Enric Reverter

Assessing portal hypertension in liver diseases

Portal hypertension is a common complication of chronic liver diseases and is responsible for most clinical consequences of cirrhosis, which represent the more frequent causes of death and liver transplantation in these patients. This review is aimed at clarifying the state-of-the art assessment of portal hypertension and at discussing recent developments in this field. Particular attention is paid to new noninvasive techniques that will be soon available for potential routine use.

A MELD-Based Model to Determine Risk of Mortality Among Patients With Acute Variceal Bleeding

BACKGROUND & AIMS Patients with cirrhosis with acute variceal bleeding (AVB) have high mortality rates (15%-20%). Previously described models are seldom used to determine prognoses of these patients, partially because they have not been validated externally and because they include subjective variables, such as bleeding during endoscopy and Child-Pugh score, which are evaluated inconsistently. We aimed to improve determination of risk for patients with AVB. METHODS We analyzed data collected from 178 patients with cirrhosis (Child-Pugh scores of A, B, and C: 15%, 57%, and 28%, respectively) and esophageal AVB who received standard therapy from 2007 through 2010. We tested the performance (discrimination and calibration) of previously described models, including the model for end-stage liver disease (MELD), and developed a new MELD calibration to predict the mortality of patients within 6 weeks of presentation with AVB. MELD-based predictions were validated in cohorts of patients from Canada (n = 240) and Spain (n = 221). RESULTS Among study subjects, the 6-week mortality rate was 16%. MELD was the best model in terms of discrimination; it was recalibrated to predict the 6-week mortality rate with logistic regression (logit, -5.312 + 0.207 • MELD; bootstrapped R(2), 0.3295). MELD values of 19 or greater predicted 20% or greater mortality, whereas MELD scores less than 11 predicted less than 5% mortality. The model performed well for patients from Canada at all risk levels. In the Spanish validation set, in which all patients were treated with banding ligation, MELD predictions were accurate up to the 20% risk threshold. CONCLUSIONS We developed a MELD-based model that accurately predicts mortality among patients with AVB, based on objective variables available at admission. This model could be useful to evaluate the efficacy of new therapies and stratify patients in randomized trials.

Acute variceal bleeding.

Bleeding from gastroesophageal varices is a frequent complication of cirrhosis. Mortality from a variceal bleeding episode has decreased in the last 2 decades from 40% to 15 to 20% due to the implementation of effective treatments and improvement in the general medical care. Initial treatment should include adequate fluid resuscitation and transfusion to maintain hemoglobin around 7 to 8 g/dL, and prophylactic antibiotics (norfloxacin or ceftriaxone). It is currently recommended that a vasoactive drug be started as soon as variceal bleeding is suspected. Vasoactive therapy should be maintained for up to 5 days to prevent early rebleeding. Where available, terlipressin, a vasopressin derivative, is the preferred agent because of its safety profile; it represents the only drug with proven efficacy in improving survival. Somatostatin and octreotide are used and are as effective as terlipressin in control of bleeding but have not been shown to reduce mortality. Endoscopic therapy must be performed within the first 12 hours after admission when the patient is stable. Variceal band ligation is the recommended endoscopic treatment, but injection sclerotherapy is an alternative if band ligation is technically difficult. Despite this standard of care, 10 to 20% of patients may still exhibit initial failure to control bleeding or early rebleeding within the first 5 days. In failures to control bleeding the use of rescue transjugular intrahepatic portosystemic shunt (TIPS) using covered stents is the best alternative. In mild early rebleeding a second course of endoscopic therapy may be attempted. If rebleeding is severe, placement of TIPS using covered stents is the first-choice rescue treatment. In refractory variceal bleeding episodes, balloon tamponade may be used as a temporary bridge to TIPS. Identification of patients that are at high risk of treatment failure may guide new strategies to improve outcomes. Indeed, a recent trial has shown that placement of TIPS, using covered stents, within 72 hours of admission in patients at high risk of treatment failure (i.e., those Child B with active bleeding or Child C less than 14 points) markedly decreased rebleeding and improved survival.

Role of hepatic vein catheterisation and transient elastography in the diagnosis of idiopathic portal hypertension

BACKGROUND Idiopathic portal hypertension is a rare cause of portal hypertension, frequently misdiagnosed as cryptogenic cirrhosis. This study evaluates specific findings at hepatic vein catheterisation or liver stiffness in idiopathic portal hypertension. METHODS 39 cases of idiopathic portal hypertension patients were retrospectively reviewed. Hepatic vein catheterisation and liver stiffness measurements were compared to matched patients with cirrhosis and portal hypertension, and non-cirrhotic portal vein thrombosis, included as controls. RESULTS Hepatic vein-to-vein communications were found in 49% idiopathic portal hypertension patients precluding adequate hepatic venous pressure gradient measurements in 12. In the remaining 27 patients, mean hepatic venous pressure gradient (HVPG) was 7.1 ± 3.1 mm Hg. Only 5 patients had HVPG≥10mmHg. HVPG was markedly lower than in cirrhosis (17 ± 3 mm Hg, p<0.001). Mean liver stiffness in idiopathic portal hypertension was 8.4 ± 3.3 kPa; significantly higher than in non-cirrhotic portal vein thrombosis (6.4 ± 2.2 kPa, p=0.009), but lower than in cirrhosis (40.9 ± 20.5 kPa, p=0.005). Only 2 idiopathic portal hypertension patients had liver stiffness >13.6 kPa. CONCLUSIONS Patients with idiopathic portal hypertension frequently have hepatic vein-to-vein communications and, despite unequivocal signs of portal hypertension, HVPG and liver stiffness values much lower than the cut-off for clinical significant portal hypertension in cirrhosis. These findings oblige to formally rule-out idiopathic portal hypertension in the presence of signs of portal hypertension.

Non-invasive diagnostic and prognostic evaluation of liver cirrhosis and portal hypertension

Cirrhosis is the final stage of most of chronic liver diseases, and is almost invariably complicated by portal hypertension, which is the most important cause of morbidity and mortality in these patients. This review will focus on the non-invasive methods currently used in clinical practice for diagnosing liver cirrhosis and portal hypertension. The first-line techniques include physical examination, laboratory parameters, transient elastography and Doppler-US. More sophisticated imaging methods which are less commonly employed are CT scan and MRI, and new technologies which are currently under evaluation are MR elastography and acoustic radiation force imaging (ARFI). Even if none of them can replace the invasive measurement of hepatic venous pressure gradient and the endoscopic screening of gastroesophageal varices, they notably facilitate the clinical management of patients with cirrhosis and portal hypertension, and provide valuable prognostic information.

Bacterial and fungal infections in acute-on-chronic liver failure: prevalence, characteristics and impact on prognosis

Bacterial infection is a frequent trigger of acute-on-chronic liver failure (ACLF), syndrome that could also increase the risk of infection. This investigation evaluated prevalence and characteristics of bacterial and fungal infections causing and complicating ACLF, predictors of follow-up bacterial infections and impact of bacterial infections on survival. Patients 407 patients with ACLF and 235 patients with acute decompensation (AD). Results 152 patients (37%) presented bacterial infections at ACLF diagnosis; 46%(n=117) of the remaining 255 patients with ACLF developed bacterial infections during follow-up (4 weeks). The corresponding figures in patients with AD were 25% and 18% (p<0.001). Severe infections (spontaneous bacterial peritonitis, pneumonia, severe sepsis/shock, nosocomial infections and infections caused by multiresistant organisms) were more prevalent in patients with ACLF. Patients with ACLF and bacterial infections (either at diagnosis or during follow-up) showed higher grade of systemic inflammation at diagnosis of the syndrome, worse clinical course (ACLF 2-3 at final assessment: 47% vs 26%; p<0.001) and lower 90-day probability of survival (49% vs 72.5%;p<0.001) than patients with ACLF without infection. Bacterial infections were independently associated with mortality in patients with ACLF-1 and ACLF-2. Fungal infections developed in 9 patients with ACLF (2%) and in none with AD, occurred mainly after ACLF diagnosis (78%) and had high 90-day mortality (71%). Conclusion Bacterial infections are extremely frequent in ACLF. They are severe and associated with intense systemic inflammation, poor clinical course and high mortality. Patients with ACLF are highly predisposed to develop bacterial infections within a short follow-up period and could benefit from prophylactic strategies.

Impact of deep sedation on the accuracy of hepatic and portal venous pressure measurements in patients with cirrhosis.

Measurement of the hepatic venous pressure gradient (HVPG) offers valuable prognostic information in patients with cirrhosis. In specific circumstances, (children, agitated patients, TIPS placement) deep sedation is required. This study aims to assess the impact of deep sedation on the accuracy of hepatic/portal pressure measurements.

Cardiovascular Risk Factors and Systemic Endothelial Function in Patients With Cirrhosis

OBJECTIVES:Cardiovascular risk factors (CVRF) lead to systemic endothelial dysfunction. It has been suggested that in cirrhosis, cardiovascular risk is low and systemic endothelial function is enhanced. However, there is no prospective study evaluating the relationship between cardiovascular risk and systemic endothelial function in cirrhosis, which was investigated here.METHODS:In 47 patients with cirrhosis (33 males; median Child-Pugh score 8; median age 55 years), we evaluated: laboratory parameters, hepatic and systemic hemodynamics, CVRF, 10-year global cardiovascular risk by Framingham score, and presence of carotid plaques. Systemic endothelial dysfunction was investigated non-invasively by flow-mediated dilatation (FMD) of the brachial artery by ultrasound and defined as FMD <10%.RESULTS:Cardiovascular risk (median 7%) was low in 25%, moderate in 26%, moderately high in 40%, and high in 9%. Fifty-three percent of patients had systemic endothelial dysfunction. Systemic endothelial dysfunction (low FMD) increased in parallel with CV risk (linear trend P=0.039) and was higher in patients overweight or obese. Conversely, FMD increased in parallel with Child-Pugh/Mayo Clinic Model for End-stage Liver Disease (MELD) score, bilirubin, serum sodium, plasma renin activity, leukocyte count, platelet count, and with lower arterial pressure, suggesting that enhanced FMD is a feature of advanced liver failure and inflammation. Cardiovascular risk, bilirubin, leukocyte count, and arterial pressure remained independently associated with systemic endothelial dysfunction.CONCLUSIONS:CV risk was not low in our studied patients with cirrhosis, and systemic endothelial dysfunction was frequent in this population. In cirrhosis, similar to general population, cardiovascular risk impaired systemic FMD, although liver failure attenuated endothelial dysfunction.

Insulin resistance in patients with cirrhosis and portal hypertension

Insulin resistance (IR) is involved in the pathogenesis of endothelial dysfunction and is also present in patients with cirrhosis. Intrahepatic endothelial dysfunction plays a major role, increasing hepatic vascular resistance and promoting portal hypertension (PH). In addition, β-adrenergic agonists and insulin share several intracellular signaling pathways. Thus IR may influence the response to β-blockers. This study aimed at evaluating the relationship between IR and hepatic hemodynamics in patients with cirrhosis and with the portal pressure response to acute β-blockade. Forty-nine patients with cirrhosis and PH were included. Hepatic and systemic hemodynamics were measured, and IR was estimated by using the updated homeostasis model assessment (HOMA)-2 index. Patients with HOMA-2 > 2.4 were considered IR. In patients with hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) [clinically significant PH (CSPH)], hemodynamic measurements were performed again 20 min after intravenous propranolol. Mean HOMA-2 index was 3 ± 1.4. Fifty-seven percent of patients had IR. A weak correlation between HOMA-2 index and HVPG was observed. Eighty-six percent of patients had CSPH. HOMA-2 index was an independent predictor of CSPH. However, in patients with CSPH, the correlation between HOMA-2 index and HVPG was lost. HVPG, but not IR, predicted the presence of esophageal varices. Response to propranolol was not different between patients with or without IR. In nondiabetic patients with cirrhosis, HOMA-2 index is directly associated with the presence of CSPH and indirectly with varices, but does not allow either grading HVPG or predicting its response to propranolol.

Reliability of the estimation of total hepatic blood flow by Doppler ultrasound in patients with cirrhotic portal hypertension

BACKGROUND & AIMS Hepatic blood flow (HBF) is best estimated by the Ficks method during indocyanine green constant infusion (ICG-HBF) on hepatic vein catheterization. We investigated the consistency and agreement of HBF measured by Doppler ultrasound (US-HBF) as compared with ICG-HBF in portal hypertensive patients with cirrhosis. METHODS In 50 patients observed for HVPG measurement (56% compensated; Child score 7 ± 2; HVPG 16.6 ± 6.0 mmHg; varices in 75%) US-HBF (Sequoia-512-Acuson; 4.5-7 MHz convex probe; US-HBF = hepatic artery blood flow+portal vein blood flow) and ICG-HBF (Ficks method after an equilibration period of at least 45 min of ICG bolus of 5 mg + constant rate infusion of 0.2 mg/min). Intraclass correlation coefficient (ICC) for consistency and absolute agreement between US-HBF and ICG-HBF were calculated. RESULTS Mean ICG-HBF and US-HBF were similar, being respectively 1004 ± 543 ml/min and 994 ± 494 ml/min (p = 0.661 vs. ICG-HBF). However, results in individual patients disclosed marked differences between the two methods (386 ± 415 ml/min) and showed only moderate consistency (ICC 0.456; p < 0.0001), absolute agreement (ICC 0.461; p < 0.0001) and linear correlation (R = 0.464; p < 0.0001). The discrepancy between the two methods was maximal in patients with poor liver function, high HBF by any technique and more arterialized liver circulation. Hepatic artery blood flow ≥40% of US-HBF indicated, with 90% specificity, a discrepancy ≥20% between US-HBF and ICG-HBF. CONCLUSIONS HBF estimations by Doppler-ultrasound and ICG are significantly correlated, but their discrepancy in individual cases is high. Estimation of HBF by Doppler-US should be considered unreliable in patients with poor hepatic function and large liver arterialization.