Cirrhosis is a chronic disorder of the liver that results in an increase in its stiffness. As a result of the increased stiffness, the pressure in the blood vessels draining into the liver - the portal system - is increased. The increased portal blood pressure can result in the development of abnormally dilated blood vessels or varicose veins in the stomach and oesophagus (gastroesophageal varices). These varices can burst and the bleeding that follows can be life-threatening. Drugs that reduce the portal blood pressure can help deflate the gastroesophageal varices and hence reduce the risk of bleeding. The drugs most commonly used are called non-selective beta-blockers. A newer drug, carvedilol, is also a beta blocker but has additional actions and may be more effective at reducing the portal pressure and hence the risk of variceal bleeding.
We investigated the effects and safety of carvedilol in people with cirrhosis and oesophageal varices by reviewing clinical trials in which people were randomly allocated to treatment with carvedilol or to a traditional beta-blocker.
Trial funding sources
Two of the 11 randomised clinical trials included in the review received no funding or other support from pharmaceutical companies. Two did receive financial support from pharmaceutical companies while a further three received free supplies of the trial drugs. Four trials did not provide funding information.
We included 11 randomised clinical trials, but were only able to gather information for our analyses from 10 trials involving 810 participants. The length of treatment ranged from one week to 30 months.
Our analyses found no differences in the effects of carvedilol on the rates of death, bleeding or serious and non-serious complications compared with traditional, non-selective beta-blockers. Carvedilol lowered the portal pressure more effectively than the traditional, non-selective beta-blockers, but did not increase the number of participants in whom the pressure was reduced enough to reduce the risk of bleeding.
Quality of the evidence
We classified the evidence as of low or very low quality, so further trials are needed.
We found no clear beneficial or harmful effects of carvedilol versus traditional, non-selective beta-blockers on mortality, upper gastrointestinal bleeding, serious or non-serious adverse events despite the fact that carvedilol was more effective at reducing the hepatic venous pressure gradient. However, the evidence was of low or very low quality, and hence the findings are uncertain. Additional evidence is required from adequately powered, long-term, double-blind, randomised clinical trials, which evaluate both clinical and haemodynamic outcomes.
Non-selective beta-blockers are recommended for the prevention of bleeding in people with cirrhosis, portal hypertension and gastroesophageal varices. Carvedilol is a non-selective beta-blocker with additional intrinsic alpha1-blocking effects, which may be superior to traditional, non-selective beta-blockers in reducing portal pressure and, therefore, in reducing the risk of upper gastrointestinal bleeding.
To assess the beneficial and harmful effects of carvedilol compared with traditional, non-selective beta-blockers for adults with cirrhosis and gastroesophageal varices.
We combined searches in the Cochrane Hepato-Biliary's Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS, and Science Citation Index with manual searches. The last search update was 08 May 2018.
We included randomised clinical trials comparing carvedilol versus traditional, non-selective beta-blockers, irrespective of publication status, blinding, or language. We included trials evaluating both primary and secondary prevention of upper gastrointestinal bleeding in adults with cirrhosis and verified gastroesophageal varices.
Three review authors (AZ, RJ and LH), independently extracted data. The primary outcome measures were mortality, upper gastrointestinal bleeding and serious adverse events. We undertook meta-analyses and presented results using risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CIs), and I2 values as a marker of heterogeneity. We assessed bias control using the Cochrane Hepato-Biliary domains and the quality of the evidence with GRADE.
Eleven trials fulfilled our inclusion criteria. One trial did not report clinical outcomes. We included the remaining 10 randomised clinical trials, involving 810 participants with cirrhosis and oesophageal varices, in our analyses. The intervention comparisons were carvedilol versus propranolol (nine trials), or nadolol (one trial). Six trials were of short duration (mean 6 (range 1 to 12) weeks), while four were of longer duration (13.5 (6 to 30) months). Three trials evaluated primary prevention; three evaluated secondary prevention; while four evaluated both primary and secondary prevention. We classified all trials as at 'high risk of bias'. We gathered mortality data from seven trials involving 507 participants; no events occurred in four of these. Sixteen of 254 participants receiving carvedilol and 19 of 253 participants receiving propranolol or nadolol died (RR 0.86, 95% CI 0.48 to 1.53; I2 = 0%, low-quality evidence). There appeared to be no differences between carvedilol versus traditional, non-selective beta-blockers and the risks of upper gastrointestinal bleeding (RR 0.77, 95% CI 0.43 to 1.37; 810 participants; 10 trials; I2 = 45%, very low-quality evidence) and serious adverse events (RR 0.97, 95% CI 0.67 to 1.42; 810 participants; 10 trials; I2 = 14%, low-quality evidence). Significantly more deaths, episodes of upper gastrointestinal bleeding and serious adverse events occurred in the long-term trials but there was not enough information to determine whether there were differences between carvedilol and traditional, non-selective beta-blockers, by trial duration. There was also insufficient information to detect differences in the effects of these interventions in trials evaluating primary or secondary prevention. There appeared to be no differences in the risk of non-serious adverse events between carvedilol versus its comparators (RR 0.55, 95% CI 0.23 to 1.29; 596 participants; 6 trials; I2 = 88%; very low-quality evidence). Use of carvedilol was associated with a greater reduction in hepatic venous pressure gradient than traditional, non-selective beta-blockers both in absolute (MD -1.75 mmHg, 95% CI -2.60 to -0.89; 368 participants; 6 trials; I2 = 0%; low-quality evidence) and percentage terms (MD -8.02%, 95% CI -11.49% to -4.55%; 368 participants; 6 trials; I2 = 0%; low-quality evidence). However, we did not observe a concomitant reduction in the number of participants who failed to achieve a sufficient haemodynamic response (RR 0.76, 95% CI 0.57 to 1.02; 368 participants; 6 trials; I2 = 42%; very low-quality evidence) or in clinical outcomes.