Understanding the Subpopulations of Pulmonary Hypertension - Episode 12
Shared insight on portopulmonary hypertension, with deference to risk factors and comorbidities.
Charles D. Burger, MD: Portopulmonary hypertension is a subgroup of Group 1 pulmonary arterial hypertension [PAH], and it occurs in the setting of hepatic cirrhosis or end-stage liver disease. When that happens, circulation from the GI [gastrointestinal] tract through the liver gets congested, and that’s referred to as portal hypertension. It produces fluid in the abdomen, ascites. It can produce a lot of collateral circulation in the GI circulation, called varices. That has a high association with development of pulmonary arterial hypertension. When you have both together, that’s called portopulmonary hypertension.
Patients with end-stage liver disease can have other causes of pulmonary hypertension [PH], which do not involve narrowing of the pulmonary vessels, and a specialist has to sort that out. It generally involves a right heart catheterization to determine whether the pulmonary hypertension is there because the patient with hepatic cirrhosis is retaining too much fluid, or perhaps they have a high cardiac output state. But they may very well have portopulmonary hypertension. If you look at populations of patients who are referred for liver transplant, up to 5% or 6% of those patients have portopulmonary hypertension that’s discovered during evaluation for whether they are eligible for a liver transplant.
In terms of risk for developing pulmonary arterial hypertension, it’s really the setting that I just described. It could be that patients have some skin manifestations, such as spider angiomas that might be similar to the telangiectasias that you see in connective tissue disease. That might be prevalent or more prominent. But in general, it’s an assessment of whether they feel like they’ve developed cardiopulmonary symptoms, such as shortness of breath or chest tightness or lightheadedness with exertion: something that might suggest they have portopulmonary hypertension that would prompt you to investigate further, typically with an echocardiogram to see if right heart pressures are elevated, the right heart is dilated, or if they’re having trouble with systolic contraction, systolic hypokinesis.
There are certain interventions that can be done for patients with portal hypertension and end-stage liver disease that are designed to try to address the combinations of liver disease that might increase their risk for portopulmonary hypertension. There’s a procedure called TIPS [transjugular intrahepatic portosystemic shunt], which is a transjugular shunt that’s created in the liver to help reduce portal hypertension. When you do that, unfortunately, in a subset of patients, it may increase their risk for developing portopulmonary hypertension. But aside from that, it’s important to interview the patient to see if they have symptoms, perhaps 1 or 2 examination findings, that might indicate you need to investigate further.
Lastly, if the patient is being referred for a liver transplant, that center will investigate this possibility in detail because it’s difficult to safely perform a liver transplant in a patient with uncontrolled pulmonary hypertension. It increases their risk of serious complication and even death. Centers will certainly want to diagnose portopulmonary hypertension, treat it, and get it under control before they would ever recommend moving forward with a liver transplant.
Hilary M. DuBrock, MD: It’s important to remember that patients with portopulmonary hypertension have 2 distinct comorbid conditions. They have pulmonary arterial hypertension, but they also have significant liver disease. In most patients with portopulmonary hypertension, their overall prognosis is determined more by the severity of their liver disease than by the severity of their pulmonary hypertension. But the PH severity also plays a role in their overall prognosis in that patients with a low cardiac index or with an elevated pulmonary vascular resistance have a worse survival over time.