Patients whose pulmonary artery pressure has risen due to liver cirrhosis—a condition in which the liver hardens—can still undergo liver transplant surgery if they receive precise evaluation and treatment optimization, according to a new study.
Samsung Medical Center said Wednesday that a multi-institutional research team analyzed 43 patients diagnosed with portopulmonary hypertension from 2009 to 2023. The team included Professor Jang Sung-a and clinical fellow Kim Ye-chan of the cardiology department, along with Professors Kim Hyung-kwan and Kwak Soon-gu of the cardiology department at Seoul National University Hospital.
Portopulmonary hypertension is a condition in which pressure rises within the portal vein—the blood vessel that carries nutrient-rich blood absorbed from digestive organs such as the stomach, intestines and spleen to the liver—due to cirrhosis, causing pulmonary artery pressure to rise as well. Liver transplant surgery has long been considered contraindicated for portopulmonary hypertension patients. A large shift of bodily fluids is inevitable during liver transplant surgery, and this process can place a sudden overload on the heart, carrying a very high risk of fatal complications such as right ventricular failure.
Generally, when the mean pulmonary artery pressure (mPAP)—the pressure within the pulmonary artery, the vessel that sends blood from the right ventricle to the lungs—is 45 mmHg or higher, a liver transplant is considered difficult. Borderline patients with mean pulmonary artery pressure between 35 and 45 mmHg also frequently gave up on transplants due to the risk burden.
Among the 43 portopulmonary hypertension patients included in this analysis, nine underwent liver transplant surgery during the study period. In particular, six of the nine patients who received liver transplants had mean pulmonary artery pressure (mPAP) between 35 and 45 mmHg. Under existing criteria, these patients would have been classified as borderline cases with high surgical risk and could have been excluded from transplant candidacy.
According to the analysis, seven of the nine patients who received liver transplants (77.7%) survived, while five of the seven patients whose transplants were withheld due to high pulmonary hypertension-related risk (71.4%) died within one year. The research team interpreted these contrasting results as indicating that the transplant feasibility of portopulmonary hypertension patients should not be determined by pulmonary artery pressure alone. They said the decision on whether to perform a liver transplant should be made by comprehensively evaluating not only the pressure within the pulmonary artery, but also pulmonary vascular resistance, right ventricular function, response to pulmonary hypertension treatment, and the severity of liver disease.
In fact, in this study, mean pulmonary artery pressure itself did not show a significant association with mortality risk. Instead, the Child-Pugh score, which reflects the severity of chronic liver disease such as cirrhosis, was closely related to the prognosis of liver transplant patients. The analysis found that mortality risk increased 1.53-fold with each one-point rise in the Child-Pugh score.
In addition, the peak pulmonary artery systolic pressure of patients who survived after liver transplant decreased significantly from 58.4 mmHg before surgery to 38.6 mmHg after surgery. This suggests that performing a liver transplant on portopulmonary hypertension patients to address the root cause—cirrhosis—can also improve pulmonary hypertension. Among the seven survivors, four saw their pulmonary hypertension completely improve to the point of discontinuing related drug treatment.
The research team concluded that considering a liver transplant in portopulmonary hypertension patients requires closely evaluating the degree of pulmonary hypertension and right ventricular function before surgery, while also reviewing the response to pulmonary hypertension treatment and management strategies before and after transplant. The key is to assess individual patient risk and establish treatment and management plans through collaboration among multiple departments, including cardiology, transplant surgery and critical care medicine, and then actively administer pulmonary arterial hypertension targeted therapies before surgery to lower pulmonary artery pressure as much as possible. They explained that even when hemodynamic problems arose after surgery, they could be resolved through active management.
Professor Kim Hyung-kwan stressed, "Grounds have now been established for borderline patients to safely receive liver transplants," adding, "The decision on whether to perform a liver transplant should not be based on pulmonary artery pressure alone."
Professor Jang Sung-a, who led the research, said, "Portopulmonary hypertension has been regarded as a condition requiring careful judgment in the liver transplant process, but we confirmed that in some patients, a liver transplant can be considered after appropriate treatment and evaluation." She added, "For this, multidisciplinary care involving cardiology, transplant surgery and critical care medicine working together is important."
The findings of this study were published in the latest issue of the Korean Circulation Journal, an international journal published by the Korean Society of Cardiology.
