PESI Score (PE Severity)

The full PESI uses 11 variables with weighted point values (age = 1 per year, cancer = 30 points, etc.), producing scores from <65 to >200+. The simplified PESI (sPESI) uses 6 binary variables (each score 0 or 1): age >80, cancer, chronic cardiopulmonary disease, heart rate ≥110, systolic BP <100, and SpO2 <90%. sPESI = 0 identifies very low-risk patients with <1% 30-day mortality. Both perform similarly for identifying low-risk patients, but the full PESI gives more granular risk stratification across all five classes.

Outpatient PE treatment is safe for PESI Class I–II or sPESI = 0 patients who also meet the Hestia criteria (no haemodynamic instability, no need for thrombolysis, no high bleeding risk, adequate social circumstances, no severe pain requiring IV opioids, no other medical reason for hospitalisation). Multiple RCTs (HOME-PE, OUTREACH) have confirmed non-inferiority of outpatient management with DOACs in appropriately selected low-risk PE.

DOACs (apixaban, rivaroxaban) are first-line for most PE patients. They have comparable efficacy and better safety than warfarin + heparin (lower major bleeding). Rivaroxaban and apixaban have PE-specific dosing regimens (rivaroxaban 15 mg twice daily for 21 days then 20 mg daily; apixaban 10 mg twice daily for 7 days then 5 mg twice daily). Warfarin + LMWH bridging is used for patients with antiphospholipid syndrome (triple positive) or severe renal failure (eGFR <15–25 mL/min/1.73m2).

Systemic thrombolysis (alteplase 100 mg IV over 2 hours) is indicated for massive PE — defined by haemodynamic compromise (systolic BP <90 mmHg for ≥15 minutes, cardiogenic shock, or cardiac arrest). For submassive PE (haemodynamically stable but RV dysfunction + troponin rise), thrombolysis should be considered only if haemodynamic deterioration occurs despite anticoagulation — the risk of major bleeding (including intracranial haemorrhage ~2%) generally outweighs benefit in haemodynamically stable patients.

The ESC 2019 PE guidelines stratify risk into: High Risk (haemodynamic instability — PE-related shock/arrest; immediate thrombolysis or embolectomy), Intermediate-High Risk (PESI III–IV or sPESI ≥1 + both RV dysfunction and elevated troponin — anticoagulate; monitor for deterioration), Intermediate-Low Risk (PESI III–IV or sPESI ≥1 + only one of RV dysfunction or troponin elevation — hospitalise and anticoagulate), and Low Risk (PESI I–II or sPESI = 0 — consider outpatient treatment).

Duration of anticoagulation after PE: 3 months minimum for all provoked PE (post-surgery, post-trauma, post-immobilisation). Unprovoked PE warrants at least 3 months, with risk-benefit reassessment for extended therapy — for most patients with a first unprovoked PE, extended therapy (indefinitely, with annual risk review) is recommended as recurrence risk is 10% in year 1, 30% at 5 years. Cancer-associated PE: LMWH traditionally, but DOACs (rivaroxaban, apixaban, edoxaban) are now preferred per ADAM VTE, SELECT-D trials.

A PERT is a multidisciplinary team — typically including pulmonology, haematology, cardiology, vascular surgery, interventional radiology, and intensivist — that provides rapid expert consultation for complex or high-risk PE cases. PERT activation is typically triggered by massive PE (haemodynamic instability), intermediate-high risk PE, contraindications to anticoagulation, or consideration of catheter-directed thrombolysis. Most major centres now have PERTs, which have been associated with reduced in-hospital mortality.

CTEPH is a long-term complication of PE occurring in 2–4% of survivors, where clot does not fully resolve and organises into fibrous tissue causing fixed vascular obstruction and progressive pulmonary hypertension. Symptoms include exertional dyspnoea, reduced exercise tolerance, and right heart failure. CTEPH is diagnosed by V/Q scan (characteristic mismatch defects) and confirmed by right heart catheterisation. Treatment is surgical (pulmonary endarterectomy — potentially curative), balloon pulmonary angioplasty, or medical (riociguat).