The European Respiratory Society (ERS) unveiled its 2026 updated clinical practice guidelines for pulmonary arterial hypertension (PAH) at its annual congress, marking the first major revision since 2022. The headline change: sotatercept — a first-in-class activin signaling pathway inhibitor approved by both the FDA and EMA in 2024 — is now formally incorporated as a fourth therapeutic pathway and recommended as a second-line treatment for patients at intermediate or high risk who haven't achieved low-risk status on existing oral therapies.

The guidelines also tackle a long-debated question: when should patients undergo repeat right heart catheterization (RHC) during follow-up? The answer is nuanced — RHC is conditionally recommended for intermediate-to-high and high-risk patients when results are likely to change management, but no firm recommendation is made for low-risk patients given the uncertain benefit-risk balance.

Key Takeaways:

• Sotatercept (given subcutaneously every 3 weeks) is now a strong, high-certainty recommendation for PAH patients already on one or more therapies who remain at low-to-intermediate, intermediate-to-high, or high mortality risk
• For low-risk patients, sotatercept decisions should be made case-by-case — no routine recommendation exists
• Repeat RHC is conditionally advised for higher-risk patients when it could change treatment strategy; for low-risk patients, the decision should be individualized and shared with the patient
• First-line therapy remains oral agents (PDE5 inhibitors + endothelin receptor antagonists); prostacyclins and lung transplant remain options for refractory disease

Why it matters: These guidelines give clinicians a clearer, evidence-backed roadmap for escalating PAH therapy — particularly with sotatercept now having a defined role — which could meaningfully improve outcomes for a disease that carries significant mortality risk.