Cardiovascular effects of canrenone in patients with preascitic cirrhosis

Doppler myocardial performance index combined with plasma B-type natriuretic peptide levels as a marker of cardiac function in patients with decompensated cirrhosis

BACKGROUND

In chronic liver diseases, cirrhosis ranks as the 14th highest death cause worldwide, developing into decompensated cirrhosis. A potential and feasible technique in assessing cardiac function is urgent. This study explores if the Doppler myocardial performance (Tei) index combined with the plasma B-type natriuretic peptide (BNP) levels can assess cardiac function in patients with decompensated cirrhosis.

METHODS

A total of 140 individuals were selected in the study and were classified into 3 groups: control group (n = 40, healthy individuals), compensated cirrhosis group (n = 50), and decompensated cirrhosis group (n = 50). Plasma BNP levels, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and albumin (ALB) were identified by an enzyme-linked immunosorbent assay (ELISA). The correlation of Tei index between left ventricle (LV) and right ventricle (RV) as well as plasma BNP levels with cardiac function was assessed using a Pearson test analysis. All patients were subjected to this experiment for 1 year to analyze the relationship between Tei index and plasma BNP levels in prognosis of decompensated cirrhosis patients.

RESULTS

Patients with decompensated cirrhosis showed significantly elevated levels of ALT, AST, and TBIL level in contrary to a reduced ALB level. Cirrhosis patients also showed a significantly reduced ejection fraction (ET) index, but an increase in isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), Tei index, and plasma BNP levels in comparison to healthy individuals. ICT, IRT, Tei index, and plasma BNP levels were elevated in decompensated cirrhotic patients as opposed to compensated cirrhotic patients. These results indicate a positive correlation of both Tei index and plasma BNP levels with cirrhosis and its progression. Tei index and plasma BNP levels are positively associated with Child-Pugh classification and negatively correlated with both cardiac function and prognosis in patients suffering from decompensated cirrhosis.

CONCLUSION

The study provided evidence supporting the correlation of Tei index and plasma BNP levels in decompensated cirrhotic patients with cardiac function, highlighting a potential value for evaluation.

Differential Sympathetic Vasomotor Activation Induced by Liver Cirrhosis in Rats

We tested the hypothesis that there is a topographical sympathetic activation in rats submitted to experimental cirrhosis. Baseline renal (rSNA) and splanchnic (sSNA) sympathetic nerve activities were evaluated in anesthetized rats. In addition, we evaluated main arterial pressure (MAP), heart rate (HR), and baroreceptor reflex sensitivity (BRS). Cirrhotic Wistar rats were obtained by bile duct ligation (BDL). MAP and HR were measured in conscious rats, and cardiac BRS was assessed by changes in blood pressure induced by increasing doses of phenylephrine or sodium nitroprusside. The BRS and baseline for the control of sSNA and rSNA were also evaluated in urethane-anesthetized rats. Cirrhotic rats had increased baseline sSNA (BDL, 102 vs control, 58 spikes/s; p<0.05), but no baseline changes in the rSNA compared to controls. These data were accompanied by increased splanchnic BRS (p<0.05) and decreased cardiac (p<0.05) and renal BRS (p<0.05). Furthermore, BDL rats had reduced basal MAP (BDL, 93 vs control, 101 mmHg; p<0.05) accompanied by increased HR (BDL, 378 vs control, 356; p<0.05). Our data have shown topographical sympathetic activation in rats submitted to experimental cirrhosis. The BDL group had increased baseline sSNA, independent of dysfunction in the BRS and no changes in baseline rSNA. However, an impairment of rSNA and HR control by arterial baroreceptor was noted. We suggest that arterial baroreceptor impairment of rSNA and HR is an early marker of cardiovascular dysfunction related to liver cirrhosis and probably a major mechanism leading to sympathoexcitation in decompensated phase.

The use of E/A ratio as a predictor of outcome in cirrhotic patients treated with transjugular intrahepatic portosystemic shunt

OBJECTIVES

The clinical significance of diastolic dysfunction in cirrhosis, a feature of cirrhotic cardiomyopathy, is unclear. The aim of this study was to assess the utility of E/A ratio, an indicator of diastolic dysfunction, to predict ascites clearance and mortality after transjugular intrahepatic portosystemic stent shunt (TIPS) insertion.

METHODS

A total of 101 cirrhotic patients who received TIPS had pre-TIPS assessments of demographics, severity of liver dysfunction (Child-Pugh and Model for End-Stage Liver Disease (MELD) scores), renal function, hemodynamics, and cardiac function (two-dimensional echocardiography). An E/A ratio of < or =1 was used to indicate diastolic dysfunction. Patients were followed-up for a mean period of 24.6+/-2.4 months post TIPS.

RESULTS

A total of 41 patients with an E/A ratio of < or =1 (group A), and 60 patients with an E/A ratio of >1 (group B) were studied. Group A had significantly higher MELD scores (14.0+/-1.0 vs. 11.4+/-0.8; P=0.03), because of higher serum creatinine levels (107+/-5 vs. 86+/-6 micromol/l; P<0.01). There was no difference in pre-TIPS systemic hemodynamics, systolic function, or portal pressure between the two groups. After TIPS, more patients in group B had ascites clearance (log rank, P=0.038), and the same patients had a higher probability of survival (log rank, P=0.046). There were three post-TIPS cardiac deaths in group A only. A multivariate analysis showed that an E/A of ratio < or =1 was predictive of slow ascites clearance (hazard ratio=7.3, 95% confidence interval=1.3-40.7, P=0.021) and death after TIPS (hazard ratio=4.7, 95% confidence interval=1.1-20.2, P=0.035).

CONCLUSIONS

Diastolic dysfunction, indicated by reduced E/A ratio, is prevalent in advanced cirrhosis and is associated with reduced ascites clearance and increased mortality post TIPS, possibly related to worsening of hemodynamic dysfunction in the post-TIPS period.

Reduced baroreflex sensitivity in alcoholic cirrhosis: relations to hemodynamics and humoral systems

In cirrhosis, arterial vasodilatation leads to central hypovolemia and activation of the sympathetic nervous and renin-angiotensin-aldosterone systems. As the liver disease and circulatory dysfunction may affect baroreflex sensitivity (BRS), we assessed BRS in a large group of patients with cirrhosis and in controls who were all supine and some after 60 degrees passive head-up and 30 degrees head-down tilting in relation to central hemodynamics and activity of the sympathetic nervous and renin-angiotensin-aldosterone systems. One-hundred and five patients (Child classes A/B/C: 21/55/29) and 25 (n=11 + 14) controls underwent a full hemodynamic investigation. BRS was assessed by cross-spectral analysis of variabilities between blood pressure and heart rate time series. The median BRS was significantly lower in the supine cirrhotic patients, 3.7 (range 0.3-30.7) ms/mmHg than in matched controls (n=11): 14.3 (6.1-23.6) ms/mmHg, P<0.001. A stepwise multiple-regression analysis revealed that serum sodium (P=0.044), heart rate (P=0.027), and central circulation time (P=0.034) independently correlated with BRS. Head-down tilting had no effects on BRS, but, after head-up tilting, BRS was similar in the patients (n=23) and controls (n=14). In conclusion, BRS is reduced in cirrhosis in the supine position and relates to various aspects of cardiovascular dysfunction, but no further reduction was observed in parallel with the amelioration of the hyperdynamic circulation after head-up tilting. The results indicate that liver dysfunction and compensatory mechanisms to vasodilatation may be involved in the low BRS, which may contribute to poor cardiovascular adaptation in cirrhosis.

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.

Disfunción diastólica en la cirrosis hepática

The presence of a hyperdynamic circulation in cirrhotic liver is currently a well established concept. The first studies of cardiac function in patients with cirrhosis suggested the existence of an alcoholic cardiomyopathy. More recently, altered left ventricular response to physiological and/or pharmacological stimuli in patients with post-viral liver cirrhosis has been established, and clinically insignificant diastolic cardiac function has also been observed. Neurohumoral hyperactivity and hyperdynamic circulation, which are associated with chronic exposure to the cardiodepressant substances present in advanced liver disease, play a decisive role in the genesis of this process. The lack of relaxation of the left ventricle and alteration in the pattern of transmitral flow, both of which are characteristics of this clinical entity, are easily detected by echocardiography. The growing evidence of diastolic dysfunction in liver cirrhosis, particularly in decompensated cirrhosis, suggests the clinical importance of the problem, thus introducing the concept of "cirrhotic cardiomyopathy". Greater insight into this phenomenon could help to decrease cardiovascular risk, especially during maneuvers commonly used in the treatment of the complications of liver cirrhosis, such as paracentesis, transjugular intrahepatic portosystemic shunt stent implantation, and liver transplantation.

Cardiac, neuroadrenergic, and portal hemodynamic effects of prolonged aldosterone blockade in postviral child A cirrhosis

OBJECTIVES

The present study was designed to determine the effects of long-term antialdosterone treatment on cardiac structural and functional alterations, portal and systemic hemodynamic as well as adrenergic dysfunction characterizing Child A cirrhotic patients with F1 esophageal varices.

METHODS

Twenty-two Child A postviral preascitic cirrhotic patients were randomly allocated to 200 mg/day K-Canrenoate (13 patients, age 59.6 +/- 2.2 yr, mean + SEM) or no-drug treatment (9 patients, age 61.8 +/- 2.3) for a 6-month-period. Measurements, which included hepatic venous pressure gradient (HVPG), left ventricular wall thickness, left ventricular end-diastolic volume and diastolic function (LVWT, LVEDV, and E/A ratio, echocardiography), and muscle sympathetic nerve activity (MSNA, microneurography, peroneal nerve), were obtained at baseline and following 6 months of drug or no-drug treatment. Ten healthy age-matched subjects served as controls.

RESULTS

Cirrhotic patients were characterized by increased HVPG, LVWT, and MSNA values and by a depressed E/A ratio. K-Canrenoate treatment significantly reduced HVPG (from 15.3 +/- 1.0 to 13.8 +/- 0.8 mmHg, p < 0.05), LVWT (from 21.8 +/- 0.5 to 20.7 +/- 0.6 mm, p < 0.02), and LVEDV (from 99.2 +/- 7 to 86.4 +/- 6 ml, p < 0.01), leaving E/A ratio and MSNA almost unaltered. No significant change was observed in the untreated group of cirrhotic patients followed for 6 months without intervention.

CONCLUSIONS

These data provide evidence that aldosterone blockade by long-term K-Canrenoate administration improves hepatic hemodynamics by lowering HVPG and ameliorates cardiac structure and function by favoring a reduction in LVWT and LVEDV as well. They also show, however, that this therapeutic intervention neither improves left ventricular diastolic dysfunction nor exerts sympathoinhibitory effects.

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.

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.

Aldosterone receptor antagonists: biology and novel therapeutical applications

Recent studies suggest that a dysregulation of the aldosterone system is involved in the pathophysiology of different cardiovascular diseases, including myocardial failure and several cases of essential hypertension. In both rat models and in humans, aldosterone action has been shown to induce heart remodeling and interstitial and perivascular fibrosis of the myocardium. For these reasons, a rationale for the use of aldosterone antagonists (ARAs) of the spirolactone family, which have been available for decades in the treatment of aldosterone excess syndromes, has now emerged. Moreover, the recent validation of their use, in combination with the current therapy, for the treatment of these cardiovascular diseases by trials like the RALES Study has further strenghtened this approach. The development of compounds, like eplerenone, with a greater selectivity for mineralocorticoid receptors, seems promising also in terms of reduction of endocrine side effects. The addition of aldosterone antagonists to the conventional therapy of myocardial failure and of selected cases of hypertension thus appears beneficial, resulting in an improved survival rate and a reduced incidence of cardiac complications. This review article, after a brief recall of the physiology of the aldosterone system, addresses the emerging role of aldosterone in cardiovascular diseases, considers the pharmacology of ARAs and the novel therapeutical applications of these compounds in hypertension and heart failure.

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.