Pulmonary Arterial Hypertension (PAH)

Pulmonary arterial hypertension (PAH) is a severe chronic pulmonary arteriole disease that leads to an increase in pulmonary vascular resistance. It has an impact on functional capacity and quality of life, and it can lead to right heart failure and a reduction in life expectancy. In the last 2 decades, many successful treatments have emerged; however, overall survival has not shown satisfactory improvement.1

Many clinical investigations have suggested that World Health Organization (WHO) functional class, 6-minute walk distance (6MWD), serum brain natriuretic peptide (BNP) level, right atrial pressure, mixed venous oxygen saturation, hematological and biochemical data are predictive markers of disease mortality. In the 2015 guidelines for the diagnosis and management of pulmonary hypertension, these characteristics are indicated as risk assessment parameters.1

The prognosis of PAH varies depending on cause, severity, and treatment.2 Better diagnostic methods contribute to quicker and more precise diagnoses, allowing treatment to begin sooner in the disease course. Early therapy can increase a patient’s quality of life as well as their overall life expectancy.3

Prognosis is better if the patient has more low-risk factors. These include congenital heart disease-related PAH, functional class I or II, normal right ventricular function, no pericardial effusion, low BNP, and high 6MWD (>400 meters). High-risk factors which contribute to a worse prognosis include familial PAH, connective tissue disease-related PAH, liver disease-related PAH, functional class III or IV, high BNP, severe impairment in right ventricular function, pericardial effusion, very high right atrial pressure, pulmonary vascular resistance, blood flow, and low 6MWD (<300 meters).4 

It has been noted in previous studies that patients with idiopathic PAH who are over the age of 65 years have a considerably higher death risk than younger patients aged between 18 and 65 years.5 

A risk stratification strategy for PAH patients has been suggested by the 2015 European pulmonary hypertension guidelines. Estimated 1-year mortality risks of <5%, 5% to 10%, and >10% are used to classify low-, intermediate-, and high-risk strata, respectively. A study analyzed 1588 patients with PAH, and the 3 risk strata had substantially different mortality rates. The overall patient death rates 1 year after diagnosis were 2.8% in the low-risk group, 9.9% in the intermediate-risk group, and 21.2% in the high-risk group. Furthermore, the risk assessment technique was found to be accurate during follow-up and in major PAH subgroups.6 

Prognosis also depends on the underlying cause of the disease. Patients with connective tissue diseases such as scleroderma and accompanying PAH have a 40% chance of living for 2 years, compared to a 48% chance of living for 3 years in patients with idiopathic PAH. Patients with HIV-associated PAH had a comparable survival rate to those with idiopathic PAH. With the use of recent HIV medications, the majority of deaths in cases with HIV and associated PAH occur due to PAH.7 

Without therapy, the 5-year survival rate from the time of diagnostic right-sided heart catheterization in the United States is 57%, according to US registry data.8 Risk score calculators for newly diagnosed PAH cases are available and validated. Male sex, age >50 years, poor WHO functional status, and right ventricular dysfunction all contribute to poor prognosis. Patients with right-sided heart failure, for example, only survive for approximately 1 year without medication.8,9  

It is worth mentioning that long-term trends imply that survival is improving in patients with PAH. Scleroderma-associated PAH, for example, has witnessed an improvement in prognosis since the development of advanced medications.10 Due to the fact that etiology has a major role in prognosis, people with PAH secondary to connective-tissue disease, portal hypertension, or familial factors have a lower survival rate than patients with other etiologies.2 


  1. Wang LY, Lee KT, Lin CP, et al. Long-term survival of patients with pulmonary arterial hypertension at a single center in Taiwan. Acta Cardiol Sin. 2017;33(5):498-509. doi:10.6515/acs20170612a
  2. Schwab KE. Pulmonary arterial hypertension: prognosis. Medscape. Updated August 6, 2021. Accessed March 28, 2022.
  3. Pulmonary hypertension life expectancy. Pulmonary Hypertension News. Accessed March 28, 2022.
  4. Feldman J. Pulmonary arterial hypertension life expectancy & survival rates. Pulmonary Hypertension RN. March 16, 2018. Accessed March 28, 2022.
  5. Hoeper MM, Boucly A, Sitbon O. Age, risk and outcomes in idiopathic pulmonary arterial hypertension. Eur Respir J. 2018;51(5):1800629. doi:10.1183/13993003.00629-2018
  6. Hoeper MM, Kramer T, Pan Z, et al. Mortality in pulmonary arterial hypertension: prediction by the 2015 European pulmonary hypertension guidelines risk stratification model. Eur Respir J. 2017;50(2):1700740. doi:10.1183/13993003.00740-2017
  7. Barst RJ. Pulmonary hypertension: past, present and future. Ann Thorac Med. 2008;3(1):1-4. doi:10.4103/1817-1737.37832
  8. Benza RL, Miller DP, Barst RJ, Badesch DB, Frost AE, McGoon MD. An evaluation of long-term survival from time of diagnosis in pulmonary arterial hypertension from the REVEAL Registry. Chest. 2012;142(2):448-456. doi:10.1378/chest.11-1460
  9. Sitbon O, Benza RL, Badesch DB, et al. Validation of two predictive models for survival in pulmonary arterial hypertension. Eur Respir J. 2015;46(1):152-164. doi:10.1183/09031936.00004414
  10. McLaughlin V. Managing pulmonary arterial hypertension and optimizing treatment options: prognosis of pulmonary artery hypertension. Am J Cardiol. 2013;111(8 Suppl):10C-5C. doi:10.1016/j.amjcard.2013.01.319

Reviewed by Debjyoti Talukdar, MD, on 3/29/2022.