Stent thrombosis: who's guilty?

Three-Year Clinical Outcomes With the Cilotax Dual Drug-Eluting Stent vs Everolimus-Eluting Stents in Patients With Acute Myocardial Infarction

BACKGROUND

This study compared the safety and effectiveness of paclitaxel/cilostazol-eluting Cilotax stents with those of everolimus-eluting stents in patients with acute myocardial infarction. Real-world data from the Korea Acute Myocardial Infarction Registry were examined.

METHODS

A total of 5,472 patients with acute myocardial infarction underwent percutaneous coronary intervention with Cilotax stents (n = 212) or everolimus-eluting stents (n = 5,260). The primary end point was the 3-year rate of target lesion failure. The other end points were major adverse cardiovascular events (a composite of cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization), target vessel revascularization, and stent thrombosis. A propensity score matching analysis was performed to adjust for potential confounders by using a logistic regression model; propensity score matching generated 2 well-balanced groups (Cilotax group, n = 180; everolimus-eluting stents group, n = 170; N = 350). After propensity score matching, baseline clinical characteristics were similar between the groups.

RESULTS

After percutaneous coronary intervention, compared with the everolimus-eluting stents group, the Cilotax group more often had major adverse cardiovascular events (24.1% vs 18.5%; P = .042), myocardial infarction (8.0% vs 3.2%; P < .001), target lesion revascularization (8.0% vs 2.6%; P < .001), target vessel revascularization (11.3% vs 4.5%; P < .001), and stent thrombosis (4.7% vs 0.5%; P < .001) before matching. Even after matching, the Cilotax group had more frequent target lesion revascularization (9.4% vs 2.9%; P = .22) and stent thrombosis (5.6% vs 1.2%; P = .34).

CONCLUSION

In patients with acute myocardial infarction who underwent percutaneous coronary intervention, use of the Cilotax stent was associated with higher rates of target lesion revascularization, target vessel revascularization, and stent thrombosis than were everolimus-eluting stents. Use of the Cilotax dual drugeluting stent should be avoided in the treatment of myocardial infarction.

Efficacy and Safety of Dual-Drug-Eluting Stents for de Novo Coronary Lesions in South Korea-The Effect Trial

Background: Drug-eluting stents (DESs) are commonly used in percutaneous coronary intervention (PCI) procedures; however, complications including in-stent restenosis and stent thrombosis are significant challenges. The dual-DES is a stent that elutes two drugs to target various stages of the restenosis reaction. This study investigated the safety and efficacy of dual-DES in clinical practice. Methods: This study included 375 patients who underwent PCI with Cilotax^™ or DXR^™ dual-DESs at one of 13 centers in South Korea. The primary endpoint was target lesion failure (TLF) within 1 year. The secondary endpoints were cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis. Results: The rates of TLF in dual-DESs (3.7%) were comparable to those reported in conventional DES. In addition, the DXR^™ group had a significantly lower rate of TLF than the Cilotax^™ group. In multivariate analysis, the DXR^™ group had a lower risk of TLF (adjusted hazard ratio (HR) 0.30, 95% CI 0.09–0.92, p = 0.036) and MI (adjusted HR 0.16, 95% CI 0.03–0.82, p = 0.027) than the Cilotax^™ group. Conclusion: Dual-DESs had similar clinical outcomes regarding efficacy and safety as conventional DES. Among the dual-DES, the DXR^™ stent as a new generation dual-DES had more favorable clinical outcomes than the Cilotax^™ stent.

Acute stent thrombosis: Should preventative measures start in the emergency department?

Stent thrombosis is a potentially life threatening condition caused by several factors or a combination factors, such as resistance to platelet agents and type of anticoagulation used as well as stent types. We report a case of acute thrombosis and discuss potential areas of intervention with literature review.

Personalized antiplatelet therapy according to CYP2C19 genotype after percutaneous coronary intervention: a randomized control trial

OBJECTIVE

The objective of this study is to compare personalized antiplatelet therapy according to CYP2C19 phenotype with conventional antiplatelet therapy in patients after percutaneous coronary intervention (PCI).

METHODS

A total of 600 patients with coronary artery disease (CAD) undergoing PCI randomly received a personalized antiplatelet therapy (group A; n=301) or conventional antiplatelet treatment (group B; n=299). For group A, antiplatelet therapy was performed according to CYP2C19 phenotype. For group B, the patients received conventional antiplatelet treatment without detected CYP2C19 genotype. The primary end point was compared between these two groups. This study is registered with the Chinese Clinical Trial Registry (ChiCTR-TRC-11001807).

RESULTS

The primary end point occurred in 27 patients assigned to conventional treatment as compared with 8 patients assigned to personalized therapy (cumulative event rate, 9.03% vs. 2.66%; P<0.01). The composite rate of death, myocardial infarction, or stroke at 180 days occurred in 3 and 18 patients in the two groups, respectively (cumulative event rate, 1.0% and 6.2%, P<0.01). The cumulative 180-day incidence of ST was significantly lower in group A than in group B (0.66% vs. 3.01%, P=0.032). The 180-day incidence of MI (0.33% vs. 3.01%, P=0.011) and death (0.33% vs. 2.34%, P=0.011) was fewer than that in control, respectively. We did not find the significant difference in bleeding events between the 2 groups.

CONCLUSION

Personalized antiplatelet therapy according to CYP2C19 genotype after PCI can significantly decrease the incidence of major adverse cardiovascular events and the risk of 180-day ST in Chinese population.

CYP2C19 phenotype, stent thrombosis, myocardial infarction, and mortality in patients with coronary stent placement in a Chinese population

Background

Several studies have indicated that CYP2C19 loss-of-function polymorphisms have a higher risk of stent thrombosis (ST) after percutaneous coronary interventions (PCIs). However, this association has not been investigated thoroughly in a Chinese population. In this study, we aimed to determine the effect of CYP2C19*2 and CYP2C19*3 loss-of-function polymorphisms on the occurrence of ST and other adverse clinical events in a Chinese population.

Methods

We designed a cohort study among 1068 consecutive patients undergoing intracoronary stent implantation after preloading with 600 mg of clopidogrel. CYP2C19*2 and CYP2C19*3 were genotyped by using polymerase chain reaction-restriction fragment length polymorphism analysis. The adverse clinical events recorded were ST, death, myocardial infarction (MI), and bleeding events. The primary end point of the study was the incidence of cumulative ST within 1 year after PCI. The secondary end point was other adverse clinical outcomes 1 year after the procedure.

Results

The cumulative 1-year incidence of ST was 0.88% in patients with extensive metabolizers (EMs) (CYP2C19*1/*1 genotype), 4.67% in patients with intermediate metabolizers (IMs) (CYP2C19*1/*2 or *1/*3 genotype), and 10.0% in patients with poor metabolizers (PMs) (CYP2C19*2/*2, *2/*3, or *3/*3 genotype) (P<0.001). The one-year event-free survival was 97.8% in patients with EMs, 96.5% in patients with IMs, and 92.0% in patients with PMs (P = 0.014). Multivariate analysis confirmed the independent association of CYP2C19 loss-of-function allele carriage with ST (P = 0.009) and total mortality (P<0.05).

Conclusion

PM patients had an increased risk of ST, death, and MI after coronary stent placement in a Chinese population.

Impact of CYP2C19 variant genotypes on clinical efficacy of antiplatelet treatment with clopidogrel: systematic review and meta-analysis

OBJECTIVE

To evaluate the accumulated information from genetic association studies investigating the impact of variants of the cytochrome P450 (CYP) 2C19 genotype on the clinical efficacy of clopidogrel.

DESIGN

Systematic review and meta-analysis with a structured search algorithm and prespecified eligibility criteria for retrieval of relevant studies; dominant genetic model assumptions and quantitative methods for calculating summary effect estimates from study level odds ratios; systematic assessment of bias within and between studies; and grading of the cumulative evidence by consensus criteria.

DATA SOURCES

Medline, Embase, the Cochrane Library, online databases, contents pages and bibliographies of general medical, cardiovascular, pharmacological, and genetic journals. Eligibility criteria for selecting studies Original full length reports assessing the cumulative incidence of major adverse cardiovascular events or stent thrombosis over a follow-up period of at least a month in association with carrier status for the loss of function or gain of function CYP2C19 allele in adult patients with coronary artery disease and a clinical presentation of acute coronary syndrome or stable angina pectoris who were taking clopidogrel.

RESULTS

15 studies met the inclusion criteria. The random effects summary odds ratio for stent thrombosis in carriers of at least one CYP2C19 loss of function allele versus non-carriers combining nine studies was 1.77 (95% confidence interval 1.31 to 2.40; P < 0.001). This nominally significant odds ratio was subject to considerable bias across the studies (small study effect bias and replication diversity). The adjustment for these quality modifiers tended to abolish the association. The corresponding random effects summary odds ratio of major adverse cardiovascular events for 12 studies combined was 1.11 (0.89 to 1.39; P = 0.36). The random effects summary odds ratio of stent thrombosis in carriers versus non-carriers of at least one CYP2C19*17 gain of function allele for three studies combined was 0.99 (0.60 to 1.62; P = 0.96), and the corresponding odds ratio of major adverse cardiovascular events in five studies was 0.93 (0.75 to 1.14; P = 0.48). The overall quality of epidemiological evidence was graded as low, which excludes reliable clinical assessments.

CONCLUSIONS

Accumulated information from genetic association studies does not indicate a substantial or consistent influence of CYP2C19 gene polymorphisms on the clinical efficacy of clopidogrel. The current evidence does not support the use of individualised antiplatelet regimens guided by CYP2C19 genotype.

Comparison of dual drug-eluting Cilotax stent and paclitaxel-eluting Taxus Liberte stent in native coronary artery lesions

Cilotax stent is a new type of drug-eluting stent (DES) designed to increase the antirestenotic performance of the paclitaxel-eluting stent and decrease the risk of stent thrombosis by the incorporation of cilostazol. Therefore, we investigated the safety and efficacy of Cilotax dual DESs and compared their performance to that of paclitaxel-eluting Taxus Liberte. Patients undergoing percutaneous coronary intervention for de novo coronary artery lesions at 2 centers in Korea were randomized to receive Cilotax (n = 55) or Taxus Liberte (n = 56) stents. The primary end point was in-segment late loss at 8 months. The 2 groups had similar baseline characteristics. Cilotax stent was not inferior to Taxus Liberte stent as determined by in-segment late loss (0.28 ± 0.30 vs 0.42 ± 0.45 mm, difference -0.14, 95% confidence interval -0.27 to -0.01, 1-sided p = 0.028 for noninferiority). In-stent late loss was significantly lower in the Cilotax than in the Taxus Liberte group (0.22 ± 0.31 vs 0.50 ± 0.55 mm, p = 0.002). Although in-segment restenosis rate did not differ significantly between the 2 groups (3.8% vs 10.9%, respectively, p = 0.271), in-stent restenosis rate was significantly lower in the Cilotax stent group (0% vs 10.9%, p = 0.027). There was no stent thrombosis at 8 months in either group. Rates of death, myocardial infarction, and any target lesion revascularization at 8 months were 0%, 0%, and 1.9%, respectively, in the Cilotax group and 1.8%, 0% and 3.6%, respectively, in the Taxus Liberte group. In conclusion, the Cilotax stent was safe and effective in decreasing late loss, indicating that this stent represents a promising new type of DES system.