Cilostazol stroke prevention study: A placebo-controlled double-blind trial for secondary prevention of cerebral infarction

Beneficial effect of cilostazol-mediated neuronal repair following trimethyltin-induced neuronal loss in the dentate gyrus

Cilostazol acts as an antiplatelet agent and has other pleiotropic effects based on phosphodiesterase-3-dependent mechanisms. We evaluated whether cilostazol would have a beneficial effect on neuronal repair following hippocampal neuronal damage by using a mouse model of trimethyltin (TMT)-induced neuronal loss/self-repair in the hippocampal dentate gyrus [Ogita et al. (2005) J Neurosci Res 82:609-621]; these mice will hereafter be referred to as impaired animals. A single treatment with cilostazol (10 mg/kg, i.p.) produced no significant change in the number of 5-bromo-2'-deoxyuridine (BrdU)-incorporating cells in the dentate granule cell layer (GCL) or subgranular zone on day 3 after TMT treatment. However, chronic treatment with cilostazol on days 3-15 posttreatment resulted in an increase in the number of BrdU-incorporating cells in the dentate GCL of the impaired animals, and these cells were positive for neuronal nuclear antigen or doublecortin. Cilostazol was effective in elevating the level of phosphorylated cyclic adrenosine monophosphate response element-binding protein (pCREB) in the dentate gyrus of impaired animals. The results of a forced swimming test revealed that the chronic treatment with cilostazol improved the depression-like behavior seen in the impaired animals. In the cultures of hippocampal neural stem/progenitor cells, exposure to cilostazol produced not only enhancement of proliferation activity but also elevation of pCREB levels. Taken together, our data suggest that cilostazol has a beneficial effect on neuronal repair following neuronal loss in the dentate gyrus through promotion of proliferation and/or neuronal differentiation of neural progenitor cells in the subgranular zone.

Advancements in understanding the mechanisms of symptomatic lacunar ischemic stroke: translation of knowledge to prevention strategies

Symptomatic lacunar ischemic stroke (25% of all brain infarctions) results from occlusion of a single penetrating artery by microatheromas or lipohyalinosis and rarely from an intracranial atheromatous branch disease. Recurrent lacunar stroke may be associated with more severe clinical features and has been involved in producing lacunar state and vascular subcortical dementia. In the first multicenter randomized clinical trial (SPS3) focused on stroke prevention among patients with recent lacunar stroke, the addition of clopidogrel to aspirin not only did not reduced significantly the risk of recurrent stroke, but also increased significantly the likelihood of hemorrhage and fatal outcome. If lacunar stroke is primarily non-atherothromboembolic, secondary prevention aimed at preventing atheroma progression may not be very effective. The efficacy of drugs that improve endothelial function in lacunar stroke patients remains to be studied in the future.

Cilostazol: improving walking distance in patients with intermittent claudication

Intermittent claudication is a common, disabling symptom of peripheral arterial disease that limits walking distance and is associated with an increased cardiovascular risk of acute limb- or life-threatening complications. Very few patients with intermittent claudication (<7%) are suitable candidates for surgical revascularization, yet in contrast to the treatment of stable angina, few effective medical therapies (apart from exercise) are available for the symptomatic relief of intermittent claudication. The phosphodiesterase-3 inhibitor, cilostazol (Pletal, Otsuka Pharmaceuticals Ltd), is the first symptom-relieving treatment for intermittent claudication that has been evaluated successfully in large multicenter placebo-controlled, double-blind clinical trials (involving >2000 patients). A meta-analysis of the eight major efficacy studies with cilostazol has shown significant improvements in pain-free and maximum walking distance, and a good overall safety and tolerability profile. Thus, in the UK, USA and Japan, cilostazol administered at 100 mg twice daily is licensed for symptom relief in patients with stable, moderate-to-severe intermittent claudication, as an adjunct to nonpharmacological approaches such as exercise.

Systematic study of cilostazol on secondary stroke prevention: a meta-analysis

BACKGROUND

To study the efficacy and safety of cilostazol on ischemic stroke prevention and treatment, systematic reviews of related clinical randomized controlled trials were analyzed.

METHODS

We searched the main databases for eligible trials including literature from January 1966 to November 2012 in MEDLINE, reports from 1980 to November 2012 in EMBASE, and all the studies published in EBSCO, Springer, Ovid, and Cochrane library citations. We also searched for keywords, including cilostazol and aspirin. RewMan 5.0 software was used to conduct the meta-analysis.

RESULTS

Our search yielded five eligible trials. The effects of cilostazol and aspirin on ischemic stroke prevention and treatment were almost equal (combined odds ratio (OR) 0.78, 95% confidence interval (CI) (0.59, 1.04)). Additionally, both magnetic resonance angiography (MRA) and transcranial Doppler (TCD) examination showed that cilostazol could significantly decrease the incidence of intracranial artery stenosis exacerbation (MRA: combined OR 0.22, 95% CI (0.07, 0.68); TCD: combined OR 0.17, 95% CI (0.05, 0.51)). In terms of adverse reactions, there were slightly fewer incidences of major bleeding with cilostazol than with aspirin (combined OR 0.38, 95% CI (0.24, 0.60)), and there was no difference in the number of heart palpitations between cilostazol and aspirin. However, the incidence of gastrointestinal disorders, dizziness, and headaches caused by cilostazol was greater.

CONCLUSIONS

Cilostazol might be a more effective and safer alternative to aspirin for patients with ischemic stroke. Further studies are required to confirm whether cilostazol is a suitable therapeutic option for secondary stroke prevention in larger cohorts of patients with ischemic stroke.

Meta-analysis of cilostazol versus aspirin for the secondary prevention of stroke

Aspirin is the most widely prescribed antiplatelet agent for the secondary prevention of stroke. Cilostazol, an antiplatelet and vasodilating agent, has shown promise for the secondary prevention of stroke. A systematic review and meta-analysis of randomized controlled trials using Ovid MEDLINE, PubMed, and Excerpta Medica (EMBASE) was searched up to October 2012. Four trials, in 3,917 patients, comparing cilostazol with aspirin were identified. Compared with aspirin, cilostazol was associated with a 73% reduction in hemorrhagic stroke (relative risk [RR] 0.27, 95% confidence interval [CI] 0.13 to 0.54, p = 0.0002), 28% reduction in the composite end point of stroke, myocardial infarction, or vascular death (RR 0.72, 95% CI 0.57 to 0.89, p = 0.003), and 48% reduction in total hemorrhagic events (RR 0.52, 95% CI 0.34 to 0.79, p = 0.002), with trend for lesser gastrointestinal bleeds (RR 0.60, 95% CI 0.34 to 1.06, p = 0.08). In conclusion, compared with aspirin, cilostazol is associated with significantly less hemorrhagic stroke, the combined end point of stroke, myocardial infarction, and vascular death, and total hemorrhagic events, with numerically fewer gastrointestinal bleeds when used for the secondary prevention of stroke.

Pilot study of the safety of starting administration of low-dose aspirin and cilostazol in acute ischemic stroke

Progressive stroke is a serious problem due to the associated morbidity and mortality. Aspirin is recommended for acute ischemic stroke, but does not reduce the frequency of stroke progression. No standard treatment has been approved for the prevention of stroke progression. Cilostazol, which reduces platelet aggregation about 3 hours after single administration, does not increase the frequency of bleeding events when compared with aspirin or a placebo. Moreover, the combination of 100 mg aspirin and 200 mg cilostazol does not increase the frequency of bleeding events compared with only 100 mg aspirin, and thus is expected to prevent stroke progression with a high degree of safety. The present study investigated the safety of this combination of two drugs administered at the above concentrations in 54 patients with acute ischemic stroke within 48 hours of stroke onset. Modified National Institutes of Health Stroke Scale (NIHSS) measurements were performed at baseline and again on day 4 to 7. Progressive stroke was defined as an increase greater than or equal to 1 point on NIHSS. Patient scores on the modified Rankin Scale (mRS) were evaluated at baseline and 3 months after enrollment. Stroke progression occurred in 11.1% of the patients. The percentages of patients with mRS score from 0 to 2 were 42.6% and 75% at baseline and 3 months, respectively. No symptomatic intracranial hemorrhage or major extracranial hemorrhage occurred. These results suggest that administration of aspirin and cilostazol is safe for acute ischemic stroke.

Platelet antiaggregants in stroke prevention

Antiplatelet agents are one of the main interventions for recurrent ischemic stroke prevention. Their time of use, dosage, and combination of therapy have different effects in terms of stroke risk reduction and adverse effects. This review provides an evidence-based update of the latest on antiplatelet therapy for stroke prevention.

Cilostazol for the prevention of acute progressing stroke: a multicenter, randomized controlled trial

BACKGROUND

Progressing stroke is one of the major determinants of outcome after acute ischemic stroke. A pilot randomized controlled trial was conducted to investigate the effect of cilostazol on progressing stroke.

METHODS

Adult patients with noncardioembolic ischemic stroke within 24 hours after onset were randomized to receive cilostazol 200 mg/day (cilostazol group) or no medication (control group) in addition to the optimum medical treatments (a free radical scavenger plus an antiplatelet agent or an antithrombin agent). The primary endpoints were the rate of progressing stroke, defined as aggravation of the National Institutes of Health Stroke Scale (NIHSS) score by ≥ 4 points on days 3 and/or 5 and a modified Rankin Scale score of 0 to 1 at 3 months after enrollment. Aggravation caused by systemic complications, edema, hemorrhagic infarction, or recurrent stroke was not considered as progressing stroke. This trial was registered as UMIN000001630.

RESULTS

A total of 510 patients were enrolled from 55 institutions in Japan between February 2009 and July 2010. The rate of progressing stroke was 3.2% and 6.3% in the cilostazol and control groups, respectively (P = .143). The modified Rankin Scale score of 0 to 1 at 3 months did not differ between the groups.

CONCLUSIONS

Cilostazol failed to show a preventive effect against acute progressing stroke. However, the tendency to reduce progressing stroke and the results of stratified analyses may encourage additional studies to clarify the effect of cilostazol in the treatment of acute ischemic stroke.

Administration of cilostazol, an antiplatelet, to patients with acute-stage cerebral infarction and its effects on plasma substance P level and latent time of swallowing reflex

BACKGROUND AND OBJECTIVE

It has been reported that medical treatment with cilostazol (cilo) as an antiplatelet may increase a substance P level in the striatum to shorten the latent time of swallowing reflex (LTSR). We undertook a pilot study to confirm whether cilo administration to patients with cerebral infarction is effective in increasing their plasma substance P level and then in ameliorating the status of LTSR.

METHODS AND SUBJECTS

Eligible subjects were recruited, after informed consents, from 20 hospitalized patients with acute-phase cerebral infarction within 72 hours from the onset. At the start of treatment, the subjects were assigned at random to those given aspirin alone (non-cilo group) and those given aspirin plus cilo (cilo group). Plasma substance P levels and LTSR values were measured at the starting point (baseline), 28 days after, and 180 days after.

RESULTS AND DISCUSSION

No significant time-dependent change in plasma substance P level was found probably because of large individual differences but, 28 days after the start of treatment, this value tended to become higher in cilo group than in non-cilo group (P<0.10). Whereas, in terms of fold changes of LTSR in cilo group, there was a significant between-term difference at P<0.05, indicating that this medication is effective in ameliorating the swallowing function is improved in the long run.

CONCLUSION

The LTSR values was significantly shortened within 180 days after the start of cilo treatment, but the result was not well explained by substance P levels as far as these were measured using the plasma, probably because this substance had diluted during blood circulation. However, it will become clinically usable as a single swallowing index, if in the future some ingeneus method of its measurement is developed. A larger-scale study would also be needed to confirm our conclusion from this pilot study.

Cilostazol for primary prevention of stroke in peripheral artery disease: a population-based longitudinal study in Taiwan

BACKGROUND

Clopidogrel, cilostazol, and aspirin were compared in terms of efficacy and safety for primary prevention of stroke in peripheral artery disease (PAD) patients.

METHODS

This retrospective cohort study analyzed data contained in the Taiwan National Health Insurance Bureau database for patients treated for PAD but not for stroke during 2002-2008. Patients were stratified according to treatment with aspirin, clopidogrel, cilostazol, or combined therapy. The primary efficacy and safety endpoints were stroke and hemorrhage.

RESULTS

Of the 931 patients enrolled in this study, 479 had received aspirin, 39 had received clopidogrel, 294 had received cilostazol alone, and 33 had received a cilostazol-based combined therapy. Compared to patients treated with aspirin, the patients treated with cilostazol had significantly lower all-stroke risk not only in the overall group (HR=0.66, 95% CI=0.48-0.90, p=0.0086), but also in the subgroup of patients with diabetes (HR=0.64, 95% CI=0.42-0.98, p=0.0394) and in the subgroup of patients with high cardiovascular risk (HR=0.66, 95% CI=0.46-0.95, p=0.0254). Additionally, compared to patients treated with aspirin, those treated with cilostazol did not have significantly more hemorrhagic events in the overall group, in the diabetes subgroup, or in the high cardiovascular risk subgroup. Clopidogrel, cilostazol-based combined therapy and aspirin did not significantly differ in terms of efficacy and hemorrhagic events.

CONCLUSION

Although this database study indicated that cilostazol therapy is an effective alternative treatment for primary prevention of stroke in PAD, further confirmation is needed in large, prospective, and randomized trials.

Effects of cilostazol on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a multicenter prospective, randomized, open-label blinded end point trial

Object

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major cause of subsequent morbidity and mortality. Cilostazol, a selective inhibitor of phosphodiesterase 3, may attenuate cerebral vasospasm because of its antiplatelet and vasodilatory effects. A multicenter prospective randomized trial was conducted to investigate the effect of cilostazol on cerebral vasospasm.

Methods

Patients admitted with SAH caused by a ruptured anterior circulation aneurysm who were in Hunt and Kosnik Grades I to IV and were treated by clipping within 72 hours of SAH onset were enrolled at 7 neurosurgical sites in Japan. These patients were assigned to one of 2 groups: the usual therapy group (control group) or the add-on 100 mg cilostazol twice daily group (cilostazol group). The group assignments were done by a computer-generated randomization sequence. The primary study end point was the onset of symptomatic vasospasm. Secondary end points were the onset of angiographic vasospasm and new cerebral infarctions related to cerebral vasospasm, clinical outcome as assessed by the modified Rankin scale, and length of hospitalization. All end points were assessed for the intention-to-treat population.

Results

Between November 2009 and December 2010, 114 patients with SAH were treated by clipping within 72 hours from the onset of SAH and were screened. Five patients were excluded because no consent was given. Thus, 109 patients were randomly assigned to the cilostazol group (n = 54) or the control group (n = 55). Symptomatic vasospasm occurred in 13% (n = 7) of the cilostazol group and in 40% (n = 22) of the control group (p = 0.0021, Fisher exact test). The incidence of angiographic vasospasm was significantly lower in the cilostazol group than in the control group (50% vs 77%; p = 0.0055, Fisher exact test). Multiple logistic analyses demonstrated that nonuse of cilostazol is an independent factor for symptomatic and angiographic vasospasm. The incidence of new cerebral infarctions was also significantly lower in the cilostazol group than in the control group (11% vs 29%; p = 0.0304, Fisher exact test). Clinical outcomes at 1, 3, and 6 months after SAH in the cilostazol group were better than those in the control group, although a significant difference was not shown. There was also no significant difference in the length of hospitalization between the groups. No severe adverse event occurred during the study period.

Conclusions

Oral administration of cilostazol is effective in preventing cerebral vasospasm with a low risk of severe adverse events. Clinical trial registration no. UMIN000004347, University Hospital Medical Information Network Clinical Trials Registry.

Effect of cilostazol in the treatment of acute ischemic stroke in the lenticulostriate artery territory

BACKGROUND

Cilostazol, an inhibitor of phosphodiesterase 3, has various pleiotropic effects besides its antiplatelet activity. This study examined the efficacy of cilostazol for the treatment of acute perforating artery infarction.

METHODS

In this prospective, randomized, open-label, blinded-end point trial, 100 patients with cerebral infarction in the territory of the lenticulostriate arteries were enrolled within 48 h of onset. Patients were randomly treated with both cilostazol and ozagrel for 14 days (n = 50, cilostazol group) or ozagrel alone for 14 days (n = 50, control group). The primary end point was the proportion of favorable outcomes 30 days after randomization as defined by a modified Rankin Scale (mRS) score of 0-2. Secondary end points included the incidence of neurological deterioration (an increase of ≥ 2 on the National Institutes of Health Stroke Scale within 7 days).

RESULTS

Favorable outcomes (mRS scores 0-2) were similar in both groups (81.3 and 82.0% in the cilostazol and control groups, respectively). The incidence of neurological deterioration was lower in the cilostazol group than the control group (12.5 and 16.0%, respectively) with a 21.9% relative risk reduction, although the difference was not statistically significant.

CONCLUSIONS

Cilostazol did not prevent the neurological deterioration of perforating artery infarction.

Effect of cilostazol in acute lacunar infarction based on pulsatility index of transcranial Doppler (ECLIPse): a multicenter, randomized, double-blind, placebo-controlled trial

BACKGROUND

This study is intended to evaluate the propensities of cilostazol to reduce the pulsatility index (PI) in patients with acute lacunar infarction using the serial transcranial Doppler (TCD) examinations.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled trial, patients were randomly assigned to receive either placebo or 100 mg cilostazol twice a day as well as aspirin 100 mg a day. The primary outcomes were the changes of middle cerebral artery (MCA) and basilar artery (BA) PIs at 14 and 90 days from the baseline TCD study. This study is registered with ClinicalTrials.gov (NCT00741286).

RESULTS

Trial medication was given to 203 patients, with 100 receiving cilostazol and 103 receiving placebo, and 164 were included in the per-protocol analysis of the primary outcome. Results from the linear mixed model showed that significant effects were obtained for time-by-group interactions (p = 0.008 in right MCA, p = 0.015 in left MCA, p = 0.002 in BA), suggesting that changes of PIs from the baseline to the 90-day study were different across the groups.

CONCLUSIONS

Cilostazol further decreased TCD PIs at 90 days from baseline compared to placebo in acute lacunar infarction. This result may be related to pleiotropic effects, such as vasodilation, beyond its antiplatelet activity.

[Results of the Cilostazol Stroke Prevention Study II (CSPS II): a randomized controlled trial for the comparison of cilostazol and aspirin in stroke patients]

We compared the efficacy and safety of cilostazol and aspirin in 2,672 Japanese patients with non-cardioembolic ischemic stroke. The patients were randomized to be allocated either on cilostazol (200 mg/day) group or aspirin (81 mg/day) group, and were followed up for one to five years (average 29 months). The primary endpoint was any stroke, and safety endpoint was hemorrhagic stroke or hemorrhage requiring hospitalization. Annual incidence of stroke was significantly lower in the cilostazol group (2.76%) than in the aspirin group (3.71%) (relative risk reduction [RRR] 25.7%, p=0.0357) and annual incidence of hemorrhagic stroke or hemorrhage requiring hospitalization was 0.77% in the cilostazol group and 1.77% in the aspirin group (RRR 54.2%, p=0.0004). The sub-analyses between subtypes of ischemic stroke showed that annual incidence of hemorrhagic stroke was much lower in the cilostazol group (0.36%) than in the aspirin group (1.20%) among patients with lacunar stroke (p=0.003). The results suggest that cilostazol has a favorable risk-benefit profile alternative to aspirin for secondary stroke prevention in patients with non-cardioembolic ischemic stroke, particularly in patients with lacunar stroke, who are at high risk of hemorrhagic stroke.

Platelet aggregometry in the presence of PGE(1) provides a reliable method for cilostazol monitoring

INTRODUCTION

Cilostazol has been shown to be effective for prevention and treatment of cerebral infarction. However, there appears to be no widely accepted method appropriate for monitoring cilostazol. We attempted to establish an assay system for cilostazol monitoring, using platelet aggregation induced by arachidonic acid (AA) in the presence of PGE(1) which upregulates intracellular cyclic AMP.

METHODS

Blood was drawn from stroke patients before and after cilostazol intake. AA-induced platelet aggregation after pretreatment with 0~30nM PGE(1) for 2minutes was measured by light transmittance aggregometry.

RESULTS

AA-induced platelet aggregation was 73.1±2.2% in the absence of PGE(1), and pretreatment with 30nM PGE(1) had virtually no inhibitory effect on platelet aggregation prior to cilostazol intake. In contrast, after cilostazol intake, 30nM PGE(1) significantly inhibited platelet aggregation to 12.7±4.5% (p=7.8×10(-11)) , while in the absence of PGE(1) platelet aggregation remained similar to that of prior-to-cilostazol value (70.6±3.5%). The plasma concentration of cilostazol ranged from 0.55 to 3.51μM. In the presence of 30nM PGE(1), all the patients with cilostazol concentrations exceeding 1μM had their platelet aggregation inhibited almost completely. ROC analysis suggests that AA-induced platelet aggregation in the presence of 30nM PGE(1) had the excellent sensitivity (90.5%) and specificity (88.4%) for monitoring cilostazol.

CONCLUSIONS

AA-induced platelet aggregation in the presence of 30nM PGE(1) could give good estimate on plasma concentrations of cilostazol. It is suggested that this system is a good tool for monitoring cilostazol.

Mixed cerebrovascular disease and the future of stroke prevention

Stroke prevention efforts typically focus on either ischemic or hemorrhagic stroke. This approach is overly simplistic due to the frequent coexistence of ischemic and hemorrhagic cerebrovascular disease. This coexistence, termed “mixed cerebrovascular disease”, offers a conceptual framework that appears useful for stroke prevention strategies. Mixed cerebrovascular disease incorporates clinical and subclinical syndromes, including ischemic stroke, subclinical infarct, white matter disease of aging (leukoaraiosis), intracerebral hemorrhage, and cerebral microbleeds. Reliance on mixed cerebrovascular disease as a diagnostic entity may assist in stratifying risk of hemorrhagic stroke associated with platelet therapy and anticoagulants. Animal models of hemorrhagic cerebrovascular disease, particularly models of cerebral amyloid angiopathy and hypertension, offer novel means for identifying underlying mechanisms and developing focused therapy. Phosphodiesterase (PDE) inhibitors represent a class of agents that, by targeting both platelets and vessel wall, provide the kind of dual actions necessary for stroke prevention, given the spectrum of disorders that characterizes mixed cerebrovascular disease.

The Neuroprotective Effects of BNG-1: A New Formulation of Traditional Chinese Medicines for Stroke

BNG-1, a novel mixture of traditional Chinese medicines with a long history in the treatment of stroke, exhibited acute neuroprotection effect on rats with middle cerebral artery occlusion (MCAO). Anti-ischemic effects were seen in both animals receiving BNG-1 before the ischemic insult as well as in animals receiving the drug formulation after surgical occlusion of the artery. Anti-thrombic activity was seen in vitro to inhibit arachidonic acid-induced platelet aggregation and in vivo to prolong bleeding time in mice. BNG-1 was also found to inhibit several phosphodiesterase (PDE) isoforms with potency order of the following rank: PDE 1>PDE 3>PDE 6>PDE 2>PDE 4>PDE 5. Other pre-clinical results and emerging clinical data coupled with the present findings suggest that BNG-1 may be a safe and effective therapy for both the prevention and treatment of cerebral stroke. Moreover, the fundamental cellular mechanism underlying its therapeutic effects may result from phosphodiesterase inhibition.

Progressive lacunar stroke: review of mechanisms, prognostic features, and putative treatments

Lacunar stroke is generally considered to have a fair outcome. However 20-30% of patients with lacunar stroke worsen neurologically in hours or days after onset, reaching eventually an unexpectedly severe disability status. In the field of acute stroke, progressive lacunar stroke remains an important unresolved practice problem, because as yet no treatment does exist proven to prevent or halt progression. Pathophysiology of progression is yet incompletely understood. Hemodynamic factors, extension of thrombosis, excitotoxicity, and inflammation, have been proposed as possible mechanisms of progression. A few clinical studies also aimed at establishing presentation features that may help identifying patients at risk of deterioration. In this paper, we review hypothesized mechanisms of lacunar stroke progression and possible markers of early deterioration. Moreover, based on putative mechanisms and suggestions from reported evidence, we propose a few treatments that seem worthy to be tested by randomized clinical trials.

Use of Cilostazol for Secondary Stroke Prevention: An Old Dog with New Tricks?

Objective:

To evaluate the safety and efficacy of cilostazol for secondary prevention of non-cardioembolic ischemic stroke.

Data Sources:

PubMed and MEDLINE searches were performed (January 1970-September 2011) using the key words cilostazol, antiplatelet, aspirin, acetylsalicylic acid, secondary stroke prevention, ischemic stroke, intracerebral hemorrhage, intracranial, cerebrovascular accident, and transient ischemic attack. Additionally, reference citations from publications identified were reviewed.

Study Selection and Data Extraction:

Articles published in English and relevant primary literature evaluating the efficacy and safety of cilostazol in the secondary prevention of atherosclerotic ischemic stroke were included.

Data Synthesis:

Antiplatelet therapy plays a vital role in the multifaceted approach to secondary stroke prevention. Current American Heart Association/American Stroke Association clinical guidelines for secondary stroke prevention support the use of aspirin, Clopidogrel, and combination aspirin/extended-release dipyridamole. The antiplatelet, antithrombotic, and vasoditatory effects of cilostazol make it a potential alternative agent for atherosclerotic stroke prevention. Recent literature has demonstrated superior efficacy of cilostazol 100 mg twice daily for secondary stroke prevention compared to placebo and aspirin. Three clinical trials were reviewed (1 placebo-controlled, 2 aspirin-controlled), all of which were conducted in Japan or China. Cilostazol reduced the primary outcome of recurrence of stroke, with significantly fewer major bleeding events when compared to aspirin.

Conclusions:

Available literature suggests that cilostazol may be safer and more effective than aspirin in the secondary prevention of stroke in Asian patients. Further large-scale studies in more heterogeneous study populations are warranted to determine whether cilostazol is a viable therapeutic option for patients with a history of non-cardioembolic ischemic stroke.

Small vessel cerebrovascular disease: the past, present, and future

Brain infarction due to small vessel cerebrovascular disease (SVCD)-also known as small vessel infarct (SVI) or "lacunar" stroke-accounts for 20% to 25% of all ischemic strokes. Historically, SVIs have been associated with a favorable short-term prognosis. However, studies over the years have demonstrated that SVCD/SVI is perhaps a more complex and less benign phenomenon than generally presumed. The currently employed diagnostic and therapeutic strategies are based upon historical and contemporary perceptions of SVCD/SVI. What is discovered in the future will unmask the true countenance of SVCD/SVI and help furnish more accurate prognostication schemes and effective treatments for this condition. This paper is an overview of SVCD/SVI with respect to the discoveries of the past, what is known now, and what will the ongoing investigations evince in the future.

Anti-platelet therapy: phosphodiesterase inhibitors

Inhibition of platelet aggregation can be achieved either by the blockade of membrane receptors or by interaction with intracellular signalling pathways. Cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP) are two critical intracellular second messengers provided with strong inhibitory activity on fundamental platelet functions. Phosphodiesterases (PDEs), by catalysing the hydrolysis of cAMP and cGMP, limit the intracellular levels of cyclic nucleotides, thus regulating platelet function. The inhibition of PDEs may therefore exert a strong platelet inhibitory effect. Platelets possess three PDE isoforms (PDE2, PDE3 and PDE5), with different selectivity for cAMP and cGMP. Several nonselective or isoenzyme-selective PDE inhibitors have been developed, and some of them have entered clinical use as antiplatelet agents. This review focuses on the effect of PDE2, PDE3 and PDE5 inhibitors on platelet function and on the evidence for an antithrombotic action of some of them, and in particular of dipyridamole and cilostazol.

Effect of cilostazol on the progression of carotid intima-media thickness: a meta-analysis of randomized controlled trials

BACKGROUND

It has been well established that cilostazol has anti-proliferative effect against in-stent restenosis. However, it remains unclear whether cilostazol can prevent the progression of carotid atherosclerosis.

METHODS AND RESULTS

We performed a meta-analysis of all relevant randomized controlled trials (RCTs) to evaluate the effect of cilostazol on the progression of carotid intima-media thickness (IMT). Five RCTs with 698 patients [597 subjects with type 2 diabetes mellitus (T2DM)] were included in this study. Cilostazol was associated with a significant reduction in the progression of carotid IMT (WMD, -0.08mm, 95% CI -0.13, -0.04; P=0.00003). Subgroup analysis shows that cilostazol monotherapy or addition to dual antiplatelet therapy (aspirin and clopidogrel) was superior to placebo (WMD, -0.04mm, 95% CI -0.05, -0.03; P<0.00001), no antiplatelet medication (WMD, -0.12mm, 95% CI -0.21, -0.03; P=0.008), aspirin monotherapy (WMD, -0.06mm, 95% CI -0.12, 0.00; P=0.04) or dual antiplatelet therapy (WMD, -0.16mm, 95% CI -0.30, -0.02; P=0.03) in preventing the progression of carotid IMT. Cilostazol resulted in a significant decrease in total cholesterol (WMD -8.47mg/dl, 95% CI -14.18, -2.75; P=0.004) and LDL-C (WMD -8.25mg/dl, 95% CI -14.15, -2.36; P=0.006) and favorable trends in reducing triglyceride (WMD -15.83mg/dl, 95% CI -32.14, 0.48; P=0.06).

CONCLUSION

It suggests that cilostazol may have beneficial effects in preventing the progression of carotid atherosclerosis and improving pro-atherogenic lipid profile, especially in patients with T2DM. Whether the anti-atherosclerotic effect of cilostazol is independent of improving pro-atherogenic dyslipidemia is worth further investigation.

Cilostazol: a drug particularly effective for Asians?

Cilostazol is an antiplatelet drug often used in Asia; however, it is rarely used in the western hemisphere, particularly for stroke patients. Further studies of cilostazol in other ethnicities are required to prove or disprove whether this drug is also beneficial in non-Asian populations.

Cilostazol: a pilot study on safety and clinical efficacy in neuropathies of diabetes mellitus type 2 (ASCEND)

BACKGROUND

Diabetic polyneuropathy may have vascular and metabolic components in its pathophysiologic mechanism. Cilostazol, aside from its antiplatelet and vasodilatory properties, may increase nerve blood flow and potentially improve neuropathy.

OBJECTIVE

To assess the efficacy and safety of cilostazol in diabetic polyneuropathy.

METHODS

Forty-seven diabetic patients were randomized into placebo, low-dose (100 mg/d), and high-dose (200 mg/d) cilostazol groups. Primary efficacy parameter was a change in neuropathy symptom scores and secondary efficacy parameter was a change in walking speed from baseline to week 12. Safety parameters were changes in nerve conduction studies as well as reporting of adverse events.

RESULTS/CONCLUSION

Despite significant improvement in the neuropathy symptom scores in the overall motor and sensory categories of the 3 arms of the study from baseline to week 12, no significant differences were found among the groups, indicating nonsuperiority of cilostazol in regard to improvement of neuropathy symptoms over the short study span. However, cilostazol, at low dose, was effective in improving walking speed from baseline to week 12, implying an improved blood flow. No significant worsening nor improvement in motor and sensory nerve conduction parameters were observed, comparing the 3 study arms from baseline to weeks 4, 12, and 16, supporting cilostazol's safety. Overall, the adverse events of the 3 study arms did not significantly differ, and neither were there serious adverse events reported, also signifying safety and tolerability in our Filipino cohort of patients with neuropathy in diabetes mellitus treated with cilostazol.

Atherothrombosis and the role of antiplatelet therapy

Atherothrombosis remains a major global public health problem. Chronic atherosclerotic disease is often clinically silent and coexists across vascular beds, but when complicated by thrombosis can result in acute coronary syndrome, stroke, transient ischaemic attack and critical limb ischaemia. Platelets play a role in the development of chronic atherosclerotic disease and are a key mediator of clinical events in atherothrombosis. Numerous trials have examined the role of antiplatelet agents in primary and secondary prevention and several new antiplatelet drugs are under development. In secondary prevention, there is evidence of clear benefit of single and in some cases dual antiplatelet therapy in the prevention of recurrent cerebro-vascular complications. Dual antiplatelet therapy has emerged as the standard of care in acute coronary syndromes, with aspirin typically being used in combination with clopidogrel or one of the newer more potent antiplatelet agents. Conversely, in chronic stable coronary disease, no benefit has yet been convincingly demonstrated from dual antiplatelet therapy. In cerebro-vascular disease, aspirin monotherapy remains the cornerstone of prevention of recurrent events, with clopidogrel or the combination of aspirin and dipyridamole being only modestly more efficacious. In primary prevention, the evidence for the routine use of aspirin or any other antiplatelet agent is mixed and suggests this should only be considered on an individual basis in high-risk groups where the thrombotic risk outweighs the risk of major bleeding complications.

Cilostazol in Acute Ischemic Stroke Treatment (CAIST Trial): a randomized double-blind non-inferiority trial

BACKGROUND

Aspirin is a proven antiplatelet agent in acute ischemic stroke, and there are no current guidelines for other antiplatelet treatments. We aimed to compare the efficacy and safety of cilostazol with aspirin in acute stroke.

METHODS

Patients with measurable neurological deficits (NIHSS score ≤15) within 48 h of onset were randomly assigned to cilostazol (200 mg/day) or aspirin (300 mg/day) for 90 days. The primary endpoint was a modified Rankin Scale (mRS) score of 0-2 at 90 days. Cardiovascular events, bleeding complications, and other functional outcomes were also assessed. Statistical analysis was carried out by intention-to-treat and per-protocol bases. This trial is registered with ClinicalTrials.gov (NCT00272454).

RESULTS

In total, 458 patients were enrolled (mean age of 63 years, median NIHSS of 3), and mRS at 90 days was obtained in 447 patients. The primary endpoint was achieved in 76% (173/228) of those randomized to cilostazol and in 75% (165/219) assigned to aspirin, which supported the pre-specified non-inferiority of cilostazol to aspirin (95% CI of proportion difference: -6.15 to 7.22%, p = 0.0004). These results were also supported by per-protocol analysis (p = 0.045). Cardiovascular events occurred in 6 patients (3%) treated with cilostazol, and in 9 patients (4%) treated with aspirin (p = 0.41). Adverse events were more common in cilostazol-treated patients during the trial (91 vs. 85%, p = 0.055), while the frequencies of bleeding complications (cilostazol 11%, aspirin 13%, p = 0.43) or drug discontinuation (cilostazol 10%, aspirin 7%, p = 0.32) were not different.

CONCLUSION

Cilostazol is feasible in acute ischemic stroke, and comparable to aspirin in its efficacy and safety.

The Secondary Prevention of Small Subcortical Strokes (SPS3) study

BACKGROUND

Small subcortical strokes, also known as lacunar strokes, comprise more than 25% of brain infarcts, and the underlying vasculopathy is the most common cause of vascular cognitive impairment. How to optimally prevent stroke recurrence and cognitive decline in S3 patients is unclear. The aim of the Secondary Prevention of Small Subcortical Strokes study (Trial registration: NCT00059306) is to define strategies for reducing stroke recurrence, cognitive decline, and major vascular events.

METHODS

Secondary Prevention of Small Subcortical Strokes is a randomised, multicentre clinical trial (n = 3000) being conducted in seven countries, and sponsored by the US NINDS/NIH. Patients with symptomatic small subcortical strokes in the six-months before and an eligible lesion on magnetic resonance imaging are simultaneously randomised, in a 2 × 2 factorial design, to antiplatelet therapy--325 mg aspirin daily plus 75 mg clopidogrel daily, vs. 325 mg aspirin daily plus placebo, double-blind--and to one of two levels of systolic blood pressure targets--'intensive' (<130 mmHg) vs. 'usual' (130-149 mmHg). Participants are followed for an average of four-years. Time to recurrent stroke (ischaemic or haemorrhagic) is the primary outcome and will be analysed separately for each intervention. The secondary outcomes are the rate of cognitive decline and major vascular events. The primary and most secondary outcomes are adjudicated centrally by those unaware of treatment assignment.

CONCLUSIONS

Secondary Prevention of Small Subcortical Strokes will address several important clinical and scientific questions by testing two interventions in patients with recent magnetic resonance imaging-defined lacunar infarcts, which are likely due to small vessel disease. The results will inform the management of millions of patients with this common vascular disorder.

Neurite outgrowth mediated by translation elongation factor eEF1A1: a target for antiplatelet agent cilostazol

Cilostazol, a type-3 phosphodiesterase (PDE3) inhibitor, has become widely used as an antiplatelet drug worldwide. A recent second Cilostazol Stroke Prevention Study demonstrated that cilostazol is superior to aspirin for prevention of stroke after an ischemic stroke. However, its precise mechanisms of action remain to be determined. Here, we report that cilostazol, but not the PDE3 inhibitors cilostamide and milrinone, significantly potentiated nerve growth factor (NGF)-induced neurite outgrowth in PC12 cells. Furthermore, specific inhibitors for the endoplasmic reticulum protein inositol 1,4,5-triphosphate (IP(3)) receptors and several common signaling pathways (PLC-γ, PI3K, Akt, p38 MAPK, and c-Jun N-terminal kinase (JNK), and the Ras/Raf/ERK/MAPK) significantly blocked the potentiation of NGF-induced neurite outgrowth by cilostazol. Using a proteomics analysis, we identified that levels of eukaryotic translation elongation factor eEF1A1 protein were significantly increased by treatment with cilostazol, but not cilostamide, in PC12 cells. Moreover, the potentiating effects of cilostazol on NGF-induced neurite outgrowth were significantly antagonized by treatment with eEF1A1 RNAi, but not the negative control of eEF1A1. These findings suggest that eEF1A1 and several common cellular signaling pathways might play a role in the mechanism of cilostazol-induced neurite outgrowth. Therefore, agents that can increase the eEF1A1 protein may have therapeutic relevance in diverse conditions with altered neurite outgrowth.

Effect of cilostazol administration on cerebral hemodynamics and rehabilitation outcomes in poststroke patients

PRIMARY OBJECTIVE

Cilostazol is an antiplatelet agent that inhibits phosphodiesterase III in platelets and the vascular endothelium. We assessed the effects of cilostazol on human cerebral hemodynamics and rehabilitation outcomes.

RESEARCH DESIGN

Prospective, consecutive, observational trial with pretreatment and posttreatment evaluations.

EXPERIMENTAL INTERVENTIONS

Cilostazol (200 mg/day) administered for 8 weeks.

METHODS AND PROCEDURES

Cerebral blood flow at rest, cerebrovascular reserve capacity, and rehabilitation outcomes (Brunnstrom stage, Barthel index score, modified Rankin Scale score, and Mini-Mental State Examination score) were measured in 104 poststroke patients with an average age ± standard deviation of 60.8 ± 9.2 years.

MAIN OUTCOMES AND RESULTS

The cerebral blood flow increased by 23.8% on the affected side of the brain and by 16.9% on the nonaffected side. The cerebrovascular reserve capacity increased by 19.0% on the affected side of the brain and by 13.3% on the nonaffected side. Improvements were observed in the Brunnstrom stage, Barthel index score, modified Rankin Scale score, and Mini-Mental State Examination score.

CONCLUSIONS

Cilostazol appeared to have beneficial effects in poststroke patients with cerebral ischemia and might improve cerebral circulation and rehabilitation outcome.

Carotid artery disease and stenting: insights from recent clinical trials

OPINION STATEMENT

Cerebrovascular disease remains a leading cause of morbidity, mortality, and health care expenditure in the United States. Approximately 80% of strokes are ischemic in origin, with 20% to 25% due to atherosclerotic disease of the carotid artery. It is well established that untreated, symptomatic carotid stenosis confers a 25% risk of stroke within 2 years, and that asymptomatic carotid stenosis > 60% is associated with an 11% stroke risk at 5 years. Over the past six decades, surgical revascularization with carotid endarterectomy, when performed by experienced surgeons, has been demonstrated to be effective in reducing stroke risk in patients with severe stenosis. During the same time, medical therapy has improved considerably, and endovascular therapy with carotid angioplasty and stenting has emerged as an important alternative strategy that may play a significant role in reducing the risk of stroke in patients with carotid disease. In this review, we examine the current evidence regarding optimal medical therapy, endarterectomy, and stenting for the management of patients with carotid stenosis. Armed with these data, we may tailor our approach to optimize care based on patient- and lesion-specific considerations.

Controversies and future perspectives of antiplatelet therapy in secondary stroke prevention

Antiplatelet agents are a cornerstone in the treatment of acute arterial thrombotic events and in the prevention of thrombus formation. However, existing antiplatelet agents (mainly aspirin, the combination of aspirin and dipyridamole and clopidogrel) reduce the risk of vascular events only by about one quarter compared with placebo. As a consequence, more efficacious antiplatelet therapies with a reduced bleeding risk are needed. We give an overview of several new antiplatelet agents that are currently investigated in secondary stroke prevention: adenosine 5'-diphosphonate receptor antagonists, cilostazol, sarpogrelate, terutroban and SCH 530348. There are unique features in secondary stroke prevention that have to be taken into account: ischaemic stroke is a heterogeneous disease caused by multiple aetiologies and the blood-brain barrier is disturbed after stroke which may result in a higher intracerebral bleeding risk. Several small randomized trials indicated that the combination of aspirin and clopidogrel might be superior to antiplatelet monotherapy in the acute and early post-ischaemic phase. There is an ongoing debate about antiplatelet resistance. Decreasing response to aspirin is correlated independently with an increased risk of cardiovascular events. However, there is still no evidence from randomized trials linking aspirin resistance and recurrent ischaemic events. Similarly, randomized trials have not demonstrated a clinical significantly decreased antiplatelet effect by the concomitant use of clopidogrel and proton pump inhibitors. Nevertheless, a routine use of this drug combination is not recommended.

Current status of antiplatelet agents to prevent stroke

Stroke is one of the leading causes of disability; most are due to atherothrombotic mechanisms. About one third of ischemic strokes are preceded by other stroke or transient ischemic attacks. Stroke survivors are at high risk for vascular events (i.e., cerebrovascular and cardiovascular). Prevention of recurrent stroke and other major vascular events can be accomplished by control of risk factors. Nonetheless, the use of antiplatelet agents remains the fundamental component of secondary stroke prevention strategy in patients with noncardioembolic disease. Currently, the uses of aspirin, clopidogrel, or aspirin plus extended-release dipyridamole are valid alternatives for stroke or transient ischemic attack patients. To maximize the beneficial effects of these agents, the treatment should be initiated as early as possible and continue on a lifelong basis.

Cilostazol improves symptomatic intracranial artery stenosis - Evaluation of cerebral blood flow with single photon emission computed tomography

Background:

To evaluate the effectiveness of cilostazol in patients with intracranial arterial stenosis, we used magnetic resonance angiography (MRA). The drug's effect on the cerebral blood flow (CBF) was examined by single photon emission computed tomography (SPECT).

Methods:

In this retrospective study, we evaluated the clinical outcomes of 20 patients with stenosis in the M1 segment of the middle cerebral artery (MCA) who had suffered ischemic stroke within 12 weeks or manifested asymptomatic stenosis exceeding 50%. All patients received cilostazol (100 mg twice daily). MRA and SPECT (at rest and after acetazolamide challenge) studies were performed before and 6 and 12 months after the start of cilostazol treatment.

Results:

In 5 patients the stenotic lesion showed improvement on MRA. Mean stenosis before cilostazol therapy was 71.7 ± 4.9%, which improved to 39.0 ± 3.2% at 6 months and to 27.2 ± 2.8% at 12 months. SPECT study showed that CBF was improved in 3 patients; in one there was improvement at rest and the other 2 manifested improvement upon acetazolamide challenge.

Conclusions:

Cilostazol had a remodeling effect on stenotic lesions due to arteriosclerotic changes and improved CBF in some patients.

Cilostazol versus aspirin for secondary prevention of vascular events after stroke of arterial origin

BACKGROUND

Aspirin is widely used for secondary prevention after stroke. Cilostazol has shown promise as an alternative to aspirin in Asian people with stroke.

OBJECTIVES

To determine the relative effectiveness and safety of cilostazol compared directly with aspirin in the prevention of stroke and other serious vascular events in patients at high vascular risk for subsequent stroke, those with previous transient ischaemic attack (TIA) or ischaemic stroke of arterial origin.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched September 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 4), MEDLINE (1950 to May 2010) and EMBASE (1980 to May 2010). In an effort to identify further published, ongoing and unpublished studies we searched journals, conference proceedings and ongoing trial registers, scanned reference lists from relevant studies and contacted trialists and Otsuka Pharmaceutical Co Ltd.

SELECTION CRITERIA

We selected all randomised controlled trials (RCTs) comparing cilostazol with aspirin where participants were treated for at least one month and followed systematically for development of vascular events.

DATA COLLECTION AND ANALYSIS

Data extracted from eligible studies included: (1) a composite outcome of vascular events (stroke, myocardial infarction or vascular death) during follow up (primary outcome); (2) separate outcomes of stroke (ischaemic or haemorrhagic, fatal or non-fatal), myocardial infarction (MI) (fatal or non-fatal), vascular death and death from all causes; and (3) main outcomes of safety including any intracranial, extracranial or gastrointestinal (GI) haemorrhage and other outcomes during treatment follow up (secondary outcomes). We computed an estimate of treatment effect and performed a test for heterogeneity between trials. We analysed data on an intention-to-treat basis and assessed bias for all included studies.

MAIN RESULTS

We included two RCTs with 3477 Asian participants. Compared with aspirin, cilostazol was associated with a significantly lower risk of composite outcome of vascular events (6.77% versus 9.39%, risk ratio (RR) 0.72, 95% confidence interval (CI) 0.57 to 0.91), and lower risk of haemorrhagic stroke (0.53% versus 2.01%, RR 0.26, 95% CI 0.13 to 0.55). In terms of outcome of safety compared with aspirin, cilostazol was significantly associated with minor adverse effects (8.22% versus 4.95%, RR 1.66, 95% CI 1.51 to 1.83).

AUTHORS' CONCLUSIONS

Cilostazol is more effective than aspirin in the prevention of vascular events secondary to stroke. Cilostazol has more minor adverse effects, although there is evidence of fewer bleeds.