Impact of cilostazol on restenosis after percutaneous coronary balloon angioplasty

Model difference in the effect of cilostazol on the development of experimental pulmonary hypertension in rats

BACKGROUND

Preventing pulmonary vascular remodeling is a key strategy for pulmonary hypertension (PH). Causes of PH include pulmonary vasoconstriction and inflammation. This study aimed to determine whether cilostazol (CLZ), a phosphodiesterase-3 inhibitor, prevents monocrotaline (MCT)- and chronic hypoxia (CH)-induced PH development in rats.

METHODS

Fifty-one male Sprague-Dawley rats were fed rat chow with (0.3% CLZ) or without CLZ for 21 days after a single injection of MCT (60 mg/kg) or saline. Forty-eight rats were fed rat chow with and without CLZ for 14 days under ambient or hypobaric (air at 380 mmHg) CH exposure. The mean pulmonary artery pressure (mPAP), the right ventricle weight-to-left ventricle + septum weight ratio (RV/LV + S), percentages of muscularized peripheral pulmonary arteries (%Muscularization) and medial wall thickness of small muscular arteries (%MWT) were assessed. Levels of the endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (peNOS), AKT, pAKT and IκB proteins in lung tissue were measured using Western blotting. Monocyte chemotactic protein (MCP)-1 mRNA in lung tissue was also assessed.

RESULTS

mPAP [35.1 ± 1.7 mmHg (MCT) (n = 9) vs. 16.6 ± 0.7 (control) (n = 9) (P < 0.05); 29.1 ± 1.5 mmHg (CH) (n = 10) vs. 17.5 ± 0.5 (control) (n = 10) (P < 0.05)], RV/LV + S [0.40 ± 0.01 (MCT) (n = 18) vs. 0.24 ± 0.01 (control) (n = 10) (P < 0.05); 0.41 ± 0.03 (CH) (n = 13) vs. 0.27 ± 0.06 (control) (n = 10) (P < 0.05)], and %Muscularization and %MWT were increased by MCT injection and CH exposure. CLZ significantly attenuated these changes in the MCT model [mPAP 25.1 ± 1.1 mmHg (n = 11) (P < 0.05), RV/LV + S 0.30 ± 0.01 (n = 14) (P < 0.05)]. In contrast, these CLZ effects were not observed in the CH model. Lung eNOS protein expression was unchanged in the MCT model and increased in the CH model. Lung protein expression of AKT, phosphorylated AKT, and IκB was downregulated by MCT, which was attenuated by CLZ; the CH model did not change these proteins. Lung MCP-1 mRNA levels were increased in MCT rats but not CH rats.

CONCLUSIONS

We found model differences in the effect of CLZ on PH development. CLZ might exert a preventive effect on PH development in an inflammatory PH model but not in a vascular structural change model of PH preceded by vasoconstriction. Thus, the preventive effect of CLZ on PH development might depend on the PH etiology.

Update on Cilostazol: A Critical Review of Its Antithrombotic and Cardiovascular Actions and Its Clinical Applications

Cilostazol, a phosphodiesterase III inhibitor, has vasodilating and antiplatelet properties with a low rate of bleeding complications. It has been used over the past 25 years for improving intermittent claudication in patients with peripheral artery disease (PAD). Cilostazol also has demonstrated efficacy in patients undergoing percutaneous revascularization procedures for both PAD and coronary artery disease. In addition to its antithrombotic and vasodilating actions, cilostazol also inhibits vascular smooth muscle cell proliferation via phosphodiesterase III inhibition, thus mitigating restenosis. Accumulated evidence has shown that cilostazol, due to its "pleiotropic" effects, is a useful, albeit underutilized, agent for both coronary artery disease and PAD. It is also potentially useful after ischemic stroke and is an alternative in those who are allergic or intolerant to classical antithrombotic agents (eg, aspirin or clopidogrel). These issues are herein reviewed together with the pharmacology and pharmacodynamics of cilostazol. Large studies and meta-analyses are presented and evaluated. Current guidelines are also discussed, and the spectrum of cilostazol's actions and therapeutic applications are illustrated.

Cilostazol: a Review of Basic Mechanisms and Clinical Uses

Primarily used in the treatment of intermittent claudication, cilostazol is a 2-oxyquinolone derivative that works through the inhibition of phosphodiesterase III and related increases in cyclic adenosine monophosphate (cAMP) levels. However, cilostazol has been implicated in a number of other basic pathways including the inhibition of adenosine reuptake, the inhibition of multidrug resistance protein 4, among others. It has been observed to exhibit antiplatelet, antiproliferative, vasodilatory, and ischemic-reperfusion protective properties. As such, cilostazol has been investigated for clinical use in a variety of settings including intermittent claudication, as an adjunctive for reduction of restenosis after coronary and peripheral endovascular interventions, and in the prevention of secondary stroke, although its widespread implementation for indications other than intermittent claudication has been limited by relatively modest effect sizes and lack of studies in western populations. In this review, we highlight the pleiotropic effects of cilostazol and the evidence for its clinical use.

Clinical expert consensus document on quantitative coronary angiography from the Japanese Association of Cardiovascular Intervention and Therapeutics

Quantitative coronary angiography (QCA) remains to play an important role in clinical trials and post-marketing surveillance related to the safety and efficacy of new PCI devices. In this document, the current standard methodology of QCA is summarized. In addition, its history, recent development and future perspectives are also reviewed.

Current concepts regarding drug dosing for peripheral stents

Drug-eluting stent (DES) are the mainstay therapy for the treatment of coronary artery disease. Stent design and drug-elution strategies have evolved over the years leading to the last generation DES which shows optimal safety and efficacy outcome. Peripheral arteries have different mechanical and biological features and the lessons learned from the coronary field have been difficult to introduce into the development of peripheral vascular technologies. First, due to its complex biomechanical behavior the use of metallic stents is limited in some vascular segments (i.e., distal superficial fermoral artery [SFA]). Also, peripheral vascular atherosclerosis is different containing higher levels of plaque burden and calcium. Finally, peripheral arterial disease tends to be more aggressive including longer lesions and higher incidence of total chronic occlusion. In general terms, restenosis in the peripheral vascular territory is more aggressive and occurs at a later time (~12 months) requiring a different pharmacokinetic profile compared to coronary technologies. Several strategies have been evaluated in the peripheral arteries raging from the bare metal stent to the drug coated balloon and drug eluting stent with outcome varying depending on the different field of application (i.e. SFA and below-the-knee). Results coming from the clinical trial are encouraging but further studies and direct comparison among the different technologies are demanded to determine the best therapy for peripheral vascular disease.

Genetics of blood lipids among ~300,000 multi-ethnic participants of the Million Veteran Program

The Million Veteran Program (MVP) was established in 2011 as a national research initiative to determine how genetic variation influences the health of US military veterans. Here we genotyped 312,571 MVP participants using a custom biobank array and linked the genetic data to laboratory and clinical phenotypes extracted from electronic health records covering a median of 10.0 years of follow-up. Among 297,626 veterans with at least one blood lipid measurement, including 57,332 black and 24,743 Hispanic participants, we tested up to around 32 million variants for association with lipid levels and identified 118 novel genome-wide significant loci after meta-analysis with data from the Global Lipids Genetics Consortium (total n > 600,000). Through a focus on mutations predicted to result in a loss of gene function and a phenome-wide association study, we propose novel indications for pharmaceutical inhibitors targeting PCSK9 (abdominal aortic aneurysm), ANGPTL4 (type 2 diabetes) and PDE3B (triglycerides and coronary disease).

MicroRNA-132 targeting PTEN contributes to cilostazol-promoted vascular smooth muscle cell differentiation

BACKGROUND AND AIMS

Cilostazol, beyond its antiplatelet effect, is also capable of promoting vascular smooth muscle cell (VSMC) differentiation. The aim of this study was to explore the potential role of PTEN, known to associate with VSMC differentiation, and its related microRNA (miRNA) in cilostazol-dependent effects.

METHODS AND RESULTS

Microarray analysis in balloon-injured rat carotid arteries comparing with and without balloon injury revealed that miR-132 was differentially expressed. Bioinformatic analysis predicts PTEN as a novel target of miR-132. Western blot and quantitative real-time reverse transcription-polymerase chain reaction along with in situ hybridization documented that cilostazol treatment enhanced PTEN and reduced miR-132 expression in the neointima of balloon-injured arteries. Treatment of cultured rat VSMCs with cilostazol resulted in the up-regulation of PTEN mRNA and the down-regulation of miR-132, supporting an in vitro relevance. Co-transfection experiments showed that transfection of miR-132 mimic into VSMCs suppressed PTEN 3'UTR activities, further reflecting that PTEN is the direct target of miR-132. Over-expression of miR-132 in VSMCs led to an attenuation of cilostazol-induced PTEN and its downstream VSMC differentiation marker (calponin) expression, confirming the critical role of miR-132 in VSMC differentiation. Transient transfection studies demonstrated that cilostazol reduced the activity of miR-132 promoter, which was mediated via cyclic AMP response element-binding protein. Notably, the use of lentivirus to over-express miR-132 in the neointima of balloon-injured arteries could reverse the effect of cilostazol in vivo.

CONCLUSIONS

These results suggest that miR-132 by targeting PTEN may be an important regulator in mediating cilostazol actions on VSMC differentiation.

Analysis of predicted loss-of-function variants in UK Biobank identifies variants protective for disease

Less than 3% of protein-coding genetic variants are predicted to result in loss of protein function through the introduction of a stop codon, frameshift, or the disruption of an essential splice site; however, such predicted loss-of-function (pLOF) variants provide insight into effector transcript and direction of biological effect. In >400,000 UK Biobank participants, we conduct association analyses of 3759 pLOF variants with six metabolic traits, six cardiometabolic diseases, and twelve additional diseases. We identified 18 new low-frequency or rare (allele frequency < 5%) pLOF variant-phenotype associations. pLOF variants in the gene GPR151 protect against obesity and type 2 diabetes, in the gene IL33 against asthma and allergic disease, and in the gene IFIH1 against hypothyroidism. In the gene PDE3B, pLOF variants associate with elevated height, improved body fat distribution and protection from coronary artery disease. Our findings prioritize genes for which pharmacologic mimics of pLOF variants may lower risk for disease.

Comparison of 1-Year Outcomes of Triple (Aspirin + Clopidogrel + Cilostazol) Versus Dual Antiplatelet Therapy (Aspirin + Clopidogrel + Placebo) After Implantation of Second-Generation Drug-Eluting Stents into One or More Coronary Arteries: from the DECREASE-PCI Trial

This study sought to evaluate the impact of triple antiplatelet therapy on clinical outcomes in patients treated with second-generation drug-eluting stents (DES) for coronary artery disease. There are limited data regarding the impact of triple antiplatelet therapy in patients who underwent implantation of second-generation DES. We planned to randomly assign 2,110 patients treated with second-generation DES to triple (aspirin, clopidogrel, and cilostazol) and dual (aspirin, clopidogrel, and placebo) antiplatelet therapy groups. The primary end point was a composite of death, myocardial infarction, ischemic stroke, or target vessel revascularization (TVR) at 1 year since randomization. The study was stopped early owing to slow enrollment. In total, 404 patients (202 patients each in the triple and dual antiplatelet therapy groups) were finally enrolled. At 1 year, the primary end point had occurred in 3.6% and 9.4% of patients in the triple and dual antiplatelet therapy groups, respectively (hazard ratio [HR] of the triple group 0.396; 95% confidence interval [CI] 0.166 to 0.949; p = 0.038). There was no significant difference between the 2 groups regarding the occurrence of a composite of all-cause death, myocardial infarction, or ischemic stroke (HR 0.583; 95% CI 0.229 to 1.481; p = 0.256). However, the rates of TVR were significantly lower in the triple antiplatelet therapy group than in the dual antiplatelet therapy group (HR 0.118; 95% CI 0.015 to 0.930; p = 0.043). In conclusion, triple antiplatelet therapy with cilostazol after implantation of second-generation DES improved clinical outcomes, mainly by reducing TVR.

Cilostazol attenuates intimal hyperplasia in a mouse model of chronic kidney disease

Intimal hyperplasia (IH) is a common cause of vasculopathy due to direct endothelial damage (such as post-coronary revascularization) or indirect injury (such as chronic kidney disease, or CKD). Although the attenuation of coronary revascularization-induced IH (direct-vascular-injury-induced IH) by cilostazol, a phosphodiesterase III inhibitor, has been demonstrated, our understanding of the effect on CKD-induced IH (indirect-vascular-injury-induced IH) is limited. Herein, we tested if cilostazol attenuated CKD-induced IH in a mouse model of ischemic-reperfusion injury with unilateral nephrectomy (Chr I/R), a normotensive non-proteinuria CKD model. Cilostazol (50 mg/kg/day) or placebo was orally administered once daily from 1-week post-nephrectomy. At 20 weeks, cilostazol significantly attenuated aortic IH as demonstrated by a 34% reduction in the total intima area with 50% and 47% decreases in the ratios of tunica intima area/tunica media area and tunica intima area/(tunica intima + tunica media area), respectively. The diameters of aorta and renal function were unchanged by cilostazol. Interestingly, cilostazol decreased miR-221, but enhanced miR-143 and miR-145 in either in vitro or aortic tissue, as well as attenuated several pro-inflammatory mediators, including asymmetrical dimethylarginine, high-sensitivity C-reactive protein, vascular endothelial growth factor in aorta and serum pro-inflammatory cytokines (IL-6 and TNF-α). We demonstrated a proof of concept of the effectiveness of cilostazol in attenuating IH in a Chr I/R mouse model, a CKD model with predominantly indirect-vascular-injury-induced IH. These considerations warrant further investigation to develop a new primary prevention strategy for CKD-related IH.

Open-Label Phase I Clinical Study to Assess the Safety and Efficacy of Cilostazol in Patients Undergoing Internal Carotid Artery Stent Placement

BACKGROUND

One-month dual antiplatelet treatment, with aspirin and clopidogrel, following internal carotid artery stent placement is the current standard of care to prevent in-stent thrombosis. Cilostazol, an antiplatelet drug, has been demonstrated to have a safety profile comparable to aspirin and clopidogrel.

OBJECTIVE

To evaluate the safety and clinical efficacy of cilostazol and aspirin therapy following internal carotid artery stent placement up to 1 month postprocedure.

METHODS

A phase I open-label, nonrandomized two-center prospective study was conducted. All subjects received aspirin (325 mg/day) and cilostazol (200 mg/day) 3 days before extracranial stent placement. Two antiplatelet agents were continued for 1 month postprocedure followed by aspirin daily monotherapy. The primary efficacy end point was the 30-day composite occurrence of death, cerebral infarction, transient ischemic attack, and in-stent thrombosis. The primary safety end point was bleeding.

RESULTS

Twelve subjects (mean age ± SD, 66 ± 12 years; 9 males) were enrolled and underwent internal carotid artery angioplasty and stent placement. None of the subjects who successfully followed the study protocol experienced any complications at the 1- and 3-month follow-ups. One patient had a protocol deviation due to concurrent use of enoxaparin (1 mg/kg twice daily) in addition to aspirin and cilostazol, resulting in a fatal symptomatic intracerebral hemorrhage following successful stent placement on postprocedure day 1. One patient discontinued cilostazol after the first dose secondary to dizziness.

CONCLUSION

The use of cilostazol and aspirin for internal carotid artery stent placement appears to be safe, but protocol compliance needs to be emphasized.

Restenosis after Coronary and Peripheral Intervention: Efficacy and Clinical Impact of Cilostazol

Restenosis is one of the main complications in patients undergoing coronary or peripheral revascularization procedures and is the leading cause for their long-term failures. Cilostazol is the only pharmacotherapy that showed an adequate efficacy for preventing restenosis in randomized, controlled studies after coronary or peripheral revascularization procedures. The present review sums up the main clinical evidence supporting the use of cilostazol after revascularization interventions, focusing on all its benefits, warnings, and administration schedules.

GT-repeat length polymorphism in heme oxygenase-1 promoter determines the effect of cilostazol on vascular smooth muscle cells

BACKGROUND

Cilostazol, a potent type 3 phosphodiesterase inhibitor, is found to reduce neointimal formation by inhibiting vascular smooth muscle cell (VSMC) proliferation. The aim of this study is to investigate whether the inhibitory effect of cilostazol on VSMC proliferation is operated via heme oxygenase-1 (HO-1).

METHODS AND RESULTS

In rat carotid arteries, cilostazol up-regulated HO-1 in the neointima of balloon-injured arteries. Treatment of human VSMCs with cilostazol enhanced the expression of HO-1, which was mainly regulated at the transcriptional level. Small interfering RNA knock-down of HO-1 attenuated the inhibitory effect of cilostazol on VSMC proliferation, suggesting the critical role of HO-1 in cilostazol effect. The transcriptional responsiveness of HO-1 to cilostazol was inversely correlated with the length of GT-repeat in human HO-1 promoter. Deletion and mutational analysis of HO-1 promoter along with chromatin immunoprecipitation showed that cyclic AMP response element (CRE)-binding protein (CREB) participated in cilostazol-induced HO-1 transcription. Furthermore, cilostazol triggered a linkage between the CRE and GT-repeat regions in the HO-1 promoter. The promoting effect of cilostazol on HO-1 expression, proliferation inhibition, and chromatin conformation in the HO-1 promoter was greater in VSMCs from subjects with shorter GT-repeat alleles than those with longer alleles.

CONCLUSIONS

Cilostazol inhibits VSMC proliferation involving an association between CREB and HO-1. The length polymorphism of GT-repeat in human HO-1 promoter determines the effect of cilostazol.

Aspirin has limited ability to modulate shear-mediated platelet activation associated with elevated shear stress of ventricular assist devices

Continuous flow ventricular assist devices (cfVADs) while effective in advanced heart failure, remain plagued by thrombosis related to abnormal flows and elevated shear stress. To limit cfVAD thrombosis, patients utilize complex anti-thrombotic regimens built upon a foundation of aspirin (ASA). While much data exists on ASA as a modulator of biochemically-mediated platelet activation, limited data exists as to the efficacy of ASA as a means of limiting shear-mediated platelet activation, particularly under elevated shear stress common within cfVADs. We investigated the ability of ASA (20, 25 and 125 μM) to limit shear-mediated platelet activation under conditions of: 1) constant shear stress (30 dynes/cm(2) and 70 dynes/cm(2)); 2) dynamic shear stress, and 3) initial high shear exposure (70 dynes/cm(2)) followed by low shear exposure - i.e. a platelet sensitization protocol, utilizing a hemodynamic shearing device providing uniform shear stress in vitro. The efficacy of ASA to limit platelet activation mediated via passage through a clinical cfVAD system (DeBakey Micromed) in vitro was also studied. ASA reduced platelet activation only under conditions of low shear stress (38% reduction compared to control, n=10, p<0.004), with minimal protection at higher shear stress and under dynamic conditions (n=10, p>0.5) with no limitation of platelet sensitization. ASA had limited ability (25.6% reduction in platelet activation rate) to modulate shear-mediated platelet activation induced via cfVAD passage. These findings, while performed under "deconstructed" non-clinical conditions by utilizing purified platelets alone in vitro, provide a potential contributory mechanistic explanation for the persistent thrombosis rates experienced clinically in cfVAD patients despite ASA therapy. An opportunity exists to develop enhanced pharmacologic strategies to limit shear-mediated platelet activation at elevated shear levels associated with mechanical circulatory support devices.

Clinical efficacy and safety of cilostazol: a critical review of the literature

Cilostazol is a unique antiplatelet agent that has been commercially available for over two decades. As a phosphodiesterase III inhibitor, it reversibly inhibits platelet aggregation yet also possesses vasodilatory and antiproliferative properties. It has been widely studied in a variety of disease states, including peripheral arterial disease, cerebrovascular disease, and coronary artery disease with percutaneous coronary intervention. Overall, cilostazol appears to be a promising agent in the management of these disease states with a bleeding profile comparable to placebo; even when combined with other antiplatelet agents, cilostazol does not appear to increase the rate of bleeding. Despite the possible benefit of cilostazol, its use is limited by tolerability as some patients often report drug discontinuation due to headache, diarrhea, dizziness, or increased heart rate. To date, it has been predominantly studied in the Asian population, making it difficult to extrapolate these results to a more diverse patient population. This paper discusses the evolving role of cilostazol in the treatment of vascular diseases.

The pharmacokinetic and pharmacodynamic interaction of clopidogrel and cilostazol in relation to CYP2C19 and CYP3A5 genotypes

AIM

The primary objective of the present study was to evaluate the pharmacokinetic and pharmacodynamic interactions between clopidogrel and cilostazol in relation to the CYP2C19 and CYP3A5 genotypes.

METHODS

In a randomized, three-way crossover study, 27 healthy subjects were administered clopidogrel (300 mg), cilostazol (100 mg) or clopidogrel + cilostazol orally. Plasma concentrations of clopidogrel, cilostazol and their active metabolites (clopidogrel thiol metabolite, 3,4-dehydrocilostazol and 4″-trans-hydroxycilostazol), and adenosine diphosphate-induced platelet aggregation were measured for pharmacokinetic and pharmacodynamic assessment.

RESULTS

The area under the plasma concentration-time curve (AUC) of the active thiol metabolite of clopidogrel was highest in the CYP2C19 extensive metabolizers (EM) and lowest in the poor metabolizers (PM). Cilostazol decreased the thiol metabolite AUC by 29% in the CYP3A5*1/*3 genotype [geometric mean ratio (GMR) 0.71; 90% confidence interval (CI) 0.58, 0.86; P = 0.020] but not in the CYP3A5*3/*3 genotype (GMR 0.93; 90% CI 0.80, 1.10; P = 0.446). Known effects of the CYP2C19 and CYP3A5 genotypes on the exposure of cilostazol and its metabolites were observed but there was no significant difference in the AUC of cilostazol and 3,4-dehydrocilostazol between cilostazol and clopidogrel + cilostazol. The inhibition of platelet aggregation from 4 h to 24 h (IPA4-24 ) following the administration of clopidogrel alone was highest in the CYP2C19 EM genotype and lowest in the CYP2C19 PM genotype (59.05 ± 18.95 vs. 36.74 ± 13.26, P = 0.023). However, the IPA of the CYP2C19 PM following co-administration of clopidogrel and cilostazol was comparable with that of the CYP2C19 EM and intermediate metabolizers (IM) only in CYP3A5*3/*3 subjects.

CONCLUSIONS

The additive antiplatelet effect of cilostazol plus clopidogrel is maximized in subjects with both the CYP2C19 PM and CYP3A5*3/*3 genotypes because of a lack of change of clopidogrel thiol metabolite exposure in CYP3A5*3/*3 as well as the highest cilostazol IPA in CYP2C19 PM and CYP3A5*3/*3 subjects.

Effect of Cilostazol Following Endovascular Intervention for Peripheral Artery Disease

Efficacy of endovascular therapy (EVT) with nitinol stents for femoropopliteal (FP) lesions is limited by restenosis. Oral cilostazol reduces angiographic restenosis rate; however, treatment duration remains unclear. In a retrospective analysis of a multicenter database of 3471 consecutive limbs in 2737 patients (mean age: 72 ± 9 years; 61% diabetic; and 26% on regular dialysis) undergoing EVT for FP lesions between January 2004 and December 2011, we compared Kaplan-Meier estimated primary patency after EVT followed or not by cilostazol treatment. We used Cox hazard regression analysis to assess temporal association between cilostazol treatment and post-EVT restenosis. Five-year primary patency was higher in the cilostazol group than in the noncilostazol group (57% vs 47%, P < .0001). Cilostazol treatment was inversely associated with restenosis for the first 2 years following EVT (P < .05); however, no significant association was observed thereafter. Cilostazol use therefore appears efficacious in preventing restenosis up to 2 years after EVT for FP lesions.

Phosphodiesterase-3 inhibitor (cilostazol) attenuates oxidative stress-induced mitochondrial dysfunction in the heart

Background

Cilostazol is a type 3 phosphodiesterase inhibitor which has been previously demonstrated to prevent the occurrence of tachyarrhythmia and improve defibrillation efficacy. However, the mechanism for this beneficial effect is still unclear. Since cardiac mitochondria have been shown to play a crucial role in fatal cardiac arrhythmias and that oxidative stress is one of the main contributors to arrhythmia generation, we tested the effects of cilostazol on cardiac mitochondria under severe oxidative stress.

Methods

Mitochondria were isolated from rat hearts and treated with H₂O₂ to induce oxidative stress. Cilostazol, at various concentrations, was used to study its protective effects. Pharmacological interventions, including a mitochondrial permeability transition pore (mPTP) blocker, cyclosporine A (CsA), and an inner membrane anion channel (IMAC) blocker, 4′-chlorodiazepam (CDP), were used to investigate the mechanistic role of cilostazol on cardiac mitochondria. Cardiac mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential change and mitochondrial swelling were determined as indicators of cardiac mitochondrial function.

Results

Cilostazol preserved cardiac mitochondrial function when exposed to oxidative stress by preventing mitochondrial depolarization, mitochondrial swelling, and decreasing ROS production.

Conclusions

Our findings suggest that cardioprotective effects of cilostazol reported previously could be due to its prevention of cardiac mitochondrial dysfunction caused by severe oxidative stress.

A randomised, multicentre, double blind, placebo controlled trial to evaluate the efficacy and safety of cilostazol in patients with vasospastic angina

OBJECTIVES

We conducted a randomised, double blind, placebo controlled trial to assess the efficacy and safety of cilostazol, a selective inhibitor of phosphodiesterase 3, in patients with vasospastic angina (VSA).

BACKGROUND

Cilostazol has been shown to induce vascular dilatation, but its efficacy in patients with VSA is unknown.

METHODS

Between October 2011 and July 2012, 50 patients with confirmed VSA who had ≥1 angina episodes/week despite amlodipine therapy (5 mg/day) were randomly assigned to receive either cilostazol (up to 200 mg/day) or placebo for 4 weeks. All patients were given diaries to record the frequency and severity of chest pain (0-10 grading). The primary endpoint was the relative reduction of the weekly incidence of chest pain.

RESULTS

Baseline characteristics were similar between the two groups. Among 49 evaluable patients (25 in the cilostazol group, 24 in the placebo group), the primary endpoint was significantly greater in the cilostazol group compared with the placebo group (-66.5±88.6% vs -17.6±140.1%, respectively, p=0.009). The secondary endpoints, including a change in the frequency of chest pain (-3.7±0.5 vs -1.9±0.6, respectively, p=0.029), a change in the chest pain severity scale (-2.8±0.4 vs -1.1±0.4, respectively, p=0.003), and the proportion of chest pain-free patients (76.0% vs 33.3%, respectively, p=0.003) also significantly favoured cilostazol. Headache was the most common adverse event in both groups (40.0% vs 20.8%, respectively, p=0.217).

CONCLUSIONS

Cilostazol is an effective therapy for patients with VSA uncontrolled by conventional amlodipine therapy, and has no serious side effects.

TRIAL REGISTRATION NUMBER

NCT01444885.

Age, male gender, and atrial fibrillation predict lower extremity amputation or revascularization in patients with peripheral artery diseases: a population-based investigation

By using the National Health Insurance (NHI) claim data of Taiwan, we sought to determine the predictors for nontraumatic lower extremity amputation (LEA) or peripheral revascularization procedures (PRP) in patients with peripheral artery disease (PAD). From the NHI claim data, we identified 12,206 patients with newly diagnosed PAD between 1998 and 2008, and followed them up to 2008. We explored the age, gender, and whether the patients had concomitant comorbid conditions, such as diabetes mellitus (DM), hypertension (HTN), atrial fibrillation (AF), stroke, hospitalization for coronary artery disease (CAD), myocardial infarction (MI), or heart failure (HF), and whether they were taking cilostazol at the time of recruitment. We searched for clinical parameters that might be important determinants for LEA or PRP in the study population. Of the 12,206 patients, 150 (1.2%) were found to undergo either LEA or PRP or both (LEA 81, PRP 53, both PRP and LEA 16). Old age, male gender, and history of hospitalization for CAD or MI and AF were found to be risk predictors for both procedures. Patients with DM were at lower risk for PRP (odds ratio 0.418, p = 0.001). Patients who were taking cilostazol had higher risk for LEA or PRP. HTN was not a risk predictor for LEA or PRP. From this nationwide study, we found that among PAD patients in Taiwan, age, male gender, AF, and hospitalization for CAD or MI are risk predictors for future LEA or PRP. DM is a negative predictor for PRP while both DM and HTN are not risk predictors for LEA.

Addition of cilostazol to conventional dual antiplatelet therapy reduces the risk of cardiac events and restenosis after drug-eluting stent implantation: a meta-analysis

This meta-analysis was performed to compare the risk of cardiac events and restenosis between triple antiplatelet therapy (TAT, addition of cilostazol to aspirin and clopidogrel) and conventional dual antiplatelet therapy (DAT, aspirin and clopidogrel) in drug-eluting stents (DES) implantation patients. We performed PUBMED, MEDLINE, EMBASE, and Cochrane CENTRAL searches for randomized clinical trials of TAT versus DAT in patients after DES implantation. Five clinical trials were involved in the study. TAT was associated with a 36% reduction in major adverse cardiac events (MACE; odds ratio (OR) = 0.64; 95% confidence interval (CI) = 0.51-0.81, P < .01), a 40% reduction (OR = 0.60, 95% CI = 0.44-0.80; P < .01) in target vessel revascularization (TVR), a 44% reduction (OR = 0.56, 95% CI = 0.34-0.91; P = .02) in target lesion revascularization (TLR) and a 47%/44% reduction in in-segment/in-stent restenosis (P < .01) and lower in-segment/in-stent late loss (P < .01). As regards to the safety assessment, there was no significant difference about the risk of stent thrombosis and bleeding between TAT and DAT group, while the risk of gastrointestinal trouble was significantly higher in TAT group (OR = 2.46, 95% CI = 1.25-4.86; P < .01). Addition of cilostazol to DAT reduced the incidence of MACE, TVR, and TLR after DES implantation. TAT also reduced the risk of restenosis and late loss in patients after DES implantation.

Efficacy and Safety of Adjunctive Cilostazol to Dual Antiplatelet Therapy After Stent Implantation

Background:

Aspirin and clopidogrel dual antiplatelet therapy (DAT) reduce ischemic events in patients with cardiovascular disease. However, recurrent ischemic event occurrence during DAT remains a major concern. This systematic review assesses the efficacy and safety of adjunctive cilostazol to DAT in combination with DAT on reducing clinical adverse events.

Methods:

We searched randomized controlled trials (RCTs) in PubMed, Embase, Cochrane library, clinicaltrial.gov, and Chinese Biomedical Database through July 2011. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated. Two independent reviewers evaluated the included studies. The extracted data were analyzed by Review Manager 5.1.2 (The Cochrane Collaboration, Oxford, UK) and GRADEprofiler 3.6 (GRADE Working Group).

Results:

A total of 7 RCTs (4351 patients) were included in the analysis, with a follow-up period of 6 to 12 months. Pooled analysis showed that cilostazol was associated with a significant reduction in major adverse cardiac events (MACEs; pooled RR 0.69, 95% CI 0.52-0.91; P = .008) and repeat revascularization (RR 0.74, 95% CI 0.61-0.89; P = .002); however, cilostazol was not associated with a reduction in the risk of stent thrombosis (RR 1.00, 95% CI 0.41-2.45; P = 1.00). Cilostazol seems to be safe, with no significant increase in the risk of bleeding (RR 1.06, 95% CI 0.72-1.56; P = .77). The 4 outcomes were low-quality evidence for MACE, moderate-quality evidence for repeat revascularization, and high-quality evidence for bleeding and stent thrombosis.

Conclusions:

When compared to the currently recommended DAT, triple antiplatelet therapy with cilostazol can reduce repeat revascularization with no increase in the risk of bleeding.

Use of Cilostazol in Percutaneous Coronary Interventions

OBJECTIVE:

To evaluate the addition of cilostazol to standard dual antiplatelet therapy (DAT) with aspirin and clopidogrel in patients receiving coronary stenting.

DATA SOURCES:

Relevant information was identified through a search of MEDLINE (1966-November 2011), International Pharmaceutical Abstracts (1960-2011), and Cochrane Databases (publications archived until November 2011) using the terms cilostazol, percutaneous coronary intervention, triple therapy, and antiplatelet agents.

STUDY SELECTION AND DATA EXTRACTION:

English-language prospective and retrospective studies, including registry data in adults, were eligible for inclusion if triple therapy with cilostazol was compared with DAT with aspirin and clopidogrel in patients undergoing percutaneous coronary intervention (PCI) with stenting. Article bibliographies were also reviewed.

DATA SYNTHESIS:

Cilostazol uniquely possesses antiproliferative properties in addition to its antiplatelet effects. Several prospective and retrospective clinical trials evaluated it as a third agent in standard antiplatelet regimens after PCI with both bare metal and drug-eluting stents. Both angiographic and clinical outcomes, including major adverse cardiac events (MACEs), have been improved with the addition of cilostazol to DAT in most trials, without increasing bleeding risk. Higher-risk patients, such as elderly individuals and patients with diabetes, long lesions, or small vessels, seem to benefit the most from triple therapy. Patients who are poor responders to clopidogrel also appear to benefit from the addition of cilostazol by improving platelet reactivity with standard DAT.

CONCLUSIONS:

Triple therapy with cilostazol has been shown to reduce MACEs by providing increased inhibition of platelet aggregation and reducing the rates of in-stent thrombosis compared to DAT without increasing the risk of bleeding complications. Further studies are needed to identify proper patient selection based on risk factors for the addition of cilostazol. Additionally, studies comparing cilostazol with newer antiplatelet therapies, such as prasugrel and ticagrelor, are needed.

Cilostazol activates function of bone marrow-derived endothelial progenitor cell for re-endothelialization in a carotid balloon injury model

BACKGROUND

Cilostazol(CLZ) has been used as a vasodilating anti-platelet drug clinically and demonstrated to inhibit proliferation of smooth muscle cells and effect on endothelial cells. However, the effect of CLZ on re-endothelialization including bone marrow (BM)-derived endothelial progenitor cell (EPC) contribution is unclear. We have investigated the hypothesis that CLZ might accelerate re-endothelialization with EPCs.

METHODOLOGY/PRINCIPAL FINDINGS

Balloon carotid denudation was performed in male Sprague-Dawley rats. CLZ group was given CLZ mixed feed from 2 weeks before carotid injury. Control group was fed normal diet. CLZ accelerated re-endothelialization at 2 weeks after surgery and resulted in a significant reduction of neointima formation 4 weeks after surgery compared with that in control group. CLZ also increased the number of circulating EPCs throughout the time course. We examined the contribution of BM-derived EPCs to re-endothelialization by BM transplantation from Tie2/lacZ mice to nude rats. The number of Tie2-regulated X-gal positive cells on injured arterial luminal surface was increased at 2 weeks after surgery in CLZ group compared with that in control group. In vitro, CLZ enhanced proliferation, adhesion and migration activity, and differentiation with mRNA upregulation of adhesion molecule integrin αvβ3, chemokine receptor CXCR4 and growth factor VEGF assessed by real-time RT-PCR in rat BM-derived cultured EPCs. In addition, CLZ markedly increased the expression of SDF-1α that is a ligand of CXCR4 receptor in EPCs, in the media following vascular injury.

CONCLUSIONS/SIGNIFICANCE

CLZ promotes EPC mobilization from BM and EPC recruitment to sites of arterial injury, and thereby inhibited neointima formation with acceleration of re-endothelialization with EPCs as well as pre-existing endothelial cells in a rat carotid balloon injury model. CLZ could be not only an anti-platelet agent but also a promising tool for endothelial regeneration, which is a key event for preventing atherosclerosis or restenosis after vascular intervention.

Cilostazol inhibits matrix invasion and modulates the gene expressions of MMP-9 and TIMP-1 in PMA-differentiated THP-1 cells

The invasion of monocytes into the subendothelium space plays an important role in the early stage of atherosclerosis. Cilostazol, a specific phosphodiesterase type III (PDE3) inhibitor, has been shown to exhibit anti-atherosclerotic effect. The present study aimed to investigate the modulating effects of cilostazol on monocyte invasion and the gene expressions of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1. We found that PMA significantly increased the invasive ability and the MMP-9 activity of THP-1 cells, as analyzed by matrix invasion assay and gelatin zymography, respectively. The increased expression of MMP-9 was demonstrated at both the RNA and protein levels by RT/real-time PCR and western blot analysis. These changes were markedly inhibited by cilostazol in a dose-dependent manner, which also could be observed when cAMP analog was used. On the contrary, the expression of TIMP-1, an inhibitor of MMP-9, was significantly upregulated by cilostazol dose dependently at both the RNA and protein levels. Reverse zymography further confirmed the increase of TIMP-1 activity after cilostazol treatment. The increase of TIMP-1 by cilostazol, however, was not cAMP-dependent. Cilostazol reduced the MMP-9 promoter activity and suppressed the nuclear translocation of NF-κB, indicating that the inhibitory effect of cilostazol is at the transcriptional level. In conclusion, the present study provides an additional mechanism underlying the anti-atherosclerotic effect of cilostazol by inhibiting the monocyte invasion and modulating the gene expressions of MMP-9 and TIMP-1 in monocytes upon differentiating to macrophages.

A better effect of cilostazol for reducing in-stent restenosis after femoropopliteal artery stent placement in comparison with ticlopidine

Purpose

The purpose of this study was to assess the preventive effect of cilostazol on in-stent restenosis in patients after superficial femoral artery (SFA) stent placement.

Materials and methods

Of 28 patients with peripheral arterial disease, who had successfully undergone stent implantation, 15 received cilostazol and 13 received ticlopidine. Primary patency rates were retrospectively analyzed by means of Kaplan–Meier survival curves, with differences between the two medication groups compared by log-rank test. A multivariate Cox proportional hazards model was applied to assess the effect of cilostazol versus ticlopidine on primary patency.

Results

The cilostazol group had significantly better primary patency rates than the ticlopidine group. Cumulative primary patency rates at 12 and 24 months after stent placement were, respectively, 100% and 75% in the cilostazol group versus 39% and 30% in the ticlopidine group (P = 0.0073, log-rank test). In a multivariate Cox proportional hazards model with adjustment for potentially confounding factors, including history of diabetes, cumulative stent length, and poor runoff, patients receiving cilostazol had significantly reduced risk of restenosis (hazard ratio 5.4; P = 0.042).

Conclusion

This retrospective study showed that cilostazol significantly reduces in-stent stenosis after SFA stent placement compared with ticlopidine.

Cilostazol promotes vascular smooth muscles cell differentiation through the cAMP response element-binding protein-dependent pathway

OBJECTIVE

Cilostazol, a potent type 3 phosphodiesterase inhibitor, has recently been found to reduce neointimal formation by inhibiting vascular smooth muscle cell (VSMC) proliferation. The aim of this study is to investigate whether cilostazol exerts an action on phenotypic modulation of VSMCs, another important process in the pathogenesis of neointimal formation.

METHODS AND RESULTS

Cilostazol may convert VSMCs from a serum-induced dedifferentiation state to a differentiated state, as indicated by a spindle-shaped morphology and an increase in the expression of smooth muscle cell differentiation marker contractile proteins. The upregulation of contractile proteins by cilostazol involves the cAMP/protein kinase A (PKA) signaling pathway, because the cAMP analog mimicked and specific cAMP/PKA inhibitors opposed the effect of cilostazol. Furthermore, cilostazol-activated cAMP response element (CRE)-binding protein (CREB), including phosphorylation at Ser133 and its nuclear translocation. Deletion and mutational analysis of the contractile protein promoters along with chromatin immunoprecipitation using anti-CREB antibody showed that CRE is essential for cilostazol-induced contractile protein expression. Transfection of dominant-negative CREB (mutated Ser133) plasmid in VSMCs blocked cilostazol-stimulated contractile protein expression. In vivo, cilostazol upregulated contractile proteins and induced the activation of CREB in the neointima of balloon-injured arteries.

CONCLUSIONS

Cilostazol promotes VSMC differentiation through the cAMP/PKA/CREB signaling cascade.

Differential gene expression in rat vascular smooth muscle cells following treatment with coptisine exerts a selective antiproliferative effect

It is known that coptisine (1), an isoquinoline alkaloid, selectively inhibits proliferation of rat primary vascular smooth muscle cells (VSMCs). In the present study, the characteristics of its antiproliferative effect on several types of smooth muscle-like cells were investigated and compared to the effects of berberine (2) and palmatine (3). To clarify further the mechanism underlying the VSMC-selective antiproliferative effect of 1, the genes responsible were investigated by determining which mRNAs showed expression regulated by 1. Coptisine (1) showed a greater antiproliferative effect on smooth muscle cells derived from the aorta than on those derived from other organs. Analysis of the mRNA expression revealed that 1 upregulated two genes, growth arrest and DNA-damage-inducible alpha (Gadd45a) and response gene to complement32 (Rgc32). Both genes remained unchanged in 3Y1 fibroblasts and were not affected by 2 and 3. Coptisine (1) was found to induce the mRNA of the Gadd45a and Rgc32 genes, specifically in VSMC. Activation of these genes by 1 may mediate inhibition of cell-cycle progression. However, as these genes are commonly expressed in various cell types, a selective target for 1 activity is likely to exist upstream of these genes.

Effects of cilostazol in the heart

Cilostazol is a selective phosphodiesterase 3 (PDE3) inhibitor approved by the Food and Drug Administration for treatment of intermittent claudication. It has also been used in bradyarrhythmic patients to increase heart rates. Recently, cilostazol has been shown to prevent ventricular fibrillation in patients with Brugada syndrome. Cilostazol is hypothesized to suppress transient outward potassium (Ito) current and increase inward calcium current, thus, maintaining the dome (phase 2) of action potential, decreasing transmural dispersion of repolarization and preventing ventricular fibrillation. Although many PDE3 inhibitors have been shown to increase cardiac arrhythmia in heart failure, cilostazol has presented effects that are different from other PDE3 inhibitors, especially adenosine uptake inhibition. Owing to this effect, cilostazol could be an effective cardioprotective drug, with its beneficial effects in preventing arrhythmia. In this review, the cardiac electrophysiological effects of cilostazol are presented and its possible cardioprotective effects, particularly in preventing ventricular fibrillation, are discussed, with emphasis on the need to further verify its clinical benefits.

Long-term (4-year) outcomes and predictors of adverse cardiac events after sirolimus-eluting stent implantation in unprotected left main coronary artery

The long-term safety and efficiency of sirolimus-eluting stent (SES) treatment in unprotected left main coronary artery (ULMCA) have not yet been ascertained.From 2003 to 2006, 126 consecutive patients with de novo lesions in ULMCA who underwent SES were retrospectively analyzed in a single center in China. During 4-year follow-up, major adverse cardiovascular event (MACE)-free survival was 74.6%. Cardiac death occurred in 5 (4.0%), and target lesion revascularization (TLR) and target vessel revascularization (TVR) occurred in 15 (11.9%) and 24 (19.0%) patients, respectively. One (0.8%) experienced probable stent thrombosis while 1 (0.8%) presented possible stent thrombosis. Impaired LVEF (< 40%) and high surgical risk (Euro score > 6) were the independent predictors of MACEs.PCI with SES for de novo lesions in ULMCA is feasible with a low procedural risk. However, SES was associated with a relatively higher rate of TLR and TVR. Impaired LVEF and high surgical risk were important predictors of MACEs.

Determinants of lower extremity amputation or revascularization procedure in patients with peripheral artery diseases: a population-based investigation

We used the National Health Insurance Claim data in Taiwan to evaluate determinants for nontraumatic lower extremity amputation (LEA) or peripheral revascularization procedures (PRP) in patients with peripheral artery diseases (PAD). We identified 14 241 patients. Sex-specific odds ratios of age, diabetes mellitus (DM), hypertension (HTN), coronary artery disease (CAD), cerebral vascular accident (CVA), or using cilostazol for LEA or PRP were explored. In patients with PAD, 14.3% of male and 7.4% of female had LEA; whereas 7.1% of male and 4.6% of female had PRP. Among male patients, HTN and CAD were significant risk factors for LEA, whereas DM and using cilostazol had protective roles. Findings in female patients were similar. For PRP, elderly patients had less such procedures. The risk/protective factors were similar. In conclusion, PAD patients having DM and using cilostazol had less LEA or PRP, whereas those having HTN and CAD had more LEA or PRP.

Study design and rationale of 'Influence of Cilostazol-based triple anti-platelet therapy on ischemic complication after drug-eluting stent implantation (CILON-T)' study: A multicenter randomized trial evaluating the efficacy of Cilostazol on ischemic vascular complications after drug-eluting stent implantation for coronary heart disease

Background

Current guidelines recommend dual anti-platelet therapy, aspirin and clopidogrel, for patients treated with drug-eluting stent for coronary heart disease. In a few small trials, addition of cilostazol on dual anti-platelet therapy (triple anti-platelet therapy) showed better late luminal loss. In the real-world unselected patients with coronary heart disease, however, the effect of cilostazol on platelet reactivity and ischemic vascular events after drug-eluting stent implantation has not been tested. It is also controversial whether there is a significant interaction between lipophilic statin and clopidogrel.

Methods/Design

CILON-T trial was a prospective, randomized, open-label, multi-center, near-all-comer trial to demonstrate the superiority of triple anti-platelet therapy to dual anti-platelet therapy in reducing 6 months' major adverse cardiovascular/cerebrovascular events, composite of cardiac death, nonfatal myocardial infarction, target lesion revascularization and ischemic stroke. It also tested whether triple anti-platelet therapy is superior to dual anti-platelet therapy in inhibiting platelet reactivity in patients receiving percutaneous coronary intervention with drug-eluting stent. Total 960 patients were randomized to receive either dual anti-platelet therapy or triple anti-platelet therapy for 6 months and also, randomly stratified to either lipophilic statin (atorvastatin) or non-lipophilic statin (rosuvastatin) indefinitely. Secondary endpoints included all components of major adverse cardiovascular/cerebrovascular events, platelet reactivity as assessed by VerifyNow P2Y12 assay, effect of statin on major adverse cardiovascular/cerebrovascular events, bleeding complications, and albumin-to-creatinine ratio to test the nephroprotective effect of cilostazol. Major adverse cardiovascular/cerebrovascular events will also be checked at 1, 2, and 3 years to test the 'legacy' effect of triple anti-platelet therapy that was prescribed for only 6 months after percutaneous coronary intervention.

Discussion

CILON-T trial will give powerful insight into whether triple anti-platelet therapy is superior to dual anti-platelet therapy in reducing ischemic events and platelet reactivity in the real-world unselected patients treated with drug-eluting stent for coronary heart disease. Also, it will verify the laboratory and clinical significance of drug interaction between lipophilic statin and clopidogrel.

Trial Registration

National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov identifier# NCT00776828).

Triple antiplatelet therapy vs. dual antiplatelet therapy in patients undergoing percutaneous coronary intervention: an evidence-based approach to answering a clinical query

AIMS

Outcomes of patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES) and bare metal stents (BMS) have not been evaluated separately for specific dual and triple antiplatelet agent use. The purpose of this meta-analysis was to determine whether triple antiplatelet therapy (combination of clopidogrel, aspirin and cilostazol) has any advantage in efficacy compared with standard dual antiplatelet therapy (aspirin and clopidogrel) in patients undergoing PCI.

METHODS

Electronic and printed sources were searched till May 2008 for randomized controlled clinical trials (RCTs) of cilostazol in combination with aspirin and clopidogrel. Pooled weighted mean difference (WMD) and pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated.

RESULTS

A total of four RCTs including 1457 patients with a median follow-up period of 6-9 months were included in the analysis. The rates of major adverse cardiac and/or cerebrovascular events (MACE/MACCE), stent thrombosis and bleeding were not significantly different between triple and dual antiplatelet therapy groups. Pooled analysis showed that cilostazol was associated with significantly decreased incidence of in segment restenosis (ISR) (OR 0.51, 95% CI 0.38, 0.68; P < 0.00001), increased minimum luminal diameter (MLD) (WMD 0.16, 95% CI 0.10, 0.22; P < 0.00001) for both DES and BMS and also individually. However, the rates of target vessel revascularization (OR 0.45, 95% CI 0.25, 0.83; P = 0.01 and late lumen loss (pooled WMD 0.14, 95% CI 0.2, 0.07; P = 0.001) were decreased significantly only in the DES group receiving triple therapy.

CONCLUSIONS

Cilostazol appears to be effective in reducing the rates of ISR without any significant benefit for MACE/MACCE.

Addition of cilostazol to aspirin and a thienopyridine for prevention of restenosis after coronary artery stenting: a meta-analysis

The purpose of this study is to evaluate the effect of adding cilostazol to dual antiplatelet therapy (aspirin and thienopyridine) on rates of restenosis after coronary artery stenting. A meta-analysis is conducted of randomized, controlled trials comparing 3 drug regimens (cilostazol, thienopyridine, aspirin [triple therapy]) with dual antiplatelet therapy to reduce restenosis after coronary stenting. A total of 5 studies are included for analysis. The analysis reveals that triple therapy is used in 796 patients, whereas dual therapy is used in 801 patients. Approximately 56% of patients receive a drug-eluting stent. The 6-month restenosis rates are significantly lower with triple versus dual antiplatelet therapy (12.7% vs 21.9%; odds ratio 0.5; 95% confidence interval, 0.38-0.66; P < .001). This benefit is seen regardless of whether a bare-metal or drug-eluting stent is used. Rates of major adverse cardiac events and bleeding are reported for 3 of the 5 studies (n = 1426); analysis of these outcomes shows no difference between treatment groups (P = .21 and .48, respectively). The addition of cilostazol to standard dual antiplatelet therapy reduces angiographic restenosis and increases MLD at 6 months without significantly affecting rates of major adverse cardiac events or bleeding.