A Prospective Pilot Study of Pocket-Carried Ultrasound Pre- and Postdischarge Inferior Vena Cava Assessment for Prediction of Heart Failure Rehospitalization

Background: Rehospitalization for heart failure (HF) is common, and subclinical congestion may be present at discharge. Larger inferior vena cava (IVC) size and lower collapsibility at discharge assessed via bedside ultrasound are predictive of rehospitalization; however, the utility of IVC assessment with the use of pocket-carried ultrasound (PCUS) during the transition from discharge to the posthospitalization follow-up visit (FU) has not been investigated. Methods and Results: IVC _max and IVC _min were measured with the use of PCUS, and the collapsibility index (IVCCI = [IVC _max − IVC _min ]/IVC _max ) was determined. The primary outcome was 90-day rehospitalization or death. We prospectively enrolled 49 adults (71 ± 13 years of age, 51% male, 47% black, 43% preserved ejection fraction) hospitalized for HF. Nineteen patients (39%) experienced the outcome. Within the rehospitalized group, discharge and FU mean IVC _max were both >2.1 cm (2.2 ± 0.5 and 2.2 ± 0.7) and IVCCIs <50% (44 ± 20% and 45 ± 24%). Within those not rehospitalized, FU IVC _max was ≤2.1 cm (2.1 ± 0.6 and 1.9 ± 0.6; P =.038) and IVCCI >50% at both time points (55 ± 25% and 62 ± 19%; P = NS). FU IVCCI below an optimal cutoff of 42% had modest discrimination alone (c-statistic = 0.73). FU IVCCI <42% was associated with a greater hazard of the outcome independent of admission log B-type natriuretic peptide (adjusted hazard ratio = 6.8; 95% confidence interval 2.4–19.0; P <.001). Conclusions: Posthospitalization IVCCI assessment with PCUS predicts HF rehospitalization and may identify patients in need of intervention.