Triple versus dual antiplatelet therapy for coronary heart disease patients undergoing percutaneous coronary intervention: A meta-analysis

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.

Stent thrombosis associated with drug eluting stents on addition of cilostazol to the standard dual antiplatelet therapy following percutaneous coronary intervention: a systematic review and meta-analysis of published randomized controlled trials

Background

In this analysis, we aimed to systematically compare stent thrombosis (ST) and its different subtypes following treatment with DAPT (aspirin + clopidogrel) versus TAPT (aspirin + clopidogrel + cilostazol).

Methods

Studies were included if: they were randomized controlled trials (RCTs) comparing TAPT (cilostazol + aspirin + clopidogrel) with DAPT (aspirin + clopidogrel); they reported ST or its subtype including definite, probable, acute, sub-acute and late ST as their clinical outcomes. RevMan software (version 5.3) was used to carry out this analysis whereby odds ratios (OR) and 95% confidence intervals (CI) were generated.

Results

Statistical analysis of the data showed no significant difference in total ST with the addition of cilostazol to the standard DAPT with OR: 0.65, 95% CI: 0.38–1.10; P = 0.11, I² = 6%. Moreover, when ST was further subdivided and analyzed, still, no significant difference was observed in acute, sub-acute, late, definite and probable ST with OR: 0.48, 95% CI: 0.13–1.74; P = 0.27, I² = 0%, OR: 0.56, 95% CI: 0.22–1.40; P = 0.21, I² = 0%, OR: 0.72, 95% CI: 0.23–2.28; P = 0.58, I² = 0%, OR: 1.18, 95% CI: 0.38–3.69; P = 0.77, I² = 3% and OR: 0.75, 95% CI: 0.17–3.55; P = 0.70, I² = 0% respectively. No change was observed during a short term (≤ 6 months) and a longer (≥ 1 year) follow-up time period.

Conclusions

This current analysis showed no significant difference in stent thrombosis with the addition of cilostazol to the standard dual antiplatelet therapy during any follow-up time period after PCI.

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.

Association of seven thrombotic pathway gene CpG-SNPs with coronary heart disease

OBJECTIVES

Coronary heart disease (CHD) has been considered a thromboembolic arterial diseases. The aim of this case-control study was to explore whether the CpG-SNPs of the thrombotic pathway genes contributed to the risk of CHD.

METHODS AND MATERIALS

A total of 784 CHD patients and 738 healthy controls were recruited in the current association study, which evaluated 7 CpG-SNPs of the thrombotic pathway genes. The CpG-SNPs included THBS4 rs17878919, CYP2C19 rs12773342, P2RY12 rs1491974, ITGA2 rs26680, FGB rs2227389, F7 rs510317 and F5 rs2269648. SNP genotyping was performed with a Sequenom Mass Spectrometry Genetic Analyzer.

RESULTS

Our results demonstrated that CYP2C19 rs12773342 polymorphism was significantly associated with CHD in the recessive model (χ(2)=5.41, df=1, P=0.020, OR=1.455, 95% CI=1.060-1.996). A breakdown analysis by age showed that the association of CYP2C19 rs12773342 with CHD was mainly found in individuals aged 55-65 (genotype: χ(2)=7.93, df=2, P=0.019; allele: χ(2)=4.45, df=1, P=0.035). In addition, we also observed a significant association between F7 rs510317 polymorphism and CHD in males (genotype: χ(2)=7.24, df=2, P=0.027). There was no significant association with CHD for the remaining CpG-SNPs.

CONCLUSION

Our results supported that the CYP2C19 rs12773342 and F7 rs510317 polymorphisms were associated with CHD in the Han Chinese population.

Simulation of the microscopic process during initiation of stent thrombosis

OBJECTIVE

Coronary stenting is one of the most commonly used approaches to open coronary arteries blocked due to atherosclerosis. However, stent struts can induce stent thrombosis due to altered hemodynamics and endothelial dysfunction, and the microscopic process is poorly understood. The objective of this study was to determine the microscale processes during the initiation of stent thrombosis.

METHODS

We utilized a discrete element computational model to simulate the transport, collision, adhesion, and activation of thousands of individual platelets and red blood cells in thrombus formation around struts and dysfunctional endothelium.

RESULTS

As strut height increased, the area of endothelium activated by low shear stress increased, which increased the number of platelets in mural thrombi. These thrombi were generally outside regions of recirculation for shorter struts. For the tallest strut, wall shear stress was sufficiently low to activate the entire endothelium. With the entire endothelium activated by injury or denudation, the number of platelets in mural thrombi was largest for the shortest strut. The type of platelet activation (by high shear stress or contact with activated endothelium) did not greatly affect results.

CONCLUSIONS

During the initiation of stent thrombosis, platelets do not necessarily enter recirculation regions or deposit on endothelium near struts, as suggested by previous computational fluid dynamics simulations. Rather, platelets are more likely to deposit on activated endothelium outside recirculation regions and deposit directly on struts. Our study elucidated the effects of different mechanical factors on the roles of platelets and endothelium in stent thrombosis.