D-Dimer Testing in Elderly Patients with Comorbidities

Limitations of D-Dimer Testing

D-dimer specificity decreases dramatically with age, reaching as low as 10% in patients over 80 years, making it a less reliable diagnostic tool in elderly patients 1
In patients over 76 years old, D-dimer has severely diminished diagnostic utility due to decreased specificity and potential false positives 1, 4
The use of age-adjusted cutoffs (age × 10 μg/L) does not significantly improve the test's performance in elderly patients with multiple comorbidities 2, 3

Recent sepsis or infection can cause D-dimer to remain elevated for weeks, leading to false positives 1, 3
Chronic kidney disease (CKD) impairs D-dimer clearance, resulting in persistently elevated levels 3
Recent deep vein thrombosis (DVT) can cause D-dimer to be elevated, even after completion of treatment 2, 5
Anemia and recent critical illness are independent factors that can elevate D-dimer levels 1, 4

The American Society of Hematology states that D-dimer has limited utility in hospitalized patients and certain patient populations, including those with recent sepsis or multiple comorbidities 2, 3
The European Society of Cardiology cautions against the use of D-dimer in elderly hospitalized patients, recommending clinical judgement in deciding whether to measure D-dimer 1

For pulmonary embolism evaluation, consider ordering chest X-ray, echocardiogram, or proceeding directly to CT pulmonary angiography (CTPA) if suspicion remains high clinically 2, 3, 6
For DVT evaluation, proximal lower extremity ultrasound is the preferred imaging modality, as recommended by the American College of Radiology 6, 7

Step 1: Obtain proximal leg ultrasound for suspected DVT; if positive, restart anticoagulation 6
Step 2: Assess cardiac causes with BNP, troponin, ECG, and chest X-ray; consider echocardiogram to evaluate pacemaker function and heart failure 3
Step 3: If above workup is negative and PE suspicion persists, proceed directly to CTPA, skipping D-dimer entirely, as recommended by the 2018 ASH guidelines 2, 3, 7