Effects of triple antiplatelet therapy (aspirin, clopidogrel, and cilostazol) on platelet aggregation and P-selectin expression in patients undergoing coronary artery stent implantation

Adjunctive Cilostazol in Patients With High Residual Platelet Reactivity After Drug-Eluting Stent Implantation: A Randomized, Open-Label, Single-Center, Prospective Study (ADJUST-HPR)

BACKGROUND

Cilostazol as an adjunct to dual antiplatelet therapy (DAPT) postcoronary stenting may further reduce vascular occlusion risks. The aim of this study was to assess the impact of cilostazol on high residual platelet reactivity (HRPR) in patients undergoing drug-eluting coronary stent implantation.

METHODS

In a randomized, open-label, single-center, prospective study, the degree of platelet inhibition by cilostazol 100 mg twice daily was assessed on top of conventional DAPT compared with standard clopidogrel and low-dose aspirin combination in poststent patients with HRPR. HRPR was defined as P2Y12 units (PRU) > 240 as measured by the VerifyNow P2Y12 assay. In addition, the platelet activity was assessed by light transmittance aggregometry (LTA) and Multiplate electrode analyzer (MEA).

RESULTS

The total of 148 patients were screened, and HRPR was observed in 64 (43.2%). Those were randomized for DAPT versus triple therapy (TAPT). After 30 days, TAPT group exhibited significantly lower rate of HRPR when assessed by all 3 devices (VerifyNow: 40.0 vs. 66.7% P = 0.04, LTA: 6.7 vs. 30.0% P = 0.02, MEA: 10.0 vs. 30.0% P = 0.05 L all vs. DAPT). Also, higher absolute mean difference in TAPT versus DAPT group after 30 days (VerifyNow: 71.3 ± 38.2 vs. 24.6 ± 40.2 P < 0.001, LTA: 23.9 ± 15.1 vs. 9.4 ± 11.8 P < 0.001, MEA: 9.3 ± 12.9 vs. 2.4 ± 17.3 P = 0.08) was observed.

CONCLUSIONS

Cilostazol in addition to standard DAPT reduces the incidence of HRPR and diminishes further platelet activity in poststent patients. Whether this favorable laboratory finding will affect clinical outcomes requires an adequately powered randomized trial.

Differential inhibition of platelet function by cilostazol in combination with clopidogrel

PURPOSE

To assess the antiplatelet effect of cilostazol clinically, we compared the effects of cilostazol in combination with clopidogrel on various platelet function tests.

METHODS

We recruited patients with ischemic stroke at high risk of recurrence who were treated with clopidogrel alone within 180 days after stroke onset. Subjects underwent baseline platelet function tests, and were then randomly assigned to receive dual antiplatelet therapy (DAPT) comprising clopidogrel and cilostazol or clopidogrel monotherapy (SAPT). After 6 months, platelet function was measured again and compared to that at baseline in each group, and the rate of change was compared between groups.

RESULTS

Thirty-four patients were enrolled, but 4 patients were excluded for various reasons. In total, 30 subjects (13 in DAPT and 17 in SAPT group) were analyzed. Adenosine diphosphate- and collagen-induced aggregation, VerifyNow P2Y12 reaction units, vasodilator-stimulated phosphoprotein (platelet reactivity index: PRI) and plasma p-selectin concentration were significantly lower (P = 0.004, 0.042, 0.049, 0.003 and 0.006 respectively), while VerifyNow % inhibition was significantly higher at 6 months compared to baseline (P = 0.003) in the DAPT group only. Comparison of the rate of change in each parameter from baseline to 6 months showed that while PRI decreased at a greater rate (P = 0.012), VerifyNow % inhibition increased at a greater rate (P = 0.003) in the DAPT group than the SAPT group.

CONCLUSIONS

The inhibitory effects of adjunctive cilostazol added to clopidogrel on platelet function differed by type of platelet function test. VerifyNow % inhibition and PRI were more inhibited than the other platelet function tests.

TRIAL REGISTRATION

CSPS.com substudy in TWMU (UMIN000026672), registered on April 1, 2017. This study was performed as a substudy of CSPS.com (UMIN000012180, registered on October 31, 2013) and was retrospectively registered.

The Clinical Efficacy of Tirofiban Combined with Ticagrelor and Aspirin in Treating Acute Myocardial Infarction by Percutaneous Coronary Intervention and Its Effect on Patients’ Cardiac Function

Objective. To explore the clinical efficacy of tirofiban combined with ticagrelor and aspirin in acute myocardial infarction treatment by percutaneous coronary intervention and its effect on patients’ cardiac function. Methods. We selected 102 patients with acute myocardial infarction who came to The First Hospital of LanZhou University for treatment from July 2018 to May 2021. On the basis of conventional treatment, patients were separated into a joint group (tirofiban combined with ticagrelor and aspirin) comprising 55 cases and a control group (conventional ticagrelor and aspirin dual treatment) involving 47 cases. Blood flow classification of the two groups of patients was immediately recorded and compared after the myocardial infarction thrombolysis test (TIMI). Left ventricular function-related indicators, platelet-related parameters, neutrophil/lymphocyte ratio (NLR), red blood cell distribution width (RDW), and platelet/lymphocyte ratio (PLR) before treatment and 7 days after PCI were evaluated and compared between the groups before treatment and 3 months after treatment. ELISA was utilized to detect the serum levels of inflammatory factors, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and hypersensitive C-reactive protein (hs-CRP) before and after treatment. Incidence of major adverse cardiovascular events (MACEs) and adverse reaction incidence was put into comparison between the two groups in the course of the 3-month follow-up period. Compared with the control group, the joint group accounted for more patients with TIMI blood flow classification level 3 ( $P<0.05$ ) and showed more drastic improvement on the left ventricular function, platelet-related parameters, and serum inflammatory factors ( $P<0.05$ ). Moreover, patients of the joint group suffered less fluctuation from RDW, NLR, and PLR ( $P<0.05$ ), and their incidence of MACE was drastically lower in contrast with the control group ( $P<0.05$ ). No notable changes were presented in terms of incidence of adverse reaction ( $P>0.05$ ). For patients who suffered from acute myocardial infarction and treated with percutaneous coronary intervention, the application of tirofiban combined with ticagrelor and aspirin could effectively reduce the incidence of no reflow or slow blood flow, improve myocardial perfusion function, and have marked curative effects. It is worthy of clinical promotion and application.

Intensified antiplatelet therapy in patients after percutaneous coronary intervention with high on-treatment platelet reactivity: the OPTImal Management of Antithrombotic Agents (OPTIMA)-2 Trial

High on-treatment platelet reactivity (HOPR) is associated with increased risk of cardiovascular events in patients undergoing percutaneous coronary intervention (PCI). We randomised post-PCI patients with HOPR after 5 days of standard dual antiplatelet therapy (DAPT) to intensified therapy with aspirin 100 mg once daily in combination with either clopidogrel 150 mg once daily, clopidogrel 75 mg once daily plus cilostazol 100 mg twice daily, ticagrelor 90 mg twice daily, or standard therapy with clopidogrel 75 mg once daily (STD) for 1 month, after which all patients were switched to standard DAPT for a further 11 months. The primary outcome was residual HOPR rate at 1 month. We screened 1724 patients with light transmission aggregation studies and randomised 434 with HOPR. At 1 month the proportion of patients with persistent HOPR was significantly lower in the intensified therapy groups compared with STD group. Compared to the group receiving STD therapy, those receiving intensified therapy had significantly lower rate of major adverse cardiovascular events (MACE) at both 1 month and 12 months with no significant increase in bleeding. In patients with post-PCI HOPR, 1 month of intensified antiplatelet therapy provides greater platelet inhibition and improves outcomes without increasing bleeding. Clinical Trial Registration URL: http://www.clinicaltrials.gov; Unique Identifier: NCT01955200.

Effects of Cilostazol-Based Triple Antiplatelet Therapy Versus Dual Antiplatelet Therapy After Coronary Drug-Eluting Stent Implantation: An Updated Meta-Analysis of the Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

The results of studies on cilostazol-based triple antiplatelet therapy (TAT) after drug-eluting stent (DES) implantation were inconsistent. To assess the effects of TAT compared with dual antiplatelet therapy (DAT) after DES/second-generation DES implantation, we performed a meta-analysis of randomized controlled trials (RCTs).

METHODS

All relevant studies evaluated were identified by searching the PubMed, EMBASE, Cochrane Library, and ISI Web of Science databases without time and language limitation. Subgroup analyses were performed to evaluate the efficacy and safety of TAT after second-generation DES implantation.

RESULTS

Eleven RCTs involving a total of 4684 patients were included. The meta-analysis showed TAT was associated with significant beneficial effects on angiographic findings of in-stent restenosis [risk ratio (RR) 0.645, 95% confidence interval (CI) 0.470-0.885; P = 0.007], in-segment restenosis (RR 0.606, 95% CI 0.450-0.817; P = 0.001), in-stent late loss (RR - 0.095, 95% CI - 0.136 to - 0.054; P < 0.0001), in-segment late loss (RR - 0.100, 95% CI - 0.139 to - 0.061; P < 0.0001), target lesion revascularization (TLR) (RR 0.570, 95% CI 0.430-0.755; P < 0.0001), and target vessel revascularization (TVR) (RR 0.523, 95% CI 0.380-0.719; P < 0.0001). No significant difference was found in outcomes of all-cause death, cardiac death, definite/probable stent thrombosis (ST), non-fatal myocardial infarction (MI), overall bleeding, and major bleeding between the two groups, as well as some minor adverse effects including palpitations, thrombocytopenia, neutropenia, and hepatic dysfunction. However, the incidence rate of rash, gastrointestinal disorders, and headache was significantly higher in TAT. The second-generation DES subgroup showed similar results, except for the indicators of all-cause death (RR 2.161, 95% CI 1.007-4.635; P = 0.048) and hepatic dysfunction (RR 0.176, 95% CI 0.031-0.995; P = 0.049).

CONCLUSIONS

Compared with DAT, cilostazol-based TAT can significantly improve the angiographic findings of in-stent and in-segment late loss, in-stent and in-segment restenosis, TLR, and TVR after DES/second-generation DES implantation. However, no benefits were observed in outcomes of all-cause death, cardiac death, ST, and MI.

Tailored Adjunctive Cilostazol Therapy Based on CYP2C19 Genotyping in Patients With Acute Myocardial Infarction - The CALDERA-GENE Study

BACKGROUND

Patients with reduced-function CYP2C19 genotypes on dual antiplatelet therapy (DAPT) with aspirin and clopidogrel show higher clinical risk for acute myocardial infarction (AMI). We investigated the effect of CYP2C19 genotype-tailored adjunctive cilostazol therapy on treatment of AMI.Methods and Results:The study group of 138 patients with suspected AMI were screened for CYP2C19 genotype immediately after percutaneous coronary intervention (PCI) using a SPARTAN RX point-of-care device. Carriers of the CYP2C19 reduced-function allele were randomized into DAPT (Carrier/DAPT) and DAPT plus 14-day cilostazol (Carrier/DAPT+Cilostazol) groups, while noncarriers were treated with DAPT (Noncarrier/DAPT). After exclusion of 10 patients, the remaining 128 patients were analyzed for P2Y12 reaction unit (PRU) using VerifyNow^®P2Y12 system, and levels of biomarkers immediately after, and 1, 14, and 28 days after PCI. DAPT+Cilostazol reduced PRU levels in carriers (n=46) to those found in the Noncarrier/DAPT group (n=40), and significantly lower than those of the Carrier/DAPT group (n=42) at 14 days post-PCI. Discontinuation of cilostazol for 14 days was associated with a significant rise in PRU levels to those of the Carrier/DAPT group at 28 days post-PCI. Plasma B-type natriuretic peptide levels at 14 days post-PCI were lower in Carrier/DAPT+Cilostazol than in the other 2 groups, and the levels increased to those of the other groups at 28 days post-PCI after withdrawal of cilostazol.

CONCLUSIONS

Adjunctive cilostazol therapy tailored to CYP2C19 genotype seemed useful in AMI patients with the CYP2C19 reduced-function allele.

Bivalirudin plus loading dose of cilostazol-based triple-antiplatelet in treatment of non-ST-elevation myocardial infarction following percutaneous coronary intervention

Objective

To study the effect of bivalirudin plus loading dose of cilostazol-based triple-antiplatelet therapy strategy in patients undergoing percutaneous coronary intervention (PCI).

Methods

One hundred and fifty-three patients with non-ST-segment elevation myocardial infarction who underwent PCI were divided into control group and cilostazol group. Patients in control group were given aspirin and clopidogrel and those in cilostazol group were given aspirin, clopidogrel, and cilostazol once 2 hours before PCI and for 30 days after PCI. Bivalirudin was given to all patients before and during the PCI.

Results

After PCI, the Thrombolysis In Myocardial Infarction myocardial perfusion grade (TMPG) III in cilostazol group was higher than that in control group (89.19% versus 72.15%, P<0.05). At 30 days, the incidence of major adverse cardiac events was significantly lower in cilostazol group compared with that in control group (6.76% versus 17.72%, P<0.05). However, the rates of cardiac death, nonfatal reinfarction, target vessel revascularization, new congestive heart failure, and subacute stent thrombosis did not significantly differ between the two groups. In addition, the rates of minor or major bleeding or thrombocytopenia did not significantly differ between the two groups.

Conclusion

Bivalirudin plus loading dose of cilostazol-based triple-antiplatelet therapy strategy in PCI increased TMPG III, decreased major adverse cardiac events, and did not increase the incidence of bleeding and thrombocytopenia.

Efficacy and safety of cilostazol based triple antiplatelet treatment versus dual antiplatelet treatment in patients undergoing coronary stent implantation: an updated meta-analysis of the randomized controlled trials

The aim of this study was to obtain best estimates of the efficacy and safety of cilostazol-based triple antiplatelet therapy (TAPT: aspirin, clopidogrel and cilostazol) compared with dual antiplatelet therapy (DAPT: aspirin and clopidogrel) in patients undergoing coronary stent implantation. We searched the literature to identify all randomized clinical trials examining efficacy and safety of TAPT versus DAPT in patients undergoing coronary stent implantation. Major efficacy outcomes were death, non-fatal myocardial infarction (MI), ischemic stroke and stent thrombosis (ST) and the safety outcome was bleeding. Data were analyzed using the Review Manager 5.0.0 software. A total of 19 trials involving 7,464 patients were included. TAPT and DAPT were associated with similar rates of death, non-fatal MI, ischemic stroke and ST, but compared with DAPT, TAPT had lower rates of target lesion revascularization (TLR) (RR 0.67, 95 % CI 0.56-0.82, P < 0.0001) and target vessel revascularization (TVR) (RR 0.65, 95 % CI 0.55-0.77, P < 0.00001), as well as less late loss of minimal lumen diameter (mean difference -0.14, 95 % CI -0.17--0.11, P < 0.00001), and less binary angiographic restenosis (RR 0.54, 95 % CI 0.45-0.65, P < 0.00001). TAPT and DAPT had similar rates of bleeding, but TAPT had significantly higher rates of headache, palpitation, rash and gastrointestinal side-effects. Cilostazol-based TAPT compared with DAPT is associated with improved angiographic outcomes and decreased risk of TLR and TVR but does not reduce major cardiovascular events and is associated with an increase in minor adverse events.

Current state and novel approaches of antiplatelet therapy

An unresolved problem with clinical use of antiplatelet therapy is that a significant number of individuals either still get thrombosis or run the risk of life-threatening bleeding. Antiplatelet drugs are widely used clinically, either chronically for people at risk of athero/thrombotic disease or to prevent thrombus formation during surgery. However, a subpopulation may be resistant to standard doses, while the platelet targets of these drugs are also critical for the normal hemostatic function of platelets. In this review, we will briefly examine current antiplatelet therapy and existing targets while focusing on new potential approaches for antiplatelet therapy and improved monitoring of effects on platelet reactivity in individuals, ultimately to improve antithrombosis with minimal bleeding. Primary platelet adhesion-signaling receptors, glycoprotein (GP)Ib-IX-V and GPVI, that bind von Willebrand factor/collagen and other prothrombotic factors are not targeted by drugs in clinical use, but they are of particular interest because of their key role in thrombus formation at pathological shear.

Efficacy of cilostazol on platelet reactivity and cardiovascular outcomes in patients undergoing percutaneous coronary intervention: insights from a meta-analysis of randomised trials

BACKGROUND

Cilostazol overcomes high on-treatment platelet reactivity (HTPR) and reduces adverse cardiovascular (CV) outcomes after percutaneous coronary intervention (PCI). However, the role for triple antiplatelet therapy (TAPT) with cilostazol in addition to aspirin and clopidogrel after PCI is not well defined.

METHODS

We conducted a MEDLINE/EMBASE/CENTRAL search for randomised trials, until May 2014, evaluating TAPT compared with dual antiplatelet therapy (DAPT) of aspirin and clopidogrel alone in patients undergoing PCI and reporting platelet reactivity and/or CV outcomes. The primary platelet reactivity outcome was differences in platelet reactivity unit (PRU) with secondary outcomes of %platelet inhibition and rate of HTPR. The primary CV outcome was major adverse cardiovascular events (MACE), with secondary outcomes of death, cardiovascular death, myocardial infarction, stent thrombosis (ST), target lesion revascularisation (TLR) and target vessel revascularisation (TVR) as well as safety outcomes of bleeding and drug discontinuations.

RESULTS

In 17 trials that evaluated platelet reactivity outcomes, the mean PRU value was 47.73 units lower with TAPT versus DAPT (95% CI -61.41 to -34.04, p<0.0001; mean PRU 182.90 vs 232.65). TAPT also increased platelet inhibition by 12.71% (95% CI 10.76 to 14.67, p<0.0001), and led to a 60% reduction in the risk of HTPR (relative risk=0.40; 95% CI 0.30 to 0.53) compared with DAPT. Moreover, among the 34 trials that evaluated CV outcomes, TAPT reduced the risk of MACE (incident rate ratio (IRR)=0.68; 95% CI 0.60 to 0.78), TLR (IRR=0.57; 95% CI 0.44 to 0.73), TVR (IRR=0.69; 95% CI 0.59 to 0.81) and ST (IRR=0.63; 95% CI 0.40 to 0.98) with no difference for other outcomes including bleeding, even in trials using drug-eluting stents. Drug discontinuation due to adverse effects was, however, higher with TAPT vs DAPT (IRR=1.59; 95% CI 1.32 to 1.91).

CONCLUSIONS

In patients undergoing PCI, addition of cilostazol to DAPT results in decreased platelet reactivity and a significant reduction in CV outcomes including ST, even in the drug-eluting stent era.

Comparison of On-Treatment Platelet Reactivity Between Triple Antiplatelet Therapy With Cilostazol and Standard Dual Antiplatelet Therapy in Patients Undergoing Coronary Interventions

Background:

The recent literature has shown that triple antiplatelet therapy with cilostazol in addition to the standard dual antiplatelet therapy with aspirin and clopidogrel may reduce platelet reactivity and improve clinical outcomes following percutaneous coronary intervention. The purpose of this meta-analysis is to compare the efficacy of triple antiplatelet therapy and dual antiplatelet therapy in regard to on-treatment platelet reactivity.

Methods:

Nine studies (n = 2179) comparing on-treatment platelet reactivity between dual antiplatelet therapy (n = 1193) and triple antiplatelet therapy (n = 986) in patients undergoing percutaneous coronary intervention were included. Primary end points were P2Y12 reaction unit (PRU) and platelet reactivity index (PRI). Secondary end points were platelet aggregation with adenosine diphosphate (ADP) 5 and 20 µmol/L and P2Y12% inhibition. Mean difference (MD) and 95% confidence intervals (CI) were computed and 2-sided α error <.05 was considered as a level of significance.

Results:

Compared to dual antiplatelet therapy, triple antiplatelet therapy had significantly lower maximum platelet aggregation with ADP 5 µmol/L (MD: −14.4, CI: −21.6 to −7.2, P < .001) and 20 µmol/L (MD: −14.9, CI: −22.9 to −6.8, P < .001), significantly lower PRUs (MD: −45, CI: −59.4 to −30.6, P < .001) and PRI (MD: −26, CI: −36.8 to −15.2, P < .001), and significantly higher P2Y12% inhibition (MD: 18.5, CI: 2.3 to 34.6, P = .025).

Conclusion:

Addition of cilostazol to conventional dual antiplatelet therapy significantly lowers platelet reactivity and may explain a decrease in thromboembolic events following coronary intervention; however, additional studies evaluating clinical outcomes will be helpful to determine the benefit of triple antiplatelet therapy.

Randomized comparison of new dual-antiplatelet therapy (aspirin, prasugrel) and triple-antiplatelet therapy (aspirin, clopidogrel, cilostazol) using P2Y12 point-of-care assay in patients with STEMI undergoing primary PCI

BACKGROUND

Both new dual antiplatelet therapy (DAT; aspirin and prasugrel) and triple antiplatelet therapy (TAT; aspirin, clopidogrel and cilostazol) are more potent than classic DAT (aspirin and clopidogrel). We compared the antiplatelet efficacy between new DAT and TAT in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary coronary percutaneous coronary intervention (PCI).

METHODS

Forty patients who were eligible for primary PCI were prospectively randomized to DAT group (n=20) or TAT group (n=20) immediately after hospital arrival. The primary end point was P2Y12 reaction unit (PRU) determined with the VerifyNow P2Y12 point-of-care assay at the time of discharge.

RESULTS

PRU value at discharge was significantly lower in patients receiving DAT compared with that of TAT (84.5 ± 44.7 vs. 128.4 ± 74.9, p=0.032). Percent platelet inhibition was significantly higher for DAT compared with TAT at discharge (72.1 ± 12.2 vs. 57.5 ± 23.5, p=0.020). Inter-patient variability of PRU values at discharge was significantly smaller in patient taking DAT compared with TAT (p=0.026).

CONCLUSION

A new DAT is more potent antiplatelet therapy than TAT in patients with STEMI undergoing primary PCI.

Loading effect of 200 mg cilostazol on platelet inhibition in patients undergoing percutaneous coronary intervention

To date, most studies conducted on cilostazol have examined its effects as an agent of maintenance-dose therapy, but its loading effects on platelet inhibition have never been reported. This study aimed to determine the loading effects of 200 mg cilostazol in addition to aspirin and clopidogrel on platelet inhibition in patients undergoing percutaneous coronary intervention.Sixty consecutive patients undergoing coronary intervention were enrolled and assigned to receive 300 mg of aspirin and clopidogrel with or without 200 mg of cilostazol. All loading doses were given at least 3 hours before percutaneous coronary intervention and followed by dual or triple maintenance-dose therapy. Platelet function tests were performed just before and at 24 hours and 30 days after percutaneous coronary intervention by light transmittance aggregometry and VerifyNow® P2Y12 assay.There were no significant differences in baseline or angiographic characteristics between the 2 groups. The results of platelet function tests revealed that the adjunctive loading dose of 200 mg of cilostazol induced more potent platelet inhibition compared to a dual regimen at each time point. Cilostazol reduced the incidence of high post-treatment platelet reactivity (HPPR).Adjunctive 200 mg cilostazol can improve platelet responsiveness to clopidogrel in the pre- and postprocedural phases, reducing the prevalence of HPPR.

Detection of clopidogrel hyporesponsiveness using a point-of-care assay and the impact of additional cilostazol administration after coronary stent implantation in diabetic patients

BACKGROUND/AIMS

Impaired responsiveness to clopidogrel is common in patients with type 2 diabetes mellitus (DM). The aim of this study was to evaluate the clinical application of a point-of-care assay to detect impaired responsiveness to clopidogrel after coronary stent implantation in patients with type 2 DM.

METHODS

We measured P2Y12 reaction units (PRU) with the VerifyNow point-of-care assay in 544 consecutive patients undergoing dual or triple (i.e., dual plus cilostazol) anti-platelet therapy after coronary stent implantation. High platelet reactivity (HPR) was defined as a PRU value ≥ 240.

RESULTS

The mean PRU values were 233.5 ± 83.2 and 190.3 ± 85.5 in patients undergoing dual or triple anti-platelet therapy, respectively (p < 0.001). Patients with DM manifested higher post treatment PRU values (238.3 ± 82.4 vs. 210.8 ± 86.8, p = 0.001) and a higher frequency of HPR (44.8% vs. 31.0%, p = 0.003) as compared to patients without DM. We also found that higher PRU values and a higher frequency of HPR were present in patients with DM who were undergoing both triple and dual anti-platelet therapy. However, the higher post-treatment PRU values observed in patients with DM decreased with triple anti-platelet therapy (219.4 ± 82.5 vs. 247.9 ± 81.1, p = 0.044).

CONCLUSIONS

A point-of-care assay can detect elevated platelet reactivity and impaired responsiveness to clopidogrel in patients with type 2 DM. The addition of cilostazol to dual anti-platelet therapy may decrease post-treatment PRU values in patients with type 2 DM.

Optimizing antiplatelet therapy in acute coronary syndrome and percutaneous coronary intervention

Dual antiplatelet therapy with aspirin and clopidogrel is the standard of care for patients with acute coronary syndrome (ACS) and those undergoing percutaneous coronary intervention (PCI). It is well established that inhibition of platelet aggregation reduces the risk of recurrent thrombotic events and stent thrombosis. However, some patients show a reduced antiplatelet response to standard clopidogrel loading (300 mg) and maintenance (75 mg day(-1)) doses, which has been associated with poorer patient outcomes. Pharmacodynamic and pharmacokinetic studies show that higher-than-standard clopidogrel dosing strategies facilitate more rapid platelet inhibition of a greater intensity as a result of greater plasma concentrations of the clopidogrel active metabolite. Recently completed studies suggest that in patients with ACS undergoing PCI, higher-than-standard clopidogrel dosing regimens provide greater inhibition of platelet function and improved clinical outcomes with a small but significant increase in major bleeding. Newer, more potent antiplatelet agents such as prasugrel and ticagrelor are other alternative strategies that result in more rapid, greater inhibition of platelet function and better outcomes than standard-dose clopidogrel. Whether platelet reactivity-guided therapy or genotyping for cytochrome P450 polymorphisms is useful in managing patients needs to be further defined. Most importantly, early and effective antiplatelet therapy results in the best short- and long-term outcomes for patients with ACS or those undergoing PCI.

Optimizing of thienopyridine therapy by multiple electrode platelet aggregometry in clopidogrel low responders undergoing PCI

AIMS

One possible cause of stent thrombosis is an insufficient effect of clopidogrel. In a prospective study, we aimed to optimize the platelet inhibition of clopidogrel low responders (CLR) by multiple electrode platelet aggregometry (MEA)-guided therapy modifications and to evaluate specific major adverse cardiac and cerebrovascular events (MACCE).

METHODS AND RESULTS

ADP-induced platelet aggregation was measured by MEA in 1,005 consecutive patients after stent implantation and 600 mg clopidogrel loading dose. All patients received at least 100 mg aspirin/day. In 118 patients (11.7%), ADP values remained in the reference range generated in 150 controls and were defined as CLR. Significant independent predictors of CLR were acute coronary syndrome (ACS) (OR = 6.54), diabetes (OR = 2.07), use of diuretics (OR = 1.93) or proton pump inhibitors (OR = 1.64) and male gender (OR = 1.83). Ninety-nine CLR were switched to clopidogrel 150 mg/day, leading to an adequate response in 54/99. Subsequently, 44 patients were changed to ticlopidine 2 × 250 mg/day, resulting in an inhibition in 24/44. The remaining 20 patients received 2 × 100 mg cilostazol/day in addition to 75 mg clopidogrel/day. After its recent availability, 19/118 primary CLR were treated with 5-10 mg prasugrel/day. One patient was a prasugrel low responder. The total thienopyridine low response-rate was 2% in our population. The specific MACCE rate (death, non-fatal target vessel myocardial infarction, non-fatal stroke) of the CLR under optimized treatment (except prasugrel) was 2.0% at 30 days and 3.0% during a mean follow-up of 44 weeks.

CONCLUSION

Clopidogrel low response is present in 1/10 patients and more frequent in ACS-PCI. MEA-guided optimizing of thienopyridine therapy is feasible and results in a very low specific MACCE rate. Low response to all thienopyridines is rare.

Triple antiplatelet therapy reduces ischemic events after drug-eluting stent implantation: Drug-Eluting stenting followed by Cilostazol treatment REduces Adverse Serious cardiac Events (DECREASE registry)

BACKGROUND

Cilostazol has reduced restenosis and repeat intervention after drug-eluting stent (DES) implantation. However, there is little data regarding impact of cilostazol on cardiac events after DES implantation. Therefore, we assessed the long-term efficacy and safety of cilostazol in patients undergoing successful DES implantation.

METHODS

The patients (n = 3,099) undergoing successful DES implantation were treated with triple (aspirin, clopidogrel, and cilostazol; triple group, n = 1,443) or dual (aspirin and clopidogrel; dual group, n = 1,656) antiplatelet therapy. We compared adverse outcomes (death, myocardial infarction [MI], or stent thrombosis) at 12 months using the inverse probability of treatment weighted (IPTW) for the entire cohort and propensity score matching.

RESULTS

After IPTW adjustment, 12-month death (hazard ratio [HR] 0.762, 95% CI 0.401-1.448, P = .4062) was not different between the 2 groups. However, 12-month MI (HR 0.233, 95% CI 0.077-0.703, P = .0097) and stent thrombosis (HR 0.136, 95% CI 0.035-0.521, P = .0036) were significantly lower in triple group with no difference of major bleeding (HR 0.969, 95% CI 0.443-2.119, P = .9372). In the propensity score-matched cohort (965 pairs), 12-month clinical outcomes were similar to those of IPTW adjustment. On extended Cox model, duration of triple antiplatelet therapy was associated with reduction of stent thrombosis (HR 0.056, 95% CI 0.003-0.916, P = .0433) and MI (HR 0.749, 95% CI 0.568-0.988, P = .0408).

CONCLUSIONS

Triple antiplatelet therapy significantly reduced 12-month risks of stent thrombosis and MI after DES implantation compared with dual antiplatelet therapy without increased risk of bleeding complications. The longer duration of triple therapy after DES implantation was associated with the lower risk of stent thrombosis and MI.

Adding cilostazol to dual antiplatelet therapy achieves greater platelet inhibition than high maintenance dose clopidogrel in patients with acute myocardial infarction: Results of the adjunctive cilostazol versus high maintenance dose clopidogrel in patients with AMI (ACCEL-AMI) study

BACKGROUND

Optimal platelet inhibition is an important therapeutic adjunct in patients acute myocardial infarction (AMI) undergoing coronary stenting. Whether adjunctive cilostazol to dual antiplatelet therapy (triple antiplatelet therapy) can inhibit enhanced platelet reactivity in patients with AMI yet has not been determined. The aim of this study was to assess the degree of platelet inhibition by triple antiplatelet therapy in patients with AMI.

METHODS AND RESULTS

Immediately after emergency room arrival, patients with AMI received clopidogrel (600-mg loading dose, followed by 75 mg daily) and aspirin (300-mg loading dose and 200 mg daily throughout the study period). After patients underwent coronary stenting (n=90), they were randomly assigned to 1 of 3 groups before discharge: standard group, clopidogrel of 75 mg daily (n=30); high maintenance dose (MD) group, clopidogrel of 150 mg daily (n=30); and triple group, adjunctive cilostazol of 100 mg twice daily to clopidogrel of 75 mg daily (n=30). Platelet reactivity was assessed at predischarge and 30-day follow-up by conventional aggregometry and the VerifyNow P2Y12 assay. Predischarge platelet reactivities were similar in the 3 groups. At 30-day follow-up, inhibition of maximal aggregation with 20 microM ADP stimuli was 6.0% in the standard group, 19.1% in the high-MD group, and 42.4% in the triple group (P<0.001), whereas inhibition of late aggregation with 20microM ADP stimuli was 10.8%, 38.1%, and 66.4%, respectively (P<0.001). Similar results were demonstrated when 5 microM ADP was used. Furthermore, percent changes of P2Y12 reaction unit were significantly different among regimens (10.6% in the standard group, 30.7% in the high-MD group, and 43.0% in the triple group; P<0.001). With respect to high-postclopidogrel platelet reactivity (prespecified as 20 microM ADP-induced maximal aggregation >50% of light transmission), fewer patients in the triple group (13.3%) met the criteria as compared with those in the standard (76.7%) and high-MD groups (56.7%) at 30-day follow-up (P<0.001). In the triple group, there were more potent and consistent platelet inhibitions by all parameters as compared with the high-MD group except for percent changes of P2Y12 reaction unit (P=0.071).

CONCLUSIONS

Among patients with AMI undergoing coronary stenting, triple antiplatelet therapy results in a greater antiplatelet effect at 30 days as compared with a high-MD clopidogrel or standard dual antiplatelet therapy.

Comparison of triple anti-platelet therapy (aspirin, clopidogrel, and cilostazol) and double anti-platelet therapy (aspirin and clopidogrel) on platelet aggregation in type 2 diabetic patients undergoing drug-eluting stent implantation

BACKGROUND AND OBJECTIVES

Triple anti-platelet therapy may produce more potent inhibition of platelet aggregation in patients undergoing coronary stent implantation. We tested whether this effect could be maintained in diabetic patients, where platelet reactivity is increased and the risk of stent thrombosis is higher.

SUBJECTS AND METHODS

Fifty five type 2 diabetic patients who had undergone drug-eluting stent (DES) implantation and chronic anti-platelet therapy (>1 month) were stratified according to the status of anti-platelet therapy. Platelet aggregation after adenosine diphosphate (ADP; 10 micromol/L and 20 micromol/L) stimulation was compared using light transmittance aggregometry between dual (aspirin plus clopidogrel, n=34) and triple therapy (aspirin, clopidogrel plus cilostazol, n=21) groups.

RESULTS

The 2 groups had similar clinical and procedural characteristics. Maximal ADP-induced platelet aggregation was significantly lower in the triple therapy group than the dual therapy group (ADP 10 micromol/L, 37.1+/-15.4 vs. 28.3+/-11.8, p=0.03; ADP 20 micromol/L, 63.1+/-15.0 vs. 49.1+/-15.1, p=0.01), but there were no differences in diabetic treatment (oral hypoglycemic agent vs. insulin) or diabetic control {hemoglobin Alc (HbA1c) </=7 vs. HbA1c >7}.

CONCLUSION

Triple anti-platelet therapy showed more potent inhibition of maximal ADP induced platelet aggregation in type 2 diabetic patients receiving chronic anti-platelet therapy. This finding suggests that triple antiplatelet therapy may be more effective in preventing thrombotic complications after DES implantation in type 2 diabetic patients.

Efficacy of cilostazol in reducing restenosis in patients undergoing contemporary stent based PCI: a meta-analysis of randomised controlled trials

AIMS

Cilostazol has been associated with reduction in restenosis in patients undergoing coronary and peripheral arterial angioplasty. Our objective was to evaluate the impact of cilostazol on restenosis in patients undergoing contemporary PCI with bare metal (BMS) or drug eluting stents (DES) and treated with aspirin and thienopyridine.

METHODS AND RESULTS

Ten randomised trials (n=2,809 patients) comparing triple antiplatelet therapy (aspirin, thienopyridine and cilostazol) with standard dual antiplatelet therapy were included. Summary risk ratios for restenosis, late loss, target lesion revascularisation (TLR) and target vessel revascularisation (TVR) were calculated using fixed-effects models. Cilostazol was associated with a significant reduction in late loss in BMS (mean difference 0.24 mm, 95% CI 0.15-0.33, p<0.001) and DES groups (mean difference 0.12 mm, 95% CI 0.07-0.18, p<0.001). Cilostazol therapy was associated with a significant reduction in angiographic restenosis (Odds ratio [OR] 0.52, 95% CI 0.41- 0.66, p<0.001) with consistent benefits in patients treated with BMS (OR 0.49, 95% CI 0.35-0.70, p<0.001) or DES (OR 0.54, 95% CI 0.38-0.76, p=0.001). Addition of cilostazol to dual antiplatelet therapy was associated with a significant reduction in TLR (OR 0.38, 95% CI 0.25-0.58, p<0.001), with no difference in subacute stent thrombosis (OR 1.91, 95% CI 0.33-11.08, p=0.47), or major bleeding (OR 0.87, 95% CI 0.44-1.74, P=0.69) but with an increased risk of skin rash (OR 3.67, 95% CI 1.86-7.24, p<0.001).

CONCLUSIONS

Cilostazol in addition to dual antiplatelet therapy is associated with a reduction in angiographic restenosis in patients undergoing stent based PCI. This inexpensive drug may be particularly beneficial in patients who are at high risk of restenosis and it should undergo further evaluation in large, definitive randomised controlled trials.

Drug-eluting stent thrombosis after cilostazol withdrawal in a patient previously treated with triple antiplatelet therapy

Antiplatelet therapy has been shown to reduce cardiac events after coronary stenting. However, despite aggressive antiplatelet therapy, stent thrombosis remains a serious complication of coronary stenting with drug-eluting stent (DES). Although several predictors for DES thrombosis have been suggested by investigators, this serious condition is still not completely preventable now. In particular, patients undergoing non-cardiac surgery or invasive procedures with bleeding risk may interrupt antiplatelet therapy and occasionally experience stent thrombosis. We report a case of DES thrombosis after cilostazol withdrawal for colonoscopic polypectomy in a patient previously treated with triple antiplatelet therapy. The patient presented with acute myocardial infarction but survived after successful emergency coronary revascularization. We discuss a plausible mechanism for DES thrombosis in the described case.

Cilostazol in addition to aspirin and clopidogrel improves long-term outcomes after percutaneous coronary intervention in patients with acute coronary syndromes: a randomized, controlled study

BACKGROUND

Cilostazol has been widely used to prevent peripheral vascular events, and its antiplatelet mechanisms may different from aspirin and clopidogrel. We hypothesized that cilostazol in addition to aspirin and clopidogrel effectively reduces systemic ischemic events after percutaneous coronary intervention (PCI) in high-risk patients.

METHODS

In this prospective study, 1,212 patients with acute coronary syndromes were randomly assigned to receive either standard dual-antiplatelet treatment with aspirin and clopidogrel (n = 608) or triple-antiplatelet therapy with the addition of a 6-month course of cilostazol (n = 604) after successful PCI. The primary end point was a composite of cardiac death, nonfatal myocardial infarction, stroke, or target vessel revascularization (TVR) at 1 year after randomization. The secondary end points were TVR and hemorrhagic events.

RESULTS

Triple-antiplatelet treatment was associated with a significantly lower incidence of the primary end points (10.3% vs 15.1%; P = .011). The need for TVR was similar between patients who received triple- and dual-antiplatelet treatment (7.9% vs 10.7%; P = .10). Multivariate analysis showed that female patients and clinically or angiographically high-risk patients benefited more from the triple-antiplatelet treatment. There were no significant differences between the 2 regimens in terms of the risks for major and minor bleeding.

CONCLUSIONS

For patients with acute coronary syndromes, triple-antiplatelet therapy consisting of cilostazol, aspirin, and clopidogrel reduced long-term cardiac and cerebral events after PCI, especially for patients with high-risk profiles.

Use of antiplatelet agents for prevention of ischemic stroke

Overall management to lower risk for ischemic stroke is multifaceted. Management includes measures to treat risk factors for accelerated atherosclerosis and stroke, antithrombotic therapies to lower the risk for thromboembolism, and surgery to treat a defined arterial or cardiac lesion. Treatment decisions are made on a case-by-case basis, with most patients receiving some combination of medication and recommendations for lifestyle modification. Some patients will also undergo surgical or endovascular interventions. This article discusses antithrombotic treatment for ischemic stroke prevention, placing major emphasis on the indications for and administration of antiplatelet therapy.

Systematic review and meta-analysis of randomized clinical trials appraising the impact of cilostazol after percutaneous coronary intervention

BACKGROUND

Drug-eluting stents reduce the risk of restenosis after percutaneous coronary intervention (PCI) but may pose a risk of thrombosis. Cilostazol, an oral antiplatelet agent with pleiotropic effects including inhibition of neointimal hyperplasia, could hold the promise of preventing both restenosis and thrombosis. We systematically reviewed randomized clinical trials (RCTs) on the angiographic and clinical impact of cilostazol after PCI.

METHODS

We searched RCT in BioMedCentral, CENTRAL, clinicaltrials.gov, EMBASE, and PubMed (November 2007). Coprimary end points were binary angiographic restenosis and repeat revascularization, abstracted and pooled by means of random-effect relative risks (RRs). Small study/publication bias was appraised with multiple methods.

RESULTS

A total of 23 RCTs were included (5428 patients), with median follow-up of 6 months. Pooled analysis showed that cilostazol was associated with statistically significant reductions in binary angiographic restenosis (RR = 0.60 [0.49-0.73], P < .001) and repeat revascularization (RR = 0.69 [0.55-0.86], P = .001). Cilostazol appeared also safe, with no significant increase in the risk of stent thrombosis (RR = 1.35 [0.71-2.57], P = .36) or bleeding (RR = 0.71 [0.43-1.16], P = .17). However, small study bias was evident for both binary restenosis (P < .001) and repeat revascularization (P < .001), suggesting that at least part of the apparent benefits of cilostazol could be due to this type of confounding effect.

CONCLUSIONS

Cilostazol appears effective and safe in reducing the risk of restenosis and repeat revascularization after PCI, but available evidence is limited by small study effects. Awaiting larger RCTs, this inexpensive treatment can be envisaged in selected patients in which drug-eluting stents are contraindicated or when there is a need for neointimal hyperplasia inhibition.