Abstract 2559: Subgroup analysis of the Cilostazol Stroke Prevention Study 2 (CSPS 2)
Background: Cilostazol has been suggested to be superior to aspirin in secondary stroke prevention in patients with non-cardioembolic ischemic stroke from the results of the CSPS 2 and meta-analysis of the Cochrane Collaboration. The purpose of this study was to investigate the efficacy and safety of cilostazol and aspirin in the various subgroups of the study population.
Methods: Recurrence of stroke was studied in the subgroup analysis according to patient's characteristics, concomitant use of drugs, and ischemic stroke subtypes. Heterogeneity of stroke risk between subgroups classified by each variable was analyzed using Log-rank test.
Results: A total of 2672 Japanese patients enrolled in the CSPS 2 (Lancet Neurol 2010;9:959-68) were analyzed. A tendency of interaction was observed in alcohol drinking (p=0.0782) and dyslipidemia (p=0.0873). Stroke rates in alcohol drinkers (HR 0.574, 95% CI 0.386-0.855) and non-dyslipidemic patients (HR 0.608, 95% CI 0.426-0.869) were lower in the cilostazol group than in the aspirin group. A significant interaction was demonstrated in the use of angiotensin receptor blocker (ARB) (p=0.0267). Stroke rate in non-users of ARB was lower in the cilostazol group than in the aspirin group (HR 0.542, 95% CI 0.370-0.793), while it was not different between both groups in users of ARB (HR 1.016, 95% CI 0.677-1.524). There was no significant difference in the rate of ischemic stroke between both treatment groups in patients with atherothrombotic stroke (cilostazol 1.77%/year, aspirin 2.45%/year, p=0.2808) and lacunar stroke (cilostazol 2.68%, aspirin 2.88%/year, p=0.7198). The rate of hemorrhagic stroke was not different between both groupsin patients with atherothrombotic stroke (cilostazol 0.31%/year, aspirin 0.59%/year, p=0.3444), while it was significantly much lower in the cilostazol group (0.36%/year) than in the aspirin group (1.20%/year) (RRR 65.0%, p=0.0030) among patients with lacunar stroke.
Conclusion: Superiority of cilostazol over aspirin in secondary stroke prevention tended to be more obvious in alcohol drinkers and non-dyslipidemics. A significant interaction was observed in the concomitant use of ARB, which might be related to pleiotropic effects of cilostazol and ARB. Cilostazol has an advantage over aspirin in lower risk of cerebral hemorrhage especially in Japanese patients with lacunar stroke.
- © 2012 by American Heart Association, Inc.