PASCAL Classification — Pulmonary Arterial Hypertension Severity

The PASCAL Classification (Prognostic Assessments Scale for CLinical evidence-based risk stratification) is a simplified, validated 3-tier risk stratification system for pulmonary arterial hypertension (PAH) developed by the European Society of Cardiology/European Respiratory Society (ESC/ERS) from large multicenter PAH registries. PASCAL classifies patients with established PAH into Low (L), Intermediate-Low (IL), Intermediate-High (IH), and High (H) risk categories based on: functional class, 6-minute walk test, BNP/NT-proBNP, echocardiographic right heart parameters, and right heart catheterization hemodynamics. PASCAL predicts 1-year mortality probability for each risk tier and guides treatment escalation decisions.