Observational study of Non-Invasive Venous waveform Analysis (NIVA) to assess intracardiac filling pressures during right heart catheterization.

Abstract

BACKGROUND\nOutpatient monitoring and management of patients with heart failure (HF) reduces hospitalizations and healthcare costs. However, the availability of non-invasive approaches to assess congestion are limited. Non-Invasive Venous waveform Analysis (NIVA) uses a unique physiologic signal, the morphology of the venous waveform, to assess intracardiac filling pressures. This study is a proof of concept analysis of the correlation between NIVA value and PCWP and the ability of NIVA value to predict PCWP >18 mmHg in subjects undergoing elective right heart catheterization (RHC). PCWP was also compared across common clinical correlates of congestion.\n\n\nMETHODS\nA prototype NIVA device which consists of a piezoelectric sensor placed over the skin on the volar aspect of the wrist, connected to a data capture control box, was used to collect venous waveforms in 96 patients during RHC. PCWP was collected at end-expiration by an experienced cardiologist. The venous waveform signal was transformed to the frequency domain (Fourier transform) where a ratiometric algorithm of the frequencies of the heart rate and its harmonics was used to derive a NIVA value.\n\n\nRESULTS\nNIVA values were successfully captured in 83 of 96 enrolled patients. PCWP ranged from 4 - 40 mmHg with a median of 13 mmHg. NIVA values demonstrated a linear correlation with PCWP (r=0.69, p<0.05).\n\n\nCONCLUSIONS\nThis observational proof of concept study utilizing a prototype NIVA device demonstrates a moderate correlation between NIVA value and PCWP in patients undergoing RHC. NIVA thus represents a promising developing technology for non-invasive assessment of congestion in spontaneously breathing patients.