Effect of Dual- versus Single-Antiplatelet Therapy on Early Neurological Deterioration in Minor Stroke of Undetermined Cause

Abstract

Background. There is insufficient evidence about the suitability of dual-antiplatelet therapy (DAPT) for different stroke subtypes. We aimed to determine the relationship between DAPT and early neurological deterioration (END) in patients with minor stroke of undetermined cause. Methods. We retrospectively collected data on patients with minor stroke treated with aspirin alone or in combination with clopidogrel and aspirin. Efficacy was the incidence of END defined as the National Institutes of Health Stroke Scale score increase of ≥2 within 7 days after admission. Safety was defined as the rate of any bleeding event. These were investigated in subtypes including the stroke of undetermined cause (SUC), large artery atherosclerosis (LAA), cardioembolism (CE), and small artery occlusion (SAO). Results. 442 patients were assigned to the SUC ( $n=91$ ), LAA ( $n=157$ ), CE ( $n=30$ ), and SAO ( $n=164$ ) groups. The incidences of END were not significantly different between patients treated with dual- versus single-antiplatelet therapy in any stroke subtypes: LAA, 17.6% vs. 12.1% ( $P=0.348$ ); CE, 0% vs. 20.0% ( $P=0.224$ ); SAO, 8.8% vs. 2.4% ( $P=0.093$ ); and SUC, 13.6% vs. 2.1% ( $P=0.053$ ). Multivariable analysis showed that after adjusting for confounding factors, DAPT was the independent factor associated with END (odds ratio 13.39, 95% confidence interval (1.16-154.81), $P=0.038$ ) in the SUC group, rather than the LAA, CE, and SAO groups. Conclusion. Combined clopidogrel and aspirin is a risk factor for the rate of END only in minor stroke patients with the SUC subtype. This suggests that cryptogenic stroke may not be suitable for DAPT in the acute phase.