Premature Ticagrelor Discontinuation in Secondary Prevention of Atherosclerotic CVD: JACC Review Topic of the Week

Ticagrelor is a cornerstone of modern antithrombotic therapy alongside aspirin in patients with acute coronary syndrome and after percutaneous coronary intervention. Adverse effects such as bleeding and dyspnea have been associated with premature ticagrelor discontinuation, which may limit any potential advantage of ticagrelor over clopidogrel. The randomized trials of ticagrelor captured adverse events, offering the opportunity to more precisely quantify these effects across studies. Therefore, a meta-analysis of 4 randomized clinical trials of ticagrelor conducted between January 2007 and June 2017 was performed to quantify the incidence and causes of premature ticagrelor discontinuation. Among 66,870 patients followed for a median 18 months, premature ticagrelor discontinuation was seen in 25%; bleeding was the most common cause of discontinuation followed by dyspnea. Versus the comparators, the relative risk of dyspnea-related discontinuation during follow-up was 6.4-fold higher, the relative risk of bleeding was 3.2-fold higher, and the relative risk of discontinuation due to any adverse event was 59% higher for patients receiving ticagrelor. Understanding these potential barriers to adherence to ticagrelor is crucial for informed patient-physician decision making and can inform future efforts to improve ticagrelor adherence. This review discusses the incidence, causes, and biological mechanisms of ticagrelor-related adverse effects and offers strategies to improve adherence to ticagrelor.     

DAPT Enhances the Apoptosis of Human Tongue Carcinoma Cells

Aim To investigate the effect of DAPT （γ-secretase inhibitor） on the growth of human tongue carcinoma cells and to determine the molecular mechanism to enable the potential application of DAPT to the treatment of tongue carcinoma. Methodology Human tongue carcinoma Tca8113 cells were cultured with DAPT. Cell growth was determined using Indigotic Reduction method. The cell cycle and apoptosis were analyzed by flow cytometry. Real-time PCR and Immuno-Fluorescence （IF） were employed to determine the intracellular expression levels. Results DAPT inhibited the growth of human tongue carcinoma Tca8113 cells by inducing G0-G1 cell cycle arrest and apoptosis, The mRNA levels of Hairy/Enhancer of Split-1 （Hes-1）, a target of Notch activation, were reduced by DAPT in a dose-dependent manner. Coincident with this observation, DAPT induced a dose-dependent promotion of constitutive Caspase-3 in Tca8113 cells. Conclusion DAPT may have a therapeutic value for human tongue carcinoma. Moreover, the effects of DAPT in tumor inhibition may arise partly via the modulation of Notch- 1 and Caspase-3.     

Advances in Percutaneous Coronary Interventions for Elderly Patients

Coronary heart disease (CHD) is one of the leading causes of morbidity and the most common cause of death in older adults. Paradoxically, elderly patients tend to be systematically excluded from randomized-controlled cardiovascular trials, which complicates decision-making in this population. Management of CHD in the elderly is frequently more difficult in virtue of chronic comorbid conditions and aging-intrinsic dynamics. Despite these challenges, the number of elderly and very elderly patients undergoing percutaneous coronary interventions (PCI) is increasing. Elderly patients in many registries and large clinical series exhibit even a greater benefit from interventional procedures than younger patients, but they have a higher rate of overall complications. We present an overview of the current available evidence of PCI in older adults with stable and unstable CHD, including comparisons between drug-eluting and bare-metal stents, transfemoral and transradial access, and methods of revascularization. Adjuvant antiplatelet and antithrombotic therapies are also discussed.     

Dual Antiplatelet Therapy Duration Determines Outcome After 2- But Not 1-Stent Strategy in Left Main Bifurcation Percutaneous Coronary Intervention

Objectives

The aim of this study was to investigate clinical outcomes after left main coronary artery (LM) bifurcation percutaneous coronary intervention (PCI) and the impact of the duration of dual antiplatelet therapy (DAPT) according to treatment strategy.

Usefulness of the PARIS Score to Evaluate the Ischemic-hemorrhagic Net Benefit With Ticagrelor and Prasugrel After an Acute Coronary Syndrome

Introduction and objectives

The PARIS score allows combined stratification of ischemic and hemorrhagic risk in patients with ischemic heart disease treated with coronary stenting and dual antiplatelet therapy (DAPT). Its usefulness in patients with acute coronary syndrome (ACS) treated with ticagrelor or prasugrel is unknown. We investigated this issue in an international registry.

Assessment of Platelet REACtivity After Transcatheter Aortic Valve Replacement: The REAC-TAVI Trial

Objectives

The REAC-TAVI (Assessment of platelet REACtivity after Transcatheter Aortic Valve Implantation) trial enrolled patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) pre-treated with aspirin + clopidogrel, aimed to compare the efficacy of clopidogrel and ticagrelor in suppressing high platelet reactivity (HPR) after TAVI.

Correlates and Outcomes of Late and Very Late Drug-Eluting Stent Thrombosis: Results From DESERT (International Drug-Eluting Stent Event Registry of Thrombosis)

ObjectivesThe aim of this study was to identify clinical, procedural, and angiographic correlates of late/very late drug-eluting stent (DES) thrombosis as well as to determine the clinical outcomes of these events.BackgroundLate/very late DES thromboses are a poorly studied phenomenon, partly due to the relative infrequency of these events, even in large cohort studies.MethodsIn the DESERT (International Drug-Eluting Stent Event Registry of Thrombosis), a retrospective, case-control registry, 492 cases of late/very late definite DES thrombosis from 21 international sites were matched in a 1:1 fashion with controls without stent thrombosis (ST). Controls were matched according to 2 criteria: same enrolling institution and date of initial DES implantation. Baseline and procedural variables were collected, and clinical follow-up was obtained for patients with ST as long as 1 year after the event. Offline quantitative coronary angiography was performed for a subset of 378 case-control pairs.ResultsThe majority of ST events occurred after 1 year (75%) and continued to occur for as long as 7.3 years. The clinical presentation of late/very late ST events was mainly myocardial infarction (66.7% ST-segment elevation myocardial infarction and 22.0% non–ST-segment elevation myocardial infarction); in-hospital mortality was 3.8%. A minority of patients (30%) with ST were receiving dual-antiplatelet therapy at the time of the event. Independent clinical correlates of late/very late ST were younger age, African-American race, current smoking, multivessel disease, longer stented length, overlapping stents, and percutaneous coronary intervention of vein graft lesions. Independent angiographic correlates for late/very late ST were lesions within the left anterior descending artery or a bypass graft, thrombus, and a larger residual diameter stenosis after the initial DES implantation. Despite the large sample of ST cases, all identified correlates of late/very late ST had weak associations with subsequent ST (all odds ratios <2.5).ConclusionsDespite a large sample of ST cases and use of limited matching to maximize the identification of predictive factors associated with late/very late ST, the variables associated with the development of late/very late ST were only weakly predictive of subsequent events. Additionally, a relatively low observed mortality rate of ST in this series may reflect a different pathophysiology of these late/very late events compared with acute/subacute ST. (Drug Eluting Stent Registry of Thrombosis [DESERT]; NCT00812552).     

A Randomized Comparison of Novel Biodegradable Polymer- and Durable Polymer–Coated Cobalt-Chromium Sirolimus-Eluting Stents

ObjectivesThe aim of this study was to investigate the hypothesis that a novel biodegradable polymer–coated, cobalt-chromium (CoCr), sirolimus-eluting stent (BP-SES) is noninferior in safety and efficacy outcomes compared with a durable polymer (DP)-SES.BackgroundNo randomized trials have the compared safety and efficacy of BP-SES versus DP-SES on similar CoCr platforms, thereby isolating the effect of the polymer type.MethodsIn this prospective, single-blind, randomized trial conducted at 32 Chinese sites, 2,737 patients eligible for coronary stenting were treated with BP- or DP-SES in a 2:1 ratio. The primary endpoint was 12-month target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, or clinically indicated target lesion revascularization. Secondary endpoints included TLF components, and definite/probable stent thrombosis.ResultsAt 12 months, the difference in the primary endpoint of TLF between BP-SES (6.3%) and DP-SES (6.1%) groups was 0.25% (95% confidence interval: −1.67% to 2.17%, p for noninferiority = 0.0002), demonstrating noninferiority of BP-SES to DP-SES. Individual TLF components of cardiac death (0.7% vs. 0.6%, p = 0.62), target vessel myocardial infarction (3.6% vs. 4.3%, p = 0.39), and clinically indicated target lesion revascularization (2.6% vs. 2.2%, p = 0.50) were similar, as were low definite/probable stent thrombosis rates (0.4% vs. 0.6%, p = 0.55).ConclusionsIn this large-scale real-world trial, BP-SES was noninferior to DP-SES for 1-year TLF. (Evaluate Safety and Effectiveness of the Tivoli ® DES and the Firebird ® DES for Treatment of Coronary Revascularization; NCT01681381)     

DAPT suppresses the proliferation of human glioma cell line SHG-44

Objective:To explore the suppressing effect ofγ-secretase inhibitor DAPT on proliferation of human glioma cell line SHG-44 in vitro and its mechanism.Methods:The SHG-44 cell was treated by DAPT with different concentration.The proliferation of cells was detected by MTT assay;cell cycle and TSC of CD133~+were determined by flow cytometry analysis technique;the key factor in Notch signaling pathway(Notch-1,Delta-1,Hes-1)was measured by reverse transcrip tase-polymerase chain reaction and western blotting.Results:DAPT inhibited the growth and proliferation of SHG-44 cells significantly(P0.05).And the inhibiting effect on SHG-44 cells produced by DAPT showed a dose-dependent manner.DAPT increased the rate of cells in G_0/G_1 phase of SHG-44 cells,while it decreased the rate of cells in S phase.TSC of CD133~+was significantly reduced after DAPT treated SHC-44 cells.The expression of protein and mRNA of Notch-1,Delta-1 and Hes-1 were gradually downregulated with the increase of DAPT doses.Conclusions:DAPT can downregulate these key factor in Notch signaling pathway,reduce the TSC of CD133+and inhibit the proliferation of SHC-44 cells.     

Notch通路对乙醛激活大鼠肝星状细胞株的增殖及转分化的影响

目的观察Notch通路对乙醛激活大鼠肝星状细胞株HSC-T6增殖并转分化为肌成纤维细胞的影响。方法 HSC-T6细胞常规培养及乙醛处理,加入Notch途径特异性阻断剂DAPT和TGF-β/ALK5途径特异性阻断剂SB-431542,分为空白组、单阻断组及双阻断组;MTT法检测细胞增殖;ELISA法检测Ⅰ型胶原蛋白(TIMPⅠ)、纤维黏连素(FN)的表达;RT-PCR检测Notch途径节点分子RBP-JK、Hes1及效应蛋白Smad3表达量;Western印迹检测细胞内效应蛋白α-SMA的表达。结果 MTT检测发现乙醛刺激明显增强HSC活性(P<0.05),阻断组明显下调(P<0.05);ELISA结果表明乙醛刺激后TIMP I和FN的表达明显上调(P<0.05),阻断组明显下调(P<0.05);RT-PCR检测Hes1乙醛刺激后上调明显(P<0.05),阻断组RBP-JK、Hes1及Smad3明显下调(P<0.05),双阻断组Hes1及Smad3下调更明显(P<0.05);Western印迹检测结果显示乙醛刺激明显促进α-SMA表达(P<0.05),阻断组明显下调(P<0.05),双阻断组下调更明显(P<0.05)。结论 Notch通路明显影响乙醛对肝星状细胞的增殖及转分化为肌成纤维细胞。