Antithrombotic strategies after cryptogenic stroke: a systematic review, pairwise, and network meta-analysis of randomized controlled trials

Abstract Background No definite etiology is identified in 30-40% of ischemic stroke cases, which is known as cryptogenic stroke. Several antithrombotic strategies have been investigated for cryptogenic stroke management; however, the optimal strategy remains unknown. Purpose We aim to assess the efficacy and safety of oral anticoagulants (OACs) versus aspirin, and the comparative efficacy and safety of different OACs after cryptogenic stroke. Methods A systematic review and meta-analysis synthesizing evidence from randomized controlled trials (RCTs) obtained from PubMed, Embase Cochrane, Scopus, and WOS until February 2024. We used the fixed-effects model to report dichotomous outcomes using a risk ratio (RR), with a 95% confidence interval (CI). Analysis was conducted using R, version 4.2.0. Results Seven RCTs with 15.240 patients were included. In pairwise analysis, there was no difference between OACs and aspirin regarding all-cause mortality (RR: 1.13, CI [0.89, 1.43], P= 0.33) and stroke recurrence (RR: 0.93, CI [0.82, 1.07], P= 0.31). However, OACs were associated with a significantly increased incidence of major bleeding (RR: 1.6, CI [1.24, 2.05], P= 0.01), with no difference regarding the incidence of intracranial hemorrhage (RR: 1.09, CI [0.3, 3.97], P= 0.9). Moreover, in network analysis, none of the OACs showed a significant efficacy in preventing all-cause mortality and stroke recurrence compared to aspirin. However, only rivaroxaban significantly increased the incidence of major bleeding (RR: 2.69, CI [1.67, 4.33]). Conclusion OACs did not protect against stroke recurrence or decrease the incidence of all-cause mortality but increased the incidence of major bleeding in patients with cryptogenic stroke.