Refining the Definition for "Low Risk" in Pulmonary Arterial Hypertension: Time to Reduce Morbidity and Mortality

Area of Science:

• Cardiology
• Pulmonology
• Clinical Epidemiology

Background:

• Current definitions of low-risk pulmonary arterial hypertension (PAH) focus on 1-year mortality (<5%).
• Improving PAH treatments necessitate updated risk assessments that incorporate morbidity and extend mortality prediction.
• A more stringent definition is needed to accurately identify patients with favorable long-term outcomes.

Purpose of the Study:

• To propose a refined definition of low-risk PAH incorporating both 3-year mortality and 1-year morbidity.
• To establish a new benchmark for identifying PAH patients with superior prognoses.

Main Methods:

• Utilized patient-level data from 8 PAH randomized controlled trials.
• Defined low risk as <5% 3-year mortality and <10% 1-year clinical worsening.
• Clinical worsening included events like transplantation, hospitalization, oxygen initiation, significant 6-minute walking distance decrease, or new PAH medication.

Main Results:

• Analyzed 1,925 PAH patients; a REVEAL 2.0 risk score ≤4 identified patients meeting the refined low-risk definition.
• Patients with a REVEAL 2.0 score ≤4 demonstrated a 2.6% 3-year mortality and 6.4% 1-year clinical worsening.
• Factors associated with refined low risk included idiopathic PAH, higher 6-minute walking distance, lower NT-proBNP, and NYHA functional class I-II.

Conclusions:

• This study introduces the first definition of low-risk PAH that integrates both morbidity and mortality.
• A REVEAL 2.0 risk score ≤4 effectively identifies PAH patients meeting this stringent refined low-risk definition.
• This refined definition aids in better risk stratification and management of pulmonary arterial hypertension.