In a patient presenting with chest pain, should I obtain a D‑dimer to evaluate for pulmonary embolism?

Should You Order D-Dimer in a Patient Presenting with Chest Pain?

Yes, you should order a D-dimer in most patients presenting with chest pain when pulmonary embolism is being considered, but only after first establishing their pretest probability using validated clinical prediction rules—and never in patients who meet all PERC criteria or those with high clinical probability. 1

Step 1: Apply PERC Criteria First (Low Probability Patients Only)

• If the patient meets ALL 8 Pulmonary Embolism Rule-Out Criteria (PERC), do NOT order D-dimer or any imaging—the risk of PE is lower than the risks of testing itself. 1, 2
• PERC criteria include: age <50, heart rate <100, oxygen saturation ≥95%, no hemoptysis, no estrogen use, no prior DVT/PE, no unilateral leg swelling, and no recent surgery/trauma. 1, 3
• This approach safely excludes PE without any testing in truly low-risk patients. 2

Step 2: Calculate Clinical Probability Using Validated Scores

• Use either the Wells score or revised Geneva score to stratify pretest probability before ordering any tests. 1, 3
• These validated tools categorize patients into low, intermediate, or high clinical probability groups, which determines the appropriate diagnostic pathway. 1
• Clinical gestalt alone is acceptable if you're experienced, but validated scores reduce variability and are preferred. 1

Step 3: D-Dimer Decision Algorithm Based on Clinical Probability

Low or Intermediate Probability (Wells ≤6 or Geneva ≤10):

• Order a high-sensitivity D-dimer as the initial diagnostic test—this is the appropriate first step, NOT imaging. 1
• If D-dimer is negative (using age-adjusted cutoffs for patients >50 years: age × 10 ng/mL), PE is safely excluded without imaging. 1
• The 3-month thromboembolic risk with negative D-dimer in low-moderate probability patients is <1%, making it safe to withhold anticoagulation. 4, 3
• If D-dimer is positive, proceed immediately to CT pulmonary angiography (CTPA). 1, 3

High Probability (Wells >6 or Geneva >10):

• Do NOT order D-dimer—proceed directly to CTPA. 1, 3
• In high-risk patients, even a negative D-dimer cannot safely exclude PE due to the high pretest probability (31-50% prevalence). 1, 5
• The high prevalence lowers the negative predictive value of D-dimer below acceptable thresholds. 5

Critical Age-Adjusted D-Dimer Interpretation

• For patients over 50 years old, use the formula: age × 10 ng/mL as the cutoff rather than the standard 500 ng/mL. 1
• This age-adjusted approach increases the proportion of elderly patients in whom PE can be safely excluded from 6.4% to 30% without missing cases. 3, 6
• D-dimer specificity drops to only 10% in patients >80 years using standard cutoffs, leading to excessive false positives. 3, 6

Populations Where D-Dimer Has Limited Utility

• D-dimer testing is of very limited value in hospitalized patients, post-surgical patients, pregnant women, and cancer patients due to high false-positive rates regardless of PE status. 1, 3, 6, 7
• In hospitalized patients, D-dimer allows PE exclusion in <10% of cases compared to 36% in emergency department patients. 3, 7
• In one study of inpatients with suspected PE, only 10.6% had negative D-dimer results, severely limiting clinical utility. 7

Common Pitfalls to Avoid

• Never use a positive D-dimer alone to diagnose PE—confirmation with CTPA is always required, as D-dimer has only 35-50% specificity. 3, 6
• Never skip clinical probability assessment—ordering D-dimer without risk stratification leads to overuse and unnecessary imaging. 1
• Never order imaging as the initial test in low-intermediate probability patients—D-dimer should come first to avoid unnecessary radiation and contrast exposure. 1
• Never order D-dimer in PERC-negative patients—this violates evidence-based guidelines and exposes patients to unnecessary downstream testing. 1, 2

What Happens After D-Dimer Results

• Negative D-dimer (below age-adjusted threshold) in low-intermediate probability: Stop—PE is excluded, no imaging needed. 1
• Positive D-dimer in any probability group: Proceed to CTPA immediately. 1, 3
• High probability patients: Skip D-dimer entirely and go straight to CTPA. 1, 3

The Evidence Hierarchy

The most recent and authoritative guidelines (American College of Physicians 2015, ACR 2022) consistently recommend this risk-stratified approach. 1 The 2025 research by Failure rate study further validated that even in high-risk patients, age-adjusted D-dimer can be safe (0% failure rate), though the confidence interval was wide and current guidelines still recommend against this practice. 5 Follow the established guidelines: use D-dimer in low-intermediate probability patients only, never in high probability or PERC-negative patients. 1