ESPRIT Investigators. Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy. Novel dosing regimen of eptifibatide in planned coronary stent implantation (ESPRIT): a randomised, placebo-controlled trial

A dual-center analysis of conservative versus liberal glycoprotein IIb-IIIa antagonist strategies in the treatment of ST-elevation myocardial infarction

While the efficacy of GpIIb-IIIa-inhibitors during primary PCI (pPCI) for ST-elevated myocardial infarction (STEMI) has previously been demonstrated, its ongoing role and safety in combination with newer P2Y12-inhibitors is unclear. We therefore sought to compare outcomes between two centers with divergent approaches to the use of GpIIbIIIa antagonists in pPCI. We performed a retrospective chart review of all-comer STEMI patients treated with pPCI at two high-volume Montreal academic tertiary care centers. One center tended to use GpIIb-IIIa-inhibitors up-front in a large proportion of patients (liberal strategy) and the other preferring a bail-out approach (conservative strategy). Baseline patient characteristics and procedural data were compared between the two groups. The main efficacy outcome was rate of no-reflow/slow-reflow and the main safety outcome was BARC ≥ 2 bleeding events. A total of 459 patients were included, of whom 167 (36.5%) were exposed to a GpIIb-IIIa-antagonist. There was a significant overall difference in use of GpIIb-IIIa-antagonist between the two centers (60.5% vs. 16.1%, p < 0.01). Rate of no-reflow/slow-reflow was similar between groups (2.6% vs. 1.4%, p = 0.22). In-hospital rates of unplanned revascularization, stroke and death were also not different between groups. Use of a liberal GpIIb--IIIa-antagonist strategy was however associated with a higher risk of bleeding (OR 3.16, 95% CI 1.57-6.37, p < 0.01), which persisted after adjustment for covariables (adjusted OR 2.85, 95% CI 1.40-5.81, p < 0.01). In this contemporary retrospective cohort, a conservative, bail-out only GpIIb--IIIa-antagonist strategy was associated with a lower incidence of clinically relevant bleeding without any signal for an increase in no-reflow/slow-reflow or ischemic clinical events.

Optimal Antithrombotic Strategies in Cardiogenic Shock

Cardiogenic shock (CS) represents a critical condition with a high mortality rate. The most common cause of CS is coronary artery disease, and patients typically present with myocardial infarction, necessitating immediate treatment through percutaneous coronary intervention (PCI) and often requiring mechanical circulatory support. CS is associated with a prothrombotic situation, while on the other hand, there is often a significant risk of bleeding. This dual challenge complicates the selection of an optimal antithrombotic strategy. The choice of antithrombotic agents must be personalized, taking into consideration all relevant conditions. Repeated risk assessment, therapeutic monitoring, and adjusting antithrombotic therapy are mandatory in these patients. This review article aims to provide an overview of the current evidence and practical guidance on antithrombotic strategies in the context of CS.

Current concepts and novel targets for antiplatelet therapy

Platelets have a crucial role in haemostasis and atherothrombosis. Pharmacological control of platelet hyper-reactivity has become a cornerstone in the prevention of thrombo-ischaemic complications in atherosclerotic diseases. Current antiplatelet therapies substantially improve clinical outcomes in patients with coronary artery disease, but at the cost of increased risk of bleeding. Beyond their role in thrombosis, platelets are known to regulate inflammatory (thrombo-inflammatory) and microcirculatory pathways. Therefore, controlling platelet hyper-reactivity might have implications for both tissue inflammation (myocardial ischaemia) and vascular inflammation (vulnerable plaque formation) to prevent atherosclerosis. In this Review, we summarize the pathophysiological role of platelets in acute myocardial ischaemia, vascular inflammation and atherosclerotic progression. Furthermore, we highlight current clinical concepts of antiplatelet therapy that have contributed to improving patient care and have facilitated more individualized therapy. Finally, we discuss novel therapeutic targets and compounds for antiplatelet therapy that are currently in preclinical development, some of which have a more favourable safety profile than currently approved drugs with regard to bleeding risk. These novel antiplatelet targets might offer new strategies to treat cardiovascular disease.

A Double-Blinded Randomized Controlled Trial Comparing Eptifibatide Bolus Only Versus Bolus Plus Infusion In Patients Undergoing Primary Percutaneous Coronary Intervention For ST-Elevation Myocardial Infarction

BACKGROUNDS

The use of eptifibatide combined with heparin during percutaneous coronary intervention (PCI) in patients presenting with ST-elevation myocardial infarction (STEMI) is recommended to be followed by continuous infusion. Recently, there are some suggestions that using bolus only may be sufficient and cost-effective but randomized trials are lacking.

AIMS

The goal of this study was to evaluate these two approaches in a double-blinded randomized control trial.

METHODS

The primary PCI patients who received bolus eptifibatide were randomized to 75 mg IV eptifibatide infusion or placebo blindly. The patients were followed up for the primary outcome of vascular or bleeding complications and secondary outcome of ischemic complications.

RESULTS

330 patients (165 from each group) completed the study. The mean age was 57.67 ± 11.53 years and 77.3 % were male. Major bleeding was seen in 1 patient in each group. Hematoma occurred in 8.5 %. The relative risk of hematoma and ecchymosis in bolus plus infusion group to bolus only group were 0.988 (95 % CI: 0.486-2.006) and 1.032 (95 % CI: 0.729-1.459). Multivariate analysis confirmed no significant differences in the bleeding event. Furthermore, there was no significant difference in in-hospital death or any ischemic events. (Cath lab death: 1.4 % in bolus only vs zero % in the control group, p = 0.217, stent thrombosis was seen in one patient in each group).

CONCLUSION

There were no differences in the risk of access site ecchymosis, hematoma or major bleeding. Ischemic events and stent thrombosis rates were also similar. Our study suggests that using eptifibatide bolus only during PCI of patients with STEMI is safe and can be cost-saving.

Impact of maintenance dose of eptifibatide in patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) is usually caused by a rupture in the atherosclerotic plaque, followed by platelet aggregation which ultimately leads to acute coronary artery occlusion. So far, few studies have investigated the effect of maintenance dose of Eptifibatide (glycoprotein IIb/IIIa inhibitor) in STEMI patients who underwent primary percutaneous coronary intervention (PPCI). Therefore, in this study, we investigated the effect of maintenance dose of Eptifibatide in patients with STEMI who underwent PPCI. 264 patients who had acute chest pain suggestive of STEMI were entered in the study. All patients received the same dose of bolus dose of Eptifibatide in the cardiac catheterization laboratory. Then the patients were randomly divided into two groups, one group (n = 147) received a maintenance dose of intravenous Eptifibatide (infusion of 2 μg/kg/min) and the other group (n = 117) did not receive this treatment. Standard medical treatment of STEMI after PPCI was performed based on guidelines and the same in both groups. All patients were evaluated 1, 2, and 3 months after the start of treatment in terms of predicted outcomes.

RESULTS

The occurrence of 3-month major adverse cardiovascular events (MACE) between the case and control groups did not have a statistically significant difference (28.6% versus 35.0%; P value: 0.286). Also, investigations showed that the rate of re-infarction (P value: 0.024) and target lesion revascularization (P value: 0.003) was significantly lower in the group that received Eptifibatide infusion.

CONCLUSIONS

Eptifibatide maintenance dose infusion in patients who undergo PPCI in the context of STEMI, does not significantly reduce MACE, although it does significantly reduce re-infarction and target lesion revascularization. It also does not increase the risk of bleeding and cerebrovascular events.

Antiplatelet Therapy in Coronary Artery Disease: Now and Then

Cardiovascular disease, particularly coronary artery disease (CAD), remains the leading cause of mortality and morbidity in industrialized countries. Platelet activation and aggregation at the site of endothelial injury play a key role in the processes ultimately resulting in thrombus formation with vessel occlusion and subsequent end-organ damage. Consequently, antiplatelet therapy has become a mainstay in the pharmacological treatment of CAD. Several drug classes have been developed over the last decades and a broad armamentarium of antiplatelet agents is currently available. This review portrays the evolution of antiplatelet therapy, and provides an overview on previous and current antiplatelet drugs and strategies.

An Updated Review on Glycoprotein IIb/IIIa Inhibitors as Antiplatelet Agents: Basic and Clinical Perspectives

The glycoprotein (GP) IIb/IIIa receptor is found integrin present in platelet aggregations. GP IIb/IIIa antagonists interfere with platelet cross-linking and platelet-derived thrombus formation through the competition with fibrinogen and von Willebrand factor. Currently, three parenteral GP IIb/IIIa competitors (tirofiban, eptifibatide, and abciximab) are approved for clinical use in patients affected by percutaneous coronary interventions (PCI) in the location of acute coronary syndrome (ACS). GP IIb/IIIa antagonists have their mechanism of action in platelet aggregation prevention, distal thromboembolism, and thrombus formation, whereas the initial platelet binding to damage vascular areas is preserved. This work is aimed to provide a comprehensive review of the significance of GP IIb/IIIa inhibitors as a sort of antiplatelet agent. Their mechanism of action is based on factors that affect their efficacy. On the other hand, drugs that inhibit GP IIb/IIIa already approved by the FDA were reviewed in detail. Results from major clinical trials and regulatory practices and guidelines to deal with GP IIb/IIIa inhibitors were deeply investigated. The cardiovascular pathology and neuro-interventional surgical application of GP IIb/IIIa inhibitors as a class of antiplatelet agents were developed in detail. The therapeutic risk/benefit balance of currently available GP IIb/IIa receptor antagonists is not yet well elucidated in patients with ACS who are not clinically evaluated regularly for early cardiovascular revascularization. On the other hand, in patients who have benefited from PCI, the antiplatelet therapy intensification by the addition of a GP IIb/IIIa receptor antagonist (intravenously) may be an appropriate therapeutic strategy in reducing the occurrence of risks of thrombotic complications related to the intervention. Development of GP IIb/IIIa inhibitors with oral administration has the potential to include short-term antiplatelet benefits compared with intravenous GP IIb/IIIa inhibitors for long-term secondary preventive therapy in cardiovascular disease. But studies showed that long-term oral administration of GP IIb/IIIa receptor inhibitors has been ineffective in preventing ischemic events. Paradoxically, they have been linked to a high risk of side effects by producing prothrombotic and pro-inflammatory events.

Eptifibatide-induced acute profound thrombocytopenia: A case report

RATIONALE

Eptifibatide is an antiplatelet agent used in the medical management of acute coronary syndrome. Although multiple studies did not reveal a significant association between eptifibatide and the development of thrombocytopenia, recent case reports brought attention to this relatively rare side effect.

PATIENT CONCERNS

We report a 61 years old male with acute coronary syndrome who underwent primary coronary intervention.

DIAGNOSIS AND INTERVENTION

The patient developed acute profound thrombocytopenia following eptifibatide administration. Following prompt offending drug discontinuation, the platelet counts recovered, without clinical sequelae or the need for platelet transfusion. Dual antiplatelet therapy with aspirin and clopidogrel was resumed after platelet count normalization.

OUTCOMES

The patient had a normal platelet count and no bleeding events on follow-up after three months upon discharge.

CONCLUSION

Eptifibatide, a glycoprotein IIa/IIIb inhibitor used in the management of acute coronary syndrome, can induce acute, profound thrombocytopenia that can have significant morbidity in patients. This case highlights this relatively rare side effect and the importance of monitoring blood counts and observing for any signs of bleeding or thrombosis that might occur in such patients.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Safety and efficacy of prophylactic tirofiban infusion for acute intracranial intraprocedural stent thrombosis

Periprocedural antithrombotic management with glycoprotein IIb/IIIa inhibitors (GPI) for intracranial artery stenting is still controversial. We sought to assess the safety and efficacy of prophylactic tirofiban infusion for acute intracranial intraprocedural stent thrombosis in routine clinical practice. From January 2013 to December 2019, consecutive patients treated with endovascular stenting for symptomatic intracranial atherosclerotic stenosis (ICAS) were identified and dichotomized by whether tirofiban was used. The efficacy and safety outcomes were compared by propensity score matching. A total of 160 consecutive patients in the tirofiban group and 177 patients in the non-tirofiban group were enrolled. Propensity score matching analysis selected 236 matched patients. One acute intraprocedural stent thrombosis (AIST) occurred in patients receiving prophylactic tirofiban, while 8 in the non-tirofiban group. The incidence of AIST in the tirofiban group was significantly lower than that in the non-tirofiban group (0.8% vs 6.8%, P = 0.039). The periprocedural ischemic events (8.5% vs 5.1%, P = 0.424), periprocedural intracranial hemorrhage (4.2% vs 0.8%, P = 0.219) and 30-day total mortality (3.4% vs 0%, P = 0.125) were not statistically different between the two groups. Compared with conventional stenting angioplasty without tirofiban, tirofiban prophylactic infusion can lower the incidence of AIST, without increasing the risk of periprocedural intracranial hemorrhage and 30-day total mortality. However, there is no superiority in reducing periprocedural ischemic events. The current study adds more important insights to the available clinical evidence on the use of tirofiban during stenting of ICAS.

Application of Auxiliary VerifyNow Point-of-Care Assays to Assess the Pharmacodynamics of RUC-4, a Novel αIIbβ3 Receptor Antagonist

Introduction  Prehospital therapy of ST-elevation myocardial infarction (STEMI) with αIIbβ3 antagonists improves clinical outcomes, but they are difficult to use in prehospital settings. RUC-4 is a novel αIIbβ3 antagonist being developed for prehospital therapy of STEMI that rapidly achieves high-grade platelet inhibition after subcutaneous administration. Standard light transmission aggregometry (LTA) is difficult to perform during STEMI, so we applied VerifyNow (VN) assays to assess the pharmacodynamics of RUC-4 relative to aspirin and ticagrelor.

Methods  Blood from healthy volunteers was anticoagulated with phenylalanyl-prolyl-arginyl chloromethyl ketone (PPACK) or sodium citrate, treated in vitro with RUC-4, aspirin, and/or ticagrelor, and tested with the VN ADP + PGE ₁ , iso-TRAP, and base channel (high concentration iso-TRAP + PAR-4 agonist) assays. The results were correlated with both ADP (20 µM)-induced LTA and flow cytometry measurement of receptor occupancy and data from individuals treated in vivo with RUC-4.

Results  RUC-4 inhibited all three VN assays, aspirin did not affect the assays, and ticagrelor markedly inhibited the ADP + PGE ₁ assay, slightly inhibited the iso-TRAP assay, and did not inhibit the base channel assay. RUC-4's antiplatelet effects were potentiated in citrate compared with PPACK. Cut-off values were determined to correlate the results of the VN iso-TRAP and base channel assays with 80% inhibition of LTA.

Conclusion  The VN assays can differentiate the early potent anti-αIIbβ3 effects of RUC-4 from delayed effects of P2Y12 antagonists in the presence of aspirin. These pharmacodynamic assays can help guide the clinical development of RUC-4 and potentially be used to monitor RUC-4's effects in clinical practice.

Evolution of antithrombotic therapy in patients undergoing percutaneous coronary intervention: a 40-year journey

Since its introduction in 1977, percutaneous coronary intervention has become one of the most commonly performed therapeutic procedures worldwide. Such widespread diffusion, however, would have not been possible without a concomitant evolution of the pharmacotherapies associated with this intervention. Antithrombotic agents are fundamental throughout the management of patients undergoing coronary stent implantation, starting from the procedure itself to the long-term prevention of cardiovascular events. The last 40 years of interventional cardiology have seen remarkable improvements in both drug therapies and device technologies, which largely reflected a progressive understanding of the pathophysiological mechanisms of coronary artery disease, as well as procedure- and device-related adverse events. The purpose of this article is to provide an overview of the important milestones in antithrombotic pharmacology that have shaped clinical practice of today while also providing insights into knowledge gaps and future directions.

Efficacy and Safety of Abbreviated Eptifibatide Treatment in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

The glycoprotein IIb/IIIa inhibitor eptifibatide, administered as bolus followed by infusion, is an adjunctive antithrombotic treatment during primary percutaneous coronary intervention (PCI) in selected patients with ST-segment elevation myocardial infarction (STEMI). Whether both bolus and infusion are necessary to improve outcomes is unknown. We hypothesized that primary PCI with eptifibatide bolus only is non-inferior to the conventional treatment (bolus and infusion) with regard to infarct size, while reducing bleeding complications. We analyzed 720 consecutive STEMI patients receiving eptifibatide bolus only or conventional treatment in an observational case-control study utilizing propensity score matching of clinical and intervention-specific confounders. Infarct size was estimated based on myocardial bound creatine kinase, creatine kinase (CK), and CK area under the curve values, with a prespecified non-inferiority margin of 20%. Major bleeding was defined as type 2, 3, or 5 on the Bleeding Academic Research Consortium classification. Eptifibatide bolus only was administered to 147 patients (20%), which were matched 1:1 to patients receiving conventional treatment. Based on peak myocardial bound creatine kinase, CK and CK area under the curve values, infarct size was -8.4% (95% CI [-31.2%, 14.4%]), -11.6% (95% CI [-33.5%, 10.3%]), and -13.9% (95% CI [-34.1%, 6.2%]) after eptifibatide bolus, respectively, reaching prespecified noninferiority compared with conventional treatment. Bolus treatment significantly reduced major bleeding complications (OR 0.48, 95% CI [0.30, 0.79]). In conclusion, eptifibatide given as abbreviated bolus only to selected STEMI patients who underwent primary PCI was noninferior regarding infarct size and resulted in less bleeding complications compared with conventional bolus and infusion treatment.

Large intracoronary thrombus and its management during primary PCI

Large intracoronary thrombus has been reported in significant number of patients with STEMI. Primary PCI is the current standard of care in patients of STEMI. Despite the availability of dual antiplatelets, GP IIb/IIIa inhibitor and effective anticoagulation regimens, large intracoronary thrombus remains one of the biggest challenge to interventional cardiologists during primary PCI. Large intracoronary thrombus may lead to distal embolization, no/slow reflow or embolization into a non-culprit vessel and is associated with adverse cardiovascular outcome. There is no ideal management strategy. We hereby discuss the current available methods/strategies to deal with large thrombus burden encountered during primary PCI, in the current manuscript.

First Human Use of RUC-4: A Nonactivating Second-Generation Small-Molecule Platelet Glycoprotein IIb/IIIa (Integrin αIIbβ3) Inhibitor Designed for Subcutaneous Point-of-Care Treatment of ST-Segment-Elevation Myocardial Infarction

Background Despite reductions in door-to-balloon times for primary coronary intervention, mortality from ST-segment-elevation myocardial infarction has plateaued. Early pre-primary coronary intervention treatment of ST-segment-elevation myocardial infarction with glycoprotein IIb/IIIa inhibitors improves pre-primary coronary intervention coronary flow, limits infarct size, and improves survival. We report the first human use of a novel glycoprotein IIb/IIIa inhibitor designed for subcutaneous first point-of-care ST-segment-elevation myocardial infarction treatment. Methods and Results Healthy volunteers and patients with stable coronary artery disease receiving aspirin received escalating doses of RUC-4 or placebo in a sentinel-dose, randomized, blinded fashion. Inhibition of platelet aggregation (IPA) to ADP (20 μmol/L), RUC-4 blood levels, laboratory evaluations, and clinical assessments were made through 24 hours and at 7 days. Doses were increased until reaching the biologically effective dose (the dose producing ≥80% IPA within 15 minutes, with return toward baseline within 4 hours). In healthy volunteers, 15 minutes after subcutaneous injection, mean±SD IPA was 6.9%+7.1% after placebo and 71.8%±15.0% at 0.05 mg/kg (n=6) and 84.7%±16.7% at 0.075 mg/kg (n=6) after RUC-4. IPA diminished over 90 to 120 minutes. In patients with coronary artery disease, 15 minutes after subcutaneous injection of placebo or 0.04 mg/kg (n=2), 0.05 mg/kg (n=6), and 0.075 mg/kg (n=18) of RUC-4, IPA was 14.6%±11.7%, 53.6%±17.0%, 76.9%±10.6%, and 88.9%±12.7%, respectively. RUC-4 blood levels correlated with IPA. Aspirin did not affect IPA or RUC-4 blood levels. Platelet counts were stable and no serious adverse events, bleeding, or injection site reactions were observed. Conclusions RUC-4 provides rapid, high-grade, limited-duration platelet inhibition following subcutaneous administration that appears to be safe and well tolerated. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NTC03844191.

Acute Stent Thrombosis Associated with Eptifibatide-Induced Profound Thrombocytopenia

Background

Eptifibatide is an inhibitor of the platelet glycoprotein (GP) IIb/IIIa receptor that is commonly used in patients undergoing percutaneous coronary intervention (PCI).

Case

We describe a case of a 62-year-old female patient admitted with acute ST-elevation myocardial infarction (STEMI) treated by primary coronary intervention (primary PCI) with a drug-eluting stent placement. She developed profound thrombocytopenia within 8 hours of first administration of eptifibatide and subsequent acute stent thrombosis next day. Other causes of thrombocytopenia were excluded and intravascular ultrasound (IVUS) showed good stent expansion and opposition to the coronary wall. Platelet count gradually returned to normal after discontinuation of eptifibatide.

Conclusion

Although Eptifibatide has been associated with the development of thrombocytopenia, to the best of our knowledge, this is the first case report in the medical literature that associates acute stent thrombosis and eptifibatide-induced thrombocytopenia.

Safety and Efficacy of Periprocedural Heparin Plus a Short-Term Infusion of Tirofiban Versus Bivalirudin Monotherapy in Patients Who Underwent Percutaneous Coronary Intervention (from the Intermountain Heart Institute STAIR Observational Registry)

Glycoprotein IIb/IIIa inhibitors, used as a standard intravenous bolus followed by a prolonged infusion for 12 to 18 hours, reduces ischemic complications during percutaneous coronary interventions (PCI) but often at a cost of increased bleeding. Today, when dual oral antiplatelet therapy is routine, heparin use plus short-term (bolus alone or with a <6 hours infusion) glycoprotein IIb/IIIa inhibitors, or bivalirudin monotherapy, have been proposed as potentially superior alternatives. This observational study evaluated the safety and efficacy of heparin plus short-term tirofiban versus bivalirudin monotherapy during PCI. Patients with successful PCI and no cardiogenic shock who were anticoagulated with either of the above regimens were followed for 30-day major bleeding and major adverse cardiovascular events (death, nonfatal myocardial infarction, and urgent target vessel revascularization) at 30 days, 1 year, and long term. A total of 727 patients receiving tirofiban (age = 63 ± 13 years, males = 76%, ACS presentation = 75%, radial access = 51%) and 459 patients receiving bivalirudin, (age = 65 ± 13 years, males = 71%, ACS presentation = 78%, radial access = 18%) were included. Thirty-day major bleeding was 0.7% and 4.1% for tirofiban and bivalirudin, respectively (adjusted odds ratio = 0.17 [0.06, 0.46], p = 0.001). During 30-day, 1-year, and long-term (1.7 ± 0.9 years) follow-up, major adverse cardiovascular events risk did not differ significantly between tirofiban and bivalirudin. However, long-term death was significantly lower in those receiving tirofiban (adjusted hazard ratio = 0.58 [0.34, 1.00], p = 0.05). In conclusion, in this observational study, PCI patients receiving heparin plus short-term tirofiban experienced significantly lower 30-day major bleeding, and improved long-term survival, than those receiving bivalirudin monotherapy.

Comparison between Bolus Intracoronary versus Bolus Intravenous Injection Regimens of Eptifibatide during Primary Percutaneous Coronary Intervention in Patients with Anterior ST-Segment Elevation Myocardial Infarction

Background.Eptifibatide achieves high local concentration via direct intracoronary (I/V) injection as it promotes clot disaggregation, but it remains unclear if it is of superior benefit than the routine intravenous (I/V) administration. Aim. The current study aimed to examine the safety and efficacy of I/C vs I/V bolus regimen dose of eptifibatide during primary percutaneous coronary intervention (PPCI).

Material and methods. Prospective, controlled, randomized study enrolled 100 patients with acute anterior ST-segment elevation myocardial infarction (STEMI) eligible for PPCI equally divided into 2 groups (group A received bolus I/C eptifibatide and group B received it I/V) followed by 12-hour continuous I/V infusion. Features related to of myocardial salvage in the form of TIMI flow grade 3, myocardial blush grade 3, ST segment resolution and left ventricular systolic function were evaluated with short-term follow up for 1 month.

Results. Mean age of the study population was 50.95±8.45years, there was statistically insignificant difference between both groups regarding baseline characteristics in age (p=0.062), gender (p=0.488), coronary artery disease risk factors (p>0.05), time from onset of pain to admission (p=0.86) or door to balloon (p=0.12). Group A achieved statistically significant better myocardial blush grade 3 (42% vs 10%, p=0.005), ejection faction 30 days after PPCI (46.11±7.81% vs 40.88±6.26%, p=0.005) but statistically insignificant TIMI flow grade 3 (p=0.29) and ST resolution (p=0.34). Incidence of complications in the hospital and 30 days after discharge was statistically insignificant (p>0.05).

Conclusion. Both regimens were safe and effective in STEMI patients undergoing PPCI and regimen of I/C bolus eptifibatide achieved better myocardial blush grade and systolic function. 

Platelet Signaling and Disease: Targeted Therapy for Thrombosis and Other Related Diseases

Platelets are essential for clotting in the blood and maintenance of normal hemostasis. Under pathologic conditions such as atherosclerosis, vascular injury often results in hyperactive platelet activation, resulting in occlusive thrombus formation, myocardial infarction, and stroke. Recent work in the field has elucidated a number of platelet functions unique from that of maintaining hemostasis, including regulation of tumor growth and metastasis, inflammation, infection, and immune response. Traditional therapeutic targets for inhibiting platelet activation have primarily been limited to cyclooxygenase-1, integrin αIIbβ3, and the P2Y12 receptor. Recently identified signaling pathways regulating platelet function have made it possible to develop novel approaches for pharmacological intervention in the blood to limit platelet reactivity. In this review, we cover the newly discovered roles for platelets as well as their role in hemostasis and thrombosis. These new roles for platelets lend importance to the development of new therapies targeted to the platelet. Additionally, we highlight the promising receptor and enzymatic targets that may further decrease platelet activation and help to address the myriad of pathologic conditions now known to involve platelets without significant effects on hemostasis.

Bivalirudin versus heparin in percutaneous coronary intervention-a systematic review and meta-analysis of randomized trials stratified by adjunctive glycoprotein IIb/IIIa strategy

Background

Bivalirudin has been shown to be associated with less major bleeding than heparin in patients undergoing percutaneous coronary intervention (PCI); but the confounding effect of concomitant glycoprotein IIb/IIIa inhibitors (GPI) limits meaningful comparison. We performed a systematic review and meta-analysis to compare bivalirudin to heparin, with and without adjunctive GPI in PCI.

Methods

We searched PubMed, Cochrane, EMBASE, CINAHL and WOS from January 2000 to December 2017 for clinical trials comparing bivalirudin to heparin, with and without adjunctive GPI during PCI. Cochrane's Q statistics were used to determine heterogeneity. Random effects model was used.

Results

Twenty-six comparison groups (22 original studies and 4 subgroup analyses) with 53,364 patients were included. Mean follow-up was 192±303 days. There was no difference between the two groups in all-cause mortality [risk ratio (RR: 0.93; 95% CI: 0.82-1.05, P=0.260), target vessel revascularization (TVR) (RR: 1.17; 95% CI: 0.93-1.46, P=0.174) or stroke (RR: 0.91; 95% CI: 0.71-1.18, P=0.490). Major bleeding was lower in the bivalirudin group with concomitant GPI in one or both arms (RR: 0.64; 95% CI: 0.53-0.77, P<0.001) and without (RR: 0.71; 95% CI: 0.51-0.99, P=0.041) provisional or routine GPIs. Bivalirudin appeared to have a higher risk of stent thrombosis (RR: 1.32; 95% CI: 1.04-1.68, P=0.022) and a trend towards more myocardial infarction (RR: 1.12; 95% CI: 0.98-1.28, P=0.098) though without statistical significance. However, exclusion of studies with GPI showed no difference in stent thrombosis or myocardial infarction with bivalirudin.

Conclusions

Bivalirudin is associated with less major bleeding compared to heparin, regardless of GPI use. The lower anticoagulant effect of bivalirudin is linked with higher stent thrombosis and a trend towards more MI, however a confounding effect of GPI use in the heparin arm cannot be excluded.

Eptifibatide Bolus Dose During Elective Percutaneous Coronary Intervention

Background

Eptifibatide is a platelet glycoprotein IIb/IIIa receptor antagonist used for the prevention of cardiac ischemic complications of percutaneous coronary intervention (PCI). Eptifibatide has been used with bolus dose only or bolus plus infusion in patients undergoing PCI which have shown less complications, but the risk of bleeding has been increased. We aimed to compare the outcome and bleeding rate of bolus dose alone or plus infusion in elective PCI.

Methods

In this quasi-experimental study, we compared the outcome of elective PCI following single bolus dose intracoronary (41 patients) or bolus plus intravenous infusion (19 patients) of eptifibatide. In-hospital and follow-up major adverse cardiac events (MACEs) and bleeding rate were recorded and evaluated between groups.

Results

Both groups were comparable regarding baseline findings. Bolus only compared to bolus plus infusion group had lower in-hospital (19.5% vs. 31.6%) and follow-up MACE (15.4% vs. 17.6%), lower bleeding in-hospital (14.6% vs. 21.1%) and follow-up (2.4% vs. 5.3%) as well as lower mortality rate in hospital (4.9% vs. 15.8%), but higher follow-up mortality (10.3% vs. 0), but the difference was not significant.

Conclusions

We observed no significant difference regarding bleeding or MACE between intracoronary bolus infusion and bolus plus intravenous infusion of eptifibatide. It seems intracoronary bolus infusion of eptifibatide due to use of lower doses is a better choice in elective PCI to prevent post-PCI MACE.

GPIIb/IIIa inhibitors: From bench to bedside and back to bench again

From the discovery of the platelet glycoprotein (GP) IIb/IIIa and identification of its central role in haemostasis, the integrin GPIIb/IIIa (αIIbβ3, CD41/CD61) was destined to be an anti-thrombotic target. The subsequent successful development of intravenous ligand-mimetic inhibitors occurred during a time of limited understanding of integrin physiology. Although efficient inhibitors of ligand binding, they also mimic ligand function. In the case of GPIIb/IIIa inhibitors, despite strongly inhibiting platelet aggregation, paradoxical fibrinogen binding and platelet activation can occur. The quick progression to development of small-molecule orally available inhibitors meant that this approach inherited many potential flaws, which together with a short half-life resulted in an increase in mortality and a halt to the numerous pharmaceutical development programs. Limited clinical benefits, together with the success of other anti-thrombotic drugs, in particular P2Y12 ADP receptor blockers, have also led to a restrictive use of intravenous GPIIb/ IIIa inhibitors. However, with a greater understanding of this key platelet-specific integrin, GPIIb/IIIa remains a potentially attractive target and future drug developments will be better informed by the lessons learnt from taking the current inhibitors back to the bench. This overview will review the physiology behind the inherent problems of a ligand-based integrin inhibitor design and discuss novel promising approaches for GPIIb/IIIa inhibition.

The in vitro effect of the new antithrombotic drug candidate ALX-0081 on blood samples of patients undergoing percutaneous coronary intervention

Compound ALX-0081 is a bivalent humanised Nanobody® that binds the A1-domain of von Willebrand factor (VWF) with high affinity. Consequently, it can block the interaction between VWF and its platelet-receptor- glycoprotein Ib, which leads inevitably to formation of arterial thrombi. It was the objective of this study to assess the in vitro effects of ALX-0081 on platelet adhesion and aggregation in coronary artery disease (CAD) patients to determine the optimal concentration of ALX-0081 and the effect of co-medication. We included nine CAD patients, who were scheduled for elective percutaneous coronary intervention (PCI), and 11 healthy volunteers. At admission all patients received aspirin, clopidogrel and heparin. Blood was drawn 24 hours (h) before and 1 h after start of the PCI procedure and was subsequently spiked with different concentrations of ALX-0081 or buffer. The efficacy of ALX-0081 was assessed by in vitro experiments: flow chamber experiments, ristocetin-induced platelet aggregation (RIPA), and the platelet function analyser (PFA-100TM). VWF levels in CAD patients were significantly higher than in healthy controls. During PCI VWF levels did not rise. In all in vitro experiments, ALX-0081 led to complete inhibition of platelet adhesion and aggregation. However, the required effective concentration was higher in patients than in controls and was related to plasma VWF levels. In conclusion, ALX-0081 is able to completely inhibit in vitro platelet adhesion and aggregation in CAD patients scheduled for elective PCI. The efficacy of ALX-0081 is not influenced by PCI or co-medication. However, due to higher VWF levels in CAD patients a higher effective concentration of ALX-0081 was required than in healthy individuals.

The comparative safety of abciximab versus eptifibatide in patients on dialysis undergoing percutaneous coronary intervention: Insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2)

OBJECTIVES

We sought to evaluate the patterns of use and outcomes associated with eptifibatide and abciximab administration among dialysis patients who underwent percutaneous coronary intervention (PCI).

BACKGROUND

Contraindicated medications are frequently administered to dialysis patients undergoing PCI often resulting in adverse outcomes. Eptifibatide is a glycoprotein IIb/IIIa inhibitor that is often used during PCI and is contraindicated in dialysis.

METHODS

We included dialysis patients who underwent PCI from January 2010 to September 2015 at 47 hospitals in Michigan. We compared outcomes between patients who received eptifibatide compared with abciximab. Both groups required concurrent treatment with unfractionated heparin only. In-hospital outcomes included repeat PCI, bleeding, major bleeding, need for transfusion, and death. Optimal full matching was used to adjust for non-random drug administration.

RESULTS

Of 177 963 patients who underwent PCI, 4303 (2.4%) were on dialysis. Among those, 384 (8.9%) received eptifibatide and 100 (2.3%) received abciximab. Prior to matching, patients who received eptifibatide had higher pre-procedural hemoglobin levels (11.3 g/dL vs. 10.7 g/dL; P < 0.001) and less frequently had a history of myocardial infarction (36.5% vs. 52.0%; P = 0.005). After matching, there were no significant differences in in-hospital outcomes between eptifibatide and abciximab including transfusion (aOR: 1.15; 95%CI: 0.55-2.40; P = 0.70), bleeding (1.47; 0.64-3.40; P = 0.36), major bleeding (4.68; 0.42-52.3; P = 0.21), repeat PCI (0.38; 0.03-4.23; P = 0.43), and death (1.53; 0.2-9.05; P = 0.64).

CONCLUSIONS

Despite being contraindicated in dialysis, eptifibatide was used approximately 3.5 times more frequently than abciximab among dialysis patients undergoing PCI but was associated with similar in-hospital outcomes.

Optimal Antiplatelet Therapy in ST-Segment Elevation Myocardial Infarction

Cardiovascular disease is the leading cause of death worldwide. Case-fatality rates for myocardial infarction (MI) in the United States have decreased over the past decades, in large part due to advances in the treatment of acute MI and secondary preventive therapy after MI. Antiplatelet therapy remains the cornerstone of treatment of MI. This article reviews the current state of antiplatelet therapy in ST-segment elevation MI.

The risk of bleeding with the use of antiplatelet agents for the treatment of cardiovascular disease

INTRODUCTION

In the presence of injured coronary vascular endothelium, platelets become activated to form hemostatic plugs. While this represents a normal healing response to disrupted vascular endothelium, occlusive cardiovascular disease, as a result of maladaptive thrombus formation, is a major cause of morbidity and mortality. Due to the platelet predominance of arterial thrombi, antiplatelet agents are the mainstay of therapy for arterial cardiovascular disease, though come with a significantly increased risk of bleeding. Areas covered: This review will provide a comprehensive overview of available antiplatelet agents used to treat coronary artery cardiovascular disease. The risks of bleeding with each agent will be considered. Expert opinion: Available antiplatelet therapies are effective in treating acute thrombotic events and preventing recurrent events, however, they also carry significant bleeding risks. The decision to use or continue antiplatelet agents remains challenging for physicians and necessitates a thorough understanding of the future risk of thrombotic risks of thrombotic or bleeding events in a patient. Clinical prediction rules and risk scores may be useful to support physician decision-making.

Antithrombotic Therapy to Reduce Ischemic Events in Acute Coronary Syndromes Patients Undergoing Percutaneous Coronary Intervention

Antithrombotic therapy is essential in the prevention of periprocedural death and myocardial infarction during and after percutaneous coronary intervention. In the pathogenesis of acute coronary syndromes (ACS), both platelets and the coagulation cascade play an important role. Therefore, periprocedural antithrombotic therapy is even more important in ACS than in elective PCI. The most used agents are aspirin, platelet P2Y12 blockers, platelet glycoprotein IIb/IIIa blockers, and parenteral anticoagulants. The P2Y12 blockers must be continued at least 12 months. High-risk patients should be treated with glycoprotein IIb/IIIa receptor antagonists, especially those undergoing primary angioplasty for ST-elevation acute coronary syndrome.

Immediate outcomes of eptifibatide therapy during intracoronary stent implantation

BACKGROUND

The objective of the present study was to assess the major immediate outcomes of eptifibatide therapy during intracoronary stent implantation.

MATERIALS AND METHODS

In an interventional study, patients undergoing percutaneous coronary intervention (PCI) were randomized into either the eptifibatide (n = 100) or the control (n = 107) group. In each group, demographic and clinical characteristics such as cardiac death, stent thrombosis (ST), myocardial infarction (MI), rates of target lesion and vessel revascularization, cerebral vascular accident (CVA), and emergency coronary artery bypass grafting (CABG) were recorded.

RESULTS

The overall rates of major adverse events such as mortality, Stent thrombosis (ST), Myocardial Infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), CVA, and emergency CABG within 24 h after stent implantation were low and comparable between the two groups; P > 0.05 considered significant for all comparisons.

CONCLUSION

There were no statistical differences between the clinical outcomes of groups administered with single-dose intracoronary eptifibatide and control groups among patients undergoing PCI during stent implantation.

Acute Severe Thrombocytopenia Occurring After Administration of Eptifibatide Postpones Emergent Coronary Artery Surgery

Introduction

Eptifibatide is a platelet glycoprotein IIb/IIIa (GP IIb/IIIa) receptor antagonist that inhibits fibrinogen binding to the activated GP IIb/IIIa site and prevents platelet-platelet interaction and clot formation. GP IIb/IIIa inhibitors improve outcome in patients undergoing percutaneous coronary intervention for acute coronary syndrome. Thrombocytopenia is a complication of GP IIb/IIIa inhibitors, but severe thrombocytopenia is unusual. Most reported cases of severe thrombocytopenia after eptifibatide occurred in patients with acute coronary syndrome. The authors describe a patient who developed acute profound thrombocytopenia after receiving eptifibatide before emergent coronary artery bypass graft surgery.

Case Presentation

A 67-year-old man with a normal platelet count (220 K/uL) developed atrial fibrillation, left bundle branch block, and respiratory insufficiency consistent with acute coronary syndrome two days after colectomy. He received eptifibatide during cardiac catheterization, where three-vessel coronary artery disease was encountered. Emergent coronary artery surgery was planned, but the platelet count before surgery was 2 K/uL. Eptifibatide was discontinued, surgery was postponed, and acute coronary syndrome was treated with intraaortic balloon counterpulsation.

Conclusions

The authors describe the second reported case of eptifibatide-induced severe thrombocytopenia associated with cardiac surgery. In this case, discontinuation of eptifibatide and transfusion of apheresis platelets increased the platelet count (137 K/uL) the following day, and the patient subsequently underwent successful coronary artery surgery using cardiopulmonary bypass.

Comparison of heparin, bivalirudin, and different glycoprotein IIb/IIIa inhibitor regimens for anticoagulation during percutaneous coronary intervention: A network meta-analysis

BACKGROUND/PURPOSE

Numerous GPIs are available for PCI. Although they were tested in randomized controlled trials, a comparison between the different GPI strategies is lacking. Thus, we performed a Bayesian network meta-analysis to compare different glycoprotein IIb/IIIa inhibitor (GPI) strategies with heparin and bivalirudin for percutaneous coronary intervention (PCI).

METHODS

MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov were searched by two independent reviewers for randomized controlled trials comparing high-dose bolus tirofiban, abciximab, eptifibatide, heparin with provisional glycoprotein IIb/IIIa inhibitors, and bivalirudin with provisional GPI that reported clinical outcomes. Mixed treatment comparison model generation was performed to directly and indirectly compare between different anticoagulation strategies for all-cause mortality, myocardial infarction, major adverse cardiovascular events, major bleeding, minor bleeding, need for transfusion, and thrombocytopenia.

RESULTS

A total of 41 randomized controlled trials with 38,645 patients were included in the analysis, among which 2654 were randomized to high-dose bolus tirofiban, 6752 to abciximab, 1669 to eptifibatide, 16,500 to heparin, and 11,070 to bivalirudin. Mean age was 64±11years, 75% were male, 91% were treated with stenting, 71% with clopidogrel, and 74% for acute coronary syndrome. High-dose bolus tirofiban was associated with a significant reduction in all-cause mortality compared with heparin (OR 0.57 [credible intervals 0.37, 0.9]) and eptifibatide (OR 0.44 [credible intervals 0.19, 1.0]). GPI regimens had less myocardial infarction and major adverse cardiovascular events but greater bleeding compared with heparin and bivalirudin. There was no difference among the GPI therapies for other outcomes, including myocardial infarction, major adverse cardiovascular events, and major bleeding.

CONCLUSIONS

Our network meta-analysis of 38,645 patients demonstrated that GPI regimens were associated with a reduction in recurrent myocardial infarction or major adverse cardiovascular events for PCI, while bivalirudin was associated with the lowest risk of bleeding.

Intracoronary versus Intravenous eptifibatide during percutaneous coronary intervention for acute ST-segment elevation myocardial infarction; a randomized controlled trial

Although aspirin and clopidogrel seem to be quite enough during low risk percutaneous coronary intervention (PCI), the combination may need some reinforcement in complex situations such as primary PCI. By modifying the route and also the duration of administration, glycoprotein IIb/IIIa inhibitors might be a viable option. The aim of this study is to compare the benefits and disadvantages of three different methods of administration of eptifibatide in primary PCI population. Primary PCI candidates were randomized in three groups on which three different methods of administration of eptifibitide were tested: intravenous bolus injection followed by 12-h infusion (IV-IV), intracoronary bolus injection followed by intravenous infusion (IC-IV) and, only intracoronary bolus injection (IC). 99 patients were included in the present study. There was no significant difference among the three groups regarding all cause in hospital and one month mortality (p value = 0.99), re-myocardial infarction (p value = 0.89), post-PCI TIMI flow grade 3 (p value = 0.97), ST segment resolution (p value = 0.77) and peak troponin levels (p value = 0.82). The comparison of vascular access and major bleeding complications were not possible due to low events rate. By modifying the route of administration of eptifibitide, the clinical effect might be preserved without increasing the short-term mortality and procedural failure.

The role of Glycoprotein IIb/IIIa inhibitors in acute coronary syndromes and the interference with anemia

The role played by glycoprotein (GP) IIb/IIIa inhibitors (GPI) has continuously evolved until the most recent Guidelines whereby they were stepped down from class I to class II recommendation for treating acute coronary syndromes (ACS). GPI compete with a wider use of ADP inhibitors and novel anticoagulant drugs although GPI use has greatly narrowed. However, GPI may still have a role. Several criteria were proposed to define post-PCI anemia which is strictly related to bleeding and transfusion. In ACS, it should be important to define anemia in comparative terms versus baseline levels: ≥ 15% of red blood cell decrease should be a practical cut-off value. If one wishes to concentrate on hemoglobin (Hb), a≥2g/dl Hb decrease from baseline should be considered. It is important to recognize post-PCI anemia in the setting of ACS. There are sub-populations exposed to short-term hemorrhagic and/or long-term ischemic risks. Ischemic and hemorrhagic risks need to be carefully evaluated along with thrombocytopenia and its prognostic significance in order to put all these blood and rheological parameters into a clinically oriented perspective on which therapeutical decisions should be based. Definition of high risk procedures (complexity, angiographic characteristics and patient's risk profile, regardless whether STEMI or NSTEMI) may help selecting GPI. There are positive elements in GPI use: efficacy, rapid onset and reversibility of action, absence of pharmacogenomic variability, pharmacoeconomic considerations and the possibility of intracoronary administration. All these elements should be evaluated when selecting these agents for therapeutics.

Preoperative Platelet Inhibition With Eptifibatide During Coronary Artery Bypass Grafting With Cardiopulmonary Bypass

Platelet glycoprotein IIb-IIIa antagonists reduce cardiac events in acute coronary syndromes (ACSs), but their use is limited during coronary artery bypass grafting (CABG) because of bleeding concerns. Patients with ACS, however, are at increased risk for cardiac events after CABG. The use of short-acting glycoprotein IIbIIIa inhibitor eptifibatide in patients with ACS undergoing CABG was investigated. Fifteen patients with ACS and undergoing CABG with cardiopulmonary bypass were enrolled. One withdrew before surgery. Patients received heparin and eptifibatide preoperatively. Eptifibatide concentration and receptor occupancy (RO) at termination of infusion were similar in the two groups. Immediately before surgery, eptifibatide levels in the 2-hour group were twice that in the 4-hour group, and platelet RO was higher. Cessation of eptifibatide 4 hours before surgery results in less bleeding and transfusions than 2 hours before surgery. The optimal balance between bleeding and platelet inhibition is approximately 60% platelet RO. Further investigation of upstream therapy should target this threshold.

Antithrombotic Therapy in Percutaneous Coronary Intervention

Numerous agents are available for anticoagulation during percutaneous coronary intervention (PCI). These agents have been evaluated in a variety of clinical settings, including elective, urgent, and emergent PCI. Although unfractionated heparin remains a frequent choice, accumulating data support the use of newer agents to mitigate bleeding risk, especially in the setting of femoral access and concomitant use of glycoprotein IIb/IIa receptor inhibition. With several antithrombotic agents available, an assessment must be made regarding the ischemic and bleeding risks. This article summarizes existing data examining the benefits and limitations of the various anticoagulants and guidelines for their use.

Antiplatelet Therapy in Percutaneous Coronary Intervention

Platelets play a key role in mediating stent thrombosis, which is the major cause of ischemic events immediately after percutaneous coronary intervention (PCI). Antiplatelet therapy is therefore the cornerstone of antithrombotic therapy after PCI. However, the use of antiplatelet agents increases bleeding risk, with more potent antiplatelet agents further increasing bleeding risk. In the past 5 years, potent and fast-acting P2Y12 inhibitors have augmented the antiplatelet armamentarium available to interventional cardiologists. This article reviews the preclinical and clinical data surrounding these new agents, and discusses the significant questions and controversies that still exist regarding the optimal antiplatelet strategy.

Relation of Activated Clotting Times During Percutaneous Coronary Intervention to Outcomes

Monitoring anticoagulation using the activated clotting time (ACT) in patients treated with heparin and undergoing percutaneous coronary intervention (PCI) is one of the most frequently used tests in invasive cardiology. However, despite its widespread use and guideline endorsement, uncertainty remains regarding the association of ACT with outcomes in contemporary practice. We reviewed all PCI procedures performed at the Mayo Clinic (Rochester, Minnesota) from October 2001 to December 2012 and evaluated the association between the ACT before device activation and in-hospital and 1-year outcomes. ACT values were grouped into tertiles for descriptive purposes and analyzed as a continuous variable for assessment of outcomes. We used logistic and Cox proportional hazards regression models to estimate the association of ACT and outcomes. Of the 12,055 patients who underwent PCI with an ACT value before device activation, 3,977 (33.0%) had an ACT <227, 4,046 (33.6%) had an ACT 227 to 285, and 4,032 (33.4%) had an ACT >285. Baseline and procedural characteristics were similar across ACT tertiles. In unadjusted analysis, higher ACT values were associated with death (p <0.001), bleeding (p = 0.024), procedural complication (p <0.001), and higher 1-year events (cardiac death, p <0.001; cardiac death/myocardial infarction, p = 0.022). After multivariable adjustment for baseline and procedural characteristics, ACT was not independently associated with in-hospital or 1-year ischemic, thrombotic, or bleeding outcomes. In conclusion, ACT values before device activation are not independently associated with clinically important outcomes in contemporary PCI practice.