Randomized Comparison of Cilostazol vs Ticlopidine for Antiplatelet Therapy After Coronary Stenting

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.

Comparison of cilostazol versus ticlopidine following coronary stenting in patients with coronary heart disease: A meta-analysis of randomized controlled trials

Previous studies have shown that the combination of cilostazol and aspirin may be a more effective regimen than ticlopidine plus aspirin in the prevention of late restenosis and acute or subacute stent thrombosis following coronary stenting; however, individually published results are inconclusive. The aim of this meta-analysis was to compare the differences in late restenosis and stent thrombosis between cilostazol plus aspirin and ticlopidine plus aspirin for patients with coronary heart disease (CHD) following coronary stenting. A literature search of Pubmed, Embase, Web of Science and Chinese BioMedicine (CBM) databases was conducted from 1998 to March 1, 2013 and statistical analysis was performed using Stata statistical software, version 12.0. Twelve randomized controlled trials were included in the study, with a total of 2,708 patients with CHD following coronary stenting. The patient population comprised 1,371 patients treated with cilostazol plus aspirin and 1,337 patients treated with ticlopidine plus aspirin. The meta-analysis showed that cilostazol plus aspirin demonstrated a lower rate of restenosis than ticlopidine plus aspirin [odds ratio (OR)=0.83, 95% confidence interval (CI)=0.69–0.99, P=0.047]. A significant difference was also observed in the average percent diameter stenosis between cilostazol plus aspirin and ticlopidine plus aspirin [standardized weight difference (SMD)= −0.57, 95% CI=−0.92, −0.23, P=0.001). However, there were no significant differences in the rates of acute or subacute stent thrombosis between cilostazol plus aspirin and ticlopidine plus aspirin. The present meta-analysis suggests that cilostazol plus aspirin may result in a lower restenosis rate and percent diameter stenosis than ticlopidine plus aspirin for patients with CHD following coronary stenting.

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.

Safety and efficacy of sirolimus-eluting stent in patients with acute coronary syndrome undergoing emergency procedure

BACKGROUND

Sirolimus-eluting stents (SES) reduce restenosis and revascularization rates, compared with bare-metal stents (BMS), in elective percutaneous coronary intervention (PCI). This study investigated the safety and efficacy of SES for emergency PCI in acute coronary syndrome (ACS) patients.

METHODS AND RESULTS

The 154 consecutive patients (SES: n=77, BMS: n=77) admitted to hospital with ACS were enrolled in this study. Procedural success (%DS <50%, Thrombolysis In Myocardial Infarction grade 3), major adverse cardiac events (MACE) at 30 days and 8 months, and the incidence of stent thrombosis were evaluated. There was no difference between the groups regarding procedural success. Patients treated with SES had smaller stent diameter (SES 3.04 mm vs BMS 3.24 mm; p=0.01) and longer stent length (25.7 mm vs 21.2 mm; p=0.01). At 30 days, there was no difference between the groups in the incidence of cardiovascular events. At 8 months, patients treated with the SES had a lower rate of repeat PCI (5.6% vs 18.6%; p=0.04) and MACE (9.7% vs 27.1%; p=0.01). Stent thrombosis was no different between groups (1.4% vs 2.9%).

CONCLUSION

In emergency PCI for ACS patients, SES implantation significantly reduced cardiovascular events, compared with BMS, by decreasing the incidence of repeat PCI. The safety profile of SES is equal to that of BMS.

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.

Cilostazol could ameliorate platelet responsiveness to clopidogrel in patients undergoing primary percutaneous coronary intervention

BACKGROUND

Cilostazol increases the cyclic adenosine monophosphate levels in platelets and might ameliorate the antiplatelet activity of clopidogrel. This study investigated the additional effect of cilostazol on platelet aggregation measured by a VerifyNow analyzer and soluble CD40 ligand (sCD40L) as a marker of activated platelet in patients undergoing primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Sixty cases of primary PCI were randomly assigned to dual (aspirin and clopidogrel) or triple (dual plus cilostazol) therapy. The antiplatelet effects of aspirin and clopidogrel were evaluated by VerifyNow tests. The plasma sCD40L levels at admission, 24 h and 21 days were measured by the ELISA method. The arachidonic acid induced platelet aggregation was similar in both groups. However, the triple group had a significantly lower P2Y12 reaction unit (dual 208.8+/-69.0 vs triple 168.2+/-79.2, p=0.041) and higher % inhibition of adenosine diphosphate (ADP)-induced platelet aggregation (dual 23.8+/-21.4% vs triple 40.5+/-21.0%, p=0.004). In the multivariate analysis, cilostazol was a negative predictor for low responders to clopidogrel (95% confidence interval 0.067-0.711). The plasma sCD40L levels were not significantly different between the 2 groups at the same point of time.

CONCLUSIONS

The addition of cilostazol to the combination of aspirin plus clopidogrel significantly increases the inhibition of ADP-induced platelet aggregation. However, there was no additive effect on aspirin-induced antiplatelet activity or lowering of sCD40L.

Incidence of side-effects of ticlopidine after sirolimus-eluting stent implantation

BACKGROUND

Because of its side-effects, long-term administration of ticlopidine limits the use of the sirolimus-eluting stent (SES) in Japan.

METHODS AND RESULTS

Side-effects of ticlopidine occurred in 41 (9.3%) of 440 patients who underwent SES implantation. The majority were liver dysfunction (4.5%) and rash (3.6%). One patient died from severe liver dysfunction. Neutropenia occurred in 3 patients (0.7%). It is remarkable that 28% of side-effects occurred >8 weeks after the initiation of ticlopidine.

CONCLUSIONS

Ticlopidine has a relative high rate of side-effects. Clopidogrel should be approved for prevention of stent thrombosis as soon as possible.

Late Angiographic Stent Thrombosis After Sirolimus-Eluting Stent Implantation

BACKGROUND

Although drug-eluting stents dramatically reduce revascularization after percutaneous coronary intervention (PCI), it is still unclear whether they increase the risk of stent thrombosis. Late stent thrombosis (>30 days) was a very rare complication after bare metal stent implantation. Four cases of confirmed late angiographic stent thrombosis (LAST) after sirolimus-eluting stent (SES) implantation are presented and the incidence, promoting factors and outcomes of such cases in Japan, where clopidogrel has not been approved, are described.

METHODS AND RESULTS

Between September 2004 and March 2006, 725 patients underwent PCI with SES implantation and 679 patients (94%) were clinically followed up (median 271 days). There were 4 cases (0.6%) of LAST (at 60, 180, 215, and 508 days, respectively) after elective SES implantation resulting in myocardial infarction. Three cases occurred soon after antiplatelet therapy discontinuation 3 patients died after LAST events. The incidence of LAST was 0.6%.

CONCLUSIONS

LAST is a rare complication, even after SES implantation, at least in patients with appropriate antiplatelet therapy. However, as it can lead to fatal complications, it must be taken into account, especially when antiplatelet therapy is discontinued.

Impact of chronotropic effect of cilostazol after acute myocardial infarction: insights from change in left ventricular volume and function

BACKGROUND

Cilostazol, a phosphodiesterase inhibitor, is an antiplatelet agent with positive chronotropic effect, the impact of which on left ventricular (LV) volume and function in acute myocardial infarction (AMI) was evaluated in the present study.

METHODS AND RESULTS

In 56 patients with AMI treated with primary coronary stenting, serial echocardiographic studies within 24 h and at 6 months were performed. Patients received a conventional antiplatelet regimen either without cilostazol (group 1, n=29) or with cilostazol (group 2, n=27). At 6 months, the difference in the change in heart rate between group 1 and group 2 was statistically significant (9.9 beats/min; p=0.04). However, changes in LV end-systolic volume (LVESV) (7.1+/-8.2 vs 10.0+/-21.7 ml, p=0.60), LV ejection fraction (EF) (8.2+/-9.9 vs 9.0+/-12.6%, p=0.85) and the ratio of early mitral inflow velocity to the mitral annular velocity (E/E') (0.6+/-3.7 vs -1.7+/-3.2) were not different between the 2 groups. Cardiac event rate was similar between the 2 groups. On multivariate regression analyses, cilostazol therapy had no significant influence on the changes in LVESV, LVEF or E/E'.

CONCLUSIONS

In this study, the addition of cilostazol on conventional drug therapy had no adverse influence on LV remodeling or LV function after AMI.