Hemodynamic Correlates and Prognostic Value of the RISA-PE Staging System in Acute Pulmonary Embolism

Emerging therapies for acute PE highlight the need for a more granular risk classification.

The objective of this study was to validate a novel risk model-the RIsk claSsification Adapted to SCAI shock stages in acute PE (RISA-PE), which applies the SCAI shock staging framework to right ventricular failure due to acute PE.

We retrospectively analyzed consecutive patients with acute intermediate- or high-risk PE treated with LBMT at a tertiary academic center (October 2020 to May 2025). Patients were stratified by RISA-PE stage (A-E) as previously described. Clinical data, including invasive pulmonary artery catheter hemodynamics and clinical outcomes were compared across stages. The primary endpoint was a composite of 30-day PE-related death, resuscitated cardiac arrest, or hemodynamic instability.

Among the 181 patients (median age 59 years, 45% women) included in the study, advancing RISA-PE stage was associated with progressive tachycardia, higher shock index, worse biomarker derangements (lactate and high-sensitivity troponin) and increasing severity of RV dysfunction on imaging (lower TAPSE, higher RV/LV diameter ratio). Pre-procedural pulmonary artery catheterization confirmed stage-dependent declines in cardiac index, with the prevalence of low CI (≤2.2 L/min/m²) rising from 25% in Stage A to 75% in Stage C (p < 0.001). Clinical outcomes paralleled stage severity. Median hospital length-of-stay increased from 5 to 6 days (Stages A/B) to 19.9 days (Stage E, p < 0.001), and ICU stay from 2.5 to 3 days to 9.5 days, respectively (p < 0.001). The primary composite outcome occurred in 0% of Stage A, 5% of Stage B, 12% of Stage C, 15% of Stage D, and 50% of Stage E patients (p < 0.001).

The RISA-PE staging system demonstrates strong correlation with RV dysfunction severity, invasive hemodynamics, and adverse outcomes in patients with acute PE treated with LBMT. RISA-PE provides a graded framework for identifying patients at highest risk of deterioration and may guide escalation of therapy.