P5417Splenic volume changes as a hemodynamic parameter in advanced heart failure with left ventricular assist device
Authors: Hiraiwa H , Okumura T , Sawamura A , Kondo T , Arao Y , Oishi H , Kato H , Kuwayama T , Yamaguchi S , Haga T , Yokoi T , Fukaya K , Furusawa K , Morimoto R , Murohara T 
Published: October 2019

Abstract

Background
The spleen has been recognized as an important organ to reserve 20–30% of the total blood volume. Generally, splenomegaly has been thought to be related to congestion. However, in the setting of hypovolemic shock or hypoxemia, it has been reported that spleen contracted and splenic volume decreased. On the other hand, in advanced heart failure (HF), the hemodynamics is characterized by both low cardiac output (LO) and systemic congestion, and patients sometimes need support of left ventricular assist device (LVAD). However, it remains unclear about the association between spleen size and hemodynamic parameters in patients with LO who need LVAD support.

Purpose
The purpose of this study was to investigate the relationship between spleen size and hemodynamic parameters in advanced HF before and after LVAD implantation.

Methods
We enrolled 12 advanced HF patients with LVAD (11 males, 45±10 years). All patients underwent blood test, echocardiography, right heart catheterization, and computed tomography (CT) before and after LVAD implantation. Spleen size was measured by CT volumetry. We excluded patients with splenic infarction, or any infections, or mean right atrial pressure (RAP) <5mmHg because of a possibility of hypovolemic status. LO was defined as CI less than 2.2L/min/m2.

Results
At pre- and post-LVAD implantation, cardiac output, cardiac index (CI), mean RAP, and mean pulmonary capillary wedge pressure were 3.1±0.6 vs. 4.9±0.9L/min, p=0.002; 1.7±0.3 vs. 2.8±0.3L/min/m2, p=0.002; 14±5 vs. 9±3mmHg, p=0.059; and 30±7 vs. 10±3mmHg, p=0.002, respectively. The serum brain natriuretic peptide level had significantly decreased (1101 [517–1446] vs 74 [35–216] pg/mL, p=0.002). In all patients, CI had increased to over 2.2L/min/m2. The splenic volume significantly increased from pre- to post-LVAD implantation (172±48 vs. 233±78mL, p=0.002) (Figure). Furthermore, all patients were divided into two groups; elevated RAP group (n=4) and non-elevated RAP group (n=8) after LVAD support. In elevated RAP group, there were no significant changes in the spleen size between pre- and post-LVAD implantation (167±45 vs. 223±111mL, p=0.068). On the other hand, in non-elevated RAP group, the spleen volume had significantly increased from pre- to post-LVAD support (172±53 vs. 231±62mL, p=0.011). In addition, there was one patient whose hemodynamic state had changed to LO again because of LVAD failure due to pump thrombosis. In this case, the splenic volume was 212mL before LVAD implantation with LO, and increased to 418mL after LVAD implantation with non-LO, although decreased to 227mL after LVAD pump failure with LO again.
Splenic volume changes

Conclusions
The spleen may change its size in order to keep cardiac output by regulating cardiac preload depending on the systemic perfusion in advanced HF with LVAD.

Acknowledgement/Funding
None