Changes of portal vein flow in heart failure patients with liver congestion

Abstract

Background: High right ventricular filling pressure lead to liver congestion and cause changes in portal vein (PV) flow. The goal of the study was to describe the changes of the PV flow in patients with an exacerbation of advanced chronic heart failure (HF) in relation to central hemodynamics and biochemical indicators of liver lesion.Patients and methods: 90 patients (76 males) aged 49.2±11.2 years admitted for an acute exacerbation of chronic HF based on severe left ventricular systolic dysfunction (LVEF 20±4,3%) were evaluated. PV flow was sampled from the main portal vein using the intercostal approach. Systolic and diastolic flow velocities were measured and the pulsatility index (PI, max - min PV flow velocity/max PV flow velocity) was calculated. Based on PI patients were assigned to the four groups. Group 1: patients with continuous or subcontinuous flow in PV, PI <0.5, n=13. Group 2: patients with pulsatile flow, PI = 0.5–0.99, n=35; Group 3: patients with intermittent flow (no portal flow during systole), PI=1, n=25. Group 4: patients with reverse flow in systole, PI >1, n=17.Results: The median of PI in all patients was 0.82 (0–2.0). PI ≥0.5 was found in 86% of the patients. There was a significant linear correlation of PI and right atrial pressure (RAP), pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (mPAP) (p<0.01, r=0.68, 0.51 and 0.49 resp.). Sixty seven (89%) out of 75 patients with RAP ≥8 mmHg had pulsatility index ≥0.5. Mean RAP was 7.2±3.1 mmHg in patients with continuous flow, 14.9±5.9 mmHg in the group with pulsatile flow pattern, and 20.1±6.3 and 21.1±6.5 mmHg in intermittent and alternating flow resp. (p<0,01). The values of serum total bilirubin (TB) in patients with continuous flow in the PV were significantly lower than in the remaining ones (11.6±4.7 vs. 28.6±10.4 umol/l, p<0.01). There was a significant difference in the concentration of serum TB among the group of patients with pulsatile and patients with alternating and intermittent flow in the PV (16.6±8.2 vs. 29.2±8.3 vs. 37.1±13.7 umol/ l, p<0.01).Conclusion: Analysis of Doppler traces of the PV in patients with HF can give an answer for at least two clinically relevant questions. Flow pulsatility increases with increasing right ventricular filling pressure so the analysis of the PV flow can detect elevation of the right atrial pressure. A finding of flat portal vein flow wave patterns in HF patients with signs of congestion draws attention to concurrent primary liver disease.