Further Workup of Elderly Female with Chest Pain, Anxiety, and D-dimer 0.53 mg/L
This patient requires immediate CT pulmonary angiography (CTPA) to rule out pulmonary embolism, as the D-dimer is elevated above the standard 0.5 mg/L threshold and she presents with chest pain—a high-risk symptom that mandates imaging regardless of anxiety as a potential confounding factor. 1
Clinical Decision Algorithm
Step 1: Assess Clinical Probability
- Calculate a validated clinical probability score (Wells score or revised Geneva score) to stratify this patient's pre-test probability of pulmonary embolism (PE), as the combination of chest pain and elevated D-dimer warrants systematic risk assessment 1, 2
- The presence of anxiety does not exclude PE and should not delay appropriate workup, as anxiety can be both a symptom of PE and a confounding presentation 1
Step 2: Interpret the D-dimer Result
- At 0.53 mg/L, this D-dimer is elevated above the standard cutoff of 0.5 mg/L, which has 99.5% sensitivity for PE and cannot safely exclude the diagnosis 3
- However, consider age-adjusted D-dimer cutoff (patient's age × 10 μg/L) if she is over 50 years old, as this improves specificity from ~10% to 30% in elderly patients without compromising safety 1, 2
- If she is 53 years old, her age-adjusted cutoff would be 530 μg/L (0.53 mg/L), making this a borderline result
- If she is older than 53, this D-dimer would be considered negative by age-adjusted criteria
Step 3: Determine Next Diagnostic Step Based on Clinical Probability
If Low Clinical Probability AND Age-Adjusted D-dimer is Negative:
- PE can be safely excluded without imaging 1, 2
- The 3-month thromboembolic risk is <1% in this scenario 1
- Focus workup on alternative causes of chest pain (cardiac ischemia, anxiety disorder, musculoskeletal pain)
If Low-to-Intermediate Clinical Probability AND D-dimer is Positive (using appropriate cutoff):
- Proceed directly to CTPA as the definitive test for PE 1, 2
- A positive D-dimer in this range (0.53 mg/L) has only 10.7% positive predictive value for PE, but imaging is mandatory to confirm or exclude the diagnosis 4
If High Clinical Probability:
- Proceed directly to CTPA without relying on D-dimer, as D-dimer has poor negative predictive value in high-risk patients 1, 5
Critical Consideration: Rule Out Aortic Dissection
- Evaluate for aortic dissection risk factors given the chest pain presentation, as D-dimer >0.5 μg/mL has 100% sensitivity for acute aortic dissection in multiple studies 1
- If the patient has sudden-onset severe chest or back pain, pulse differential, blood pressure differential, or widened mediastinum on chest X-ray, obtain CT angiography of the chest, abdomen, and pelvis to evaluate for dissection 1
- The median D-dimer in aortic dissection is 1.80 μg/mL, but levels as low as 0.42 μg/mL have been seen in patients without dissection 1
Alternative Diagnoses to Consider
If imaging is negative for PE/dissection:
- Cardiac evaluation for acute coronary syndrome, especially given chest pain in an elderly patient
- Infection/sepsis workup, as 24% of patients with elevated D-dimer have sepsis 6
- Occult malignancy screening if D-dimer remains unexplained, as 29% of patients with extremely elevated D-dimer (>5 mg/L) have cancer, though this patient's level is not in that range 6
- Heart failure assessment, as this is significantly associated with elevated D-dimer 7
Common Pitfalls to Avoid
- Never attribute elevated D-dimer solely to anxiety without excluding life-threatening causes—anxiety may coexist with PE or dissection 1, 2
- Never use positive D-dimer alone to diagnose thromboembolism—imaging confirmation is mandatory 2, 8
- Do not skip D-dimer testing in hospitalized or acutely ill elderly patients if they have low clinical probability, though recognize specificity drops to ~10% in patients >80 years 1, 5
- Do not order repeat D-dimer testing if initial imaging is negative and symptoms resolve—this adds no clinical value 2