Assessment of beta-adrenergic blockade with propranolol in patients with cirrhosis

The use of beta-blockers is associated with the occurrence of acute kidney injury in severe alcoholic hepatitis

BACKGROUND & AIMS

The beneficial effect of nonselective beta-blockers (NSBB) has recently been questioned in patients with end-stage cirrhosis. We analysed the impact of NSBB on outcomes in severe alcoholic hepatitis (AH).

METHODS

This study was based on a prospective database of patients with severe, biopsy-proven AH. Patients admitted from July, 2006 to July, 2014 were retrospectively studied. Patients were divided into two groups (with and without NSBB) and assessed for the occurrence of Acute Kidney Injury (AKI) and transplant-free mortality during a 168-day follow-up period.

RESULTS

One hundred thirty-nine patients were included, the mean Maddrey score was 71 ± 34 and 86 patients (61.9%) developed AKI. Forty-eight patients (34.5%) received NSBB. The overall 168-day transplant-free mortality was 50.5% (95%CI, 41.3-60.0%). The overall 168-day cumulative incidence of AKI was 61.9% (95%CI, 53.2-69.4%). When compared, patients with NSBB had a lower heart rate (65 ± 13 vs 92 ± 12, P < 0.0001) and a lower mean arterial pressure (MAP, 78 ± 3 vs 87 ± 5, P < 0.0001). Patients with NSBB had comparable MELD scores, Maddrey scores, and medical histories. The 168-day transplant-free mortality was 56.8% (95%CI, 41.3-69.7%) in patients with NSBB and 46.7% (95%CI, 35.0-57.6%) without NSBB (P = 0.25). The 168-day cumulative incidence of AKI was 89.6% (95%CI, 74.9-95.9%) with NSBB compared to 50.4% (95%CI: 39.0-60.7) for no NSBB (P = 0.0001). The independent factors predicting AKI were a higher MELD score and the presence of NSBB.

CONCLUSIONS

The use of NSBB in patients with severe AH is independently associated with a higher cumulative incidence of AKI.

Propranolol stereoisomer plasma concentrations and portal haemodynamic response in patients with liver cirrhosis

BACKGROUND

The haemodynamic effect of propranolol on portal pressure in patients with portal hypertension is highly variable and does not correlate with propranolol racemate plasma concentrations.

AIM

To investigate the stereoselective metabolism of the propranolol enantiomers and its impact on portal haemodynamics in patients with liver cirrhosis since only S-propranolol is haemodynamically active.

METHODS

Twenty patients with liver cirrhosis and portal hypertension received 40 mg propranolol orally. Portal blood velocity (PBV) and propranolol stereoisomer plasma concentrations were determined.

RESULTS

During the 4 h examination period we observed a significant reduction in PBV (18.3 +/- 2.2%, P < 0.0001) vs. baseline. The area under the curve (AUC) during the study period was significantly different for the two isomers (S-propranolol 1217.0 +/- 118.5 nmol.h/L; R-propranolol 728.8 +/- 103.8 nmol.h/L, P < 0.0001). Seven patients (35%) were portal haemodynamic non-responders to propranolol. Propranolol stereoisomer AUC values were no different between responders (S-propranolol 1133. 3 +/- 132.0 nmol.h/L; R-propranolol 718.0 +/- 129.7 nmol.h/L) and non-responders (S-propranolol 1371.8 +/- 250.5 nmol.h/L; R-propranolol 746.9 +/- 200.3 nmol.h/L); neither was there a correlation between propranolol enantiomer plasma concentrations and the portal haemodynamic effect.

CONCLUSIONS

Our data demonstrate a stereoselective metabolism of propranolol enantiomers in liver cirrhosis. However, following oral propranolol administration, stereoisomer plasma concentrations do not predict the portal haemodynamic effect.

Effect of propranolol on portosystemic collateral circulation estimated by per-rectal portal scintigraphy with technetium-99m pertechnetate

BACKGROUND/AIMS

Propranolol is widely used in the prevention of variceal bleeding. However, in certain patients with cirrhosis, the portal hypotensive effect of propranolol cannot be obtained. An explanation for portal unresponsiveness to propranolol could be an increase in portocollateral vascular resistance mediated by this drug.

METHODS

In 33 patients with cirrhosis the effect of chronic administration of propranolol on portocollateral blood flow from the inferior mesenteric vein was examined by means of per-rectal portal Tc-99m pertechnetate scintigraphy.

RESULTS

Propranolol significantly reduced the shunt index by 15.3 +/- 4.2%. This reduction was observed only in patients with cirrhosis classified as Child-Pugh A and B groups, but not group C. Differences between groups in portosystemic shunt index changes after propranolol were significant (F = 3.4, p < 0.05).

CONCLUSIONS

The data presented suggest that propranolol changes the distribution of blood between the portal and systemic circulation, which is probably due to the increase in vascular resistance of portocollateral vessels. The magnitude of the vascular response to propranolol depends on the severity of liver disease.

Pharmacological treatment of portal hypertension: hemodynamic effects and prevention of bleeding

In the past 10 years, it has been clearly shown that vasoactive substances reduce portal pressure in patients or animals with portal hypertension. Some of these substances act by inducing splanchnic vasoconstriction, while others reduce hepatic and porto-systemic collateral vascular resistance and, thus, induce a portal hypotensive effect. Still others induce arterial hypotension, which causes a vasoconstrictive effect in the splanchnic territory. Since these drugs act on different vascular receptors, their combination should have a more marked effect on portal hypertension. Up to now, only nonselective beta-blockers have been used in the prevention of first gastrointestinal bleeding in patients with portal hypertension and esophageal varices and in the prevention of recurrent gastrointestinal bleeding. These trials have shown that propranolol or nadolol significantly reduce either a first episode of bleeding or recurrent bleeding. This pharmacological treatment also improves the survival rate in these patients. All of these studies have helped us to understand, in part, why gastrointestinal hemorrhage occurs in certain patients. Additional studies of beta-blockers or other substances are, nevertheless, necessary to select patients who will respond to this type of treatment. Finally, it is possible that the pharmacological treatment of portal hypertension may also be used before esophageal varices occur.

Duplex-Doppler ultrasonography in the evaluation of cirrhotic patients with portal hypertension and in the analysis of their response to drugs

Sixteen patients (15 males, aged 48-70) affected by liver cirrhosis and oesophageal varices were subjected to duplex-Doppler ultrasonographic study (DDUS). Four patients (three with a portal thrombosis and one with a hepatofugal portal flow) were excluded from the subsequent pharmacological test. The twelve remaining patients took part in a double blind cross-over study that evaluated the variations of heart rate (HR), mean systemic arterial pressure (SAP), portal vein diameter (PVD), maximal and mean portal flow velocity (PFV) after the administration of either 40 mg of propranolol or placebo per os, on two consecutive days. Propranolol caused no significant variation in mean SAP and in PVD, whereas it reduced the HR from 67.7 +/- 8.0 to 58.4 +/- 7.0 beats/min (mean +/- s.d.; P less than 0.001); the maxPFV dropped from 18.2 +/- 5.4 to 14.0 +/- 3.7 cm/s (P less than 0.001) and the meanPFV dropped from 15.3 +/- 4.1 to 13.2 +/- 3.1 cm/s (P less than 0.005). No significant variation was observed with placebo. After propranolol administration eight patients exhibited a significant maxPFV decrease, whereas the other four patients exhibited only a drop in HR, suggesting either drug inefficacy, inappropriate dosage or inadequate duration of treatment. DDUS is the only non-invasive method for the examination of the portal vein system.(ABSTRACT TRUNCATED AT 250 WORDS)

Current status and future goals of the pharmacologic reduction of portal hypertension

The continuous oral administration of different drugs can produce a sustained reduction in portal pressure in patients with portal hypertension. beta-Adrenergic antagonists, alpha 2-adrenergic agonists, and 5-hydroxytryptamine-receptor antagonists have been evaluated for their long-term effects on portal pressure reduction. Clinical studies show that gastrointestinal bleeding can be prevented by pharmacologic therapy. This type of treatment is efficient and safe, and, if a drug has no clinical effect, a different drug or a combination can be used. Several problems, however, need to be addressed, including patient compliance, selection of responders, and hemodynamic evaluation of the treatment and its duration. Although pharmacologic treatment of portal hypertension is known to be efficient, there are advances still to be made.

Long-term pharmacologic therapy of portal hypertension

Beta-blockers modify splanchnic hemodynamics in cirrhotic patients. Nonselective beta-blockers are more effective than selective beta-blockers. Azygos blood flow, as a measure of collateral circulation, including that through varices, is always reduced, but the effects on portal pressure, whether measured directly or by the wedged hepatic venous pressure, are variable. The initial reported correlation between a 25% reduction of resting pulse rate and similar percentage reduction in the wedged free hepatic venous gradient has not been reproduced in subsequent studies. Therefore, to study the effect of changes in hemodynamic indices and the likelihood of variceal bleeding, direct measurements of such indices need to be made in clinical trials. At present, only one primary-prevention trial of propranolol suggests that a hemodynamic index can be used to identify patients given propranolol who will not bleed. Some clinical factors may be important in identifying nonresponders in trials of secondary prevention, but these are not universally recognized. The results of secondary-prevention studies are very heterogeneous, and it is difficult to understand why this is so. However, comparative studies versus sclerotherapy suggest that reductions in rebleeding and mortality are similar. Pharmacologic treatment, including beta-blockade, is ideal for primary prevention of variceal bleeding. The initial results from randomized studies are more homogeneous regarding the benefit of beta-blockers than in the secondary-prevention studies, although there is still doubt about the response in cirrhotics with ascites. No fatal complications due to propranolol administration have been reported in cirrhotic patients, and the complications are reversible. The future of pharmacologic therapy for portal hypertension lies in combination therapy. The addition of vasodilators to beta-blockers appears to potentiate their effect on portal pressure reduction. The results of clinical trials are awaited with great interest.

The effect of propranolol on the hyperaemic response of the hepatic artery to portal venous occlusion in the dog

1. It has been reported that activation of beta-adrenoceptors may be responsible for the hyperaemic response of the hepatic artery to portal venous blood flow reduction. 2. The effect of beta-adrenoceptor blockade on the hepatic arterial response to portal vein occlusion was investigated in 6 anaesthetized dogs. A side-to-side portacaval shunt was established to prevent loss of venous return and arterial blood pressure during periods of portal occlusion. Measurements of hepatic arterial and portal venous blood flows were made by use of electromagnetic flow probes. 3. Intravenous propranolol injection, at a dose sufficient to block the vasodilator effect of low doses of exogenous adrenaline, did not alter the magnitude of the hyperaemic response of the hepatic artery. Propranolol also produced no change in baseline portal venous pressure. 4. It is concluded that hepatic beta-adrenoceptors are unlikely to be involved in the arterial response to portal occlusion. The absence of any reduction in basal portal venous pressure by propranolol is of interest in view of the current application of the drug in the treatment of patients with portal hypertension.

Propranolol in the primary prevention of upper gastrointestinal tract haemorrhage in patients with cirrhosis of the liver and oesophageal varices

A prospective, randomised, multicentre, single-blind comparison of propranolol with placebo in the primary prevention of upper gastrointestinal haemorrhage was conducted in 230 cirrhotic patients with large oesophageal varices. The dose of propranolol was progressively increased until resting heart rate was reduced by 20 to 25%. The final doses were 40 mg of conventional propranolol and 160 and 320 mg of long-acting propranolol daily in 22, 60 and 18% of patients, respectively. Patients who survived without bleeding were followed up for 436 +/- 172 days (mean +/- SD). After 2 years, the cumulative percentages of patients free from bleeding were 74% in the propranolol group and 39% in the placebo group (p less than 0.05). Similarly, cumulative 2-year survival was 72% in the propranolol group and 51% in the placebo group (p less than 0.05). Propranolol was well tolerated and only 13 patients were withdrawn from treatment. We concluded that propranolol treatment decreased the incidence of first bleeding and death during a period of 2 years in patients with cirrhosis and large esophageal varices.

Relationship among beta-adrenergic blockade, propranolol concentration, and liver function in patients with cirrhosis

In 20 patients with cirrhosis we studied the relationship among the efficiency of beta-adrenergic blockade induced by oral administration of 40 mg propranolol, the plasma level of propranolol, and the liver function. The beta-adrenergic blockade was studied 2 h and 8 h after propranolol administration and assessed by the cardiac chronotropic response to isoprenaline. Liver function was evaluated by a standard liver function test and the Child-Turcotte or Pugh score. The beta-adrenergic blockade and propranolol plasma concentration were higher 2 h than 8 h after propranolol administration. The beta-adrenergic blockade and the propranolol plasma concentration varied widely among patients. No significant correlation was found between the efficiency of beta-blockade and propranolol concentration. The beta-adrenergic response before propranolol administration was correlated with bilirubin level and Child scores, but no significant correlation was found between the beta-blockade and the severity of liver disease. These results suggest that in patients with cirrhosis, differences in response to propranolol are not related to differences in the severity of the liver disease or to differences in propranolol concentration.

Propranolol in the prevention of first upper gastrointestinal tract hemorrhage in patients with cirrhosis of the liver and esophageal varices

We conducted a prospective, randomized, multicenter, single-blind trial of propranolol as compared with placebo in the prevention of first upper gastrointestinal tract bleeding in patients with cirrhosis of the liver. A total of 230 patients (90 percent with alcoholism and 46 percent with a Child-Pugh grade C classification) with large esophageal varices without previous bleeding were randomly assigned to receive either propranolol (n = 118) or placebo (n = 112), after they had been divided into two groups according to the severity of their liver disease. The end points of the study were bleeding and death. The dose of propranolol was progressively increased to decrease the heart rate by 20 to 25 percent. The final doses were 40 mg of conventional propranolol and 160 and 320 mg of long-acting propranolol daily in 22 percent, 60 percent, and 18 percent of patients, respectively. The mean (+/- SD) follow-up time among survivors without bleeding was 436 +/- 172 days. The cumulative percentages of patients free of bleeding two years after inclusion in the study were 74 percent (95 percent confidence limits, 61 and 83) in the propranolol group and 39 percent (95 percent confidence limits, 15 and 69) in the placebo group (P less than 0.05). Cumulative two-year survival was 72 percent (95 percent confidence limits, 60 and 81) in the propranolol group and 51 percent (95 percent confidence limits, 37 and 64) in the placebo group (P less than 0.05). The advantage of propranolol over placebo was maintained when potentially confounding variables were adjusted with use of the Cox model. Side effects occurred in 17 percent of the patients who received propranolol and led to the stopping of treatment in 11 percent. We conclude that propranolol can decrease the incidence of first bleeding and death during a period of two years in patients with cirrhosis and large varices.

Review article: beta-adrenoceptor blockers for the treatment of portal hypertension

beta-Adrenoceptor blockers always change splanchnic haemodynamics in cirrhotic patients. Azygous blood flow, as a measure of collateral circulation including that through varices, is always reduced, but the effects on portal pressure, whether measured directly or by the wedged hepatic venous pressure, are variable. The initial correlations between a 25% reduction of resting pulse rate and similar percentage reduction in the wedge-free hepatic venous gradient, has not been reproduced in subsequent studies. Therefore, to study the effect of changes in haemodynamic indices and the likelihood of variceal bleeding, direct measurements of such indices need to be made in clinical trials. At present there are no haemodynamic or clinical factors which can be used to select patients who will have a good therapeutic response to propranolol other than those documented in the first clinical trial of propranolol for the prevention of variceal re-bleeding from Paris. Thus the hypothesis that beta-adrenoceptor blockers may lessen the incidence of bleeding in cirrhotics, by partially reducing portal pressure or flow or both, needs testing in further clinical studies. The selection criteria of the first clinical trial of propranolol in Paris need to be confirmed. Two subsequent trials, in which patients were not selected but in which many patients had similar clinical characteristics to the Paris patients, could not confirm a therapeutic effect of propranolol. No fatal complications due to propranolol administration have been reported in cirrhotic patients. Complications are reversible. Pharmacological treatment including beta-adrenoceptor blockade appears ideal for trials of primary prevention of variceal bleeding. Some preliminary results including use in decompensated cirrhotics are encouraging. However, as for trials for prevention of re-bleeding, the design and analysis of such trials needs careful evaluation to take into account the outcome of patients who discontinue medication, whether due to simple noncompliance or due to side-effects, and also the influence of abstinence from alcohol on bleeding from varices.

Alterations in isoprenaline sensitivity in patients with cirrhosis: evidence of abnormality of the sympathetic nervous activity

Isoprenaline sensitivity and plasma catecholamine concentrations were studied to assess the sympathetic nervous activity in 13 patients with alcoholic cirrhosis and were compared with five controls. In patients with cirrhosis, the dose of isoprenaline required to increase the resting heart rate by 25 beats min-1 (chronotropic dose 25 or CD25) ranged from 2.50 to 34.73 micrograms (median: 4.47 micrograms) and was significantly higher than in controls (range: 0.66 to 2.76 micrograms, median: 1.34 micrograms). In cirrhotic patients, CD25 values were significantly correlated with plasma albumin concentration, resting heart rate and wedged hepatic venous pressure. In patients with cirrhosis, plasma noradrenaline concentrations ranged from 192 to 978 pg ml-1 (median: 444 pg ml-1) and adrenaline concentrations ranged from 5 to 183 pg ml-1 (median: 47 pg ml-1). No correlation was found between noradrenaline or adrenaline concentrations and CD25 values in cirrhotic patients. In conclusion, in patients with cirrhosis, beta-adrenoceptor responsiveness assessed by isoprenaline sensitivity is altered.