D-dimer: a characteristic of the coagulation state of each patient with chronic atrial fibrillation

Abstract

Background and objective: It is accepted that patients with atrial fibrillation (AF) are characterised by increased levels of plasmatic D-dimers, with a wide inter-individual variability depending on the patients and therapeutic characteristics, but it has not been established if this level was predictive of the risk of arterial thromboembolic event. In order to answer such a question, it has to be established if the D-dimer level in a given patient is characteristic of such a patient (stable over time) if also fluctuating with time (and useless to characterise the patient).

Methods and results: One hundred thirty clinically stable patients with chronic AF were recruited (anticoagulant: group 1, antiaggregant aspirin: group 2, no antithrombotic: group 3). During the follow-up of patients without clinical events (n=63), it is notable that in patients with D-dimer levels <500 ng/ml, these remained <1000 ng/ml, in patients with levels between 500 and 1000 ng/ml, these did not reach 1590 ng/ml, and in those with D-dimers >1000 ng/ml, the levels remained relatively stable. Mean age and D-dimer levels were lower in group 1 (74.4 years and 509.1 ng/ml, respectively) than in group 2 (82.4 years, p=0.0003 and 1015.7 ng/ml, p<0.0001, respectively) and in group 3 (79.3 years and 1289.3 ng/ml, p<0.0001, respectively). The effect of the antithrombotic therapy was independent of the age of patients (p=0.017).

Conclusion: D-dimer levels in patients with chronic AF remain in the same range over time. They are lower on anticoagulant therapy than on antiaggregant or no antithrombotic therapy, irrespective of age. Thus, D-dimers appear to be a useful parameter for assessing the degree of hypercoagulability of patients whatever their age.