Assessing Portal Hypertension With Methacetin Breath Test

Inclusion Criteria: * Adult men or women (\>18 years of age) * Known chronic liver disease with cirrhosis * Europe: Indicated to undergo HVPG testing * US: Consented for HVPG * For patients treated with beta blockers: They have to be on a stable dose for at least 6 weeks prior to any study related tasks * For patients who stopped their treatment with beta blockers: Their last dose should be at least 6 weeks prior to any study related tasks Exclusion Criteria: * Decompensated cirrhosis as clinically defined by the presence of ascites, hepatic encephalopathy, variceal bleeding or hepatorenal syndrome * Renal failure (creatinine \> 2.5 mg/dl) * Known acute renal tubular disease Known hypotension (Systolic Pressure \<100mmHg) * Hypocoagulablity defined as PT \>6 and INR \>2.3. * Congestive heart failure (assessed clinically as NIHA \>2) * Known pulmonary hypertension (right ventricular systolic pressure \> 45 mm Hg) * Uncontrolled diabetes mellitus (HBA1C \>9.5gr%) * Concurrent prednisone or immunosuppressive treatment, if therapy and/or response to treatment are not stable for at least 3 months. * Documented or suspected hepatocellular carcinoma * Gastric bypass surgery or extensive small bowel resection * Total parenteral nutrition * Any organ transplant recipient * Pregnant or breast feeding * Allergy to acetaminophen and/or other related medications * Documented drug-related concurrent hepatotoxicity or drug-related silent steatosis or drug-related fibrosis (e.g. amiodarone, methotrexate and tamoxifen) * Uncontrolled malabsorption or diarrhea * Documented non-cirrhotic PHT, partial / complete portal venous occlusion, hepatic venous occlusion, previous PHT surgery, or placement of a transjugular intrahepatic portosystemic shunt (TIPS) * Primary or secondary biliary cirrhosis, primary or secondary sclerosing cholangitis, hepatic sarcoidosis, or other cholestatic disorders * Subjects unable to perform the MBT within 7 days of HVPG procedure. * Subject should not have taken any of the following for at least 48 hours prior to the breath test: Acyclovir , allopurinol, amiodarone, carbamazepine, cimetidine, ciprofloxacin, daidzein, (herbal) disulfiram, echinacea, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, montelukast, norfloxacin, phenylpropanolamine, phenytoin, propafenone, rifampin, terbinafine, ticlopidine, thiabendazole, verapamil, zileuton or oral contraceptives or any medication that might interfere with Methacetin metabolism or might affect CYP 1A2 * Subject should not have taken amiodarone or statins within the last 30 days prior to the breath test or HVPG procedure