Portopulmonary Hypertension (PoPH)
Definition
Portopulmonary Hypertension (PoPH) is a form of pulmonary arterial hypertension (PAH, Group 1 PH) that develops in patients with:
- Portal hypertension (with or without cirrhosis)
- Increased pulmonary vascular resistance due to pulmonary arteriopathy
- Normal left-sided filling pressures
Diagnosis requires:
1. Portal Hypertension
Evidence of:
- Cirrhosis
- Non-cirrhotic portal hypertension
- Portosystemic shunts
AND
2. Precapillary Pulmonary Hypertension on Right Heart Catheterization
Current definition (2022 ESC/ERS):
|
Parameter |
Value |
|
Mean Pulmonary Artery Pressure (mPAP) |
>20 mmHg |
|
Pulmonary Artery Wedge Pressure (PAWP) |
≤15 mmHg |
|
Pulmonary Vascular Resistance (PVR) |
>2 Wood Units |
Pathophysiology
Portal hypertension causes development of:
- Portosystemic shunts
- Hyperdynamic circulation
These allow vasoactive mediators to bypass hepatic metabolism.
Increased Vasoconstrictors
- Endothelin-1
- Thromboxane A2
- Serotonin
Decreased Vasodilators
- Nitric oxide imbalance
- Prostacyclin deficiency
Clinical Features
Symptoms are often nonspecific.
- Dyspnea-Most common symptom.
Initially:Exertional dyspnea
Later:Dyspnea at rest
- Fatigue-Due to:Reduced cardiac output/RV dysfunction
- Chest Pain-May occur due to:
- RV ischemia
- Pulmonary artery dilation
- Presyncope/Syncope
- Peripheral Edema
Findings of Portal Hypertension
- Ascites
- Splenomegaly
- Varices
- Spider angiomas
- Caput medusae
Findings of Pulmonary Hypertension
- Elevated JVP
- Loud P2
- Right ventricular heave
- Tricuspid regurgitation murmur
- Holosystolic murmur at LLSB.
- Hepatomegaly
- Peripheral edema
May be difficult to distinguish from liver disease itself.
Diagnostic Evaluation
Transthoracic Echocardiography
Screening test of choice.
|
Finding |
Significance |
|
Elevated RVSP |
Suggests PH |
|
RV enlargement |
Common |
|
RA enlargement |
Common |
|
Septal flattening |
RV pressure overload |
|
TR jet velocity ↑ |
Screening marker |
High-Risk Echo Features
TR velocity >3.4 m/s
or
TR velocity 2.9–3.4 m/s plus:
- RV enlargement
- Septal flattening
Right Heart Catheterization (Gold Standard)
Additional Investigations
ECG
May show:
- Right axis deviation
- RV hypertrophy
- Right atrial enlargement
Chest X-ray
May reveal:
- Enlarged pulmonary arteries
- Cardiomegaly
- RV enlargement
Pulmonary Function Tests
Often:Mild reduction in DLCO
Arterial Blood Gas
May show:
- Mild hypoxemia
- Increased A-a gradient
NT-proBNP
Useful for:
- Severity assessment
- Follow-up
Six-Minute Walk Test
Functional assessment.
Differential Diagnosis
Hepatopulmonary Syndrome (HPS)
Most important differential.
|
Feature |
PoPH |
HPS |
|
Mechanism |
Vasoconstriction |
Vasodilation |
|
Pulmonary pressure |
Increased |
Normal/Low |
|
PVR |
Increased |
Decreased |
|
Hypoxemia |
Mild |
Severe |
|
Orthodeoxia |
Rare |
Typical |
|
Liver transplant |
May worsen peri-op risk |
Curative |
Other Differentials
- Chronic thromboembolic PH
- Left heart disease
- COPD
- Interstitial lung disease
- Idiopathic PAH
Management
Goals
- Reduce PVR
- Improve RV function
- Improve exercise capacity
- Enable liver transplantation
General Measures
Oxygen–Maintain:SpO₂ >90%
Diuretics
For:
- Edema
- Ascites
Use carefully.
Common agents:
- Furosemide
- Spironolactone
Avoid Pregnancy—High maternal mortality.
Vaccination
- Influenza
- Pneumococcal
Pulmonary Arterial Hypertension–Specific Therapy
|
Drug/Class |
Key Points |
Dose/Route |
|
Endothelin Receptor Antagonists (ERAs) Reduce endothelin-mediated pulmonary vasoconstriction and vascular remodeling; important PAH-specific therapy in PoPH — |
||
|
Macitentan |
Most evidence in PoPH. The PORTICO trial demonstrated significant reduction in pulmonary vascular resistance (PVR) and improved hemodynamics. Considered the preferred ERA in many patients with PoPH. |
10 mg orally once daily |
|
Ambrisentan |
Alternative ERA; improves pulmonary hemodynamics and exercise capacity. |
5–10 mg orally once daily |
|
Bosentan |
Effective ERA but use is limited by hepatotoxicity; requires regular liver function monitoring. |
62.5 mg orally twice daily for 4 weeks, then 125 mg twice daily |
|
PDE-5 Inhibitors Increase nitric oxide signaling causing pulmonary vasodilation; improve exercise capacity, functional status, and hemodynamics. Frequently used as first-line or combination therapy. — |
||
|
Sildenafil |
Well-studied PDE-5 inhibitor in PAH and PoPH. |
20 mg orally three times daily |
|
Tadalafil |
Long-acting PDE-5 inhibitor allowing once-daily dosing. |
40 mg orally once daily |
|
Prostacyclin Pathway Agents-Reserved for severe PoPH, advanced right ventricular dysfunction, WHO Class III–IV symptoms, or as a bridge to liver transplantation. Produce potent pulmonary vasodilation and antiproliferative effects. — |
||
|
Epoprostenol |
Most potent therapy. Produces dramatic reduction in PVR, improves cardiac output, right ventricular function, and may improve eligibility for liver transplantation. |
Continuous IV infusion; usually started at 1–2 ng/kg/min and titrated gradually according to response and tolerance |
|
Treprostinil |
Alternative prostacyclin analogue; useful when long-term prostacyclin therapy is required. |
IV, subcutaneous, inhaled, or oral formulations available |
|
Iloprost |
Inhaled prostacyclin analogue; may improve symptoms and pulmonary hemodynamics. |
Inhaled therapy administered multiple times daily |
|
Prostacyclin Receptor Agonist Targets prostacyclin pathway without prostacyclin infusion. — |
||
|
Selexipag |
Oral prostacyclin receptor agonist; can be considered in selected patients with PoPH, particularly as part of combination PAH therapy. |
Oral; initiated at 200 μg twice daily and titrated to maximally tolerated dose (up to 1600 μg twice daily) |
Combination Therapy
Current PAH approach favors:
Initial Combination Therapy
Example:Macitentan + Sildenafil
or. Ambrisentan + Tadalafil
Role of Anticoagulation
Unlike idiopathic PAH: Routine anticoagulation is NOT recommended.
Reasons:
- Varices
- Coagulopathy
- Bleeding risk
Liver Transplantation
Potentially Curative
Successful transplantation may lead to:
- Hemodynamic improvement
- Resolution of PH in some patients