Choi KH, Kim JH, Kim JM, et al. - In the present study, the researchers sought to examine the value of D-dimer levels in anticipating recurrent stroke in patients with embolic stroke of undetermined source, as well as to evaluate the underlying causes of recurrent stroke based on D-dimer levels. In total, 1,431 patients with undetermined source were recruited in this investigation and divided into quartiles according to their baseline plasma D-dimer levels. Multivariate analysis showed that patients in Q3 and Q4 had a significantly increased risk of recurrent stroke compared with those in Q1. Binary analyses displayed a significant link between a high D-dimer level above normal range and the risk of recurrent stroke. The findings imply that D-dimer levels could be a useful risk assessment biomarker for anticipating recurrent stroke, particularly embolic ischemic stroke, in patients with undetermined source.