From the Guidelines
Pulmonary hypertension (PH) is a progressive condition characterized by elevated blood pressure in the pulmonary arteries, defined as a mean pulmonary arterial pressure ≥20 mmHg at rest, and should be treated based on the underlying cause, with a focus on managing precapillary and postcapillary types, and prioritizing medications such as endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclin analogs, and soluble guanylate cyclase stimulators for pulmonary arterial hypertension, and managing left heart disease for postcapillary PH, as recommended by the most recent guidelines 1.
Clinical Presentation
Patients with PH typically present with dyspnea on exertion, fatigue, chest pain, syncope, and signs of right heart failure in advanced cases. The pathophysiology involves vascular remodeling, vasoconstriction, and thrombosis leading to increased pulmonary vascular resistance.
Pathophysiology and Classification
PH is classified into precapillary and postcapillary types. Precapillary PH (Groups 1,3,4,5) is characterized by a pulmonary arterial wedge pressure ≤15 mmHg and includes pulmonary arterial hypertension, PH due to lung diseases, chronic thromboembolic PH, and PH with unclear mechanisms. Postcapillary PH (Group 2) has a pulmonary arterial wedge pressure >15 mmHg and is caused by left heart disease.
Treatment Options
Treatment depends on the underlying cause. For pulmonary arterial hypertension, medications include:
- Endothelin receptor antagonists (bosentan 62.5-125 mg twice daily, ambrisentan 5-10 mg daily)
- Phosphodiesterase-5 inhibitors (sildenafil 20 mg three times daily, tadalafil 40 mg daily)
- Prostacyclin analogs (epoprostenol 2-20 ng/kg/min IV, treprostinil 1.25-40 ng/kg/min subcutaneous/IV)
- Soluble guanylate cyclase stimulators (riociguat 0.5-2.5 mg three times daily) Supportive care includes diuretics, oxygen therapy, and anticoagulation when appropriate. For postcapillary PH, treatment focuses on managing the underlying left heart disease. Advanced cases may require atrial septostomy or lung transplantation.
Diagnosis and Management
Early diagnosis through echocardiography and right heart catheterization is crucial for optimal management and improved outcomes, as recommended by recent guidelines 1. The 2018 updated clinical classification has been simplified and now includes group 1, PAH; group 2, PH due to left heart disease; group 3, PH due to lung diseases and/or hypoxia; group 4, PH due to PA obstructions; and group 5, PH with unclear and/or multifactorial mechanisms 1.
Key Considerations
It is essential to note that the treatment of PH should be individualized, and the choice of medication should be based on the patient's specific condition, as well as the presence of any comorbidities. Additionally, the importance of expert referral centers in the management of PH patients has been highlighted in both the diagnostic and treatment algorithms 1.
From the Research
Clinical Presentation of Pulmonary Hypertension
- Pulmonary hypertension (PH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated 2
- Early presenting symptoms are nonspecific and typically consist of dyspnea on exertion and fatigue 3
- Patients with PH require careful evaluation and management at an expert center 4
Pathophysiology of Pulmonary Hypertension
- PH is characterized by elevation of mean pulmonary arterial pressure (mPAP) >20 mmHg, assessed by right heart catheterisation 5
- Pulmonary arterial wedge pressure (PAWP) and pulmonary vascular resistance (PVR) distinguish pre-capillary PH (PAWP ≤15 mmHg, PVR >2 Wood Units (WU)), isolated post-capillary PH (PAWP >15 mmHg, PVR ≤2 WU) and combined post- and pre-capillary PH (PAWP >15 mmHg, PVR >2 WU) 5
- Pulmonary arterial hypertension (PAH) is a subtype of PH, characterized by pulmonary arterial remodeling 3
Treatment Options for Pulmonary Hypertension
- The therapy of PAH consists of non-specific drugs including oral anticoagulation and diuretics as well as PAH specific therapy 2
- Targeted treatments (phosphodiesterase type 5 inhibitors, soluble guanylate cyclase stimulators, endothelin receptor antagonists, prostacyclin analogues, and prostacyclin receptor agonists) are licensed for patients with PAH 6
- Current treatment consists of combination drug therapy that targets more than 1 biological pathway, such as the nitric oxide-cyclic guanosine monophosphate and endothelin pathways 3
- Surgical pulmonary endarterectomy is the treatment of choice for eligible patients with chronic thromboembolic PH (CTEPH) 6
Differentiation between Precapillary and Postcapillary Pulmonary Hypertension
- Precapillary PH is characterized by a PAWP ≤15 mmHg and PVR >2 WU, while postcapillary PH is characterized by a PAWP >15 mmHg and PVR ≤2 WU 5
- The assessment of PAWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg) 2
- Combined post- and pre-capillary PH is characterized by a PAWP >15 mmHg and PVR >2 WU 5