Pulmonary hypertension (PH) is defined hemodynamically as a mean pulmonary artery pressure (mPAP) >20 mm Hg, confirmed by right heart catheterization.
Definitive diagnosis of PH requires right heart catheterization (RHC), which directly measures mPAP, PAWP, cardiac output, and PVR.
Guidelines define PH as mPAP >20 mm Hg, with pre-capillary PH requiring PAWP ≤15 mm Hg and PVR >2 WU.
PH is classified into five clinical groups: (1) primary pulmonary arterial hypertension (PAH), (2) PH due to left-sided heart disease, (3) PH due to lung diseases and/or hypoxia, (4) chronic thromboembolic PH (CTEPH), and (5) PH with unclear or multifactorial mechanisms.
It is recommended that all patients with suspected or confirmed PAH be evaluated at a center with expertise in PH, ideally prior to initiation of therapy.
Acute vasodilator testing (AVT) during RHC is indicated in idiopathic, heritable, or drug-induced PAH to identify candidates for high-dose calcium channel blocker therapy.
A positive response is defined as a reduction in mPAP by at least 10 mm Hg to ≤40 mm Hg with unchanged or increased cardiac output.
Right heart catheterization is required for definitive diagnosis and hemodynamic assessment, and risk stratification tools are used to guide therapy and monitor response.
General Principles of Management
The initial evaluation includes a comprehensive history and physical examination, focusing on symptoms such as exertional dyspnea, fatigue, syncope, and signs of right heart failure.
Laboratory studies should include complete blood count, metabolic panel, liver function tests, thyroid function, BNP or NT-proBNP, antinuclear antibody, and HIV serology.
Supportive therapies include supplemental oxygen for hypoxemia, diuretics for right heart failure or volume overload, anticoagulation in select cases and supervised exercise rehabilitation.
Management of PH is tailored to the underlying WHO group, with PAH (Group 1) being the primary focus of targeted pharmacologic therapy, while other groups rely on treating the underlying disease process.
Management by PH Group
Group 1 (PAH):
For patients with a positive acute vasoreactivity test (a minority, typically idiopathic PAH), high-dose calcium channel blockers are indicated.
For most patients, initial therapy consists of combination oral therapy with a phosphodiesterase-5 inhibitor (PDE5i; e.g., sildenafil or tadalafil) and an endothelin receptor antagonist (ERA; e.g., ambrisentan, bosentan, or macitentan).
Pharmacologic management is most advanced for Group 1 PAH, with three major therapeutic pathways targeted: the nitric oxide (NO) pathway, the endothelin pathway, and the prostacyclin pathway.
Phosphodiesterase type 5 (PDE5) inhibitors (sildenafil, tadalafil) enhance NO-mediated vasodilation and are first-line oral agents for low- and intermediate-risk PAH patients.
Tadalafil is typically dosed at 40 mg once daily, while sildenafil is dosed at 20 mg three times daily.
Soluble guanylate cyclase (sGC) stimulators, such as riociguat, increase cGMP independently of NO and are approved for PAH and inoperable or persistent/recurrent CTEPH, with a starting dose of 1 mg three times daily, titrated to a maximum of 2.5 mg three times daily.
For high or intermediate-high risk, or with inadequate response, escalation to triple therapy including a parenteral prostacyclin analog intravenous epoprostenol or subcutaneous/inhaled treprostinil is recommended.
Monotherapy may be considered for select low-risk patients or those with significant comorbidities.
The mainstay of management is treatment of the underlying cardiac or pulmonary disorder.
Surgical pulmonary endarterectomy is the treatment of choice for operable patients.
For those who are inoperable or have persistent/recurrent PH after surgery, medical therapy with riociguat (a soluble guanylate cyclase stimulator) or balloon pulmonary angioplasty is recommended.
Group 5 (PH with unclear/multifactorial mechanisms):
Management is individualized based on the underlying etiology. PDE5 inhibitors should be avoided in PH associated with sickle cell disease due to increased risk of painful crises.
Patients with PAH or CTEPH who remain at high risk or are refractory to maximal medical therapy should be referred for lung transplantation evaluation.
The recommended management of pulmonary hypertension is highly dependent on accurate classification, with PAH and CTEPH requiring specialized, often combination, targeted therapies, while PH due to left heart or lung disease is managed by treating the underlying condition.
Transthoracic echocardiography (TTE) is the cornerstone of noninvasive screening, providing estimates of right ventricular systolic pressure, assessment of right ventricular size and function, septal flattening, and pericardial effusion. TTE also evaluates left ventricular function and valvular disease, which are critical for distinguishing Group 2 PH.
Meta-analyses indicate that echocardiography has a sensitivity of approximately 85% and specificity of 70–74% for detecting PH, but definitive diagnosis requires invasive confirmation.
Chest radiography and computed tomography (CT) are used to assess cardiac silhouette, pulmonary arteries, and lung parenchyma. CT pulmonary angiography is essential for evaluating for CTEPH.
Ventilation–perfusion (V/Q) scanning is the gold standard for excluding CTEPH, as a normal perfusion scan makes CTEPH unlikely.
Pulmonary function tests (PFTs), including DLCO, are recommended to assess for underlying lung disease and severity of vascular involvement.
In patients with suspected sleep-disordered breathing, polysomnography is indicated.
Management of pulmonary hypertension focuses on treating underlying causes, relieving symptoms, slowing disease progression, and improving quality of life.
Lifestyle modification and supportive care are foundational for all PH patients.
Exercise training, once considered risky, is now recognized as beneficial for improving exercise tolerance and quality of life in PAH.
The approach varies depending on the type and severity of pulmonary hypertension.
Main treatment strategies include:
General/Supportive measures:
Oxygen therapy for hypoxemia
Diuretics for fluid overload
Anticoagulants (e.g., warfarin) to prevent blood clots (especially in some PAH and CTEPH patients)
Digoxin for right heart failure or arrhythmias
Pulmonary arterial hypertension (PAH)-specific therapies:
Endothelin receptor antagonists: bosentan, ambrisentan, macitentan
Phosphodiesterase-5 (PDE5) inhibitors: sildenafil, tadalafil
Soluble guanylate cyclase (sGC) stimulators: riociguat
Prostacyclin pathway agents: epoprostenol, treprostinil, iloprost, selexipag (routes: intravenous, subcutaneous, inhaled, or oral)
These agents are used alone or in combination based on disease severity and individual response.
Calcium channel blockers: For a select minority high-dose agents such as nifedipine, amlodipine, or diltiazem may be effective.
Treatment of underlying disease management centers on optimizing heart or lung conditions rather than using PAH-targeted drugs.
Surgical/procedural interventions for advanced/refractory cases:
Atrial septostomy by creation of a right-to-left atrial shunt.
Lung or heart-lung transplantation for severe, progressive disease not controlled by medication
There is no cure for pulmonary hypertension, but these interventions can significantly improve symptoms and prolong life.
Supervised aerobic and inspiratory muscle training can improve six-minute walk distance (6MWD), peak oxygen consumption, and pulmonary artery pressures.
Typical regimens involve aerobic exercise at 50–85% of maximal capacity for 30 minutes, three to seven days per week, and inspiratory muscle training at >30% maximal inspiratory pressure.
Oxygen supplementation is indicated for patients with hypoxemia (oxygen saturation.
Diuretics are used to manage volume overload and right heart failure, aiming for euvolemia.
Anticoagulation is recommended for patients with idiopathic or heritable PAH on a case-by-case basis, and is standard for those with CTEPH.
Immunizations, including influenza and pneumococcal vaccines, should be kept up to date.
Endothelin receptor antagonists (ERAs), including bosentan (62.5 mg twice daily, titrated to 125 mg twice daily), ambrisentan (5–10 mg once daily), and macitentan (10 mg once daily), block endothelin receptors, leading to vasodilation and antiproliferative effects.
Prostacyclin analogs (epoprostenol, treprostinil, iloprost) and the oral prostacyclin receptor agonist selexipag promote vasodilation and inhibit vascular remodeling.
Epoprostenol is administered as a continuous intravenous infusion, starting at 2 ng/kg/min and titrated as tolerated, with demonstrated mortality benefit in randomized trials.
Selexipag is initiated at 200 mcg twice daily and titrated to a maximum of 1600 mcg twice daily.
Initial combination therapy targeting multiple pathways (e.g., PDE5 inhibitor plus ERA) is now standard for most patients with PAH, based on randomized trials showing superior outcomes compared to monotherapy.
Triple therapy, including a parenteral prostacyclin, is considered for high- or intermediate-high-risk patients.
Initial oral combination therapy (PDE5 inhibitor plus ERA) recommended for most, and parenteral prostacyclin prioritized for high-risk or WHO functional class IV patients.
Sequential escalation is advised for inadequate response, and lung transplantation is considered for refractory cases.
Calcium channel blockers (CCBs) are reserved for the minority of PAH patients who demonstrate acute vasoreactivity during RHC, with high-dose amlodipine (up to 20 mg daily), nifedipine (up to 240 mg daily), or diltiazem (up to 720 mg daily) used in responders.
CCBs are contraindicated in non-responders and those with right ventricular dysfunction due to risk of worsening heart failure.
For Group 1 PH, targeted PAH therapies are generally not indicated.
In Group 2 PH (left heart disease), management focuses on optimizing heart failure therapy; PAH-specific drugs have not shown benefit and may be harmful.
In Group 3 PH (lung disease), treatment of the underlying pulmonary condition is primary, but inhaled treprostinil (starting at 18 mcg four times daily, titrated as tolerated) has demonstrated benefit in interstitial lung disease-associated PH.
For Group 4 PH (CTEPH), pulmonary endarterectomy is the treatment of choice for operable disease, while riociguat and, in some cases, macitentan or treprostinil are used for inoperable or persistent PH.
Group 5 PH management is individualized, with limited evidence for PAH-targeted therapies.
Non-pharmacologic interventions, exercise-based rehabilitation, are now recommended as adjuncts to medical therapy in PH, with evidence supporting improvements in exercise capacity, health-related quality of life, and functional status.
Pulmonary rehabilitation leads to a mean increase in 6MWD (^ minute walk0 of approximately 48 meters compared to control, with significant improvements in peak oxygen uptake and quality of life.
Pregnancy in women with PH, particularly PAH, is associated with a maternal mortality rate of 40–100%, and pregnancy is generally contraindicated.
If pregnancy occurs, ERAs and riociguat are contraindicated due to teratogenicity, while PDE5 inhibitors and prostacyclin analogs are considered safer options.
Anticoagulation is frequently indicated, with low-molecular-weight heparin preferred, but must be managed with caution due to increased bleeding risk, especially when combined with prostacyclin therapy.
In elderly patients, individualized treatment, with a preference for single-agent regimens and close monitoring for adverse effects and comorbidities.
Polypharmacy and frailty are major concerns, and regular reassessment of functional status and goals of care is essential.
In patients with significant comorbidities, accurate classification is critical, and therapy should be directed at the underlying disease process, with PAH-specific drugs reserved for Group 1 PAH.
Pediatric PH management:
First-line therapy includes pulmonary vasodilators (sildenafil, endothelin receptor antagonists, prostacyclin analogs).
Interventional strategies (ASD intervention, shunt creation, lung transplantation) are reserved for children with progressive disease despite optimal therapy.
Common complications of PH include right ventricular failure, arrhythmias, thromboembolic events, syncope, hemoptysis, end-organ dysfunction, and therapy-related adverse effects.
Risk stratification and prognostic assessment guide therapeutic decisions and follow-up strategies.
Serial risk assessment is essential, as changes in risk status over time are strongly associated with changes in long-term mortality risk.
Achieving or maintaining low-risk status is consistently associated with the best survival outcomes, while movement between intermediate-low and intermediate-high risk categories carries important prognostic implications.
Echocardiographic assessment of right ventricular size and function provides incremental prognostic value beyond traditional risk scores.
Reduced RV function, is associated with increased NT-proBNP, reduced 6 minute walk distance higher risk scores, and increased mortality.
The addition of echocardiographic variables increases predictive accuracy, with studies showing a 10% increase in the C-statistic when echocardiographic parameters are included.
Serial measurement of natriuretic peptides (BNP, NT-proBNP) is recommended for monitoring RV strain and heart failure status.
Elevated or rising levels are associated with worse prognosis and may indicate disease progression or inadequate therapeutic response.
At each visit, a comprehensive history and physical examination should be performed, with assessment of symptoms, functional status, and signs of right heart failure.
Functional capacity is most commonly assessed by the 6 minute walk test, which is recommended at least every 3 to 6 months.
Serial echocardiography is recommended at intervals of 4 to 6 months in the setting of disease progression or changes.
Right heart catheterization is recommended at diagnosis, prior to initiation of PAH-targeted therapy, and serially during follow-up to assess prognosis and guide changes in therapy
Long-term outcomes and survival rates in PH vary substantially.
In the REVEAL registry, 1- and 5-year survival rates for PAH were 85% and 57%, respectively.
Recent data indicate that 5-year survival for PAH now exceeds 60%, compared to 34% in the pre-therapy era.
Survival within PAH subgroups varies: patients with PAH associated with congenital heart disease have better outcomes than those with idiopathic PAH, while PAH associated with connective tissue disease or portopulmonary hypertension is associated with a worse prognosis.
PH secondary to left heart disease (Group 2) and PH associated with chronic lung disease (Group 3) are associated with the highest mortality, with 5-year mortality rates of 62.4% and 62.4%, respectively.
CTEPH (Group 4) has intermediate survival, with 5-year survival of 44.3%.
Prognosis in PH is determined by a combination of factors: clinical, and hemodynamic factors, with exercise capacity (6MWD), RV function, age, sex, etiology, and comorbidities being key determinants.
The hemodynamic threshold for the diagnosis of PH has been lowered to mPAP >20 mm Hg, facilitating earlier recognition and intervention.
Initial combination therapy (PDE5 inhibitor plus ERA) is now standard for most treatment-naïve PAH patients, with escalation to triple therapy, including parenteral prostacyclin, for high-risk or non-responders.
Sotatercept, a novel TGF-β ligand trap, which represents a fourth therapeutic pathway targeting pulmonary vascular remodeling,
suggesting significant improvements in hemodynamics and exercise capacity.
Inhaled treprostinil has shown benefit in interstitial lung disease-associated PH (Group 3), and riociguat is approved for non-operable CTEPH (Group 4).