Why this combination matters

Priority Diagnoses (must rule out urgently)

1. Pulmonary Embolism (PE) - the top concern

• Key features: pleuritic pain, dyspnea, tachycardia, hypoxia, low-grade fever, leg swelling/DVT
• Next step: apply Wells or Geneva score, PERC rule; proceed to CT pulmonary angiography if indicated
• Harrison's 22e, Chap. 290; Tintinalli's EM; Rosen's EM

2. Acute Aortic Dissection

• Key features: tearing/ripping pain radiating to the back, pulse/BP differential between arms, wide mediastinum on CXR, hypertension history, Marfan features
• The ADD-RS (Aortic Dissection Detection Risk Score) + D-dimer strategy: ADD-RS of 0 + negative D-dimer = 99.7% sensitivity. A positive D-dimer with any ADD-RS points mandates CT aortography.
• Rosen's EM, p. 1161; Fuster and Hurst's The Heart, 15th ed.

Important Secondary Diagnoses (D-dimer elevated but less immediately life-threatening)

3. Pericarditis

4. Pneumonia / Pleuritis

5. Pneumothorax

6. Esophageal Rupture (Boerhaave Syndrome)

Non-life-threatening causes of elevated D-dimer with chest pain

Clinical Approach Summary

Chest pain + Normal Troponin + Positive D-dimer
          |
          v
  Apply clinical probability scores
  (Wells for PE, ADD-RS for dissection)
          |
  Low probability PE + PERC-negative? --> No further workup needed
  Low-intermediate probability PE?    --> D-dimer effectively rules out
  High probability PE?                --> CT pulmonary angiography (D-dimer is not enough)
  Any suspicion for dissection?       --> CT aortography (do NOT anticoagulate first)
  ECG: diffuse ST-elev + PR dep?      --> Pericarditis workup
  CXR: infiltrate/effusion?           --> Pneumonia, effusion, esophageal rupture

• Normal cutoffs including the age-adjusted formula (age x 10 ng/mL) and the YEARS algorithm threshold
• Life-threatening vs. other causes of a positive result, color-coded for fast scanning
• Rule-out algorithm for PE and aortic dissection with decision branch logic
• Key pitfalls in a warning box - the ones that cause real harm if missed

2026 AHA/ACC PE Guidelines: What's New

• Full guideline in Circulation [PMID: 41712677]

The Biggest Change: A New 5-Category Risk Classification

Key Recommendation Changes

Diagnosis & D-Dimer

• D-dimer remains central to ruling out PE in low-pretest probability patients, balancing "potential harms of testing with the risk of missed diagnosis"
• Age-adjusted D-dimer (age × 10 ng/mL for >50 years) and the YEARS algorithm (D-dimer threshold 1000 ng/mL if no YEARS criteria met) both endorsed
• New: Every patient must have a CT-PA to enter Categories B-E subgroups - which has been criticized as removing the option of ruling in PE via limb ultrasound alone

Biomarkers for Risk Stratification

• Strong recommendation (LOE B-NR): Measure at least 1 cardiac biomarker (troponin or BNP) in Category C patients (symptomatic, no shock) to assess short-term risk
• Strong recommendation (LOE B-NR): Measure lactate in Categories C-E patients at an acute care facility to further stratify mortality risk - this is a new emphasis

Treatment Setting

• More aggressive push for outpatient management of Category B (low-risk) PE when social/clinical criteria are met (Hestia criteria endorsed)
• Category A (incidental PE): individualized anticoagulation decision - not automatic treatment

Anticoagulation

• DOACs over VKAs (warfarin) for eligible patients: strong recommendation
• Apixaban and rivaroxaban are the preferred DOACs (most evidence)

PERT (PE Response Teams)

• New strong recommendation to implement PERTs at acute care facilities when resources permit
• PERTs shown to reduce hospital length of stay and improve decision-making for advanced therapies (catheter-directed thrombolysis, mechanical thrombectomy)

Score Comparison: What the Evidence Now Says

Expert Criticism of the 2026 Guidelines (EMCrit/PulmCrit analysis)

1. PESI blind spot not patched: The ESC 2019 guidelines required low-risk patients to have both a low sPESI and no RV dilation. The 2026 AHA/ACC guidelines omit this requirement, risking misclassification of genuinely sick patients into Category B (undertreated)
2. Troponin vs. BNP conflated: The guideline treats them as equivalent "biomarkers," but troponin is more specific for adverse outcomes. Patients with chronic heart failure (elevated BNP, normal troponin) may be falsely triaged to a higher-risk category
3. Three competing severity scores allowed: The guideline endorses PESI, sPESI, or Bova to define Category C - using different scores in practice will produce contradictory classifications between providers
4. CT-PA required for all: Requiring CT-PA even in Category B subcategorization removes the option of diagnosing PE via compression ultrasound alone (the ESC 2019 approach), leading to more contrast and radiation exposure in otherwise low-risk patients

How This Compares to ESC 2019 (still in use in Europe)

Bottom Line for Practice

• The 2026 AHA/ACC guideline is the current US standard for acute PE management
• The new A-E categories add nuance at both ends (incidental PE and refractory shock) but the intermediate categories remain contested
• Use 3-tier Revised Geneva or 3-tier Wells for pretest probability (per the 2025 meta-analysis)
• DOACs first, measure troponin + lactate in intermediate/high-risk patients
• Push for outpatient treatment in Category B when Hestia criteria are met
• If your institution doesn't have a PERT yet, the 2026 guideline makes it a formal quality benchmark