IVC diameter in patients with chronic heart failure: relationships and prognostic significance.

OBJECTIVES

The aim of this study was to assess the relation between inferior vena cava (IVC) diameter, clinical variables, and outcome in patients with chronic heart failure (HF).

BACKGROUND

The IVC distends as right atrial pressure rises. Therefore it might represent an index of HF severity independent of left ventricular ejection fraction (LVEF). The relation between IVC diameter and other clinical variables and its prognostic significance in patients with HF has not been explored.

METHODS

Outpatients attending a community HF service between 2008 and 2010 were enrolled. Heart failure was defined as the presence of relevant symptoms and signs and objective evidence of cardiac dysfunction: either LVEF <45% or the combination of both left atrial dilation (≥4 cm) and raised amino-terminal pro-brain natriuretic peptide (NT-proBNP) ≥400 pg/ml. Patients were followed for a median of 567 (interquartile range: 413 to 736) days. The primary composite endpoint was cardiovascular death and HF hospitalization.

RESULTS

Among the 693 patients enrolled, median age was 73 years, 33% were women, and 568 had HF. Patients with HF in the highest tertile of IVC diameter were older; had lower body mass index; were more likely to have atrial fibrillation and to be treated with diuretics; and had larger left atrial volumes, higher pulmonary pressures, and less negative values for global longitudinal strain. The LVEF and systolic blood pressure were similar across tertiles of IVC diameter. The IVC diameter and log [NT-proBNP] were correlated (r = 0.55, p < 0.001). During follow-up, 158 patients reached a primary endpoint. In a multivariable Cox regression model, including NT-proBNP, only increasing IVC diameter, urea, and the trans-tricuspid systolic gradient independently predicted a poor outcome. Neither global longitudinal strain nor LVEF were adverse predictors.

CONCLUSIONS

In patients with chronic HF with or without a reduced LVEF, increasing IVC diameter identifies patients with an adverse outcome.