Pulmonary Disorders II
PAH risk stratification is a multiparametric risk assessment tool approach that is recommended for
quantifying the severity of disease, predicting patient outcomes, and guiding the treatment of PAH.
The most predictive prognostic factors are 3 noninvasive parameters (WHO functional class [Table 3],
6MWD, and natriuretic peptides) that are included in all currently validated risk stratification tools.
The European Society of Cardiology/European Respiratory Society (ECS/ERS) and REVEAL
methods are the 2 risk stratification models recommended by guidelines. Each model stratifies a
patient at diagnosis as low-, intermediate-, or high-risk status. On reassessment, a 4-stratification
system is used: low-, intermediate-low, intermediate-high, or high-risk status. Risk categories are
associated with 1-year mortality rates.
The ECS/ERS 3-strata (Table 4) or REVEAL 2.0 models are recommended to be used at diagnosis
at baseline.
The ECS/ERS 4-strata (Table 5) or REVEAL Lite models are recommended to be used at 3- to
4-month intervals to assess a patientβs response to therapy.
Class
Definition
I
No symptoms (dyspnea, fatigue, syncope, chest pain) with normal activities
II
Symptoms with strenuous normal daily activities that slightly limit functional status and
activity level; no symptoms at rest
III
Symptoms of dyspnea, fatigue, syncope, and chest pain with normal daily activities that
severely limit functional status and activity level; no symptoms at rest
IV
Symptoms at rest; cannot perform normal daily activities without symptoms
aHumbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. Eur Heart J 2022;43:3618-731.
Multivariable Assessment of Mortality Risk to Guide Initial Therapy
Assessment
3-Risk Strata
Estimation of 1-year
mortality
Low Risk < 5%
Intermediate Risk 5%β20%
High Risk > 20%
Points assigned per
variablea
1 point
2 points
3 points
Signs of right heart
failure
No
No
Yes
Progression of
symptoms and clini-
cal manifestations
No
Slow
Rapid
Syncope
No
Occasional during strenuous
exercise
Repeated with little or normal
physical activity
WHO-FC
I, II
III
IV
6-Minute walk
distance
> 440 m
165β440 m
< 165 m
Cardiopulmonary
exercise testing
Peak VO2 > 15
mL/min/kg (> 65%
predicted) VE/VCO2
slope < 36
Peak VO2 11β15
mL/min/kg (35%β65%
predicted) VE/VCO2
slope 36β44
Peak VO2 < 11 mL/min/kg
(< 35% predicted) VE/VCO2
slope > 44