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Background: Pulmonary hypertension (PH) exists when mean pulmonary artery pressure (mPAP) is 25 mm Hg or greater. mPAP of 35 mm Hg or greater, with increased pulmonary vascular resistance from portopulmonary hypertension, has been associated with increased post-liver transplant (LT) mortality. However, mPAP of 35 mm Hg or greater can also occur in the setting of normal pulmonary vascular resistance from a high flow state and/or increased pulmonary venous volume. We describe the frequency of patients with mPAP of 35 mm Hg or greater at LT and correlate their clinical outcomes with hemodynamic characteristics., Methods: We reviewed hemodynamics of 300 consecutive adult patients undergoing LT. Primary and secondary outcomes were transplant hospitalization mortality and 1-year mortality., Results: Overall, PH was documented in 117 (39%) of 300 transplant recipients. Five patients were receiving ongoing treatment for portopulmonary hypertension at the time of transplant. mPAP of 35 mm Hg or greater was seen in 31 of 300 patients (10.3%; median, 38 mm Hg; range, 35-46 mm Hg). No intraoperative deaths occurred. Transplant hospitalization mortality was 0% for those with mPAP of 35 mm Hg or greater (vs 2.2% if mPAP < 35 mm Hg, P = 1.0). One-year mortality was similar for patients with and without mPAP of 35 mm Hg or greater (3.2% vs 6.0%, P = 1.0). No deaths were associated with right heart failure., Conclusions: At the time of LT, 39% of recipients had PH (mPAP ≥ 25 mm Hg) and 10.3% had mPAP ≥ 35 mm Hg. When associated with a high flow state and/or increased volume, transplant hospitalization and 1-year posttransplant outcomes were not adversely affected.

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are pulmonary vascular complications of portal hypertension with divergent clinicopathologic features and management. The presence of intrapulmonary vascular dilatations (IPVDs), detected by agitated saline contrast-enhanced transthoracic echocardiography (cTTE), is an essential feature of HPS but is not typically characteristic of POPH. Although IPVDs have been reported rarely in POPH, the prevalence and significance of this finding have not been systematically studied. We conducted a retrospective chart review of 80 consecutive patients diagnosed with POPH from January 1, 2002 to June 30, 2014 with documentation of cTTE findings, pulmonary hemodynamics, oxygenation, and survival. A total of 34 of the 80 patients (42%) underwent cTTE during initial diagnosis of POPH. IPVDs were detected in 20/34 patients (59%); intracardiac shunting was detected in 9/34 patients (26%; 4 also had IPVDs); and 9 patients (26%) had negative cTTE with no evidence of IPVD or intracardiac shunting. Patients with IPVD had decreased survival as compared to those without IPVD (P = 0.003), a trend that persisted after exclusion of liver transplant recipients (P =  0.07). The IPVD group had a trend toward higher Model for End-Stage Liver Disease score with and without incorporating sodium (MELD or MELD-Na; P = 0.05 for both). The right ventricular index of myocardial performance (RIMP) was lower in the IPVD group (median, 0.4 versus 0.6; P = 0.006). Patients with moderate or large IPVDs (n = 6) had worse oxygenation parameters (partial pressure of arterial oxygen, diffusing capacity of the lung for carbon monoxide, and alveolar-arterial oxygen gradient) as compared to the rest of the cohort. Unexpectedly, IPVDs were frequently documented in POPH and associated with decreased survival. To further understand this observation, we recommend screening for IVPD in all patients with POPH., (© 2015 American Association for the Study of Liver Diseases.)

Pulmonary arteriovenous malformations (PAVMs) are abnormal vascular structures that most often connect a pulmonary artery to a pulmonary vein, bypassing the normal pulmonary capillary bed and resulting in an intrapulmonary right-to-left shunt. As a consequence, patients with PAVM can have hypoxemia and paradoxical embolization complications, including stroke and brain abscess. PAVMs may be single or multiple, unilateral or bilateral, and simple or complex. Most PAVMs are hereditary and occur in hereditary hemorrhagic telangiectasia, an autosomal dominant vascular disorder, and screening for PAVM is indicated in this subgroup. PAVMs may also be idiopathic, occur as a result of trauma and infection, or be secondary to hepatopulmonary syndrome and bidirectional cavopulmonary shunting. Diagnostic testing involves identifying an intrapulmonary shunt, with the most sensitive test being transthoracic contrast echocardiography. Chest CT scan is useful in characterizing PAVM in patients with positive intrapulmonary shunting. Transcatheter embolotherapy is the treatment of choice for PAVM. Lifelong follow-up is important because recanalization and collateralization may occur after embolization therapy. Surgical resection is rarely necessary and reserved for patients who are not candidates for embolization. Antibiotic prophylaxis for procedures with a risk of bacteremia (eg, dental procedures) is recommended in all patients with PAVM because of the risk of cerebral abscess.

Pulmonary artery hypertension may develop in some patients with liver disease and portal hypertension. Although pulmonary artery hypertension may be asymptomatic in its early stages, it should be looked for especially if a patient is a candidate for liver transplantation, as it may make transplantation riskier.

Pulmonary arterial hypertension (PAH) is diagnosed by various investigations that are essential for making the diagnosis, and by additional tests to clarify the category of pulmonary hypertension (PH). A diagnostic algorithm can guide the evaluation of PH, but like all guidelines the algorithm can be modified according to specific clinical circumstances. Most patients are diagnosed as the result of an evaluation of symptoms, whereas others are diagnosed during screening of asymptomatic populations at risk. Right heart catheterization (RHC) must be performed in patients with suspected PH to establish the diagnosis and document pulmonary hemodynamics. Before initiation of medical therapy, assessment of acute vasoreactivity (during catheterization) is necessary to determine the appropriate therapy for an individual patient. An acute response is generally defined as a decrease in mean pulmonary arterial pressure of at least 10 mm Hg with the mean pulmonary arterial pressure decreasing to 40 mm Hg or below, accompanied by a normal or high cardiac output. After PAH is diagnosed, disease severity should be assessed in order to accurately determine risk:benefit profiles for various therapeutic options. Useful tools to predict outcome include functional class, exercise capacity, pulmonary hemodynamics, acute vasoreactivity, right ventricular function, as well as brain natriuretic peptide, endothelin-1, uric acid, and troponin levels. Repeating these tests serially on treatment is useful for monitoring the response to a given therapy. Close follow-up at a center specializing in management of PH is recommended, with careful periodic reassessment and adjustment of therapy.