The following is a summary of “D-dimer measurement is useful irrespective of time from the onset of acute aortic syndrome symptoms,” published in the September 2023 issue of Emergency Medicine by Otani, et al.

In screening acute aortic syndrome (AAS), D-dimer is a recognized biomarker, but the timing of its measurement has yet to be extensively studied. For a study, researchers sought to assess the effectiveness of D-dimer-based AAS screening concerning the time elapsed between the onset of AAS symptoms and the measurement of D-dimer.

A retrospective analysis was conducted on consecutive patients diagnosed with AAS who visited a hospital between 2011 and 2021. For the primary analysis, patients were categorized based on quartiles of the time interval between the onset of AAS symptoms and the D-dimer measurement. A D-dimer level of ≥0.5 μg/mL and an age-adjusted D-dimer level of ≥[age (years) × 0.01] μg/mL (with a minimum of 0.5 μg/mL) were considered positive. The primary endpoint was to compare D-dimer’s ability to detect AAS within and across each time quartile. In an exploratory secondary analysis, patient and AAS characteristics were reported for the subgroup of patients with D-dimer measurements repeated within 48 hours of the initial measurement.

The 273 AAS patients were divided into four groups based on quartiles of the time interval (Group 1: ≤1 hour; Group 2: 1–2 hours; Group 3: 2–5 hours; and Group 4: >5 hours). No significant differences were observed in D-dimer levels or the proportions of positive D-dimer (Group 1: 97%, Group 2: 96%, Group 3: 99%, Group 4: 99%; P = 0.76) or positive age-adjusted D-dimer (Group 1: 96%, Group 2: 90%, Group 3: 96%, Group 4: 97%; P = 0.32) between the groups. Among the 147 patients who underwent repeat D-dimer measurements, nine had negative D-dimer levels in either the primary or secondary measurements. Of these nine patients, eight had AAS with a thrombosed false lumen, and one patient with a patent false lumen had a short dissection length. In all nine patients, D-dimer levels remained low (maximum of 1.4 μg/mL).

Elevated D-dimer levels were detected early in AAS. The clinical utility of D-dimer was not influenced by the time elapsed between the onset of AAS and D-dimer measurement. Still, it was instead affected by the characteristics of AAS.

Source: sciencedirect.com/science/article/abs/pii/S0735675723002942