Risk Stratification in CTD-PAH Patients on Selexipag

Introduction to Risk Stratification

The European Society of Cardiology (ESC) and European Respiratory Society (ERS) recommend risk-stratifying patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) using the ESC/ERS 4-strata risk assessment method every 3-6 months, with the treatment goal being achievement and maintenance of low-risk status 1, 2, 3, 4

The ESC/ERS 4-strata risk model classifies patients into four risk categories based on estimated 1-year mortality, using parameters such as WHO functional class, 6-minute walk distance, and biomarkers like BNP/NT-proBNP 2, 3, 4, 5
The 6-minute walk distance is a key parameter, with a target of >440 meters indicating low risk, 165-440m indicating intermediate risk, and <165m indicating high risk 2
Biomarkers like BNP/NT-proBNP levels are also important, with normal or near-normal levels indicating low risk, moderately elevated levels indicating intermediate risk, and markedly elevated levels indicating high risk 5

Regular monitoring should be performed every 3-6 months in stable patients, with reassessment 3-6 months after any treatment changes, including selexipag initiation or dose escalation 3
Immediate reassessment is necessary with any clinical worsening 6

The primary treatment goal is achievement and maintenance of low-risk status, which translates to WHO FC I-II, 6MWD >440m, normal or near-normal BNP, and preserved right ventricular function 4
Inadequate response to treatment is defined as intermediate-risk status, which warrants treatment escalation 6

CTD-PAH patients have a higher baseline risk profile compared to idiopathic PAH, with 67-70% of patients at intermediate or high risk at treatment initiation despite background therapy 1, 7
The 4-strata risk assessment remains prognostic in CTD-PAH patients treated with selexipag, with one-year survival estimates ranging from 98% (low risk) to 80% (high risk) 1

For patients remaining at intermediate or high risk, consider adding intravenous prostacyclin analogues or evaluating for riociguat as alternative or additional therapy 1, 6
Earlier and more frequent risk assessment with proactive treatment escalation is critical to avoid delayed treatment escalation 1, 6