New risk classification adapting SCAI shock stages to patients with pulmonary embolism (RISA-PE).

Background: Pulmonary embolism (PE) treatment is based on risk stratification according to European Society of Cardiology (ESC) guidelines. However, emerging therapies in acute PE may require a more granular risk classification. Therefore, the objective of the present study was to propose a new RIsk claSsification Adapting the SCAI shock stages to right ventricular failure due to acute PE (RISA-PE).

Methods: This registry included consecutive intermediate-high risk (IHR) or high-risk (HR)-PE patients selected for catheter-directed interventions (CDI) from 2018 to 2023 in 15 Spanish centers (NCT06348459). Patients were grouped according to RISA-PE classification as A (right ventricular dysfunction and troponin elevation); B (A + serum lactate >2 mmol/L OR shock index ≥1); C (persistent hypotension); D (obstructive shock); and E (cardiac arrest). In-hospital adverse events were assessed to evaluate RISA-PE performance.

Results: A total of 334 patients were included (age 62.1±15.2 years, 55.7% males). The incidence of in-hospital all-cause death was progressively higher with increasing RISA-PE stage (1.2%, 6.4%, 19.0%, 25.6%, and 57.7% for stages A, B, C, D, and E, respectively, P value for linear trend<0.001). However, using the ESC classification, there was an abrupt difference between IHR- and HR-PE patients regarding mortality (4.3% vs. 29.3%, P<0.001). The incidence of in-hospital major bleeding and acute kidney injury followed a similar pattern.

Conclusions: The user-friendly RISA-PE classification may improve the granularity in stratifying PE patients' risk and warrants evaluation in larger studies with different therapeutic approaches in order to detect its utility as a decision-making scale.