From the Guidelines
Pulmonary hypertension (PH) is a pathophysiological disorder characterized by high blood pressure in the arteries of the lungs, with a mean pulmonary arterial pressure ≥25 mmHg at rest, and can complicate the majority of cardiovascular and respiratory diseases. It is classified into five groups based on etiology: Group 1 (pulmonary arterial hypertension), Group 2 (due to left heart disease), Group 3 (due to lung disease), Group 4 (chronic thromboembolic PH), and Group 5 (unclear mechanisms) 1. The diagnosis and treatment of PH involve a multidisciplinary approach, including members of different medical societies, associations, and working groups.
Key Characteristics of PH
- PH is a heterogeneous group of disorders characterized by increased pulmonary vascular resistance that results in progressive right ventricular failure 1
- The term pulmonary hypertension (PH) describes a group of devastating and life-limiting diseases, defined by a mean pulmonary artery pressure (¯ pa) ≥25 mmHg at rest
- PH remains poorly characterized as it is a rare disorder and because there is an incomplete understanding of the diverse underlying pathogenic conditions and mechanisms
Diagnosis and Treatment
- Early diagnosis is crucial as PH progressively damages the right ventricle, leading to right heart failure
- Treatment depends on the underlying cause and severity, with medications including phosphodiesterase-5 inhibitors, endothelin receptor antagonists, prostacyclin analogs, and soluble guanylate cyclase stimulators for Group 1 PAH
- Supportive care includes oxygen therapy for hypoxemia, diuretics for fluid retention, and anticoagulation in specific cases
- For Group 2-5, treating the underlying condition is paramount, with advanced therapies for severe cases including atrial septostomy and lung transplantation 1
Monitoring and Follow-up
- Regular monitoring with echocardiography, 6-minute walk tests, and right heart catheterization helps assess disease progression and treatment response
- 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
Definition of Pulmonary Hypertension (PH)
- Pulmonary hypertension (PH) is defined as a mean pulmonary arterial pressure (mPAP) of >20mmHg in combination with a PVR threshold value of >2 Wood units to define a precapillary component 2
- PH is a hemodynamic state characterized by a resting mean pulmonary artery pressure ≧ 25 mmHg 3
Forms of Pulmonary Hypertension
- The common forms of PH are:
- Pulmonary arterial hypertension (PAH)
- Chronic thromboembolic pulmonary hypertension (CTEPH)
- PH caused by left-heart disease
- PH due to lung disease 3
- The clinical classification of PH still distinguishes 5 main groups 2
Pathogenesis of PH
- The pathogenesis of PAH is multifactorial, with endothelial cell dysfunction playing an integral role 4
- Endothelial dysfunction is characterized by an overproduction of vasoconstrictors and proliferative factors, and a reduction of vasodilators and antiproliferative factors 4
Treatment of PH
- Treatment is focused on targeting the underlying complex etiology via the endothelin, prostacyclin, and nitric oxide (NO) pathways 5
- Drugs available for the specific treatment of PAH include:
- Endothelin-receptor antagonists
- Phosphodiesterase type 5 inhibitors
- Soluble guanylate cyclase stimulators
- Prostacyclin analogs
- Prostacyclin-receptor agonists 3
- Initial combination therapy with a phosphodiesterase type 5 inhibitor and an endothelin receptor antagonist is recommended for low or intermediate risk patients 2