Cilostazol

Global estimates suggest that sub-Saharan Africa (SSA) now has the highest incidence, prevalence, and worst survival outcomes of stroke. With an estimated 1.4 million stroke survivors, outcomes of stroke in SSA are abysmal with 1-month case fatality at 30% and 3-year mortality rate of 84%. Stroke survivors in Africa are at an inordinately high (and worsening) risk of adverse outcomes including recurrent stroke and cardiac events over the medium- to longterm. Given the paucity of resources in the region, testing of therapies, which are potentially highly clinically efficacious and cost-effective, while developing local stroke research capacity and contributing to the global secondary stroke prevention evidence base, is urgently needed. Cilostazol, a phosphodiesterase 3 inhibitor, has shown promising efficacy and safety mainly among an Asian population by cutting risk of major adverse cardiovascular events including stroke, in half, when added to aspirin or clopidogrel (8% vs. 4%, HR 0.52, 95% CI 0.35-0.77), with no increased risk in bleeding or serious adverse events. Cilostazol's potentially strong efficacy, presumed pleiotropic effects, and relatively low cost, make it a highly appealing agent for use in stroke-prone, low-resource settings. Therefore, the overall objective of the CiLostAzol for pReventIon of recurrent sTroke in Africa (CLARITY-AFRICA) study is to deploy a hybrid study design to demonstrate the efficacy and safety of cilostazol twice daily in reducing MACE over 24 months vs. placebo among 1100 recent stroke patients encountered at 12 hospitals in Ghana. Secondly, CLARITY-AFRICA also seeks to develop an implementation strategy for routine integration and policy adoption of cilostazol for post-stroke cardiovascular risk reduction in an under-resourced system. Given its compelling efficacy among a predominantly Asian population, the National Institute of Neurological Disorders and Stroke (NINDS) is poised to fund a US-based clinical trial to assess the longer-term efficacy and safety of cilostazol in a study titled CiLostAzol for pReventIon of recurrent sTroke (CLARITY). The investigators are also aware that European and Australian funding agencies are considering stroke trials of cilostazol. A concurrently executed CLARITYAfrica trial would allow recruitment of a historically underrepresented and high-risk group (Africans), test a therapy that if efficacious could be affordable for broader regional implementation, permit transcontinental mentorship/collaborations, and leverage NINDS impending investment. CLARITY-AFRICA will assess implementation outcomes such as adoption, acceptability, cost, pertinent to uptake of cilostazol in Ghana to inform policy. Regardless of its outcome, findings from CLARITYAFRICA will contribute meaningful information from the African perspective to inform the formulation of guidelines for global adoption of cilostazol into routine care for secondary CVD risk prevention by international bodies such as the World Health Organization. This application will focus on the first 2 aims of CLARITY-AFRICA to conduct the trial and assess secondary outcomes.

Through a single-center retrospective cohort study of acute ischemic stroke (AIS) patients receiving secondary prevention with indobufen, clopidogrel, cilostazol, or aspirin as monotherapy or dual therapy, we aim to compare the real-world effectiveness and safety of these four antiplatelet regimens. Through closely tracking the recurrence of stroke (including ischemic and hemorrhagic stroke) and bleeding events (GUSTO-defined) within one year of treatment, we evaluate the association between each antiplatelet agent and the risk of stroke recurrence, thereby providing critical evidence to guide individualized antiplatelet therapy in AIS patients.