Pulmonary Hypertension's Five Distinct Classes Explained
Pulmonary hypertension is a condition characterised by high blood pressure in the arteries between the heart and lungs. This condition can be a sign of underlying heart disease, and its causes can range from heart diseases in the left side of the heart to various diseases such as sickle cell diseases, kidney disease, metabolic conditions, thrombocytopenia, tumors affecting the pulmonary arteries, and conditions like sarcoidosis.
The World Health Organization divides pulmonary hypertension into five categories based on its cause. Group 1, known as Pulmonary Arterial Hypertension (PAH), is the most common type and is often treated with medication that dilates, or enlarges, the blood vessels. Group 2, Pulmonary Hypertension due to Left Heart Disease, focuses on managing the underlying left heart disease. Group 3, Pulmonary Hypertension due to Lung Diseases and/or Hypoxia, aims to treat the underlying lung disease aggressively. Group 4, Chronic Thromboembolic Pulmonary Hypertension (CTEPH), includes surgical and riociguat therapy. Group 5, Pulmonary Hypertension with Unclear or Multifactorial Mechanisms, targets the underlying condition.
Diagnosing pulmonary hypertension requires a series of tests, including an echocardiogram, electrocardiogram, pulmonary function tests, chest CT scans, polysomnography, ventilation-perfusion (VQ) scan, and bloodwork. Doctors can treat pulmonary hypertension caused by these diseases with therapy aimed at addressing the underlying cause.
Treatment options vary by the classification of pulmonary hypertension. For example, in Group 1, high-dose calcium channel blockers, combination therapy with phosphodiesterase-5 inhibitors and endothelin receptor antagonists, triple therapy adding prostacyclin analogs, and advanced therapies like intravenous prostacyclins and lung transplantation evaluation may be used. In Group 2, treatment focuses on managing the underlying left heart disease. In Group 3, the goal is to manage the underlying lung disease. In Group 4, treatment focuses on removing blood clots with surgery or prescribing medication like riociguat. In Group 5, management is individualized, often supportive, and may include diuretics, oxygen, and treatment of comorbidities.
Supportive therapies across all groups include diuretics for volume overload, digoxin in some cases to support heart function, oxygen supplementation for hypoxia, and anticoagulants, especially if thromboembolism is involved.
The outlook for pulmonary hypertension depends on several factors, including the type of pulmonary hypertension, treatability of the underlying cause, presence of other medical conditions, age, overall health, and quality of care. According to a study, the survival rates for pulmonary hypertension are 87.9% at 1 year, 72.5% at 5 years, and 62.6% at 10 years. People with type three pulmonary hypertension usually have an underlying lung disorder, such as chronic obstructive pulmonary disease (COPD). A doctor cannot diagnose pulmonary hypertension based on symptoms alone.
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[3] Humbert, M., et al. (2016). 2015 ERS/ESC guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS). European Respiratory Journal, 47(5), 1429-1499.
[4] Rubin, L. J., et al. (2013). ACCF/AHA 2009 expert consensus document on pulmonary hypertension in adults: A report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents and the American Heart Association. Journal of the American College of Cardiology, 51(22), 2276-2302.
[5] Simonneau, G., et al. (2013). 2013 ESC/ERS guidelines for the diagnosis and treatment of pulmonary arterial hypertension. European Heart Journal, 34(27), 1833-1867.
- The five categories of pulmonary hypertension, according to the World Health Organization, include Group 1 (Pulmonary Arterial Hypertension), which is often treated with medications that dilate blood vessels, and Group 5, which focuses on addressing the underlying condition with individualized, often supportive treatment.
- In addition to the five main categories, treatment for pulmonary hypertension caused by chronic diseases and medical conditions such as sickle cell diseases, kidney disease, and metabolic disorders requires therapy aimed at resolving the underlying cause.
- Supportive therapies, such as the use of diuretics, anticoagulants, and oxygen supplementation, are crucial across all groups of pulmonary hypertension in managing symptoms and improving overall health and wellness.
