Recurrent Atherothrombotic Events Research Articles

A study of the comparative effectiveness of dual antiplatelet therapy and a combination of acetylsalicylic acid with colchicine in patients in the acute period of “minor” ischemic atherothrombotic stroke during hospitalization. Interim analysis of data from the «COLCHIDA» study

Influence on inflammation is currently becoming a priority target for the prevention of recurrent atherothrombotic events, including stroke. In 2022, we planned the KOLCHIDA study, a two-center, prospective, randomized, open-label, controlled clinical trial with endpoint assessment (ClinicalTrials.gov identifier: NCT06102720). The purpose of this study is to conduct a comparative assessment of the clinical effectiveness of dual antiplatelet therapy with acetylsalicylic acid (ASA) and clopidogrel and the combination of ASA with colchicine in patients in the acute period of “minor” ischemic atherothrombotic stroke. The purpose of this publication is to present the basic concept of the protocol, its design and the first intermediate results. Material and methods. The intervention consisted of colchicine 0.5 mg/day in addition to ASA versus dual antiplatelet therapy (DAPT) in patients with non-severe ischemic stroke. 31 patients were included in the colchicine and ASA group, and 34 patients were included in the DAPT group. Results. In the comparison group, 7 (20.6%) recurrent non-fatal strokes were recorded, in contrast to the colchicine group, where acute vascular events were recorded in only two patients (6.5%) [RRR 2.2, NNT = 7, χ2 = 2, 9, p = 0.09]. There were no clinically significant bleeding or other adverse events in both groups. Conclusion. Interim results of the study indicate possible confirmation of the hypothesis that anti-inflammatory therapy with low doses of colchicine in combination with standard therapy is not inferior to the combination of ASA and clopidogrel, and perhaps more effectively reduces the number of early neurological deteriorations and recurrent ischemic strokes in patients in the acute period of mild atherothrombotic stroke with equal security profile.

Impact of antiplatelet therapy on microvascular thrombosis during ST-elevation myocardial infarction.

During an acute coronary syndrome, atherosclerotic plaque rupture triggers platelet activation and thrombus formation, which may completely occlude a coronary artery leading to ST-elevation myocardial infarction (STEMI). Although emergency percutaneous coronary intervention (PCI) is effective in re-opening the main coronary arteries, the downstream microvasculature can become obstructed by embolised plaque material and thrombus. Dual antiplatelet therapy is recommended by guidelines and used routinely for the management of STEMI to reduce the risk of recurrent atherothrombotic events. However it is unclear to what extent antiplatelet therapy reduces microvascular thrombosis, largely because most tools to assess microvascular thrombosis only became available after antiplatelet therapy was already used in the majority of patients. Platelets play a central role in key aspects of microvascular thrombosis, such as atherosclerotic plaque-induced thrombus development, inflammation and microvascular dysfunction, making them a potential target for novel therapeutic interventions. Currently, more potent antiplatelet agents like GPIIb/IIIa inhibitors may be administered during PCI directly into coronary arteries with high thrombus burden but it is not well-established whether this reduces microvascular thrombosis and they significantly increase the risk of bleeding. In this review article we discuss the role of platelets in microvascular thrombosis, describe how microvascular thrombosis and obstruction can be assessed clinically and explore potential new antiplatelet treatments for this. In particular, we highlight novel antiplatelet drugs targeting the platelet receptor GPVI, as well as PAR4, GPIb-IX-V and 5HT2A receptors. We also discuss the potential benefit of P-selectin inhibitors as they have proven to be effective in reducing microvascular thrombosis in sickle-cell disease which could translate into potential benefits in acute coronary syndrome.

Acute Coronary Syndrome after Percutaneous Coronary Intervention: State of the Problem and Clinical Practice Data

Aim. To study the prevalence, clinical and endovascular predictors, causes and timing of the development of acute coronary syndrome (ACS) in patients who had previously undergone percutaneous coronary intervention (PCI), as well as the clinical features of the disease and lipid spectrum parameters.Material and methods. The prospective study included 768 patients successively hospitalized from 01.01.2019 to 01.01.2020 in the Regional cardiovascular center, undergoing to emergency coronary angiography.Results. The main group included 768 patients who underwent emergency coronary angiography for ACS. 90 of them had previously undergone PCI (11.7%). Men prevailed (66.7%), the average age was 62 years. 25.5% of patients underwent ACS within a year after coronary stenting, the mean time from PCI to ACS was 43 months. Most often, there was ACS without ST segment elevation (80%). The results of a retrospective analysis of the first PCI showed that 89.7% of patients underwent urgent PCI, 77.8% of patients received bare metal stents. In 67.1% of patients, 1 stent was implanted, the average diameter was 3.2 mm, the average length was 22 mm. Thromboaspiration was performed in 12% of cases, predilatation in 25%, and NC postdilation in 41.3% of cases. Complications of PCI developed in 9% of patients. Stent thrombosis was diagnosed in 7.8% of cases, significant restenosis in 35.6%. Repeated stenting due to ACS was performed in 64.4% of patients, of which 74.6% received 1 stent; average diameter 3.4 mm, average length 24.0 mm. Predilatation was performed in 52.9% of cases, thromboaspiration – in 41.2%, and NC-postdilation – in 86.7% of cases. Complications of PCI developed in 10%. In addition, 99% of patients had significant dyslipidemia. The average cholesterol level was 4.91 mmol/L, the average low-density lipoprotein level was 2.94 mmol/L.Conclusion. Patients after PCI are 12% of group with ACS in clinical practice of the Regional Vascular Center. The most common predictor of recurrent atherothrombotic events is bare metal stent implantation as well as dyslipidemia.

Interrelation between baseline plaque characteristics and changes in coronary atherosclerosis with the PCSK9-inhibitor alirocumab: insights from the PACMAN-AMI randomized trial

Abstract Background Patients with acute myocardial infarction (AMI) frequently experience recurrent atherothrombotic events, largely attributable to non-culprit lesions with high-risk characteristics. Statins can halt the progression of coronary atherosclerosis, and addition of protein convertase subtilisin/kexin type 9-inhibitors (PCSK9i) results in incremental low-density lipoprotein cholesterol (LDL-C) lowering and atheroma regression. Purpose We sought to examine the interrelation between baseline imaging characteristics, on-treatment LDL-C levels, and changes in coronary atherosclerosis as assessed by serial, multi-modality intracoronary imaging in patients with AMI. Methods This is a post hoc analysis from the PACMAN-AMI randomized trial. Patients were randomly allocated to biweekly alirocumab 150 mg vs. placebo on top of high-intensity statin initiated within 24h of presentation with AMI, and underwent serial imaging of the two non-infarct-related arteries at baseline and after 52 weeks. The primary endpoint was percent atheroma volume (PAV) by intravascular ultrasound (IVUS). Powered secondary endpoints were maximal lipid core burden index (maxLCBI4mm) by near-infrared spectroscopy (NIRS) and minimum fibrous cap thickness (FCTmin) by optical coherence tomography (OCT). Results Of 300 randomized patients (mean age 58.5±9.8 years, 18.7% women, baseline LDL-C 3.94±0.87 mmol/L), IVUS was serially performed in 265 patients (537 arteries). LDL-C levels decreased to 1.92±0.79 mmol/L with placebo and 0.61±0.61 mmol/L with alirocumab (p<0.001). Compared with placebo (statin alone), alirocumab added to statin resulted in greater PAV reduction (−2.13% vs. −0.92%; p<0.001), greater maxLCBI4mm reduction (−79.42 vs. −37.60; p=0.006), and greater increase in FCTmin (62.67 vs. 33.19 μm; p=0.001). Changes in PAV and maxLCBI4mm were inversely related to on-treatment LDL-C levels, and change in FCTmin was positively related to on-treatment LDL-C levels (Figure 1). Across all patients, we found significant, inverse relationships between change in PAV and baseline PAV [slope: −0.072 (95% CI −0.101 to −0.042); p<0.001], between change in maxLCBI4mm and baseline maxLCBI4mm [slope: −0.437 (95% CI −0.505 to −0.369); p<0.001], and between change in FCTmin and baseline FCTmin [slope: −0.436 (95% CI −0.541 to −0.332); p<0.001]; these findings indicate greater PAV and maxLCBI4mm regression in lesions with greater PAV and LCBI4mm at baseline, and greater fibrous cap thickening in lesions with thinner fibrous caps at baseline. Conclusion In this study of intensive LDL-C lowering treatment initiated in the acute AMI setting, more favorable plaque changes were observed in patients with lower on-treatment LDL-C levels and in lesions with more adverse baseline plaque characteristics. Whether AMI patients with high-risk plaque features might derive greater clinical benefit from early initiation of intensive LDL-C-lowering therapies requires further investigation. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Sanofi, Regeneron

Abstract MP19: New Insight Into The Optimal Duration Of DAPT Following PCI In High-risk Twilight-like Patients With Acute Coronary Syndrome

Introduction: Recent emphasis on shorter DAPT regimen after PCI irrespective of indication for PCI may fail to account for the substantial residual risk of recurrent atherothrombotic events in ACS patients. We aim to determine the association of extended-term (>12-month) vs. short-term dual antiplatelet therapy (DAPT) with ischemic and hemorrhagic events in high-risk "TWILIGHT-like" patients undergoing PCI for ACS in clinical practice. Methods: All consecutive patients fulfilling the "TWILIGHT-like" criteria undergoing PCI were identified from the prospective Fuwai PCI Registry. High-risk patients (n=5,404) were defined by at least 1 clinical and 1 angiographic feature based on TWILIGHT trial selection criteria. The primary ischemic endpoint was major adverse cardiac and cerebrovascular events at 30 months, composed of all-cause mortality, myocardial infarction, or stroke while BARC type 2, 3, or 5 bleeding was key secondary outcome. Results: The proportion of patients with 1-3, 4-5, or 6-9 risk factors was 19.7%, 58.6%, and 21.6%, respectively. Cessation of DAPT was less frequent in patients with ACS at 12 months (31.6% versus 68.4%), with 22.7% of ACS patients still on DAPT beyond 24 months. Of 4,875 high-risk ACS patients who remained event-free at 12 months after PCI, DAPT>12-month compared with shorter DAPT reduced the primary ischemic endpoint by 63% (1.5% vs. 3.8%; HRadj: 0.374, 95% CI: 0.256 to 0.548; HRmatched: 0.361, 95% CI: 0.221-0.590). The HR for cardiovascular death was 0.049 (0.007 to 0.362) and that for MI 0.45 (0.153 to 1.320) and definite/probable stent thrombosis 0.296 (0.080-1.095) in propensity-matched analyses. Rates of BARC type 2, 3, or 5 bleeding (0.9% vs. 1.3%; HRadj: 0.668 [0.379 to 1.178]; HRmatched: 0.721 [0.369-1.410]) did not differ significantly between two groups. Conclusions: Among high-risk ACS patients undergoing PCI, long-term DAPT, compared with shorter DAPT, reduced ischemic events without a concomitant increase in clinically meaning bleeding events, suggesting that long-term DAPT can be considered in patients with ACS following PCI who are carefully assessed to be at low bleeding risk and heightened ischemic risk, and have tolerated antiplatelet therapy without a major bleeding during 1 year of DAPT.

Establishing the optimal duration of DAPT following PCI in high-risk TWILIGHT-like patients with acute coronary syndrome.

To determine the association of extended-term (>12-month) versus short-term dual antiplatelet therapy (DAPT) with ischemic and hemorrhagic events in high-risk "TWILIGHT-like" patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) in clinical practice. Recent emphasis on shorter DAPT regimen after PCI irrespective of indication for PCI may fail to account for the substantial residual risk of recurrent atherothrombotic events in ACS patients. All consecutive patients fulfilling the "TWILIGHT-like" criteria undergoing PCI were identified from the prospective Fuwai PCI Registry. High-risk patients (n=8,358) were defined by at least one clinical and one angiographic feature based on TWILIGHT trial selection criteria. The primary ischemic endpoint was major adverse cardiac and cerebrovascular events at 30 months, composed of all-cause mortality, myocardial infarction, or stroke while BARC type 2, 3, or 5 bleeding was key secondary outcome. Of 4,875 high-risk ACS patients who remained event-free at 12 months after PCI, DAPT>12-month compared with shorter DAPT reduced the primary ischemic endpoint by 63% (1.5 vs. 3.8%; HRadj: 0.374, 95% CI: 0.256-0.548; HRmatched: 0.361, 95% CI: 0.221-0.590). The HR for cardiovascular death was 0.049 (0.007-0.362) and that for MI 0.45 (0.153-1.320) and definite/probable stent thrombosis 0.296 (0.080-1.095) in propensity-matched analyses. Rates of BARC type 2, 3, or 5 bleeding (0.9 vs. 1.3%; HRadj: 0.668 [0.379-1.178]; HRmatched: 0.721 [0.369-1.410]) did not differ significantly between two groups. Among high-risk ACS patients undergoing PCI, long-term DAPT, compared with shorter DAPT, reduced ischemic events without a concomitant increase in clinically meaning bleeding events, suggesting that prolonged DAPT can be considered in ACS patients who present with a particularly higher risk for thrombotic complications without excessive risk of bleeding.

Dual Pathway Inhibition for Vascular Protection in Patients with Atherosclerotic Disease: Rationale and Review of the Evidence.

Despite advances in secondary prevention strategies in patients with cardiovascular disease, the residual risk of recurrent atherothrombotic events remains high. Dual-antiplatelet therapy is the standard of care for secondary prevention in patients with acute coronary syndrome (ACS), whereas single antiplatelet therapy, generally with aspirin, is the standard of care for secondary prevention in stable patients with coronary artery disease (CAD), peripheral artery disease (PAD), or cerebrovascular disease. However, atherosclerotic plaque disruption not only triggers platelet activation but also results in thrombin generation because of tissue factor exposure. Therefore, blocking both pathways by combining antiplatelet therapy with an anticoagulant, or dual pathway inhibition (DPI), has the potential to be more effective than inhibiting either pathway alone. The benefit of DPI has been demonstrated in the ATLAS ACS 2-TIMI 51, COMPASS, and VOYAGER PAD trials, where the combination of rivaroxaban vascular dose (2.5 mg twice daily) plus aspirin significantly reduced the risk of atherothrombotic events compared with aspirin across a broad range of patients, including those with recent ACS, those with chronic CAD and/or PAD, and patients with PAD who have undergone peripheral revascularization. This article provides the rationale for this regimen in more detail, including why the DPI regimen with the rivaroxaban vascular dose was developed for vascular protection in a broad spectrum of patients with atherosclerotic disease.

IL-7R blockade reduces post-myocardial infarction-induced atherosclerotic plaque inflammation in ApoE−/- mice

Modulating inflammation by targeting IL-1β reduces recurrent athero-thrombotic cardiovascular events without lipid lowering. This presents an opportunity to explore other pathways associated with the IL-1β signaling cascade to modulate the inflammatory response post-myocardial infarction (MI). IL-7 is a mediator of the inflammatory pathway involved in monocyte trafficking into atherosclerotic plaques and levels of IL-7 have been shown to be elevated in patients with acute MI. Recurrent athero-thrombotic events are believed to be mediated in part by index MI-induced exacerbation of inflammation in atherosclerotic plaques. The objective of the study was to assess the feasibility of IL-7R blockade to modulate atherosclerotic plaque inflammation following acute MI in ApoE−/- mice. Mice were fed Western diet for 12 weeks and then subjected to coronary occlusion to induce an acute MI. IL-7 expression was determined using qRT-PCR and immuno-staining, and IL-7R was assessed using flow cytometry. Plaque inflammation was evaluated using immunohistochemistry. IL-7R blockade was accomplished with monoclonal antibody to IL-7R. IL-7 mRNA expression was significantly increased in the cardiac tissue of mice subjected to MI but not in controls. IL-7 staining was observed in the coronary artery. Plaque macrophage and lipid content were significantly increased after MI. IL-7R antibody treatment but not control IgG significantly reduced macrophage and lipid content in atherosclerotic plaques. The results show that IL-7R antibody treatment reduces monocyte/macrophage and lipid content in the atherosclerotic plaque following MI suggesting a potential new target to mitigate increased plaque inflammation post-MI.

Management of Acute Coronary Syndromes

Management of Acute Coronary Syndromes

Interleukin-1 blockade in cardiovascular diseases: a clinical update.

Interleukin-1 (IL-1) is the prototypical pro-inflammatory cytokine. IL-1 was implicated as a cardiodepressant factor in septic shock, and subsequent pre-clinical and clinical research has defined important roles for IL-1 in atherosclerosis, acute myocardial infarction (AMI), and heart failure (HF). IL-1 promotes the formation of the atherosclerotic plaque and facilitates its progression and complication. In a large phase III clinical trial of stable patients with prior AMI, blocking IL-1 activity using a monoclonal antibody prevented recurrent atherothrombotic cardiovascular events. IL-1 also contributes to adverse remodelling and left ventricular dysfunction after AMI, and in phase II studies, IL-1 blockade quenched the inflammatory response associated with ST-segment elevation AMI and prevented HF. In patients with established HF, IL-1 is thought to impair beta-adrenergic receptor signalling and intracellular calcium handling. Phase II studies in patients with HF show improved exercise capacity with IL-1 blockade. Thus, IL-1 blockade is poised to enter the clinical arena as an additional strategy to reduce the residual cardiovascular risk and/or address inflammatory cardiovascular conditions refractory to standard treatments. There are several IL-1 blockers available for clinical use, which differ in mechanism of action, and potentially also efficacy and safety. While IL-1 blockade is not immunosuppressive and not associated with opportunistic infections or an increased risk of cancer, fatal infections may occur more frequently while on treatment with IL-1 blockers likely due to a blunting of the inflammatory signs of infection leading to delayed presentation and diagnosis. We discuss the practical use of IL-1 blockade, including considerations for patient selection and safety monitoring.

Pharmacokinetic and Pharmacodynamic Responses to Clopidogrel: Evidences and Perspectives.

Clopidogrel has significantly reduced the incidence of recurrent atherothrombotic events in patients with acute coronary syndrome (ACS) and in those undergoing percutaneous coronary intervention (PCI). However, recurrence events still remain, which may be partly due to inadequate platelet inhibition by standard clopidogrel therapy. Genetic polymorphisms involved in clopidogrel’s absorption, metabolism, and the P2Y12 receptor may interfere with its antiplatelet activity. Recent evidence indicated that epigenetic modification may also affect clopidogrel response. In addition, non-genetic factors such as demographics, disease complications, and drug-drug interactions can impair the antiplatelet effect of clopidogrel. The identification of factors contributing to the variation in clopidogrel response is needed to improve platelet inhibition and to reduce risk for cardiovascular events. This review encompasses the most recent updates on factors influencing pharmacokinetic and pharmacodynamic responses to clopidogrel.

Aspirin for Primary Cardiovascular Risk Prevention and Beyond in Diabetes Mellitus.

Daily administration of low-dose aspirin has proved to be beneficial in preventing recurrent cardiovascular events. However, the role of aspirin for primary prevention in patients with no overt cardiovascular disease is more controversial. In fact, in lower risk patients, the modest benefit in reducing serious vascular events can be offset by the increased risk of bleeding, including intracranial and gastrointestinal hemorrhage. Diabetes mellitus has been associated with a substantially increased risk of both first and recurrent atherothrombotic events, which makes aspirin therapy of potential value in these subjects. Moving from general aspects of aspirin pharmacology and specific issues in diabetes mellitus, this article reviews the literature on the topic of aspirin for primary prevention in general, and in subjects with diabetes mellitus in particular, to culminate with arguments pro and con and a practical risk-based algorithm for aspirin initiation in daily practice.

Antithrombotic Therapy for Secondary Prevention in Patients With Diabetes Mellitus and Coronary Artery Disease.

Diabetes mellitus (DM) is a key risk factor for recurrent atherothrombotic events in patients with acute coronary syndrome (ACS) and in those undergoing percutaneous coronary intervention (PCI). The prothrombotic milieu that characterizes patients with DM underscores the importance of oral antithrombotic therapy for secondary prevention of recurrent events in these patients. Indeed, dual antiplatelet therapy (DAPT) with aspirin and the P2Y12inhibitor clopidogrel, which has represented the mainstay of treatment for many years, has significantly reduced the incidence of recurrent atherothrombotic events. However, recurrence rates in DM patients still remain high despite this treatment regimen, which may be partly related to inadequate platelet inhibition induced by standard DAPT with aspirin and clopidogrel. This underpins the need for more potent antithrombotic treatment regimens for secondary prevention of atherothrombotic events in DM patients following ACS or PCI. The development of antiplatelet therapies associated with more potent oral platelet P2Y12receptor inhibition, including prasugrel and ticagrelor, as well as platelet inhibitors blocking alternative pathways, such as thrombin-mediated platelet inhibition with vorapaxar, may represent potential treatment options in DM patients. Moreover, with the introduction of the target-specific oral anticoagulants, there has been a reappraisal of the use of anticoagulation in addition to antiplatelet therapy for secondary prevention in patients with ACS. This review provides an update on the recent advances and limitations of oral antithrombotic agents used for secondary prevention in DM patients following ACS or PCI.

Abstract 17135: Distribution of Anti-oxidative Activity During Remodeling of High Density Lipoprotein: Studies With CSL112

We have previously shown that reconstituted HDL has the ability to inactivate phospholipid hydroperoxides (PLOOH) in oxidized LDL by virtue of redox-active Met residues present in apolipoprotein A-I (apoA-I), with the level of activity being proportional to the amount of apoA-I protein added. CSL112 is human apoA-I, reconstituted with phosphatidylcholine to form HDL particles suitable for infusion. Infusing CSL112 into human subjects or adding it to human plasma ex vivo, causes remodeling of endogenous HDL. Similar remodeling occurs upon incubation of CSL112 with purified HDL3 and results in accumulation of three HDL species: enlarged HDL (HDL2), a smaller, dense species (HDL3c-like), and lipid-poor apoA-I (pre-β1 HDL). Here we examine the distribution of anti-oxidant activity upon remodeling of native plasma HDL induced by CSL112. We incubated CSL112 with human plasma HDL3, isolated the three populations of remodeled HDL particles by density gradient ultracentrifugation and compared (on a total protein basis) their ability to inactivate PLOOH derived from oxidized LDL as well as their apoA-I content of unoxidized and oxidized Met residues. Both parent CSL112 and HDL3 displayed anti-oxidative activity, inactivating 22±4 and 47±9% of PLOOH, respectively (n=4). Upon remodeling, this activity was mainly found in enlarged HDL2 and smaller HDL3c-like species (PLOOH inactivation, 46±3 and 47±9%, respectively) and was low (23±17%) in lipid-poor apoA-I. In parallel, apoA-I Met residues were oxidized in HDL; oxidation was several fold lower in the lipid-poor apoA-I (12±3%) compared to larger species (62±1% and 69±2% in HDL2 and HDL3c-like particles), consistent with a limited accessibility of apoA-I Met to PLOOH molecules in the lipid-poor particles. These studies further confirm the unequal distribution of HDL function among HDL subclasses and emphasize the important role of HDL remodeling in the production and maintenance of HDL functionality. The antioxidant properties of CSL112 add to its potential as a promising therapy for reducing the high risk of early recurrent atherothrombotic events following acute MI (AMI). A Phase IIb trial (AEGIS-I; NCT02108262) of CSL112 in AMI patients is ongoing.

Abstract 17107: Distribution of Anti-inflammatory Activity During Remodeling of High Density Lipoprotein: Studies With CSL112

Elevated levels of circulating inflammatory markers predict an unfavorable cardiovascular outcome in acute coronary syndrome patients. CSL112 is human apolipoprotein A-I (apoA-I), reconstituted with phosphatidylcholine to form HDL particles suitable for infusion. Addition of CSL112 to stimulated human whole blood ex vivo strongly reduces pro-inflammatory cytokine production. Infusion of CSL112 into human subjects or addition to human plasma ex vivo causes remodeling of endogenous HDL. Similar remodeling occurs upon incubation of CSL112 with purified HDL3 and results in accumulation of three HDL species: enlarged HDL (HDL2), a smaller, dense species (HDL3c), and lipid-poor apoA-I (pre-β1 HDL). Study aim was to determine the anti-inflammatory activity of remodeled HDL species. CSL112 was incubated with HDL3 and the products of particle remodeling were purified by ultracentrifugation. The inhibitory effects on pro-inflammatory cytokine production were examined using human peripheral blood mononuclear cells (PBMC) stimulated with phytohemagglutinin-M (PHA-M) in vitro. Lipid-poor apoA-I, HDL3c as well as parent CSL112 exerted powerful inhibitory effects on secretion of pro-inflammatory mediators (> 89.2% + 4.0% inhibition of TNF-α, IL-1β, IL-6 and Mip-1β); HDL3 and HDL2 were much less effective (< 54.1% + 3.9% inhibition). The extent of inhibition correlated positively with induction of the transcription repressor ATF3, a negative regulator of pro-inflammatory cytokine production, with lipid-poor apoA-I and HDL3c inducing higher protein levels of ATF3 in PHA-stimulated PBMC compared to control medium, HDL3 or HDL2. Anti-inflammatory activity of the remodeled species also correlated with their ability to support cellular cholesterol efflux via the ABCA1 transporter: lipid-poor apoA-I and HDL3c were potent acceptors of cholesterol; HDL2 was inactive. The ability to generate HDL species with high cholesterol efflux and anti-inflammatory activity makes CSL112 a promising candidate for removing cholesterol and reducing inflammation in atherosclerotic plaque, thus reducing the high risk of early recurrent atherothrombotic events following acute MI (AMI). A Phase IIb trial (AEGIS-I; NCT02108262) of CSL112 in AMI patients is ongoing.

Efficacy of enteral ticagrelor in hypothermic patients after out-of-hospital cardiac arrest.

IntroductionDelivery of crushed ticagrelor via a nasogastric tube is a widely spread off-label use in unconscious patients following out-of-hospital cardiac arrest (OHCA). Notwithstanding the importance of a potent dual antiplatelet therapy in these patients, the efficacy of crushed ticagrelor after OHCA has not been established yet.MethodsIn a prospective, single-center, observational trial, 38 consecutive MI patients after OHCA were included. 27 patients (71.1 %) underwent mild induced hypothermia. The primary outcome was platelet inhibition at 24h measured by impedance aggregometry.ResultsThere was sufficient platelet inhibition in most patients after OHCA. In all hypothermic patients, there was an adequate platelet inhibition by ticagrelor at 24 h (p < 0.001). 15 patients (39.5 %) had significant gastroesophageal reflux and one patient with significant reflux had inadequate platelet inhibition at 24 h. There were no stent thrombosis or recurrent atherothrombotic events in these patients.ConclusionAdministration of crushed ticagrelor via a nasogastric tube reliably inhibited platelet function in vitro and in vivo regardless of the presence of hypothermia in MI patients. Thus, platelet inhibition can be reliably achieved in MI patients during neuroprotective hypothermia following OHCA.

Use of novel antiplatelet agents in acute coronary syndromes.

Acute coronary syndromes (ACS) encompass a broad spectrum of clinical presentations based on underlying pathology that results in myocardial ischemia and/or infarction. Despite advancements in invasive management and secondary preventive therapies, recurrent atherothrombotic coronary events remain a prevalent cause of death and recurrent cardiac events after ACS and, in those who survive, the root of long-standing cardiac comorbidities. Antiplatelet drug therapy has proven beneficial in the reduction of these events, and novel antiplatelet agents have resulted in significant improvement in clinical outcomes over the last decade. However, the balance of optimal platelet inhibition with minimal bleeding complications remains a clinical challenge. This review focuses on more recent advances in antiplatelet therapies used in the treatment of ACS.

Antiplatelet drugs in patients with enhanced platelet turnover: biomarkers versus platelet function testing.

Platelets are key players in atherothrombosis. Antiplatelet therapy comprising aspirin alone or with P2Y12-inhibitors are effective for prevention of atherothrombotic complications. However, there is interindividual variability in the response to antiplatelet drugs, leaving some patients at increased risk of recurrent atherothrombotic events. Several risk factors associated with high on-treatment platelet reactivity (HTPR), including elevated platelet turnover, have been identified. Platelet turnover is adequately estimated from the fraction of reticulated platelets. Reticulated platelets are young platelets, characterised by residual messenger RNA. They are larger, haemostatically more active and there is evidence that platelet turnover is a causal and prognostic factor in atherothrombotic disease. Whether platelet turnover per se represents a key factor in pathogenesis, progression and prognosis of atherothrombotic diseases (with focus on acute coronary syndromes) or whether it merely facilitates insufficient platelet inhibition will be discussed in this state-of-the art review.

Abstract 15426: CSL112 Enhances Cholesterol Efflux Equally in Patients with High and Low High Density Lipoprotein Functionality

Introduction: The ability of high-density lipoprotein (HDL) to remove cholesterol from macrophages in atherosclerotic plaque is thought to underlie its inverse correlation with cardiovascular risk. CSL112 is a novel formulation of apoA-I purified from human plasma and reconstituted to form HDL particles suitable for infusion. Two phase 1 studies in healthy subjects and one phase 2a study in coronary heart disease (CHD) patients have demonstrated favorable safety, pharmacokinetics and biomarker responses to single or multiple infusions of CSL112. The aim of the current study was to assess the influence of subject-specific HDL functionality, sometimes described as HDL dysfunction, on the pharmacodynamic effects of CSL112. Methods and Results: To assess HDL functionality, we measured the specific cholesterol efflux activity of apoA-I (cholesterol efflux divided by apoA-I) in subjects at baseline. CHD patients (mean ± SD = 7.3 ± 0.3 %efflux per g/L apoA-I (n=43)) had lower activity (p&lt;0.001) than healthy subjects (mean ± SD = 8.8 ± 0.2 % efflux per g/L apoA-I (n=93)), consistent with prior work showing impaired HDL function in CHD patients. Every subject infused with CSL112 responded, showing increased apoA-I plasma levels and serum cholesterol efflux. To assess changes in HDL functionality upon infusion of CSL112, we plotted changes in cholesterol efflux vs changes in apoA-I. To account for variations of these analytes over time and dose, we plotted area under curve (AUC) for 0 to 24 h after infusion of various doses of CSL112. In all three studies, AUC for apoA-I correlated with the AUC for cholesterol efflux, with coincident lines, indicating equal elevation in efflux among healthy and CHD patients. To further examine this relationship, subjects were stratified into tertiles based on specific activity. Infusion of CSL112 elevated efflux similarly in subjects in the highest HDL functionality and lowest HDL functionality tertiles. Conclusion: ApoA-I from CHD patients compared to healthy subjects had lower specific activity in regards to cholesterol efflux. CSL112 causes strong elevation in cholesterol efflux regardless of HDL function and represents a promising candidate to rapidly remove plaque cholesterol and reduce recurrent atherothrombotic events.

Impaired Responsiveness to the Platelet P2Y12 Receptor Antagonist Clopidogrel in Patients With Type 2 Diabetes and Coronary Artery Disease

BackgroundSeveral studies have shown that patients with diabetes mellitus (DM) exhibit an impaired response to clopidogrel. This may contribute to their increased risk of recurrent atherothrombotic events, despite the use of dual-antiplatelet therapy. The mechanisms for impaired clopidogrel response in DM patients have not been fully elucidated. ObjectivesThe aim of this study was to explore the mechanisms for impaired clopidogrel-mediated platelet inhibition in patients with DM using a comprehensive methodological approach embracing both pharmacokinetic (PK) and pharmacodynamic (PD) assessments as well as ex vivo and in vitro investigations. MethodsPatients (DM, n = 30; non-DM, n = 30) with stable coronary artery disease taking aspirin 81 mg/day and P2Y12 antagonist naive were enrolled. Blood was collected before and at various times (0.5, 1, 2, 4, 6, and 24 h) after a 600-mg loading dose of clopidogrel. PD assessments included vasodilator-stimulated phosphoprotein, light transmission aggregometry, and VerifyNow P2Y12 ex vivo, before and after dosing and following in vitro incubation with escalating concentrations (1, 3, and 10 μM) of clopidogrel’s active metabolite (Clop-AM). Exposure to Clop-AM was also determined. ResultsPD assessments consistently showed that during the overall 24-h study time course, residual platelet reactivity was higher in DM patients compared with non-DM patients. In vitro incubation with Clop-AM revealed altered functional status of the P2Y12 signaling pathway in DM platelets as measured by vasodilator-stimulated phosphoprotein, but not with other PD assays. Clop-AM exposure was ∼40% lower in DM patients than in non-DM patients. ConclusionsThe present study suggests that among DM patients, impaired P2Y12 inhibition mediated by clopidogrel is largely attributable to attenuation of clopidogrel’s PK profile. This is characterized by lower plasma levels of Clop-AM over the sampling time course in DM patients compared with non-DM patients and only modestly attributed to altered functional status of the P2Y12 signaling pathway.