Understanding PAH

PAH: A rare and progressive disease
The cause of PAH is often unknown
PAH prevalence and characteristics

PAH: A rare and progressive disease

Group 1 pulmonary arterial hypertension (PAH) is a rare subset of pulmonary hypertension.¹ PAH is a serious, progressive disease of the lungs, primarily affecting small pulmonary arterioles.² Over time, the pathophysiology of PAH causes progressive blood flow restriction and right heart ventricular dysfunction, eventually leading to heart failure and death.^2,3

PAH is WHO Group 1

PH is categorized into 5 groups based on pathophysiology, clinical features, and therapeutic approaches¹:

Heart and lung image showing how WHO categorizes PH into 5 groups, along with the effects and location of PAH Group 1, a rare subset

Group 1
PAH: Precapillary PH characterized by increased pulmonary vascular resistance in the absence of other causes of precapillary PH (ie, lung diseases or thromboembolic events)
Group 2
PH due to left heart disease: Includes patients with PH caused by left heart conditions (ie, left ventricular dysfunction or valvular disease), where elevated left heart pressures lead to increased pulmonary pressures
Group 3
PH due to lung diseases and/or hypoxia: Includes patients with PH who have chronic lung diseases (eg, ILD or COPD) or low oxygen levels, leading to high pulmonary pressure
Group 4
CTEPH: Patients with PH caused by chronic blood clots in the lungs, often treated surgically
Group 5
PH with unclear and/or multifactorial mechanisms: Encompasses PH cases with complex or unknown causes, including blood, systemic, or metabolic disorders

The cause of PAH is often unknown³

PAH falls into 6 general clinical classifications based on etiology:

Classification¹

Details^1,4

Idiopathic

Cause is unknown

Includes PAH long-term responders to CCBs

Heritable

BMPR2 is the most commonly mutated gene

Drug- and toxin-induced

May include:

Aminorex
Benfluorex
Dasatinib
Dexfenfluramine
Fenfluramine
Methamphetamines
Toxic rapeseed oil

Associated

May include:

CTD
HIV infection
Portal hypertension
CHD
Schistosomiasis

PVOD/PCH involvement

Persistent PH of the newborn

For most patients, PAH has an unknown etiology or is associated with another condition⁵

Who Group 1 PAH etiologies by prevalence pie chart

Image Description

The breakdown of PAH by etiology is:

Associated PAH: 51%
Idiopathic PAH: 44%
Heritable: 4%
Other: 1%

Adapted from Badlam JB, et al. Chest. 2021;159(1):311-327.

The most common associated condition is CTD, followed by CHD⁵

PAH associated conditions composition pie chart

Image Description

The prevalence of associated conditions is:

CTD: 67%
Portal hypertension: 9%
Drugs/Toxins: 9%
HIV: 4%
CHD: 12%
Other: 1%

PAH prevalence and patient characteristics

PAH affects

15 to ~60

people per 1 million individuals

in countries where studies have been conducted^6,7

~1000 new cases are diagnosed in the United States every year⁸

PAH is more commonly diagnosed in women (70%-80% of cases)³

~2 years from symptom onset to diagnostic catheterization⁵

Average age: 50 years⁹*

61% 5-year survival average¹⁰

*Based on a total of 2716 patients from the REVEAL Registry (standard deviation: 16.8 years).⁹

"Early recognition is really important and it’s important to collaborate … to recognize this patient population because they’re not all in highly dense areas. The earlier we recognize pulmonary hypertension, the earlier we can treat pulmonary hypertension, and the better the patients do."

— Dan Lachant, DO, Assistant Professor of Medicine, Strong Memorial Hospital/University of Rochester, Rochester, NY

Examine the therapeutic classes available to treat PAH

PAH Treatments

Explore the pathophysiology of PAH

PAH Pathophysiology

CCB=calcium channel blocker; CHD=congenital heart disease; COPD=chronic obstructive pulmonary disease; CTD=connective tissue disease; CTEPH=chronic thromboembolic pulmonary hypertension; HIV=human immunodeficiency virus; ILD=interstitial lung disease; PH=pulmonary hypertension; PVOD/PCH=pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis; WHO=World Health Organization.

References: 1. Humbert M, et al. Eur Heart J. 2022;43(38):3618-3731. 2. Lai YC, et al. Circ Res. 2014;115(1):115‐130. 3. Hoeper MM, et al. Eur Respir Rev. 2014;23(134):450‐457. 4. Kovacs G, et al. Eur Respir J. 2024;64(4):2401324. 5. Badlam JB, et al. Chest. 2021;159(1):311‐327. 6. Galiè N, et al. Eur Heart J. 2016;37(1):67‐119. 7. Humbert M, et al. Am J Respir Crit Care Med. 2006;173(9):1023‐1030. 8. National Institutes of Health, US National Library of Medicine. Accessed April 30, 2025. https://medlineplus.gov/genetics/condition/pulmonary‐arterialhypertension/ 9. Benza RL, et al. Circulation. 2010;122(2):164-172. 10. Farber HW, et al. Chest. 2015;148(4):1043‐1054.

Understanding PAH

PAH: A rare and progressive disease

PAH is WHO Group 1

The cause of PAH is often unknown3

Classification1

Details1,4

For most patients, PAH has an unknown etiology or is associated with another condition5

The most common associated condition is CTD, followed by CHD5