What are the types of Pulmonary Hypertension (PH)?

From the Guidelines

Pulmonary hypertension is classified into five main types, with the most recent and highest quality evidence from 1 supporting this classification system. The five types are:

• Type 1: Pulmonary Arterial Hypertension (PAH), which includes idiopathic PAH, heritable PAH, and PAH associated with conditions like connective tissue diseases or congenital heart disease
• Type 2: Pulmonary Hypertension due to Left Heart Disease, occurring when left heart problems cause increased pressure in the pulmonary circulation
• Type 3: Pulmonary Hypertension due to Lung Diseases and/or Hypoxia, resulting from conditions like COPD or interstitial lung disease
• Type 4: Chronic Thromboembolic Pulmonary Hypertension (CTEPH), caused by blood clots that obstruct pulmonary vessels
• Type 5: Pulmonary Hypertension with Unclear or Multifactorial Mechanisms, including disorders like sarcoidosis or metabolic disorders. This classification is important because treatment approaches differ significantly between types, with targeted therapies available primarily for Type 1 PAH, while other types require management of the underlying condition, as noted in 1 and 1. Accurate diagnosis through right heart catheterization and comprehensive testing is essential for proper classification and treatment planning. Key considerations in the diagnosis and treatment of pulmonary hypertension include:
• The use of right heart catheterization to confirm the diagnosis and assess disease severity
• The importance of identifying the underlying cause of pulmonary hypertension, as this can impact treatment decisions
• The availability of targeted therapies for Type 1 PAH, and the need for management of the underlying condition for other types of pulmonary hypertension. Overall, the classification of pulmonary hypertension into five main types provides a framework for understanding the different causes and treatment approaches for this complex condition, as supported by the evidence from 1.

From the Research

Types of Pulmonary Hypertension

• Pulmonary arterial hypertension (PAH) 2, 3, 4, 5
• Pulmonary hypertension due to left-sided heart disease 2, 3, 4
• Pulmonary hypertension due to chronic lung disease and/or hypoxia 2, 3, 4
• Chronic thromboembolic pulmonary hypertension (CTEPH) 2, 3, 4
• Pulmonary hypertension with unclear and/or multifactorial mechanisms 2, 3, 4

Classification of Pulmonary Hypertension

• The clinical classification of pulmonary hypertension categorizes PH into groups which share similar pathophysiological and hemodynamic characteristics and treatments 3
• The revised classification of pulmonary hypertension still consists of five major groups: (1) PAH, (2) pulmonary hypertension due to left heart disease, (3) pulmonary hypertension due to chronic lung disease and/or hypoxia, (4) chronic thromboembolic pulmonary hypertension, and (5) miscellaneous forms 4

Diagnostic Criteria for Pulmonary Hypertension

• Mean pulmonary artery pressure at rest ≥25 mmHg 3, 4, 6
• Pulmonary capillary wedge pressure ≤15 mmHg 3, 4
• Mean pulmonary artery pressure during exercise ≥30 mmHg 6

Treatment Options for Pulmonary Hypertension

• 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 2, 3, 5
• Surgical pulmonary endarterectomy is the treatment of choice for eligible patients with CTEPH 2, 3
• Management of PH resulting from left-sided heart disease primarily involves treatment of the underlying condition 2