How does PESI differ from sPESI for PE risk stratification?

PESI uses 11 weighted variables and produces 5 risk classes. sPESI uses 6 binary variables and produces a binary classification (0 = low, ≥1 = elevated). Both have similar prognostic accuracy in meta-analyses. ESC 2019 PE Guidelines use sPESI as the primary bedside tool due to simplicity; PESI is useful when more granular class-specific mortality estimates are needed for prognosis discussions.

Is PESI used in clinical guidelines for PE management?

Yes. ESC 2019 PE Guidelines (Konstantinides et al., Eur Heart J 2020) and ACCP guidelines endorse both PESI and sPESI as validated clinical severity assessment tools. IDSA/ATS guidelines and the BTS PE guidelines also reference PESI for risk stratification. PESI Class I–II is specifically cited as the population eligible for outpatient treatment in the pivotal Aujesky et al. randomized trial (Lancet 2011).

What role do troponin and BNP play alongside PESI?

Troponin and BNP are biomarkers of cardiac injury and RV pressure overload, respectively. ESC 2019 PE risk stratification integrates PESI/sPESI with biomarker data: PESI Class I–II + negative troponin + normal RV = low risk (outpatient eligible). PESI ≥III or sPESI ≥1 + elevated troponin + RV dysfunction = intermediate-high risk (close monitoring, consider PERT). Biomarkers provide independent prognostic information beyond PESI.

How does PESI compare to the Revised Geneva Score?

These tools serve different purposes. Revised Geneva Score is a pre-test probability tool for suspected PE (used before diagnosis to decide whether to order CT-PA). PESI is a post-diagnosis prognostic tool (used after CT-PA confirms PE to guide treatment intensity and level of care). They are not interchangeable — Revised Geneva guides the diagnostic workup; PESI guides post-diagnosis management.

What makes PESI Class V patients uniquely high-risk?

PESI Class V (>125 points) patients typically have multiple concurrent adverse features: advanced age, multiple comorbidities, hemodynamic compromise (BP <100 mmHg, tachycardia), respiratory failure (RR ≥30, SpO2 <90%), and possibly altered mental status. 30-day mortality approaches 24%. These patients require ICU-level monitoring, early PERT activation, echocardiography, biomarker assessment, and consideration of thrombolysis or mechanical embolectomy.

Can PESI be applied to hospital-acquired or ventilator-associated PE?

PESI was derived and validated specifically for community-acquired PE presenting to emergency departments or hospitals. It was not validated for hospital-acquired PE, ventilator-associated PE, or PE in critically ill patients with multiple confounding comorbidities. In these settings, clinical assessment, hemodynamic status, and institutional protocols should guide management rather than PESI alone.

What is the evidence for outpatient PE treatment with PESI?

The pivotal evidence comes from Aujesky et al. (Lancet 2011) — a randomized trial comparing inpatient vs outpatient PE treatment in 344 PESI Class I–II patients. 30-day recurrent VTE: 0.6% outpatient vs 0% inpatient; major bleeding 0% vs 0.6%; 3-month mortality 0.6% vs 1.8% — demonstrating non-inferior outcomes for outpatient management in low-risk PE. This study established PESI Class I–II as the evidence-based outpatient eligibility threshold.

Online Medical Tools — PESI Score

Printed on 9/2/2026

For informational purposes only. This is not medical advice.

Emergency

PESI Score

The Pulmonary Embolism Severity Index (PESI) is a validated prognostic score for adults with confirmed acute PE. It combines demographics, comorbidities, and physiologic findings to stratify short-term mortality risk into five classes. PESI supports disposition planning and intensity-of-care decisions after PE diagnosis.

Formula: PESI = age + male sex(10) + cancer(30) + heart failure(10) + chronic lung disease(10) + pulse≥110(20) + SBP<100(30) + RR≥30(20) + temp<36(20) + altered mental status(60) + SpO2<90(20).

Age

years

Sex Assigned at Birth

History of Cancer

Heart Failure

Chronic Lung Disease

Pulse ≥ 110 bpm

Systolic BP < 100 mmHg

Respiratory Rate ≥ 30/min

Temperature < 36°C

Altered Mental Status

SpO2 < 90%

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How It Works

Apply the Class I screening step first

Before scoring all 11 variables, apply the Class I screening: if the patient is under 50 years old, has no comorbidities (no cancer, heart failure, or chronic lung disease), has normal mental status, normal vital signs (HR <100, SBP ≥90, RR <30, temp 36–39.9°C), and SpO2 ≥90% — they qualify as Class I (lowest risk) and can be considered for outpatient care without full scoring.

Score all 11 weighted variables

For patients not meeting Class I criteria, score: age in years (direct points), male sex (+10), cancer (+30), heart failure (+10), chronic lung disease (+10), pulse ≥110 bpm (+20), systolic BP <100 mmHg (+30), respiratory rate ≥30/min (+20), temperature <36°C (+20), altered mental status (+60), SpO2 <90% (+20). Sum all applicable points.

Assign risk class and interpret 30-day mortality

Class I = <66 points (0.1–1.6% 30-day mortality); Class II = 66–85 points (~3.5%); Class III = 86–105 points (~7%); Class IV = 106–125 points (~11%); Class V = >125 points (~24%). Classes I–II generally support outpatient treatment consideration when other criteria are met; Classes III–V require inpatient care; Class V warrants high-acuity monitoring.

Who Uses the PESI Score

Detailed PE Risk Stratification When sPESI is Indeterminate

Hospitalists, emergency physicians, pulmonologists

When sPESI gives limited guidance (e.g., patient is exactly at the boundary), PESI provides more granular 5-class risk stratification. PESI Class III (intermediate) benefits from additional clinical analysis to decide between ward observation and outpatient discharge.

Outpatient PE Treatment Eligibility (Classes I–II)

Emergency physicians, anticoagulation clinics

PESI Classes I–II (30-day mortality <3.5%) represent the clinical threshold below which outpatient treatment is evidence-based. Combined with Hestia criteria assessment, negative troponin, and normal RV function, Class I–II patients can be safely discharged with DOAC anticoagulation.

Prognostication Discussion With Patients and Families

Hospitalists, palliative care, pulmonologists

PESI provides quantitative 30-day mortality estimates for each class that can be used in patient and family discussions about prognosis, goals of care, and treatment intensity in confirmed PE, especially in patients with Class IV–V risk.

Hospital Resource Allocation and Quality Benchmarking

Hospital quality teams, administrators

PESI class distribution can be tracked across admitted PE patients to assess appropriateness of hospitalization, ICU utilization, and treatment pathways. Institutions with high Class I–II admission rates may have opportunities to increase safe outpatient PE management.

Research and Quality Benchmarking

Clinical researchers, PE registries

PESI is a standard variable in PE registries (e.g., RIETE, PEITHO) and clinical trials. Its 5-class system enables finer subgroup analysis than sPESI's binary classification, particularly for intermediate-risk PE subgroups.

Pro Tips

PESI Classes I–II = 30-day mortality <3.5% — outpatient treatment eligible

PESI Class I and II patients have very low short-term mortality (0.1–3.5%). When combined with Hestia criteria (no exclusions), negative troponin, normal RV function on imaging, and adequate follow-up access, these patients can be safely managed as outpatients with DOAC. The Aujesky et al. randomized trial (Lancet 2011) validated outpatient PE treatment in Class I–II patients.

PESI has more granularity than sPESI — use when class-specific mortality matters

sPESI provides binary (low/elevated) classification. PESI provides 5 classes with distinct mortality estimates. When the clinical question involves prognostication or borderline outpatient eligibility, PESI's granularity is more informative. In routine clinical practice, sPESI is faster and equally valid for risk stratification.

Class I–II roughly corresponds to sPESI 0

PESI Class I and II typically correspond to sPESI 0 patients. Class III broadly corresponds to sPESI ≥1. This alignment allows cross-reference between the two tools, though individual patients may be classified differently due to the different variable weighting systems.

Altered mental status (60 points) dominates the PESI score

The altered mental status criterion carries the highest weight in PESI (60 points). A single point for this item can push a patient from Class I into Class III–IV territory. Always assess orientation to person, place, and time carefully and document the basis for this criterion.

SBP <100 mmHg (30 points) reflects significant cardiovascular compromise

Systolic BP <100 mmHg (30 points) is the second-highest weighted item in PESI. In combination with tachycardia and altered mental status, it can rapidly push patients to Class V. Hemodynamic instability in confirmed PE requires thrombolysis evaluation independent of PESI class.

Biomarkers add independent prognostic value beyond PESI

Troponin (cardiac injury) and BNP/NT-proBNP (RV pressure overload) provide prognostic information independent of PESI class. PESI Class II patients with elevated troponin may warrant closer inpatient monitoring than PESI class alone suggests — this is why ESC guidelines integrate PESI/sPESI + biomarkers + RV imaging into the full risk stratification algorithm.

PESI predicts 30-day mortality — not long-term outcomes

PESI was derived and validated for short-term (30-day) mortality prediction. Long-term outcomes in PE — including post-PE syndrome, CTEPH (chronic thromboembolic pulmonary hypertension), and recurrent VTE — are not captured in PESI and require separate follow-up assessment.

PESI Class I screening avoids full calculation in young healthy patients

The Class I screening criteria allow rapid identification of the lowest-risk patients without performing full PESI calculation: age <50, no comorbidities, normal vitals, normal mental status, SpO2 ≥90%. If all criteria are met, the patient is automatically Class I — full scoring is unnecessary.

Common Questions About Your Results

PESI Class III (30-day mortality ~7%) represents an intermediate zone. Guidelines generally support inpatient observation or a short stay for Class III patients, particularly when troponin or RV dysfunction is present. Outpatient treatment may be considered in carefully selected Class III patients with no Hestia exclusions, negative biomarkers, and normal RV — but this requires shared decision-making and very close follow-up.

Trust clinical assessment when PESI seems discordant. A young patient in Class II who appears clinically distressed with tachycardia trending up, rising troponin, and RV dilation on echo should not be discharged based on Class II alone. Conversely, an elderly patient in Class III who is stable, comfortable, and able to take oral medications may be safely managed at home with close follow-up. PESI informs — it does not decide.

Evidence-Based Methodology

PESI developed and validated by Aujesky et al. (Am J Respir Crit Care Med 2005) from 15,531 PE patients. C-statistic 0.78 for 30-day mortality. Class I 30-day mortality 0.1-1.6%, Class V 10-24.5%. Randomized trial of outpatient vs inpatient PE management using PESI (Aujesky et al., Lancet 2011). ESC 2019 PE Guidelines endorse PESI and sPESI as clinical severity assessment tools. PESI and sPESI compared in Lankeit et al. (Chest 2011).

Clinical Content Trust

Last reviewed:: April 21, 2026
Guideline version:: General evidence framework v2026.04
Source set version:: Primary-source set v1

How to Interpret Your Result

PESI classifies confirmed PE into five mortality-risk classes. Class I-II generally represent lower short-term risk, Class III intermediate risk, and Class IV-V higher risk. As class increases, closer monitoring and higher-intensity inpatient care become more likely.

PESI supports prognosis and disposition planning, but should be integrated with RV assessment, biomarkers, bleeding risk, and clinician judgment.

When to Use This Tool

Use PESI in adults with confirmed acute pulmonary embolism to estimate 30-day mortality risk and guide level-of-care planning.

It is especially useful when deciding between outpatient pathway eligibility and standard inpatient management.

Limitations

PESI estimates mortality risk but does not directly determine treatment strategy by itself. Some clinically important factors (for example clot burden, RV strain details, and evolving instability) are not captured in the score.

A low-risk class does not guarantee safe outpatient care; local pathway criteria, anticoagulation suitability, social support, and follow-up access remain essential.

Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.

Sources

Changelog

April 21, 2026 · trust-baseline
Clinical trust metadata enabled for this tool page with structured review/version fields.

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Frequently Asked Questions

The Pulmonary Embolism Severity Index (PESI) is a validated prognostic scoring tool for confirmed PE. It combines 11 variables — demographics, comorbidities, and physiologic findings — to assign patients to one of 5 risk classes (I through V) with corresponding 30-day mortality estimates. It is used after PE diagnosis to guide level-of-care decisions, prognostication, and outpatient treatment eligibility.

PESI Class I: <66 points, 30-day mortality 0.1–1.6% (very low risk). Class II: 66–85 points, mortality ~3.5% (low risk). Class III: 86–105 points, mortality ~7% (moderate risk). Class IV: 106–125 points, mortality ~11% (high risk). Class V: >125 points, mortality ~24% (very high risk). Classes I–II are the outpatient treatment-eligible zone; Classes IV–V require close inpatient monitoring.

PESI Class I patients (age <50, no comorbidities, normal vitals and mental status) have 30-day mortality <1.6% and are the strongest candidates for outpatient PE treatment. Eligibility also requires: negative troponin, absence of RV dysfunction on CT-PA or echo, no Hestia exclusion criteria, ability to take oral anticoagulation, access to reliable follow-up within 48–72 hours, and adequate home support.

Start with the patient's age in years as the base score. Add: male sex (+10), cancer (+30), heart failure (+10), chronic lung disease (+10), pulse ≥110 bpm (+20), SBP <100 mmHg (+30), respiratory rate ≥30/min (+20), temperature <36°C (+20), altered mental status (+60), SpO2 <90% (+20). If the patient is under 50 with no comorbidities and normal vitals/mental status/SpO2, they are automatically Class I without full scoring.

PESI has a C-statistic of 0.78 for 30-day mortality prediction in the original Aujesky et al. derivation cohort (n=15,531). It performs well at identifying low-risk patients (high negative predictive value in Class I–II) but provides population-level estimates, not individual guarantees. Clinical factors not captured in PESI — such as clot burden, RV strain dynamics, and concurrent illness — should supplement score-based risk assessment.

Online Medical Tools — PESI Score

PESI Score

How It Works

Apply the Class I screening step first

Score all 11 weighted variables

Assign risk class and interpret 30-day mortality

Who Uses the PESI Score

Detailed PE Risk Stratification When sPESI is Indeterminate

Outpatient PE Treatment Eligibility (Classes I–II)

Prognostication Discussion With Patients and Families

Hospital Resource Allocation and Quality Benchmarking

Research and Quality Benchmarking

Pro Tips

PESI Classes I–II = 30-day mortality <3.5% — outpatient treatment eligible

PESI has more granularity than sPESI — use when class-specific mortality matters

Class I–II roughly corresponds to sPESI 0

Altered mental status (60 points) dominates the PESI score

SBP <100 mmHg (30 points) reflects significant cardiovascular compromise

Biomarkers add independent prognostic value beyond PESI

PESI predicts 30-day mortality — not long-term outcomes

PESI Class I screening avoids full calculation in young healthy patients

Common Questions About Your Results

Evidence-Based Methodology

Clinical Content Trust

How to Interpret Your Result

When to Use This Tool

Limitations

Sources

Changelog

Related Tools

sPESI Score

Wells Score (PE)

PERC Rule

Shock Index

Further Reading

A Complete Guide to Emergency Medicine: Decision Tools, Scoring Systems, and Clinical Protocols

Frequently Asked Questions