Hyperdynamic circulation of advanced cirrhosis: a re-appraisal based on posture-induced changes in hemodynamics

The role of transjugular intrahepatic portosystemic shunt in patients with cirrhosis and ascites: Recent evolution and open questions

In selected patients with cirrhosis and ascites, transjugular intrahepatic portosystemic shunt (TIPS) placement improves control of ascites and may reduce mortality. In this review, we summarize the current knowledge concerning the use of TIPS for the treatment of ascites in patients with cirrhosis, from pathophysiology of ascites formation to hemodynamic consequences, patient selection, and technical issues of TIPS insertion. The combination of these factors is important to guide clinical decision-making and identify the best strategy for each individual patient. There is still a need to identify the best timing for TIPS placement in the natural history of ascites (recurrent vs. refractory) as well as which type and level of renal dysfunction is acceptable when TIPS is proposed for the treatment of ascites in cirrhosis. Future studies are needed to define the optimal stent diameter according to patient characteristics and individual risk of shunt-related side effects, particularly hepatic encephalopathy and insufficient cardiac response to hemodynamic consequences of TIPS insertion.

Covered transjugular intrahepatic portosystemic stent-shunt vs large volume paracentesis in patients with cirrhosis: A real-world propensity score-matched study

BACKGROUND

Refractory ascites has a 1-year survival rate of 50%. In selected patients, treatment options include liver transplantation (LT) or transjugular intrahepatic portosystemic stent shunt (TIPSS).

AIM

To assess the outcomes of patients who underwent a TIPSS compared to large volume paracentesis (LVP).

METHODS

Retrospective study of patients who underwent a covered TIPSS or LVP for refractory or recurrent ascites over 7 years. Primary outcome was transplant-free survival (TFS). Further analysis was done with propensity score matching (PSM).

RESULTS

There were 150 patients [TIPSS group (n = 75), LVP group (n = 75)]. Seven patients in the TIPSS group underwent LT vs 22 patients in the LVP group. Overall median follow up, 20 (0.47-179.53) mo. In the whole cohort, there was no difference in TFS [hazard ratio (HR): 0.80, 95% confidence interval (CI): 0.54-1.21]; but lower de novo hepatic encephalopathy with LVP (HR: 95%CI: 0.20-0.96). These findings were confirmed following PSM analysis. On multivariate analysis albumin and hepatocellular carcinoma at baseline were associated with TFS.

CONCLUSION

Covered TIPSS results in similar TFS compared to LVP in cirrhotic patients with advanced liver failure. Liver transplant assessment should be considered in all potential candidates for TIPSS. Further controlled studies are recommended to select appropriate patients for TIPSS.

Echocardiography in the Liver Transplant Patient

PURPOSE OF REVIEW

The aim of this study is to review current echocardiographic modalities utilized in the assessment of the preoperative liver transplant candidate with an emphasis on newer techniques. We sought to assess if newer methods imparted additional diagnostic or prognostic accuracy compared to prior methods based on existing studies.

RECENT FINDINGS

Standard dobutamine stress echocardiography offers important information regarding operative risk and post-operative survival in liver transplant candidates; however, technologies such as speckle-tracking echocardiography (STE) and evaluation of diastolic function have emerged as useful tools as well. 2D-STE and diastolic echocardiography offer additional parameters such as global longitudinal strain and measures of diastolic dysfunction that can better predict peri-operative and post-operative complications in liver transplant candidates. If able, practitioners should utilize these methods routinely in their assessment of liver transplant candidates.

Clinical implications of inducible left ventricular outflow tract obstruction among patients undergoing liver transplant evaluation

Introduction

Patients with end stage liver disease (ESLD) have a hyperdynamic state due to decreased systemic vascular resistance and increased cardiac output. Preoperative evaluation with dobutamine stress echocardiography (DSE) is used to risk-stratify patients prior to liver transplant. We sought to identify the impact of inducible left ventricular outflow tract obstruction (LVOTO) on DSE on post-operative liver transplant outcomes.

Methods

Patients with ESLD who underwent liver transplant at Cleveland Clinic between January 2007 and August 2016 were identified. Pre-operative DSE data, and post-operative intensive care unit (ICU) data were extracted. Patients with inducible LVOTO were compared to those without LVOTO.

Results

Of the 515 patients identified who underwent DSE prior to liver transplant, 165 (30%) were female, and 95 (18%) had LVOTO. There were no major differences in baseline characteristics between the two groups. In the LVOTO group, rest gradients were 10.8 ± 3 mm Hg while peak gradients were 90 ± 48.2 mm Hg. No significant differences in ICU length of stay or duration of mechanical ventilation between both groups were noted. There were 21 deaths at 30 days. There were 2 (2.1%) deaths in the LVOTO group, versus 19 (4.5%) deaths in the non LVOTO group (p = 0.28). Higher Model for End Stage Liver Disease (MELD) scores predicted longer duration of mechanical ventilation and ICU length of stay.

Conclusion

Inducible LVOTO on DSE does not adversely affect the short-term outcomes post liver transplant. Presence of inducible LVOTO should not be the mere reason to deny liver transplant among patients with ESLD.

Myocardial structural and functional changes in patients with liver cirrhosis awaiting liver transplantation: a comprehensive cardiovascular magnetic resonance and echocardiographic study

BACKGROUND

Cardiac dysfunction is increasingly recognized in patients with liver cirrhosis. Nevertheless, the presence or absence of structural alterations such as diffuse myocardial fibrosis remains unclear. We aimed to investigate myocardial structural changes in cirrhosis, and explore left ventricular (LV) structural and functional changes induced by liver transplantation.

METHODS

This study included 33 cirrhosis patients listed for transplantation and 20 healthy controls. Patients underwent speckle-tracking echocardiography and cardiovascular magnetic resonance (CMR) with extracellular volume fraction (ECV) quantification at baseline (n = 33) and 1 year after transplantation (n = 19).

RESULTS

CMR-based LV ejection fraction (CMRLV-EF) and echocardiographic LV global longitudinal strain (LV-GLS) demonstrated hyper-contractile LV in cirrhosis patients (CMRLV-EF: 67.8 ± 6.9% in cirrhosis vs 63.4 ± 6.4% in healthy controls, P = 0.027; echocardiographic GLS: - 24.2 ± 2.7% in cirrhosis vs - 18.6 ± 2.2% in healthy controls, P < 0.001). No significant differences in LV size, wall thickness, mass index, and diastolic function between cirrhosis patients and healthy controls were seen (all P > 0.1). Only one of the cirrhosis patients showed late gadolinium enhancement. However, cirrhosis patients showed a higher ECV (31.6 ± 5.1% vs 25.4 ± 1.9%, P < 0.001) than healthy controls. ECV showed a positive correlation with Child-Pugh score (r = 0.564, P = 0.001). Electrocardiogram-based corrected QT interval was prolonged in cirrhosis (P < 0.001). One-year post-transplantation, echocardiographic LV-GLS (from - 24.9 ± 2.4% to - 20.6 ± 3.4%, P < 0.001) and ECV (from 30.9 ± 4.5% to 25.4 ± 2.6%, P = 0.001) moved to the normal ranges. Corrected QT interval decreased after transplantation (from 475 ± 41 to 429 ± 30 msec, P = 0.001).

CONCLUSIONS

Myocardial extracellular volume expansion with augmented resting LV systolic function was characteristic of cirrhotic cardiomyopathy, which normalizes 1-year post-transplantation. Thus, myocardial extracellular expansion represents a structural component of myocardial changes in cirrhosis.

Left ventricular systolic function is associated with sympathetic nervous activity and markers of inflammation in cirrhosis

An accurate evaluation of cardiac function in patients with cirrhosis remains a challenge. We used robust echocardiographic indices to characterize left ventricular (LV) systolic function and its relationship to activation of the sympathetic nervous system and inflammation in 59 patients with cirrhosis and 59 age-matched controls. Additionally, in 11 patients we withdrew beta-blockers and diuretics and used phenylephrine and albumin infusion to evaluate the response to acute afterload and preload changes (interventional substudy). Measures of systolic LV function such as the ejection intraventricular pressure difference (EIVPD) and the systolic strain rate were higher in patients with cirrhosis than in controls (median [1st-3rd quartile], 4.0 [3.1-5.1] versus 2.9 [2.4-3.6] mm Hg and -1.3 [-1.6 to -1.1] versus -1.2 [-1.6 to -1.1)] s^-1 , respectively; P < 0.05 for both). EIVPD was related to the severity of liver disease (Model for End-Stage Liver Disease, rho = 0.45, P < 0.001), the degree of sympathetic nervous system activation (noradrenaline, rho = 0.26, P = 0.05; heart rate variability, rho = -0.43, P = 0.003), and treatment with beta-blockers (P = 0.001). In the interventional substudy, EIVPD was higher in patients with ascites (6.5 [5.4-8.5] versus 4.0 [3.9-5.1] mm Hg, P = 0.045). The decrease in EIVPD induced by phenylephrine was inversely related to baseline systolic function (P < 0.05) and associated with markers of systemic vasodilatation (nitric oxide, rho = -0.66, P = 0.06; diastolic blood pressure, rho = 0.68, P = 0.04) and inflammation (interleukin-1beta, rho = -0.80, P = 0.009).

CONCLUSION

LV systolic function is enhanced in cirrhosis due to augmented adrenergic tone and modulated by treatment with beta-blockers; acute afterload stress induces a deeper impairment of systolic function in patients with more advanced degrees of vasodilatation and inflammation; these changes in LV function related to cirrhosis can be assessed using robust echocardiographic methods. (Hepatology 2017;65:2019-2030).

The role of autonomic dysfunction in cirrhotic patients before and after liver transplantation. Review of the literature

In patients affected by hepatic cirrhosis, autonomic dysfunction is a common finding; usually it is asymptomatic but it may correlate with increased mortality and morbidity before, during and after liver transplant, due to hemodynamic instability in the course of stressful events like sepsis, gastrointestinal bleeding and reperfusion after transplantation surgery. Hyperdynamic circulation and hepatic dysfunction seem to play a role in the pathogenesis of autonomic dysfunction, even if pathophysiological mechanisms are not completely known. We present a revision of previous literature about prevalence, pathophysiological mechanisms, clinical features, and mortality and morbidity of autonomic dysfunction secondary to hepatic cirrhosis.

Decreased excitability and voltage-gated sodium currents in aortic baroreceptor neurons contribute to the impairment of arterial baroreflex in cirrhotic rats

Cardiovascular autonomic dysfunction, which is manifested by an impairment of the arterial baroreflex, is prevalent irrespective of etiology and contributes to the increased morbidity and mortality in cirrhotic patients. However, the cellular mechanisms that underlie the cirrhosis-impaired arterial baroreflex remain unknown. In the present study, we examined whether the cirrhosis-impaired arterial baroreflex is attributable to the dysfunction of aortic baroreceptor (AB) neurons. Biliary and nonbiliary cirrhotic rats were generated via common bile duct ligation (CBDL) and intraperitoneal injections of thioacetamide (TAA), respectively. Histological and molecular biological examinations confirmed the development of fibrosis in the livers of both cirrhotic rat models. The heart rate changes during phenylephrine-induced baroreceptor activation indicated that baroreflex sensitivity was blunted in the CBDL and TAA rats. Under the current-clamp mode of the patch-clamp technique, cell excitability was recorded in DiI-labeled AB neurons. The number of action potential discharges in the A- and C-type AB neurons was significantly decreased because of the increased rheobase and threshold potential in the CBDL and TAA rats compared with sham-operated rats. Real-time PCR and Western blotting indicated that the NaV1.7, NaV1.8, and NaV1.9 transcripts and proteins were significantly downregulated in the nodose ganglion neurons from the CBDL and TAA rats compared with the sham-operated rats. Consistent with these molecular data, the tetrodotoxin-sensitive NaV currents and the tetrodotoxin-resistant NaV currents were significantly decreased in A- and C-type AB neurons, respectively, from the CBDL and TAA rats compared with the sham-operated rats. Taken together, these findings implicate a key cellular mechanism in the cirrhosis-impaired arterial baroreflex.

Preoperative cardiovascular investigations in liver transplant candidate: An update

Cardiovascular complications are a major cause of morbidity and mortality in patients with end-stage liver disease (ESLD) undergoing liver transplantation. Identifying candidates at the highest risk of postoperative cardiovascular complications is the cornerstone for optimizing the outcome. Ischaemic heart disease contributes to major portion of cardiovascular complications and therefore warrants evaluation in the preoperative period. Patients of ESLD usually demonstrate increased cardiac output, compromised ventricular response to stress, low systemic vascular resistance and occasionally bradycardia. Despite various recommendations for preoperative evaluation of cardiovascular disease in liver transplant candidates, a considerable controversy on screening methodology persists. This review critically focuses on the rapidly expanding body of evidence for diagnosis and risk stratification of cardiovascular disorder in liver transplant candidates.

Pathophysiology of ascites formation in liver cirrhosis

Liver cirrhosis has a high morbidity and poses a large threat to human health worldwide. In China, viral hepatitis, especially hepatitis B, is the main pathogenic factor of liver cirrhosis. Ascites formation in cirrhosis is the result of combined action of portal hypertension and liver function impairment, and it is the most prominent clinical manifestation of decompensated cirrhosis. The understanding of pathophysiology of ascites formation can help provide more accurate treatment of this condition so as to alleviate patients' mental and economic burdens.

Non invasive continuous hemodynamic evaluation of cirrhotic patients after postural challenge

AIM

To assess whether Most Care is able to detect the cardiovascular alterations in response to physiological stress (posture).

METHODS

Non invasive hemodynamic was assessed in 26 cirrhotic patients compared to healthy subjects, both in the supine and standing positions.

RESULTS

In baseline conditions, when compared to healthy subjects, cirrhotic patients showed significantly lower values of dicrotic and diastolic pressures and systemic vascular resistance. While in the standing position, cirrhotic patients showed higher values of cardiac index, stroke volume index and cardiac cycle efficiency. When returning to the supine position, cirrhotic patients exhibited lower values of dicrotic and diastolic pressures and systemic vascular resistance in the presence of higher values of cardiac index, stroke volume index and cardiac cycle efficiency.

CONCLUSION

Most Care proved to be able to detect cardiovascular abnormalities bedside in the resting state and after postural challenge in cirrhotic patients.

Multivessel coronary artery disease predicts mortality, length of stay, and pressor requirements after liver transplantation

The optimal preoperative cardiac evaluation strategy for patients with end-stage liver disease (ESLD) undergoing liver transplantation remains unknown. Patients are frequently referred for cardiac catheterization, but the effects of coronary artery disease (CAD) on posttransplant mortality are also unknown. We sought to determine the contribution of CAD and multivessel CAD in particular to posttransplant mortality. We performed a retrospective study of ESLD patients undergoing cardiac catheterization before liver transplant surgery between August 1, 2004 and August 1, 2007 to determine the effects of CAD on outcomes after transplantation. Among 83 patients who underwent left heart catheterization, 47 underwent liver transplantation during the follow-up period. Twenty-one of all ESLD patients who underwent liver transplantation (45%) had CAD. Fifteen of the transplant patients with CAD (71%) had multivessel disease. Among transplant patients, the presence of multivessel CAD (versus no CAD) was predictive of mortality (27% versus 4%, P = 0.046), increased length of stay (22 versus 15 days, P = 0.050), and postoperative pressor requirements (27% versus 4%, P = 0.029). Interestingly, neither the presence of any CAD nor the severity of stenosis in any single coronary artery predicted mortality. Furthermore, none of the traditional clinical predictors (age, gender, diabetes, creatinine, ejection fraction, and Model for End-Stage Liver Disease score) were predictive of mortality among transplant recipients. In conclusion, multivessel CAD is associated with higher mortality after liver transplantation when it is documented angiographically before transplantation, even in the absence of severe coronary artery stenosis. This study provides preliminary evidence showing that there may be significant prognostic value in coronary angiography as a part of the pretransplant workup.

Cirrhotic cardiomyopathy

Cirrhotic cardiomyopathy is a clinical syndrome in patients with liver cirrhosis characterized by an abnormal and blunted response to physiologic, pathologic, or pharmacologic stress but normal to increased cardiac output and contractility at rest. As many as 50% of cirrhotic patients undergoing liver transplantation show signs of cardiac dysfunction, and 7% to 21% of deaths after orthotopic liver transplantation result from overt heart failure. In this review, we critically evaluate the existing literature on the pathophysiology and clinical implications of cirrhotic cardiomyopathy.

Doppler ultrasound of hepatic and system hemodynamics in patients with alcoholic liver cirrhosis

OBJECTIVE

The progression of liver cirrhosis eventually increases cardiac output, while blood pressure and systemic vascular resistance are reduced. A complex behavior of portal hemodynamic to hepatic artery and system circulation has not yet been presented. There is a lack in knowledge about the correlation of local and systemic circulation parameters to the degree of liver failure, with respect to presence of ascites and esophageal varices.

PATIENTS AND METHODS

The study sample was 76 patients hospitalized for established alcoholic liver cirrhosis. Patients were divided into groups according to Child-Pugh clinical score; grade A (n = 24), B (n = 18) and C (n = 18). Ascites was found in 28 patients and esophageal varices in 46. Portal vein flow velocity (PVFV), hepatic artery resistance index (HARI), heart and great vessels within mediastinal cavity were assessed with ultrasound devices equipped with spectral Doppler.

RESULTS

Significant differences in mean blood pressure, systemic vascular resistance index (SVRI) minute volume, cardiac index and PVFV were found in the group of patients with the most severe stage (C). In regard to presence of ascites statistically significant difference was observed in elevated mean blood pressure and SVRI. Correlation was found between conjugated HARI to blood pressure and to SVRI.

CONCLUSIONS

In patients with liver cirrhosis there is an inversely reciprocal relationship of conjugated HARI with PVFV, correlating to disease grade. PVFV in cirrhosis decreases and HARI values were over 0.7. Study demonstrated that combining echocardiography with abdominal Doppler ultrasound served as valuable non-invasive diagnostic insight in liver and systemic circulation among different grade of cirrhosis.

Liver-kidney pathophysiological interrelationships in liver diseases

On the basis of several clinical and experimental researches, it is possible today to deepen the different mechanisms regarding kidney and liver relationships. However, the most studied field remains the renal function during liver disease. These alterations can be divided into: 1. Renal functional impairment is mainly considered due to hemodynamic derangement with a progressive decrease in peripheral vascular resistance (PVR) and an increase in cardiac output and rate, characteristic of hyperdynamic circulation, and outer cortex renal ischemia. Two principal forms of RFI characterize the hepatorenal syndrome (HRS) while in the first stage is based on the simple decrease in renal clearances with avid sodium retention. 2. Metabolic renal damage is principally due to abnormal serum levels of bile acids, bilirubin and perhaps toxic hepatic molecules which induce tubular dysfunction leading to RTA, of which type I, in the incomplete form, is the most common, varying between 30% and 50% of cases. It is mainly studied during cholestatic disease. 3. Organic renal impairment is principally based on immunological response to viral antigens and abnormal hepatic products which lead to the presence of immunocomplexes and cryoglobulins on the blood which tend to be deposited in the subendothelial and subepithelial glomerular areas, inducing complement activation, mesangial cell proliferation and monocyte-macrophage cell infiltration.

The liver transplant recipient with cardiac disease

Liver transplantation is a stressful condition for the cardiovascular system of patients with advanced hepatic disease. The underlying hemodynamic and cardiac status of patients with cirrhosis is crucial to determine which patients should became recipients. Generally preoperative cardiovascular testing is performed on potential candidates who are more than 45 years old, or have diabetes mellitus, or peripheral vascular disease, or more than two standard cardiac risk factors. Recent data suggest that the prevalence of coronary artery disease among patients with cirrhosis is much greater than previously believed; it likely mirrors or exceeds the prevalence rate in the healthy population. The morbidity and mortality of patients with coronary artery disease who undergo orthotopic liver transplantation (OLT) without treatment are unacceptably high. In conclusion, accurate preoperative cardiac evaluation according to the new American Heart Association & American College of Cardiology should lead to detect and treat coronary artery disease before liver transplantation. In case of alcohol-related cardiomyopathy, portopulmonary hypertension, and hypertrophic cardiomyopathy, there should be a case-by-case discussion by the hepatologist and cardiologist to consider the patient for liver transplantation. No robust data are available on the impact of decompensated dilated heart failure in this setting. If a recipient with cardiac disease is scheduled for OLT, we strongly suggest advanced intra- and postoperative hemodynamic monitoring plus transesophageal echocardiography.

Role of echo Doppler ultrasonography in the evaluation of postprandial hyperemia in cirrhotic patients

AIM: To assess the role of echo-Doppler ultrasonography in postprandial hyperemia in cirrhotic patients by comparing the results with the hepatic vein catheterization technique.

METHODS: Patients with cirrhosis, admitted to the portal hemodynamic laboratory were included into the study. After an overnight fast, echo-Doppler ultrasonography (basal and 30 min after a standard meal) and hemodynamic studies by hepatic vein catheterization (basal, 15 min and 30 min after a standard meal) were performed. Ensure Plus (Abbot Laboratories, North Chicago, IL) was used as the standard liquid meal. Correlation analysis of the echo-Doppler and hepatic vein catheterization measurements were done for the basal and postprandial periods.

RESULTS: Eleven patients with cirrhosis (5 Child A, 4 Child B, 2 Child C) were enrolled into the study. After the standard meal, 8 of the 11 patients showed postprandial hyperemia with increase in portal blood flow, portal blood velocity and hepatic venous pressure gradient. Hepatic venous pressure gradient in the postprandial period correlated positively with postprandial portal blood velocity (r = 0.8, P < 0.05) and correlated inversely with postprandial superior mesenteric artery pulsatility index (r = -1, P < 0.01).

CONCLUSION: Postprandial hyperemia can be efficiently measured by echo-Doppler ultrasonography and the results are comparable to those obtained with the hemodynamic studies.

Hemodynamic alterations in liver cirrhosis

In cirrhotic patients, portal hypertension is often associated with a hyperdynamic circulatory syndrome, with high cardiac output and reduced systemic vascular resistance and arterial pressure. The hyperdynamic circulatory syndrome is due to arterial vasodilation that mainly occurs in the splanchnic circulation, while vascular resistance in the other circulatory districts is normal or increased, accordingly with the degree of portal hypertension, liver impairment and activation of the renin-aldosterone and sympathetic nervous system. The mechanism(s) leading to splanchnic vasodilation is unclear. A favored hypothesis translocation of intestinal bacteria and/or some their products, such as endotoxin, into the interstitial space in the splanchnic organs results in the local release of vasodilating factors such as nitric oxide, carbon monoxide and others.

Diurnal variation and dispersion in QT interval in cirrhosis: relation to haemodynamic changes

BACKGROUND/AIMS

A long QT(C) interval has been described in a substantial fraction of patients with cirrhosis, but information on QT variation and dispersion is sparse. The aim was to determine QT variation with time and QT dispersion (QT(disp)).

METHODS

The study population comprised 23 patients with cirrhosis, undergoing a haemodynamic investigation. 24-h 12 lead Holter monitoring provided information on QT and heart rate variability.

RESULTS

Mean QT(C) was above upper normal limit (440 ms(1/2)) in eleven patients (47%) and significantly higher than in controls (441 vs 400 ms(1/2), p<0.01). The minimum value of QT(C) (but not the maximum value) showed a significant diurnal variation both in cirrhosis and controls. QT(disp) in cirrhosis and controls was similar (33 vs 36 ms, ns), but related to indicators of liver dysfunction, central circulation time, and arterial blood pressure (r=0.44-0.58, p=0.03-0.001). No diurnal variation of QT(disp) was found in cirrhosis. Heart rate variability was reduced with a significant relation to central hypovolaemia (r=0.55, p=0.01).

CONCLUSIONS

Twenty-four hours QT(C) is prolonged in a substantial fraction of patients with cirrhosis, but with normal diurnal variation. The combination of long QT(C) and normal QT(disp) suggests delayed myocyte repolarisation on the cellular level, rather than temporal and spatial heterogeneity in the myocardial wall.

Cirrhotic cardiomyopathy

Decompensated liver cirrhosis is characterized by a peripheral vasodilation with a low-resistance hyperdynamic circulation. The sustained increase of cardiac work load associated with such a condition may result in an inconstant and often subclinical series of heart abnormalities, constituting a new clinical entity known as "cirrhotic cardiomyopathy". Cirrhotic cardiomyopathy is variably associated with baseline increase in cardiac output, defective myocardial contractility and lowered systo-diastolic response to inotropic and chronotropic stimuli, down-regulated beta-adrenergic function, slight histo-morphological changes, and impaired electric "recovery" ability of ventricular myocardium. Cirrhotic cardiomyopathy is usually clinically latent or mild, likely because the peripheral vasodilation significantly reduces the left ventricle after-load, thus actually "auto-treating" the patient and masking any severe manifestation of heart failure. In cirrhotic patients, the presence of cirrhotic cardiomyopathy may become unmasked and clinically evident by certain treatment interventions that increase the effective blood volume and cardiac pre-load, including surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts (LeVeen) and orthotopic liver transplantation. Under these circumstances, an often transient overt congestive heart failure may develop, with increased cardiac output as well as right atrial, pulmonary artery and capillary wedge pressures.

The effect of single oral low-dose losartan on posture-related sodium handling in post-TIPS ascites-free cirrhosis

Post-TIPS ascites-free patients with cirrhosis and previous refractory ascites demonstrate subtle sodium retention when challenged with a high sodium load. This is also observed in pre-ascitic patients with cirrhosis. This phenomenon is dependent on an intrarenal angiotensin II (ANG II) mechanism related to the assumption of erect posture. We investigated whether similar mechanisms were involved in post-TIPS ascites-free patients, by studying 10 patients with functioning TIPS and no ascites. We measured the effect of changing from supine to erect posture on sodium excretion at baseline and after single oral low dose losartan (7.5 mg) which has been shown to blunt proximal and distal tubular sodium reabsorption in pre-ascites. At baseline, the assumption of erect posture produced a reduction in sodium excretion (from 0.30+/-0.06 to 0.13+/-0.02 mmol/min, P=.05), which was mainly due to an increase in proximal tubular reabsorption of sodium (PTRNa) (69.7+/-3.1% to 81.1+/-1.8%, P=.003). The administration of losartan resulted in a blunting of PTRNa (supine 69.7+/-3.1% to 63.9+/-3.9%, P=.01 and erect 81.1+/-1.8% to 73.8+/-2.4%, P=.01), accompanied by an increased distal tubular reabsorption of sodium in both postures, with no overall improvement in sodium excretion on standing. In conclusion, post-TIPS ascites-free patients with cirrhosis exhibit erect posture-induced sodium retention. We speculate that (1) this effect is partly mediated by the effect of ANG II on PTRNa and (2) that the inability of low dose losartan to block the erect posture-induced sodium retention may be related to the erect posture-induced rise in aldosterone which is unmodified by losartan.

Value of dobutamine stress myocardial contrast perfusion echocardiography in patients with advanced liver disease

Although dobutamine stress echocardiography has been used for the preoperative evaluation of patients with advanced liver disease (ALD), no data exist regarding the value of myocardial perfusion imaging (MPI) with real-time myocardial contrast echocardiography (RTMCE) in this patient population. We sought to determine the value of MPI during dobutamine stress RTMCE for predicting prognosis in patients with ALD. We examined both wall motion and MPI in 230 patients with ALD who underwent dobutamine stress RTMCE using intravenous commercially available contrast agents (Optison, GE-Amersham, Princeton, NJ; or Definity, Bristol-Myers Squibb Medical Imaging, North Billerica, MA). The prognostic value of clinical variables, including the Model for End-Stage Liver Disease (MELD) score, and echocardiographic data were examined using a Cox Hazard model. The primary endpoint was mortality of all causes. Among the 85 patients who underwent orthotopic liver transplantation, 4 had abnormal MPI and 81 had normal perfusion. The hospital mortality rate was 50% (2/4) in patients with abnormal MPI and 2% (2/81) in patients with normal MPI (P = 0.01). Among patients with abnormal MPI, 1 died from myocardial infarction in the first postoperative day and the second 1 from hemorrhagic shock. During a median follow-up of 15 months, 53 (23%) patients died. The independent predictors of death were an age of > or = 65 yr (RR = 2.2; 95% confidence interval (CI) = 1.1-4.4; P = 0.03), MELD score of > or = 25 (RR = 3.2; 95% CI = 1.8-5.5; P < 0.0001), and abnormal MPI (RR = 2.4; 95% CI = 1.1-5.2; P = 0.02). The 2-yr mortality was 24% for patients with normal MPI and 45% for those with inducible MPI abnormalities (P = 0.003). In conclusion, MPI obtained by RTMCE appears to be a useful tool in predicting mortality in patients with ALD. Further studies are required to verify its independent value.

Cardiopulmonary complications in chronic liver disease

Patients with cirrhosis and portal hypertension exhibit characteristic cardiovascular and pulmonary hemodynamic changes. A vasodilatatory state and a hyperdynamic circulation affecting the cardiac and pulmonary functions dominate the circulation. The recently defined cirrhotic cardiomyopathy may affect systolic and diastolic functions, and imply electromechanical abnormalities. In addition, the baroreceptor function and regulation of the circulatory homoeostasis is impaired. Pulmonary dysfunction involves diffusing abnormalities with the development of the hepatopulmonary syndrome and portopulmonary hypertension in some patients. Recent research has focused on the assertion that the hemodynamic and neurohumoral dysregulation are of major importance for the development of the cardiovascular and pulmonary complications in cirrhosis. This aspect is important to take into account in the management of these patients.

Deoxycholyltaurine-induced vasodilation of rodent aorta is nitric oxide- and muscarinic M3 receptor-dependent

Emerging evidence indicates that some secondary bile acids interact functionally with muscarinic cholinergic receptors. Using thoracic aortic rings prepared from rats and mice, we examined the mechanism of deoxycholyltaurine-induced vasorelaxation. Increasing concentrations of both acetylcholine (1 nM to 0.1 mM) and deoxycholyltaurine (0.1 microM to 1 mM) stimulated relaxation of phenylephrine-constricted rings prepared from rat thoracic aortae. These effects were reduced by endothelial denudation and by treatment with an inhibitor of nitric oxide formation and with a synthetic acetylcholine:bile acid hybrid that acts as a muscarinic receptor antagonist. Likewise, both acetylcholine (1 nM to 0.1 mM) and deoxycholyltaurine (0.1 microM to 0.1 mM) stimulated relaxation of phenylephrine-constricted rings prepared from mouse thoracic aortae. These effects were reduced by endothelial denudation, addition of an inhibitor of nitric oxide formation, and by muscarinic M(3) receptor knockout. We conclude that the systemic vasodilatory actions of deoxycholyltaurine are mediated in part by a nitric oxide-, muscarinic M(3) receptor-dependent mechanism. In advanced liver disease, interaction of serum bile acids with endothelial muscarinic receptors may explain nitric oxide overproduction in the systemic circulation and resulting peripheral arterial vasodilation.

Loss of tubuloglomerular feedback in decompensated liver cirrhosis: physiopathological implications

In healthy subjects, arterial pressure reduction or renal ischemia produces renal artery dilatation through autoregulation and tubuloglomerular feedback (TuGF). Patients with decompensated cirrhosis have reduced kidney perfusion pressure but show renal vasoconstriction instead of autoregulation-mediated vasodilation. This study investigates the consequences of kidney autoregulation loss on renal perfusion, glomerular filtration rate, and tubular handling of electrolytes in both compensated and ascitic nonazotemic cirrhotic patients. Forty-two consecutive patients with diuretic-free liver cirrhosis (32 with preascitic and 10 with ascitic disease) and 10 controls were submitted to the following determinations: (a) basal plasma renin activity and aldosterone levels; (b) endogenous dopaminergic activity measured as incremental aldosterone responses during metoclopramide administration; and (c) renal clearances of sodium, potassium, inulin, para-aminohippurate and lithium. Compared with the other groups, ascitic patients showed lower renal plasma flow (P < 0.01) and lithium clearance (P < 0.05), a higher filtration fraction (P < 0.01), and secondary aldosteronism. Controls and preascitic patients displayed tubuloglomerular feedback (the mechanism increasing the glomerular filtration rate when a reduced sodium load reaches the distal tubule), as demonstrated by negative correlations between fractional excretion of lithium (an expression of fractional delivery of sodium to the distal nephron) and glomerular filtration rate (respectively, r = -0.73, P < 0.03, and r = -0.48, P < 0.01). Conversely, patients with ascites showed a positive correlation between lithium fractional excretion and glomerular filtration rate (r = 0.64, P < 0.05). Reduction in renal perfusion, increased filtration fraction, and TuGF derangement, as found in decompensated patients, are indicative of prevalent postglomerular arteriolar vasoconstriction, with ensuing stimulation of proximal tubular sodium reabsorption.

Pathophysiological basis of pharmacotherapy in the hepatorenal syndrome

Hepatorenal syndrome (HRS) is a functional and reversible impairment of renal function in patients with severe cirrhosis. Major pathophysiological elements include liver dysfunction, a circulatory derangement with central hypovolaemia and neurohumoral activation of potent vasoactive systems leading to a pronounced renal vasoconstriction. The prognosis of patients with HRS is poor but recent research has spread new enthusiasm for treatment. Efforts at treatment should seek to improve liver function, to ameliorate arterial hypotension and central hypovolaemia, and to reduce renal vasoconstriction. Therefore a combined approach should be applied with reduction of portal pressure with e.g. ss-adrenergic blockers and transjugular intrahepatic portosystemic shunt (TIPS), with amelioration of arterial hypotension and central hypovolaemia with vasoconstrictors such as terlipressin and plasma expanders. New experimental treatments with endothelin- and adenosine antagonists and long-acting vasoconstrictors may have a future role in the management of HRS.

Liver cirrhosis: evaluation of haemodynamic changes using an ultrasound contrast agent

Liver cirrhosis is associated with haemodynamic changes. Using Levovist, we measured and compared Doppler signal arrival and peak enhancement times in the hepatic vein of patients with cirrhosis (n= 12) or chronic liver disease (n= 16) and in 12 healthy subjects. There were six patients with Child stage A, one patient with B, and five patients with C. The signal was recorded starting 20 s before contrast infusion until 2 h 20 min after its end. A software of the ultrasound (US) machine automatically sampled time-intensity values. Arrival times were significantly shorter (P < 0.001) in cirrhotic than non-cirrhotic (chronic liver disease + controls) and in patients with Child stage C compared with A. Differences in peak enhancement were weakly significant between cirrhotic and chronic patients (P < 0.04) and highly significant between the former and controls (P < 0.001), whereas differences between Child stages C and A were not significant (P > 0.05). Finally, cirrhotic patients had arrival times consistently shorter than 17 s. Automatic time-intensity curve analysis made measurements objective and conceptual error systematic, thus identifiable. Analysis of the passage of Levovist at the hepatic vein can thus become a non-invasive, well-tolerated and cost-effective diagnostic and monitoring tool in a larger number of patients with liver disease.

Effects of tilting on central hemodynamics and homeostatic mechanisms in cirrhosis

Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous system (SNS) as well as the renin-angiotensin-aldosterone system (RAAS). As the hyperdynamic circulation in cirrhosis may be present only in the supine patient, we studied the humoral and central hemodynamic responses to changes with posture. Twenty-three patients with alcoholic cirrhosis (Child-Turcotte-Pugh classes A/B/C: 2/13/8) and 14 healthy controls were entered. Measurements of central hemodynamics and activation of SNS and RAAS were taken in the supine position, after 30 degrees head-down tilting, and after 60 degrees passive head-up tilting for a maximum of 20 minutes. After the head-up tilting, the central blood volume (CBV) decreased in both groups, but the decrease was significantly smaller in patients than in controls (-19% vs. -36%, P <.01). Central circulation time increased only in the patients (+30% vs. -1%, P <.01). The absolute increases in circulating norepinephrine and renin after head-up tilting were significantly higher in the patients than in the controls (P <.05 and P <.01, respectively). In patients with cirrhosis, changes in SNS and RAAS were related to changes in arterial blood pressure, systemic vascular resistance, heart rate, non-CBV, plasma volume, and arterial compliance. In conclusion, cardiovascular and humoral responses to changes in posture are clearly abnormal in patients with cirrhosis. Head-up tilting decreases the CBV less in patients with cirrhosis, and the results suggest a differential regulation of central hemodynamics in patients with cirrhosis.

Effects of tilting on central hemodynamics and homeostatic mechanisms in cirrhosis

Patients with cirrhosis have a hyperdynamic circulation and an abnormal blood volume distribution with central hypovolemia, an activated sympathetic nervous system (SNS) as well as the renin-angiotensin-aldosterone system (RAAS). As the hyperdynamic circulation in cirrhosis may be present only in the supine patient, we studied the humoral and central hemodynamic responses to changes with posture. Twenty-three patients with alcoholic cirrhosis (Child-Turcotte-Pugh classes A/B/C: 2/13/8) and 14 healthy controls were entered. Measurements of central hemodynamics and activation of SNS and RAAS were taken in the supine position, after 30 degrees head-down tilting, and after 60 degrees passive head-up tilting for a maximum of 20 minutes. After the head-up tilting, the central blood volume (CBV) decreased in both groups, but the decrease was significantly smaller in patients than in controls (-19% vs. -36%, P <.01). Central circulation time increased only in the patients (+30% vs. -1%, P <.01). The absolute increases in circulating norepinephrine and renin after head-up tilting were significantly higher in the patients than in the controls (P <.05 and P <.01, respectively). In patients with cirrhosis, changes in SNS and RAAS were related to changes in arterial blood pressure, systemic vascular resistance, heart rate, non-CBV, plasma volume, and arterial compliance. In conclusion, cardiovascular and humoral responses to changes in posture are clearly abnormal in patients with cirrhosis. Head-up tilting decreases the CBV less in patients with cirrhosis, and the results suggest a differential regulation of central hemodynamics in patients with cirrhosis.

Review article: pathogenesis and pathophysiology of hepatorenal syndrome--is there scope for prevention?

The hepatorenal syndrome (HRS) is a functional impairment of the kidneys in chronic liver disease caused by a circulatory failure. The prognosis is poor, particularly with type 1 HRS, but also type 2, and only liver transplantation is of lasting benefit. However, recent research into the pathophysiology of ascites and HRS has stimulated new enthusiasm in their prevention and treatment. Patients with HRS have hyperdynamic circulatory dysfunction with reduced arterial blood pressure and reduced central blood volume, owing to preferential splanchnic arterial vasodilatation. Activation of potent vasoconstricting systems, including the sympathetic nervous and renin-angiotensin-aldosterone systems, counteracts the arterial vasodilatation and leads to a pronounced renal vasoconstriction with renal hypoperfusion, a reduced glomerular filtration rate, and intense sodium-water retention. Thus prevention of HRS should seek to improve liver function, limit arterial hypotension and central hypovolaemia, and reduce renal vasoconstriction and the renal and interstitial pressures. Portal pressure can be reduced with beta-adrenergic blockers and transjugular intrahepatic portosystemic shunt (TIPS). Precipitating events, like infections, bleeding, and postparacentesis circulatory syndrome, should be treated to avoid further circulatory failure. Improvement in arterial blood pressure and central hypovolaemia can be achieved with vasoconstrictors, such as terlipressin (Glypressin), and plasma expanders such as human albumin. In the future endothelins, adenosine antagonists, long-acting vasoconstrictors, and antileukotriene drugs may play a role in preventing and treating HRS.

Systemic and regional hemodynamics in pre-ascitic cirrhosis: effects of posture

BACKGROUND/AIMS

To clarify the hemodynamic pattern of pre-ascitic cirrhosis, we compared the impact of posture on systemic and regional hemodynamics of patients and healthy subjects without and with plasma volume expansion.

METHODS

Cardiac index (CI), peripheral vascular resistance (PVRi), heart rate, mean arterial pressure, and the mean blood flow velocities of superior mesenteric (SMAV) and common femoral arteries were evaluated by duplex-Doppler techniques in 10 patients and 20 healthy controls after 2 h of standing and 2 h after lying down. Ten healthy controls received saline infusion (15 ml/kg body weight) when they changed their posture, and five were also evaluated after plasma volume expansion in the upright posture.

RESULTS

Standing systemic and regional hemodynamics did not differ between patients and controls. After saline infusion, standing control subjects showed greater CI and SMAV than patients. Recumbency caused changes of CI, PVRi and SMAV greater in patients and controls with plasma expansion than in controls without expansion, so that supine patients and controls with expansion were indistinguishable, showing higher CI and SMAV and lower PVRi than controls without expansion.

CONCLUSIONS

Systemic and regional hemodynamics of patients with pre-ascitic cirrhosis are mainly determined by blood volume expansion which is compartmentalized within the splanchnic venous bed during standing and translocates towards the central and arterial circulatory districts during recumbency.

Plasma volume expansion by albumin in cirrhosis. Relation to blood volume distribution, arterial compliance and severity of disease

BACKGROUND/AIMS

The aim of the study was to investigate the effect of a standard albumin load on blood volume distribution, arterial compliance, and the renin-angiotensin-aldosterone system in patients with different degrees of cirrhosis.

METHODS

31 patients with cirrhosis (Child classes A/B/C=8/14/9) received an intravenous infusion of 40 g human serum albumin during a haemodynamic investigation.

RESULTS

Whereas plasma- and blood volume increased by 23 and 15%, respectively (P<0.001), a significant increase in central blood volume was found only in class A patients (+8%, P<0.05), but not in class B or class C patients (+2.7%, not significant (n.s.)). In contrast, arterial compliance only increased significantly in class C patients (+18%, P<0.05), but not in class A or class B patients (+6%, n.s.). Plasma renin activity (PRA) decreased significantly in class C patients (-31%, P<0.05). When all patients were compared, the change in arterial compliance was inversely correlated to the change in PRA (r=-0.50, P<0.01).

CONCLUSIONS

Although infusion of albumin does not expand the central blood volume in patients with advanced cirrhosis, the results indicate a significant improvement in the low effective arterial blood volume of such patients, which may be important in the prevention of circulatory dysfunction.

Pathophysiology and management of pediatric ascites

Ascites accumulation is the product of a complex process involving hepatic, renal, systemic, hemodynamic, and neurohormonal factors. The main pathophysiologic theories of ascites formation include the "underfill," "overflow," and peripheral arterial vasodilation hypotheses. These theories are not necessarily mutually exclusive and are linked at some level by a common pathophysiologic thread: The body senses a decreased effective arterial blood volume, leading to stimulation of the sympathetic nervous system, arginine-vasopressin feedback loops, and the renin-angiotensin-aldosterone system. Cornerstones of ascites management include dietary sodium restriction and diuretics. Spironolactone is generally tried initially, with furosemide added if clinical response is suboptimal. More refractory patients require large-volume paracentesis (LVP) accompanied by volume expansion with albumin. Placement of a transjugular intrahepatic portosystemic shunt is reserved for individuals with compensated liver function who require very frequent sessions of LVP. Peritoneovenous shunts are not used in contemporary ascites management. Liver transplantation remains the definitive therapy for refractory ascites. Although treatment of ascites fails to improve survival, it benefits quality of life and limits the development of such complications as spontaneous bacterial peritonitis.

Increased arterial compliance in cirrhosis is related to decreased arterial C-type natriuretic peptide, but not to atrial natriuretic peptide

BACKGROUND

Increased arterial compliance (COMPart) has recently been described in patients with cirrhosis, particularly in advanced disease. The aim of the present study was to relate COMPart with arterial levels of the circulating natriuretic peptides: atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP), both of which are vasodilators.

METHODS

Thirty-one patients with cirrhosis, 14 non-cirrhotic patients with circulatory disturbances of the ischaemic and hypertensive type, and 10 healthy controls were investigated during a haemodynamic examination.

RESULTS

The patients with cirrhosis showed the well-known hyperdynamic circulation with elevated cardiac output, low arterial blood pressure, and reduced systemic vascular resistance. COMPart in the patients with cirrhosis (1.30 mL/mmHg) was significantly (P < 0.01) increased compared to that of non-cirrhotic patients (0.99 mL/mmHg) and controls (1.01 mL/mmHg). In the patients with cirrhosis, a significant inverse correlation was found between CNP and COMPart (r = -0.42, P < 0.01), but not between CNP and systemic vascular resistance (r = 0.31, P = 0.08). In the non-cirrhotic patients, CNP had a significant inverse correlation to COMPart (r = -0.68, P < 0.01) and a direct correlation to systemic vascular resistance (r = 0.62, P < 0.02). ANP was not significantly related to COMPart nor to systemic vascular resistance in any of the groups.

CONCLUSION

The finding of an inverse relation between CNP and COMPart may suggest that a compensatory down-regulation of CNP occurs in patients with cirrhosis and other types of circulatory disorders when vasodilation persists. Regulation of large and small arteries by CNP may be different in cirrhosis. Arterial ANP is not related to properties of the large or small arteries.

Cardiac output determined by echocardiography in patients with cirrhosis: comparison with the indicator dilution technique

BACKGROUND/AIMS

Measurement of cardiac output in hyperkinetic patients with cirrhosis by Doppler echocardiography is increasingly reported, but has not been validated. We have compared simultaneous measurements of cardiac output by Doppler echocardiography (CO(d)) and by the indicator dilution technique (CO(I)).

METHODS

Twelve patients with cirrhosis were studied. CO(d) was measured as the spatial mean velocity of the left ventricular outflow tract, multiplied by the cross-sectional area and the heart rate. CO(I) was determined by the standard indicator dilution technique after injection of 125I albumin and 99mTc albumin into the right atrium and subsequent sampling from the femoral artery.

RESULTS

The mean CO(d) and CO(I) were similar (7.20 vs 7.15 l/min, NS). A highly significant correlation was present between CO(d) and CO(I) (r = 0.86, P < 0.0001; slope 0.91, Y(0) = 0.78 l/min). However, the mean squared difference between CO(d) and CO(I) was 2.3 (l/min)2. A Bland-Altman plot revealed no trend with the level of cardiac output. The standard deviation (0.79 vs 0.30 l/min, P < 0.01) and the coefficient of variation (10.5 vs 4.2%, P < 0.01) of duplicate measurements were significantly higher with the Doppler technique.

CONCLUSION

Doppler measurements of cardiac output in groups of patients with cirrhosis are accurate with respect to the group mean, but marked disagreements of over- and underestimation were seen in individual patients. The reproducibility of the Doppler technique is acceptable, although not as good as that of the indicator dilution technique.

Nitric oxide synthase inhibition does not improve renal function in cirrhotic patients with ascites

OBJECTIVES

Based mainly on animal experiments, nitric oxide (NO) has been proposed to account for the peripheral arterial vasodilation and hyperdynamic circulation in liver cirrhosis. The aim of this study was to clarify whether a reduction of NO synthesis would ameliorate the circulatory and renal dysfunction in decompensated cirrhotic patients.

METHODS

The effects of N(G)-monomethyl-L-arginine-acetate (L-NMMA), an NO synthesis inhibitor, were studied. After a 60-min basal period, a total of 10 patients received increasing doses of L-NMMA, five patients (Low) received 12.5, 25, and 50 microg/kg/min, and five patients (High) received 25, 50, and 100 microg/kg/min as a constant infusion during 3 h, followed by a postinfusion period. Five patients (Placebo) received saline infusions only. Glomerular filtration rate and renal plasma flow were measured by clearance techniques with (99m)Tc-diethylenetriamine-pentaacetate and (131)I-Hippuran.

RESULTS

L-NMMA infusion resulted in an increased blood pressure, decreased heart rate, and dose-dependent suppression of renin of up to 42.1 +/- 7.1% (p < 0.01) and angiotensin II of up to 39.9 +/- 9.6%, (p < 0.01) levels. Sodium and water excretion were not improved, most likely because of a reduction in renal blood flow of up to 29.1 +/- 8.1% (p < 0.01).

CONCLUSION

Despite a partial correction of the hyperdynamic circulation, inhibition of NO synthesis does not improve sodium and water excretion in decompensated cirrhosis, probably because of an accompanying decrease in renal plasma flow. Intrarenal NO synthesis may be important for maintaining intrarenal hemodynamics in decompensated cirrhotic patients.

Update on ascites and hepatorenal syndrome

Ascites is the most common complication occurring during liver cirrhosis. Even if a significant decrease in renal clearance may be observed in the first step of chronic active liver disease, renal impairment, at times complicated by the typical signs of hepatorenal syndrome, occurs only in patients with ascites, especially when tense and refractory. Experimental and clinical data seem to suggest a primary sodium and water retention in the pathogenesis of ascites, in the presence of an intrahepatic increase of hydrostatic pressure, which, by itself, physiologically occurs during digestion. Abnormal sodium and water handling leads to plasma volume expansion, followed by decreased peripheral vascular resistance and increased cardiac output. This second step is in agreement with the peripheral arterial vasodilation hypothesis, depicted by an increase in total blood volume, but with a decreased effective arterial blood volume. This discrepancy leads to the activation of the sympathetic nervous and renin-angiotensin-aldosterone systems associated with the progressive activation of the renal autacoid systems, especially, that of the arachidonic acid. During advanced cirrhosis, renal impairment becomes more sustained and renal autacoid vasodilating substances are less available, possibly due to a progressive exhaustion of these systems. At the same time ascites becomes refractory inasmuch as it is no longer responsive to diuretic treatment. Various pathogenetic mechanisms leading to refractory ascites are mentioned. Finally, several treatment approaches to overcome the reduced effectiveness of diuretic therapy are cited. Paracentesis, together with simultaneous administration of human albumin or other plasma expanders is the main common approach to treat refractory ascites and to avoid a further decrease in renal failure. Other effective tools are: administration of terlipressin together with albumin, implantation of the Le Veen shunt, surgical porto-systemic shunting or transjugular intrahepatic portosystemic stent-shunt, or orthotopic liver transplantation, according to the conditions of the individual patient.

Cardiovascular effects of canrenone in patients with preascitic cirrhosis

In patients with cirrhosis and portal hypertension, standing induces a reduction in cardiac index (CI) and an increase in systemic vascular resistance index. Our previous studies indicate that this abnormal hemodynamic response to standing is due to an altered myocardial function, because cirrhotic patients are unable to compensate for the reduced preload with an increase in left ventricular (LV) ejection fraction (EF) and stroke volume. To evaluate whether the cardiac dysfunction in cirrhosis is influenced by canrenone, an aldosterone antagonist, 8 patients with preascitic, nonalcoholic cirrhosis, and portal hypertension underwent echocardiographic assessment of LV function and systemic hemodynamics and determinations of plasma volume, urinary sodium excretion, and plasma renin activity (PRA), aldosterone (PAC), and norepinephrine (PNE) when on a 150-mmol/d-sodium diet (baseline), after 1 month on canrenone (100 mg/d) plus a 40-mmol/d-sodium diet and after 1 month on canrenone plus a 150-mmol/d-sodium diet. Echocardiographic evaluation was performed with the patient in the supine position and during active standing. At baseline, patients had high plasma volume and normal renal function, PRA, PAC, and PNE. CI, LVEF, and stroke volume index were also normal. Standing caused a significant reduction in CI and LVEF. After canrenone and either sodium diet, CI significantly decreased, and PRA and PNE increased in the supine position. On standing, LVEF and CI did not decrease further. Plasma volume significantly decreased only after low-sodium diet plus canrenone. In conclusion, canrenone normalizes the cardiac response to the postural challenge in patients with preascitic cirrhosis.

Cirrhotic cardiomyopathy: a pathophysiological review of circulatory dysfunction in liver disease

The systemic circulation in patients with cirrhosis is hyperdynamic with an increased cardiac output and heart rate and a reduced systemic vascular resistance as the most pronounced alterations. The concomitant cardiac dysfunction has recently been termed "cirrhotic cardiomyopathy", which is an entity different from that seen in alcoholic heart muscle disease. Clinically, these patients present with sodium fluid retention and strain often unmasks the presence of latent heart failure. No specific treatment can yet be recommended but caution should be used with respect to procedures that may stress the heart such as shunt implantation and liver transplantation.

Enhancement of endothelial nitric oxide production by chenodeoxycholic acids in patients with hepatobiliary diseases

The purpose of this study was to clarify whether physiological concentrations of bile acids could affect endothelial nitric oxide production. We investigated the relationships between clinical concentrations of individual bile acids observed in patients with hepatobiliary diseases and endothelial nitric oxide production induced by each bile acid. Fifteen serum bile acids were measured using high-performance liquid chromatography combined with enzymatic fluorometry in 8 patients with liver cirrhosis, obstructive jaundice, and 8 healthy subjects. The effects of individual bile acids on nitric oxide production were examined in human umbilical endothelial cells by measuring the concentration of NO2- in the cultured medium. NO release in the blood was also determined by measuring the NO2-/NO3- concentration in these patients. In patients with hepatobiliary diseases, the plasma concentrations of chenodeoxycholic acid, ursodeoxycholic acid and cholic acid (free acid, taurine and glycine conjugates) were markedly elevated. Incubation of cells with chenodeoxycholic acid and deoxycholic acid (free acid, taurine and glycine conjugates) enhanced NO2- production in a concentration-dependent manner, while cholic acid (free and its conjugates) did not. The effects of individual bile acids on nitric oxide production were additive. Patients with liver cirrhosis and obstructive jaundice had higher plasma levels of NO2-/NO3- levels than the control subjects. These results suggest that increased plasma concentrations of chenodeoxycholic acid (free, taurine and glycine conjugates) in patients with hepatobiliary diseases may induce endothelial nitric oxide production. Thus, nitric oxide production induced by bile acids may be involved in the pathogenesis of circulatory abnormalities in patients with liver diseases.

Ascites and hepatorenal syndrome

Ascites is a frequent complication of chronic liver disease with severe portal hypertension. Moreover, in the presence of tense ascites, renal dysfunction and hepatorenal syndrome may occur. Unfortunately, there is no explanation that thoroughly describes the complex relationship between the liver and kidney in either physiological or pathological conditions. Nevertheless, available evidence indicates that early sodium and water retention precedes decompensation, characterized by hyperdynamic circulation. The best approach to the treatment of these patients should be aimed at the prevention of ascites formation. An accurate sequential treatment is indicated in patients with ascites. In the case of hepatorenal syndrome, the only definitive approach is liver transplantation.