Impact of cytochrome P450 2C19 loss-of-function polymorphism on intra-stent thrombi and lesion outcome after everolimus-eluting stent implantation compared to that after first-generation drug-eluting stent implantation

Impact of the Antithrombotic Effects of Prasugrel on Mid-Term Vascular Healing in Acute Coronary Syndrome vs. Stable Coronary Artery Disease

BACKGROUND

The impact of antiplatelet drug effects on mid-term local arterial responses following percutaneous coronary intervention (PCI) remains uncertain. We evaluated the impact of the platelet reactivity of prasugrel on mid-term vascular healing between acute coronary syndrome (ACS) and stable coronary artery disease (CAD).

METHODS AND RESULTS

We conducted a prospective, 12-center study in 125 patients with ACS and 126 patients with stable CAD who underwent PCI with an everolimus-eluting stent (EES) and received dual antiplatelet therapy (DAPT) with prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed immediately after PCI and at the 9-month follow-up to assess the association of P2Y12reaction units (PRU) with the frequency of malapposed or uncovered struts and intrastent thrombi (IST). The incidence of abnormal mid-term OCT findings did not different between the ACS and CAD arms, regardless of clinical presentation, except that uncovered struts were more frequent in the ACS than CAD arm. PRU at PCI was significantly associated with the frequency of IST at follow-up, but not with uncovered and malapposed struts. PRU at PCI was the only independent predictor of IST detected at follow-up (odds ratio 1.009).

CONCLUSIONS

In patients undergoing EES implantation and receiving prasugrel, achieving an adequate antiplatelet effect at the time of stent implantation may regulate thrombus formation throughout the follow-up period.

Impact of dual antiplatelet therapy with adjusted-dose prasugrel on mid-term vascular response in patients undergoing elective percutaneous coronary intervention with everolimus-eluting stents

The impact of dual antiplatelet therapy (DAPT) with adjusted-dose (3.75 mg/day) prasugrel for Japanese patients has not been fully investigated in terms of local arterial healing following the elective percutaneous coronary intervention (PCI). The ROUTE-01 elective study was a prospective, 12-center and single-arm registry that enrolled 123 patients who underwent elective PCI with everolimus-eluting stents (EESs) under DAPT with a combination of adjusted-dose prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed at the index PCI and 9-month follow-up to assess the relationship between in-stent thorombus (IST) and residual platelet reactivity measuring platelet reactivity unit (PRU). The patients were classified as extensive, intermediate, and poor metabolizers by cytochrome P450 2C19 (CYP2C19) loss-of-function polymorphisms. The prevalence of IST was 9.0% by 9-month OCT, with no difference amongst the three groups (p = 0.886). The incidences of malapposed and uncovered struts were not different among the groups. PRU was not statistically different among the groups. In multivariate logistic regression analysis, the independent predictor for IST on 9-month OCT was irregular protrusion (odds ratio = 8.952, p = 0.037) on post-PCI OCT, not CYP2C19 loss-of-function polymorphisms. An adequate anti-thrombotic effect with an acceptable incidence of IST was observed irrespective of CYP2C19 loss-of-function polymorphisms. Our data suggests that adjusted-dose prasugrel and aspirin is a feasible treatment option in Japanese patients treated with EESs in elective PCI.

Lower on-treatment platelet reactivity during everolimus-eluting stent implantation contributes to the resolution of post-procedural intra-stent thrombus: serial OCT observation in the PRASFIT-Elective study

Intra-stent thrombus (IS-Th) formed immediately after percutaneous coronary intervention (PCI) is associated with subsequent adverse coronary events. However, the impact of on-treatment platelet reactivity on IS-Th is unknown. PRASFIT-Elective is a multicenter study of PCI patients receiving prasugrel (20/3.75 mg, loading/maintenance dose) or clopidogrel (300/75 mg), with aspirin (100 mg). Among the 742 study patients, 111 were pre-specified for the OCT sub-study. Of these, 82 underwent OCT immediately after PCI to assess IS-Th and at an 8-month follow-up to evaluate the fate of the IS-Th. Lesions were considered resolved when IS-Th were detected after PCI but not on the follow-up or persistent when IS-Th were observed on both scans. The P2Y12 Reactive Unit (PRU) value was determined at the initial PCI and 4 and 48 weeks post-PCI. In 76 patients (86 lesions), we detected 230 IS-Th initially, and 196 IS-Th (85.2%) were resolved at the 8-month OCT. At PCI, but not 4 or 48 weeks after, the resolved IS-Th group had a lower PRU than the persistent IS-Th group (199 ± 101 vs. 266 ± 102, p = 0.008). Multivariate logistic regression analyses revealed that lower PRU at PCI and less calcified lesions were independent predictive factors for the resolution of IS-Th. Local lesion-related factors and lower on-treatment platelet reactivity at the time of PCI may contribute to the resolution of IS-Th after EES implantation, potentially improving clinical outcome.

High-risk Plaque and Calcification Detected by Coronary CT Angiography to Predict Future Cardiovascular Events After Percutaneous Coronary Intervention

RATIONALE AND OBJECTIVES

The purpose of this study was to investigate whether high-risk plaque (HRP) and calcium assessed by coronary computed tomography (CT) could predict future cardiovascular events after second-generation drug-eluting stent (DES) placement.

MATERIALS AND METHODS

We analyzed 317 patients from December 2012 to April 2015 who underwent coronary CT followed by DES placement. HRP was defined as a plaque with positive remodeling and low attenuation or a plaque with a napkin-ring sign. Coronary calcium was assessed by Agatston score (AS). Patients were divided into three groups: low risk, HRP negative and AS <400; intermediate risk, HRP positive and AS ≥400; high risk, HRP positive and AS ≥400. The primary end point was a composite of all-cause mortality, myocardial infarction, fatal arrhythmia, or repeated revascularization. Kaplan-Meier analysis was used to estimate the distribution of time to events.

RESULTS

A total of 74 events (23%) occurred during a median follow-up of 25.8 months. Patients with primary end points had HRP more frequently (70% vs 51%, P = 0.003) and were more calcified (AS, 471 [interquartile range, 143-1614] vs 289 [interquartile range, 63-787]; P = 0.01) than patients without primary end points. The frequency of primary end point increased significantly in the intermediate- and high-risk patients (P = 0.0011). Multivariate analysis showed that the hazard ratio of the intermediate- and high-risk groups was 1.91 (95% confidence interval, 1.04-3.77; P = 0.037) and 2.66 (95% confidence interval, 1.27-5.73; P = 0.009), respectively.

CONCLUSION

Plaque and calcification analysis by coronary CT could predict future cardiovascular events after second-generation DES placement.

CYP2C19 loss-of-function alleles are not associated with clinical outcome of clopidogrel therapy in patients treated with newer-generation drug-eluting stents

CYP2C19 loss-of-function (LOF) alleles adversely affect clinical outcome of clopidogrel therapy. Recent introduction of a newer-generation drug-eluting stent (DES) has significantly reduced the occurrence of stent thrombosis.The aim of this study was to evaluate the impact of CYP2C19 LOF alleles on clinical outcome in patients treated with the newer-generation DES.The effects of CYP2C19 genotypes were evaluated on clinical outcome of clopidogrel therapy in 2062 patients treated with percutaneous coronary intervention using either first-generation DES (sirolimus- and paclitaxel-eluting stent, n = 1349) or newer-generation DES (everolimus- and zotarolimus-eluting stent, n = 713). The primary clinical outcome was major cardiac and cerebrovascular event (MACCE) including cardiac death, nonfatal myocardial infarction, stroke, and stent thrombosis during 1 year of follow-up.CYP2C19 LOF alleles were significantly associated with a higher risk of MACCE in patients treated with first-generation DES (hazard ratio [HR] 2.599, 95% confidence interval [CI] 1.047-6.453; P = 0.034). In contrast, CYP2C19 LOF alleles were not associated with primary outcome in newer-generation DES (HR 0.716, 95% CI 0.316-1.622; P = 0.522). In the further multivariate analysis, CYP2C19 LOF alleles were not associated with MACCE in patients receiving newer-generation DES (adjusted HR 0.540, 95% CI 0.226-1.291; P = 0.166), whereas they were demonstrated to be an independent risk factor for MACCE in those implanted with first-generation DES (adjusted HR 3.501, 95% CI 1.194-10.262; P = 0.022).In contradiction to their clinical impact in first-generation DES era, CYP2C19 LOF alleles may not affect clinical outcome of clopidogrel therapy in patients treated with newer-generation DES.