Adjunctive cilostazol versus high maintenance dose of clopidogrel in patients with hyporesponsiveness to chronic clopidogrel therapy

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.

Adverse clinical outcomes associated with double dose clopidogrel compared to the other antiplatelet regimens in patients with coronary artery disease: a systematic review and meta-analysis

BACKGROUND

Recently, several newer antiplatelet treatment strategies have been used in patients with coronary artery disease (CAD). Apart from the dual antiplatelet therapy (DAPT) consisting of aspirin and clopidogrel, double dose clopidogrel (DDC), triple antiplatelet therapy (TAPT) consisting of aspirin, clopidogrel and cilostazol and other newer antiplatelet agents have shown to be effective in different ways. In this analysis, we aimed to systematically compare the adverse clinical outcomes and the bleeding events which were observed when DDC was compared to the other antiplatelet regimens in patients with CAD.

METHODS

English publications comparing DDC with other antiplatelet regimens were searched from MEDLARS/MEDLINE, EMBASE, www.ClinicalTrials.gov and Google Scholar. Adverse cardiovascular outcomes and bleeding events were the study endpoints. Statistical analysis was carried out by the RevMan 5.3 software whereby odds ratios (OR) with 95% confidence intervals (CIs) were calculated.

RESULTS

A total number of 23,065 participants were included. Results of this analysis showed major adverse cardiac events (MACEs), all-cause mortality, cardiac death, stroke, stent thrombosis, revascularization and myocardial infarction (MI) to have been similarly manifested in patients who were treated with DDC versus the control group with OR: 0.98, 95% CI: 0.78-1.22; p = 0.83, OR: 0.95, 95% CI: 0.77-1.17; p = 0.62, OR: 0.97, 95% CI: 0.79-1.20; p = 0.81, OR: 0.98, 95% CI: 0.65-1.48; p = 0.94, OR: 0.84, 95% CI: 0.40-1.75; p = 0.64, OR: 0.88, 95% CI: 0.52-1.49; p = 0.63, and OR: 0.89, 95% CI: 0.65-1.21; p = 0.45 respectively. Any minor and major bleedings were also similarly manifested. When DDC was compared to DAPT, no significant difference was observed in any bleeding event with OR: 1.58, 95% CI: 0.86-2.91; p = 0.14. Even when DDC was compared with either ticagrelor or prasugrel or TAPT, still no significant difference was observed in terms of bleeding outcomes.

CONCLUSIONS

In patients with CAD, adverse clinical outcomes were not significantly different when DDC was compared to the other antiplatelet regimens. In addition, bleeding events were also similarly manifested when DDC was compared to DAPT, TAPT or ticagrelor/prasugrel.

[Correlation between cytochrome 3A4+894C>T P450 gene polymorphism and outcomes of coronary intervention in patients with acute coronary syndrome]

OBJECTIVE

To investigate the relationship between plasma cytochrome P450 3A4 (CYP3A4) 894C>T gene polymorphism and the risk of recurrence of adverse cardiac events after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS).

METHODS

A total of 275 patients with ACS received standard dual antiplatelet therapy and PCI. Platelet aggregation rate (PAR) was detected in each patient before and 7 days after administration of the anti-platelet drugs. Single nucleotide polymorphism of CYP3A4 gene 894C>T was detected with PCR and microarray technique. The number of coronary artery lesions was determined by PCI and the Gensini score was calculated. The patients were followed up for 3-12 months after discharge.

RESULTS

No significant difference was found in CYP3A4 gene polymorphism between patients with clopidogrel resistance (CR group) and those without CR (NCR group) (P>0.05). Multivariate logistic regression analysis showed that CYP3A4 gene 894C>T polymorphism was not correlated with CR in patients with ACS (OR 1.359, P>0.05). During the follow-up, the incidence of cardiovascular events was significantly higher in CR group than in NCR group (P<0.05), but this difference was not related to the mutation type of 894C>T locus of CYP3A4 gene.

CONCLUSION

The CYP3A4 gene 894C>T polymorphism is not associated with the effect of anti-platelet therapy and the risk of cardiovascular event in patients with ACS following PCI.

Triple antiplatelet therapy with addition of cilostazol to aspirin and clopidogrel for Y-stent-assisted coil embolization of cerebral aneurysms

BACKGROUND

Dual antiplatelet therapy for stent-assisted coiling of cerebral aneurysms is essential to prevent thromboembolic complications. There is concern that Y-stent-assisted coiling may increase thromboembolic complications compared with coiling with a single stent. Several reports have demonstrated that cilostazol may improve clopidogrel responsiveness. We investigated whether triple antiplatelet therapy with addition of cilostazol to aspirin plus clopidogrel for Y-stents can prevent thromboembolic events.

METHODS

Between July 2010 and October 2012, we treated 40 consecutive aneurysms with coil embolization using Enterprise stents. At the peri-procedural period, dual antiplatelet agents (100 mg aspirin and 75 mg clopidogrel) were used for the single stent group (n = 36), and triple antiplatelet agents (addition of 200 mg cilostazol) were used for the Y-stent group (n = 4). We evaluated post-operative diffusion-weighted imaging (DWI) and any complications. We assessed the following for statistical analysis: age, sex, aneurysm location, shape, and size, neck size, size of parent vessels, and stent length.

RESULTS

We found two neurological peri-procedural complications: one transient ischemic attack and one infarction. Both complications belonged to the Y-stent group, which was a significant factor of thromboembolic events (P = 0.008). There were no other significant factors related to neurological complications or positive DWI. For subgroup analysis of the single stent group, stent length was significantly longer in positive DWI than negative DWI (P = 0.04). In the follow-up period of 20 ± 8.6 months, there were no symptomatic late complications in any patients.

CONCLUSIONS

Although the number of patients in the Y-stent group is small, this group had a significantly higher risk of thromboembolic complications. While our protocol of a routine dose of dual antiplatelet therapy may be sufficient for single stent therapy, our protocol of a routine dose of triple antiplatelet therapy for Y-stents may not prevent thromboembolic events. This suggests that evaluation of platelet function may be essential, especially for Y-stents.