Age-Adjusted Cutoff D-Dimer Level to Rule Out Acute Pulmonary Embolism A validation cohort study.
Am J Med. 2016 Apr 1;
Authors: Fuchs E, Asakly S, Karban A, Tzoran I
BACKGROUND: The diagnosis of pulmonary embolism in the Emergency Room setting is challenging. Multiple patients have to undergo radiological assessment with its inherent shortcomings. The D-dimer test with accepted cutoff level of 500μg/L is associated with a high proportion of false positive results. The current study aimed to validate the advantages of using an age-adjusted D-dimer cutoff level, compared to 500μg/L value in the diagnosis of acute pulmonary embolism.
METHODS: This study evaluated patients admitted to the Rambam Emergency Room between 2011and 2014 with a suspected diagnosis of pulmonary embolism. Patient data, D-dimer plasma levels and imaging results were collected. The study cohort was subdivided according to the D-dimer levels below and above 500μg/L. The group with the levels above 500μg/L was further assessed using the newly suggested age-adjusted D-dimer cutoff level, defined as age multiplied by 10.
RESULTS: Files of 1241 patients were reviewed; 654 patients with low or intermediate risk for pulmonary embolism had a D-dimer level above 500μg/L. 208 patients had a D-dimer level above 500μg/L but below the age-adjusted cutoff value; one of them was diagnosed with pulmonary embolism (0.48% [95% CI, 0%-2.6%]). 446 patients had a D-dimer level above the age-adjusted cutoff value and 28 of them were diagnosed with pulmonary embolism (6.28% [CI, 4.2%-8.9%]), representing a negative predictive value of 99.5% for the age-adjusted cutoff level.
CONCLUSIONS: Age-adjusted D-dimer cutoff level may be safely used to exclude pulmonary embolism in patients with a low or intermediate probability for acute pulmonary embolism, alleviating the need to perform unnecessary imaging evaluations.
PMID: 27046241 [PubMed - as supplied by publisher]