What are the groups of Pulmonary Hypertension (PH)?

From the Guidelines

Pulmonary hypertension is classified into five main groups based on the European Society of Cardiology (ESC) and European Respiratory Society (ERS) guidelines, which include pulmonary arterial hypertension, pulmonary hypertension due to left heart disease, pulmonary hypertension due to lung diseases and/or hypoxia, chronic thromboembolic pulmonary hypertension, and pulmonary hypertension with unclear or multifactorial mechanisms. The classification of pulmonary hypertension into these groups is crucial for determining the treatment approach, as different groups require different management strategies 1.

Groups of Pulmonary Hypertension

The five main groups of pulmonary hypertension are:

• Group 1: Pulmonary arterial hypertension, which includes idiopathic, heritable, drug-induced, and associated forms, such as those linked to connective tissue diseases, HIV infection, portal hypertension, and congenital heart disease.
• Group 2: Pulmonary hypertension due to left heart disease, including left ventricular systolic or diastolic dysfunction and valvular disease.
• Group 3: Pulmonary hypertension due to lung diseases and/or hypoxia, such as chronic obstructive pulmonary disease, interstitial lung disease, sleep-disordered breathing, and chronic exposure to high altitude.
• Group 4: Chronic thromboembolic pulmonary hypertension (CTEPH), resulting from persistent obstruction of pulmonary arteries following pulmonary embolism.
• Group 5: Pulmonary hypertension with unclear or multifactorial mechanisms, such as hematologic disorders, systemic disorders, metabolic disorders, and other conditions.

Clinical Importance of Classification

The classification of pulmonary hypertension into these groups is clinically important because treatment approaches differ significantly between groups, with targeted pulmonary vasodilator therapies primarily benefiting Group 1 patients, while management of the underlying cause is the focus for other groups 1. Understanding the specific group of pulmonary hypertension a patient belongs to is essential for providing effective treatment and improving patient outcomes.

From the Research

Classification of Pulmonary Hypertension

The classification of pulmonary hypertension includes five clinical subgroups, as stated in the studies 2, 3, 4, 5, 6. These subgroups are:

• Pulmonary arterial hypertension (PAH)
• PH due to left-sided heart disease
• PH due to chronic lung disease
• Chronic thromboembolic PH (CTEPH)
• PH with an unclear and/or multifactorial mechanisms

Subgroups of Pulmonary Hypertension

The subgroups can be further divided into more specific categories, such as:

• Group 1: idiopathic or familial PAH, with or without germline mutations, as well as pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis 4
• Group 2: PH due to left heart diseases, including systolic dysfunction, diastolic dysfunction, and valvular dysfunction 4
• Group 3: PH due to respiratory diseases, such as pulmonary fibrosis, COPD, lung emphysema, or interstitial lung disease 4
• Group 4: chronic thromboembolic pulmonary hypertension 4, 5
• Group 5: PH patients with unclear multifactorial mechanisms 2, 4