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

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 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.

Relationship between smoking and responsiveness to clopidogrel in non-cardiogenic ischemic stroke patients

OBJECTIVE

Clopidogrel is used to prevent the recurrence of non-cardiogenic ischemic stroke, but individual responsiveness to the drug varies. Moreover, it is known that smoking, which is a risk factor for ischemic stroke, affects the drug's pharmacokinetics. The objective of the present study was to investigate a possible relationship between smoking and responsiveness to clopidogrel in non-cardiogenic ischemic stroke patients.

METHODS

The study involved 209 non-cardiogenic ischemic stroke patients who were administered oral clopidogrel at a dosage of 75 mg/day for at least 1 week. Platelet aggregation in response to adenosine diphosphate (20 μM) was measured in each patient using the VerifyNow P2Y12 Assay. Platelet aggregation and the incidence of resistance to clopidogrel were compared between a smokers group (70 patients) and a non-smokers group (139 patients). Clopidogrel resistance was defined as a P2Y12 Reaction Units (PRU) value >230 and/or % inhibition <20%.

RESULTS

The mean PRU was 128.3±85.5 in the smokers group and 167.7±86.6 in the non-smokers group (p=0.002). The incidence of PRU >230 was 12.9% (9 patients) in the smokers group and 25.9% (36 patients) in the non-smokers group (p=0.033). The mean % inhibition was 48.6±30.7% in the smokers group and 36.9±27.6% in the non-smokers group (p=0.009). The incidence of patients with % inhibition <20% was 24.3% (17 patients) in the smokers group and 34.5% (48 patients) in the non-smokers group (p=0.155).

CONCLUSION

The incidence of clopidogrel resistance was lower in the non-cardiogenic ischemic stroke patients who were smokers, thus indicating that these patients' responsiveness to this drug may be enhanced.

Response to clopidogrel and its association with chronic kidney disease in noncardiogenic ischemic stroke patients

OBJECTIVE

Noncardiogenic ischemic stroke patients with chronic kidney disease (CKD) are known to have a greater rate of ischemic stroke recurrence than those without. Although clopidogrel is often used to prevent the recurrence of noncardiogenic ischemic stroke, the relationship between the response to clopidogrel and CKD is unclear. In the present study, the relationship between the response to clopidogrel and the presence of CKD was investigated in noncardiogenic ischemic stroke patients.

METHODS

A total of 129 noncardiogenic ischemic stroke patients receiving 75 mg/day of clopidogrel for ≥1 week were evaluated. The VerifyNow P2Y12 Assay was used to measure the level of platelet aggregation induced by 20 μM of adenosine diphosphate, and the degree of platelet aggregation and frequency of clopidogrel resistance were compared between 34 patients with CKD and 95 patients without CKD. Clopidogrel resistance was defined as a P2Y12 Reaction Units (PRU) value of >230 and/or % inhibition <20%.

RESULTS

The PRU value was 201.9±91.3 in the patients with CKD and 163.3±86.4 in the patients without CKD (p=0.035). The frequency of a PRU value of >230 was 44.1% (15 patients) among the patients with CKD and 17.9% (17 patients) among those without CKD (p=0.002). The percent inhibition was 29.9%±28.1% among the patients with CKD and 41.1%±28.0% among the patients without CKD (p=0.030). The frequency of % inhibition <20% was 47.1% (16 patients) among the patients with CKD and 26.3% (25 patients) among those without CKD (p=0.026).

CONCLUSION

The present study showed that noncardiogenic ischemic stroke patients with CKD have a greater frequency of clopidogrel resistance, thus suggesting that the response to clopidogrel is diminished in these patients.

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.

Dual antiplatelet therapy clopidogrel with low-dose cilostazol intensifies platelet inhibition in patients with ischemic stroke

OBJECTIVE

We previously reported that the antiplatelet action is intensified with combined use of clopidogrel and cilostazol in ischemic stroke patients using the VerifyNow P2Y12 Assay. In this study, the relationship between the cilostazol dose and the platelet function achieved with combination therapy was investigated.

METHODS

The subjects included 231 patients with noncardiogenic ischemic stroke treated at our hospital (18 patients treated with a combination of clopidogrel (75 mg) and cilostazol (100 mg), 52 patients treated with a combination of clopidogrel (75 mg) and cilostazol (200 mg), 126 patients treated with clopidogrel (75 mg) alone and 35 patients treated with cilostazol (200 mg) alone). The platelet function achieved with 20 μM of adenosine diphosphate was measured using the VerifyNow P2Y12 Assay. Clopidogrel resistance was defined as P2Y12 Reaction Units (PRU) >230 and/or % inhibition <20%. Results The PRU was >230 in 32 patients (25.4%) receiving clopidogrel alone, one patient (5.6%) receiving combination therapy with cilostazol (100 mg) and one patient (1.9%) receiving combination therapy with cilostazol (200 mg). The rate of PRU >230 was significantly lower in both of the cilostazol combination groups than in the clopidogrel alone group. The percent inhibition was <20% in 41 patients (32.5%) receiving clopidogrel alone, one patient (5.6%) receiving a combination with cilostazol (100 mg) and one patient (1.9%) receiving a combination with cilostazol (200 mg). The rate of % inhibition <20% was significantly lower in both of the cilostazol combination groups than in the clopidogrel alone group.

CONCLUSION

Clopidogrel resistance was clearly decreased with combination clopidogrel (75 mg) and low-dose (100 mg) cilostazol therapy. The use of combination therapy with clopidogrel and low-dose cilostazol may be one means of overcoming clopidogrel resistance.

Effect of premedication method and drug resistance of antiplatelet agent on periprocedural thromboembolic events during coil embolization of an unruptured intracranial aneurysm

Objective

A retrospective review of premedication method and drug resistance of aspirin and clopidogrel in association with thromboembolic events during and after coil embolization of an unruptured intracranial aneurysm was conducted.

Methods

Our premedication policy for coil embolization of an unruptured intracranial aneurysm has changed from administration of the loading dose before the procedure (i.e. loading group) to repeated administration of the maintenance dose for several days (i.e. preparation group). The loading group (27 patients with 29 aneurysms) and the preparation group (30 patients with 35 aneurysms) were compared for identification of the effect of premedication method on periprocedural thromboembolic events. The results of drug response assays of the preparation group were analyzed with respect to periprocedural thromboembolic events.

Results

No statistically significant difference in incidence of thromboembolic events was observed between the loading group and the preparation group. Analysis of the results of the drug response assay showed high prevalence (56.7%, 73.3%) of clopidogrel resistance and relatively low prevalence (6.7%) of aspirin resistance. Patients who had thromboembolic events tended to have lower responsiveness to both aspirin and clopidogrel than patients without it.

Conclusion

The method of antiplatelet premedication does not affect the rate of periprocedural thromboembolic events in coil embolization for treatment of an unruptured intracranial aneurysm. Nevertheless, considering the high prevalence of drug resistance, it is reasonable to premedicate antiplatelet agents in the preparation method for the drug response assay. Use of a higher dose of aspirin and clopidogrel or addition of an alternative drug (cilostazol or triflusal) can be applied against antiplatelet agent resistance. However, because the hemorrhagic risk associated with this supplementary use of antiplatelet agent has not been well-documented, the hemorrhagic risk and the preventive benefit must be weighed.