Development of hepatopulmonary syndrome during combination therapy for portopulmonary hypertension

[Hepatopulmonary syndrome]

The hepatopulmonary syndrome (HPS) is one of the lung diseases associated with cirrhosis and portal hypertension. It should be discussed for any dyspnea in cirrhotic patients. HPS is a pulmonary vascular disease characterized by intrapulmonary vascular dilatations (IPVD). The pathogenesis is complex and seems to rely on communications between the portal and pulmonary circulations. The diagnosis is based on a triad of liver disease and portal hypertension, evidence of IPVDs, and impaired gas exchange (alveolar-arterial oxygen difference [A-aO2]≥15mmHg). HPS impairs prognosis (23% survival at 5years) and patients' quality of life. Liver transplantation (LT) allows regression of IPDVD in almost 100% of cases, normalization of gas exchange and improves survival with a 5-year post-LT survival between 76 and 87%. It is the only curative treatment, indicated in patients with severe HPS, defined by an arterial partial pressure of oxygen (PaO2) below 60mmHg. When LT is not indicated or feasible, long-term oxygen therapy may be proposed as a palliative treatment. A better understanding of the pathophysiological mechanisms is needed to improve the therapeutic possibilities in a near future.

Pulmonary hypertension, nephrotic syndrome, and polymyositis due to hepatitis C virus infection: A case report

BACKGROUND

Hepatitis C infection not only damages the liver but also often accompanies many extrahepatic manifestations. Incidences of pulmonary hypertension (PH) caused by hepatitis C are rare, and incidences of concurrent nephrotic syndrome and polymyositis are even rarer.

CASE SUMMARY

Herein we describe the case of a 57-year-old woman who was admitted to our department for intermittent chest tightness upon exertion for 5 years, aggravated with dyspnea for 10 d. After relevant examinations she was diagnosed with PH, nephrotic syndrome, and polymyositis due to chronic hepatitis C infection. A multi-disciplinary recommendation was that the patient should be treated with sildenafil and macitentan in combination and methylprednisolone. During treatment autoimmune symptoms, liver function, hepatitis C RNA levels, and cardiac parameters of right heart catheterization were monitored closely. The patient showed significant improvement in 6-min walking distance from 100 to 300 m at 3-mo follow-up and pulmonary artery pressure drops to 50 mmHg. Long-term follow-up is needed to confirm further efficacy and safety.

CONCLUSION

Increasing evidence supports a relationship between hepatitis C infection and diverse extrahepatic manifestations, but it is very rare to have PH, nephrotic syndrome, and polymyositis in a single patient. We conducted a literature review on the management of several specific extrahepatic manifestations of hepatitis C.

Porto-pulmonary arterial hypertension: Translation of pathophysiological concepts to the bedside

Porto-pulmonary arterial hypertension (PoPAH) is a form of pulmonary arterial hypertension (PAH) that affects patients with cirrhosis, and - to a lesser extent - patients with non-cirrhotic liver diseases. Compared with other forms of PAH, PoPAH is more prevalent in male, in older subjects, and is characterized by lower mean pulmonary arterial pressure (mPAP) and lower pulmonary vascular resistance (PVR) with higher cardiac output. Despite more favorable hemodynamics and functional class, patients with PoPAH have a significantly worse survival than patients with other forms of PAH, likely because of liver-related events and therapeutic barriers to PAH-specific therapy. Furthermore, here cardiopulmonary and hepatic complications may affect treatment efficacy. These patients have been excluded from most randomized clinical trials testing PAH-specific treatments. To date, there is only one study investigating efficacy, safety, tolerability and pharmacokinetics of PAH-specific therapy in patients with PoPAH in a randomized placebo-controlled setting. In this trial the use of the endothelin-1 receptor antagonist macitentan showed clear hemodynamic benefit without safety concerns. However, the drug effects on functional capacity and mortality remain unclear. Here we review the current knowledge on the pathophysiology and management of PoPAH and report a case vignette of a patient with PoPAH due to hepatorenal polycystic disease.

Pulmonary Complications of Portal Hypertension

The most common pulmonary complications of chronic liver disease are hepatic hydrothorax, hepatopulmonary syndrome, and portopulmonary hypertension. Hepatic hydrothorax is a transudative pleural effusion in a patient with cirrhosis and no evidence of underlying cardiopulmonary disease. Hepatic hydrothorax develops owing to the movement of ascitic fluid into the pleural space. Hepatopulmonary syndrome and portopulmonary hypertension are pathologically linked by the presence of portal hypertension; however, their pathophysiologic mechanisms are significantly different. Hepatopulmonary syndrome is characterized by low pulmonary vascular resistance secondary to intrapulmonary vascular dilatations and hypoxemia; portopulmonary hypertension features elevated pulmonary vascular resistance and constriction/obstruction within the pulmonary vasculature.

Macitentan for the treatment of portopulmonary hypertension (PORTICO): a multicentre, randomised, double-blind, placebo-controlled, phase 4 trial

BACKGROUND

No dedicated randomised clinical trials have evaluated therapies for pulmonary arterial hypertension in patients with portopulmonary hypertension. The endothelin receptor antagonist macitentan has demonstrated long-term efficacy in pulmonary arterial hypertension with a good hepatic safety profile. We aimed to evaluate efficacy and safety of macitentan in patients with portopulmonary hypertension.

METHODS

PORTICO was a phase 4 study done in 36 centres in seven countries, consisting of a 12-week double-blind period (randomly assigned 1:1 to macitentan 10 mg or placebo once daily) followed by a 12-week open-label period. Adults (≥18 years) with portopulmonary hypertension, a 6-minute walk distance of 50 m or more, and with pulmonary vascular resistance of 320 dyn·s·cm^-5 or more without severe hepatic impairment (Child-Pugh class C or model for end-stage liver disease score ≥19) were eligible. The primary endpoint was pulmonary vascular resistance at week 12, expressed as ratio of baseline in the full analysis set. Safety was assessed throughout. This trial is registered at ClinicalTrials.gov, number NCT02382016.

FINDINGS

Between June 23, 2015, and July 28, 2017, 85 patients were randomly assigned to macitentan (n=43) or placebo (n=42). At baseline, 54 (64%) were receiving background therapy for pulmonary arterial hypertension. Most patients were WHO functional class II (50, 59%) or III (33, 39%) with a mean 6-minute walk distance of 384·5 m (SD 103·9). At week 12, the geometric mean ratio of baseline pulmonary vascular resistance was 0·63 (95% CI 0·58-0·67) in the macitentan group and 0·98 (95% CI 0·91-1·05) in the placebo group, corresponding to a ratio of geometric mean for pulmonary vascular resistance of 0·65 (95% CI 0·59-0·72, p<0·0001), which in turn represented a 35% (95% CI 28-41) reduction in pulmonary vascular resistance with macitentan versus placebo. During the double-blind period, 36 (84%) macitentan-treated and 33 (79%) placebo-treated patients had adverse events, and nine (21%) and six (14%), had serious adverse events. Four (9%) macitentan-treated patients had an adverse event leading to discontinuation versus none in the placebo group. The most frequent adverse event during the double-blind period was peripheral oedema (11 [26%] in the macitentan group and five [12%] in the placebo group).

INTERPRETATION

Macitentan significantly improved pulmonary vascular resistance in portopulmonary hypertension patients, with no hepatic safety concerns.

FUNDING

Actelion Pharmaceuticals Ltd.