Inferior Vena Cava Diameter Independently Predicts Acute Decompensated Heart Failure Rehospitalizations

Abstract

<h3>Objectives</h3> The aim of this study was to assess the relationship between inferior vena cava (IVC) diameter, clinical variables, and acute decompensated heart failure (ADHF) rehospitalizations. Background: The vast majority of ADHF hospitalizations are due to symptomatic volume overload rather than low cardiac output. Serial volume status assessment is crucial in ADHF yet routinely used measures are inexact. IVC diameter may be a surrogate for volume status in ADHF. The utility of IVC diameter measurement is under studied. <h3>Methods</h3> Retrospective chart review was conducted for 200 patients admitted from 2018-2019 for primary diagnosis of ADHF who had a transthoracic echocardiogram during the index hospitalization. Charts were assessed for ADHF rehospitalization within one year. Correlates of IVC diameter were determined using Pearson correlation coefficients. Unpaired t-test and chi-squared test were used to compare variables between groups. Univariable and multivariable cox proportional hazards regression analysis with forwards and backwards procedures were used to determine independent predictors of ADHF rehospitalization. Receiver operating curve was plotted for IVC diameter as a continuous variable in predicting rehospitalization. Optimal IVC diameter cut off was calculated by Youden index. Kaplan-Meier curve with log-rank statistic was used to assess rehospitalization within one year. <h3>Results</h3> The median age was 64, 30.5% were female, and average left ventricular ejection fraction was 41% ± 20%. IVC diameter correlated to pulmonary arterial (PA) pressure (R=0.347, P<0.0001) and body surface area (BSA) (R=0.424 P<0.0001). IVC diameter corrected for BSA correlated to PA pressure (R=0.287, P<0.0001) and log NT-proBNP (R=0.247, P=0.001). Patients rehospitalized within one year had significantly greater mean IVC diameter compared to those not rehospitalized (P<0.0001) while there was no difference in mean net weight lost during index hospitalization or mean log NT-proBNP. Patients with IVC diameter greater than 2.07 cm had significantly increased ADHF rehospitalization (85.6% vs 49.3%, log rank P<0.0001) with hazard ratio 2.44 (95% CI 1.85-3.23, P<0.0001). In multivariable cox regression only IVC diameter (P<0.0001), presence of tricuspid regurgitation (P=0.022), and NYHA class III/IV (P<0.0001) independently predicted ADHF rehospitalization within one year. <h3>Conclusions</h3> IVC diameter is predictive of rehospitalization in patients with ADHF and may identify patients in need of greater monitoring and diuresis. We are conducting a prospective study to further test this hypothesis.