Background Heart failure is one of the most costly diagnosis-related groups, largely because of hospital readmissions. Objective assessment of volume status to ensure optimization before hospital discharge could significantly reduce readmissions. We previously demonstrated an ultrasound method of quantifying percentage of cross-sectional area ( CSA ) change of the right internal jugular vein with Valsalva that reliably estimates central venous pressure. Methods and Results Patients admitted with acute decompensated heart failure ( ADHF ) underwent ultrasound measurements of the right internal jugular vein at end-expiration and during the strain phase of Valsalva to determine a percentage of CSA change. An initial subgroup of patients with right heart catheterization and accompanying ultrasound measurements of the right internal jugular vein identified a percentage of CSA change predictive of right atrial pressure ( RAP ) ≥12 mm Hg. Images of admitted ADHF patients were obtained at admission and discharge for final analysis. Simultaneous right heart catheterization and right internal jugular vein ultrasound measurements demonstrated that a <66% CSA change predicted RAP ≥12 mm Hg (positive predictive value: 87%; P<0.05, receiver operating characteristic curve). Elevated admission RAP by percentage of CSA change normalized by discharge ( P<0.05), indicating that this test is significantly responsive to therapeutic interventions. Using the cutoff value of 66% CSA change, normal RAP at discharge had 91% predictive value for patients avoiding 30-day readmission ( P<0.05). Conclusions This bedside ultrasound technique strongly correlates to invasive RAP measurement in ADHF patients, identifies restoration of euvolemia, and is predictive of 30-day ADHF readmission. This tool could help guide inpatient ADHF treatment and may lead to reduced readmissions.

Flexible electronics have enabled catheter-based intravascular sensing. However, real-time interrogation of unstable plaque remains an unmet clinical challenge. Here, we demonstrate the feasibility of stretchable electrochemical impedance spectroscopy (EIS) sensors for endoluminal investigations in New Zealand White (NZW) rabbits on diet-induced hyperlipidemia. A parylene C (PAC)-based EIS sensor mounted on the surface of an inflatable silicone balloon affixed to the tip of an interrogating catheter was deployed (1) on the explants of NZW rabbit aorta for detection of lipid-rich atherosclerotic lesions, and (2) on live animals for demonstration of balloon inflation and EIS measurements. An input peak-to-peak AC voltage of 10 mV and sweeping-frequency from 300 kHz to 100 Hz were delivered to the endoluminal sites. Balloon inflation allowed EIS sensors to be in contact with endoluminal surface. In the oxidized low-density-lipoprotein (oxLDL)-rich lesions from explants of fat-fed rabbits, impedance magnitude increased significantly by 1.5-fold across the entire frequency band, and phase shifted ~5° at frequencies below 10 kHz. In the lesion-free sites of the normal diet-fed rabbits, impedance magnitude increased by 1.2-fold and phase shifted ~5° at frequencies above 30 kHz. Thus, we demonstrate the feasibility of stretchable intravascular EIS sensors for identification of lipid rich lesions, with a translational implication for detecting unstable lesions.