal was to compare amino-terminal pro-B-type NP (NT-proBNP), IVCu, and BIA for identifying ADHF. The ADHF group showed significantly (P<.001) higher NT-proBNP values (5801 vs 599 pg/mL), higher maximum IVC diameter (2.26 vs 1.58 cm), higher minimum IVC diameter (1.67 vs 0,7 cm), and lower CIx (27% vs 59%), as well as lower Rz (458.8 vs 627.1 Ohm) and lower Xc (23.5 vs 38.4 Ohm) compared with the non-ADHF group. The estimated area under the curve for ADHF diagnosis was 0.84 for NT-proBNP, 0.90 for maximum IVC diameter, 0.93 for minimum IVC diameter, and 0.90 for CIx, as well as 0.83 and 0.80 for Rz and Xc respectively, without finding significant difference. Cutoff values for diagnosis of ADHF with IVCu and BIA are proposed. Amino-terminal pro-B-type NP values significantly varied in patients with renal impairment, independently of ADHF status, whereas neither IVCu nor BIA did.

CONCLUSIONS: Inferior vena cava ultrasonography and BIA analysis are as useful as NT-proBNP to ADHF diagnosis, validated in an elderly population with kidney disease.