Association of anticoagulant and antiplatelet therapy with acute cerebral infarction in patients presenting with isolated vertigo or dizziness: A retrospective cohort study.

backgroundAcute cerebral infarction (ACI) is a critical concern in patients presenting with isolated vertigo or dizziness (IVD). The use of antiplatelet or anticoagulant agents may influence the incidence of ACI in both protective and adverse directions, due to their preventive effects and associated comorbidities. This study aimed to determine the incidence of ACI among emergency department (ED) patients with IVD, stratified by the use of antiplatelet and anticoagulant medications. We also evaluated the association between antiplatelet and anticoagulant therapies and ACI incidence.

methodsThis was a retrospective cohort study. ED patients with IVD over four consecutive years were identified. The main outcome was ACI, which was determined by brain magnetic resonance imaging with diffusion-weighted imaging (bMRI-DWI). The primary independent variable was the use of antiplatelet or anticoagulant medications, which was categorized into two models. In Model 1, patients were divided into three groups: a no-medication group (patients who did not take any antiplatelet or anticoagulant agents), an antiplatelet group (patients who took aspirin or clopidogrel but no anticoagulants), and an anticoagulant group (patients who took warfarin or non-vitamin K antagonist oral anticoagulants [NOACs], regardless of concurrent antiplatelet use). Model 2 provided a more detailed classification of medication use: no-medication group, aspirin-only group, clopidogrel-only group, aspirin and clopidogrel group, and anticoagulant group. In addition, based on whether comorbidities were adjusted for, the multiple logistic regression models were categorized into Model A (without adjustment for comorbidities) and Model B (with adjustment for comorbidities). A total of four multivariable logistic regression models were developed for analysis.

resultsAmong the 1,875 patients enrolled, 153 (8.2%) were diagnosed with ACI. The incidence of ACI was 6.7% (74/1,104) in the no-medication group, 8.8% (59/670) in the antiplatelet group, and 19.8% (20/101) in the anticoagulant group. In the more detailed classification, the incidence was 7.4% (28/377) in the aspirin-only group, 6.6% (10/152) in the clopidogrel-only group, and 14.9% (21/141) in the dual antiplatelet group (aspirin and clopidogrel). In all four multivariable models, the use of anticoagulants emerged as an independent predictor of ACI (adjusted odds ratio [AOR], 2.46; 95% confidence interval [CI], 1.20-5.08; p = 0.014 in Model 2B). The dual antiplatelet group was significantly associated with ACI in Model 2A (AOR, 1.74; 95% CI, 1.02-2.97; p = 0.044), but this association was no longer significant after adjusting for comorbidities in Model 2B (AOR, 1.34; 95% CI, 0.77-2.34; p = 0.297). The antiplatelet group, aspirin-only group, and clopidogrel-only group were not significantly associated with ACI occurrence in any model.

conclusionNearly 20% of patients in the anticoagulant group and 15% in the dual antiplatelet group (aspirin and clopidogrel) experienced ACI among ED patients with IVD. The use of anticoagulants was a significant predictor of ACI occurrence. The association between dual antiplatelet therapy and ACI lost statistical significance after adjusting for comorbidities. These two medication groups may serve as clinical proxies for elevated ACI risk in ED patients presenting with IVD.