Usefulness of Serial Measurements of Inferior Vena Cava Diameter by VscanTM to Identify Patients With Heart Failure at High Risk of Hospitalization

Abstract

Estimation of volume status is integral to heart failure (HF) management. Measurement of inferior vena cava (IVC) diameter (IVCd) by ultrasound provides a noninvasive estimate of right atrial pressures. The GE Vscan is a handheld ultrasound (HHU) device that allows for point-of-care measurements to assess volume status. We hypothesize that IVCd measurements using HHU can predict the risk of HF admission. We retrospectively analyzed a cohort of patients with HF treated in an ambulatory care setting over 17 months. Serial measurements of IVCd were obtained using HHU in the supine position from the subcostal window. Log-binomial regression models were used to compare IVCd measurements between patients with and without HF admissions and to estimate the association between IVCd and risk of HF admission. Of the 355 patients with systolic (38%) and diastolic HF (62%) who were analyzed, 45% were women with a mean age of 73 years at the time of the first IVCd measurement. Overall, 3,488 measurements were obtained, and 32.4% of patients were hospitalized during follow-up. Patients with at least 1 hospital admission had a greater mean IVCd than those who were not admitted (2.0 vs 1.8 cm, p <0.01). In our analysis, every 0.5-cm increase in the mean IVCd was associated with a 38% increase in risk of HF admission (risk ratio [RR] 1.38, 95% CI 1.16 to 1.62, p <0.01). The risk of HF admission was also significantly increased in patients with IVCd 2.0 to 2.49 cm (RR 1.79, 95% CI 1.27 to 2.52, p <0.01) and ≥2.5 cm (RR 2.39, 95% CI 1.55 to 3.67, p <0.01), compared with patients with an IVCd < 2.0 cm. Increasing IVCd as measured by HHU at the point-of-care is associated with an increased risk of HF admission and may provide clinically useful information at the point-of-care to guide HF management.