Pulmonary hypertension in chronic lung diseases

Area of Science:

• Pulmonary Medicine
• Cardiology
• Respiratory Diseases

Background:

• Chronic obstructive lung disease (COPD) and diffuse parenchymal lung diseases (DPLD), including idiopathic pulmonary fibrosis (IPF), frequently cause pulmonary hypertension (PH).
• Combined pulmonary fibrosis and emphysema (CPFE) patients have a high risk of developing PH, impacting exercise capacity and prognosis.
• Accurate diagnosis and differentiation of PH in lung disease are essential for appropriate management.

Purpose of the Study:

• To define criteria for discriminating between PH groups in patients with lung diseases.
• To establish definitions for PH severity in COPD, IPF, and CPFE.
• To guide research and clinical care for patients with severe PH and chronic lung conditions.

Main Methods:

• Review of diagnostic modalities including echocardiography and right heart catheterization.
• Development of classification criteria for Group 3 PH (PH due to lung disease).
• Definition of PH severity based on mean pulmonary artery pressure (mPAP) and cardiac index (CI).

Main Results:

• Defined criteria for differentiating PH in respiratory conditions.
• Established categories: PH without PH (mPAP <25 mm Hg), PH (mPAP ≥25 mm Hg), and severe PH (mPAP ≥35 mm Hg or mPAP ≥25 mm Hg with CI <2.0 l/min/m²).
• Identified a 'severe PH group' with vascular remodeling and exhausted circulatory reserve, exhibiting disproportionate exertional dyspnea and poor prognosis.

Conclusions:

• Accurate identification of severe PH in COPD, IPF, and CPFE is critical.
• This severe subgroup requires specialized evaluation and care at expert centers.
• Future clinical trials for Group 3 PH should focus on this severe PH population.