Glycoprotein IIb/IIIa inhibitors with or without thienopyridine pretreatment improve outcomes after primary percutaneous coronary intervention in high-risk patients with ST elevation myocardial infarction--a meta-regression of randomized controlled trials

Dual Role of Guide Extension Catheters for the Management of High Thrombus Burden in STEMI: Case Report and Mini Review

High thrombus burden in ST segment elevation myocardial infarction (STEMI) patients increases the risk of adverse events. In this report, we review current strategies for high thrombus burden and present a case report with the combination of two different techniques: aspiration through a guide extension catheter followed by local intracoronary thrombolysis with 'marinade' technique.

The role of platelet glycoprotein IIb / IIIa inhibitors in current treatment of acute coronary syndrome

Current management of patients with acute coronary syndrome (ACS) includes a dual antiplatelet therapy with acetylsalicylic acid and a platelet P2Y12 receptor inhibitor. For patients without a high risk of bleeding, prasugrel and ticagrelor are preferred, since their effect is more pronounced, less dependent on metabolism of a specific patient, and occurs faster that the effect of clopidogrel. The prescription rate of platelet glycoprotein IIb/IIIa (GP IIb / IIIa) receptor inhibitors has considerably decreased. However, these drugs remain relevant in percutaneous coronary interventions in patients with a high risk of coronary thrombosis or a massive coronary thrombus, in thrombotic complications of the procedure, and in the "no-reflow" phenomenon. The intravenous route of GP IIb / IIIa inhibitor administration provides their effectiveness in patients with difficulties of drug intake or with impaired absorption of oral medications. This review presents clinical and pharmacological characteristics of various GP IIb / IIIa inhibitors and data of randomized clinical studies and registries of recent years that evaluated results of their use in patients with ACS.

Acute coronary syndromes with high thrombotic burden: therapeutic innovations

Antiplatelet agents represent one of the cornerstones of drug therapy for acute coronary syndromes (ACS). In the last decade, the arrival of prasugrel and ticagrelor, faster and more powerful oral platelet receptor P2Y12 inhibitors compared to clopidogrel, significantly improved platelet inhibition in patients with ACS. However, the reduction of thrombotic risk came at the cost of increased bleeding risk. Despite having similar indications, prasugrel and ticagrelor have different characteristics and methods of use, essentially due to a different design of the trials in which they have been studied. The optimal use of these antiplatelets in clinical practice should therefore be tailored in individual patients. In the acute phase of ACS with high thrombotic burden, all oral P2Y12 inhibitors have limitations, mainly due to the delay of onset of action related to oral administration. In this scenario, parenteral antiplatelet agents (glycoprotein inhibitors IIb/IIIa and cangrelor) may play a key role in case of percutaneous coronary interventions of high thrombotic coronary lesions and in the prevention of early thrombotic complications. Cangrelor, an intravenous inhibitor of the P2Y2 receptor, has peculiar pharmacokinetic and pharmacodynamic characteristics that make it particularly suitable to be used as an antiplatelet during coronary angioplasty as it achieves a rapid and powerful antiplatelet effect in patients not pretreated with oral medications, and has a favourable safety profile in relation to the bleeding risk.

Intracoronary compared with intravenous bolus tirofiban on the microvascular obstruction in patients with STEMI undergoing PCI: a cardiac MR study

To investigate the potential effect of intracoronary administration of the glycoprotein IIb/IIIa inhibitor tirofiban on the microvascular obstruction (MVO) assessed by cardiac magnetic resonance (CMR) imaging compared to the intravenous route in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Two hundred eight patients were randomized into two groups (tirofiban i.v. and tirofiban i.c.). CMR was completed within 3-7 days after ST-segment-elevation myocardial infarction. One hundred thirty-two patients had a follow-up CMR at 6 months after discharge. The primary end point was the CMR measurements including myocardium strain, myocardial perfusion index, final infarct size, prevalence and extent of MVO, and the change of left ventricular end-diastolic volume (LVEDV) at six months follow-up. The second endpoint was major adverse cardiovascular events (composite of all-cause death, nonfatal reinfarction and congestive heart failure) in one year. The MVO prevalence and extent [56% versus 36%, p = 0.004; 2.08 (IQR: 1.18-5.07) g versus 1.68 (IQR: 0.30-3.28) g, p = 0.041] showed a significant difference between the intravenous and intracoronary groups. Global left ventricular peak longitudinal strain was significantly different in intracoronary groups compared to intravenous groups, - 12.5 [IQR: - 13.4 to - 10.9] versus - 12.3 [IQR: - 13.4 to - 10.4], respectively (P = 0.042). Infarcted myocardial perfusion index was significantly different in intracoronary groups compared to intravenous groups, 0.11 [IQR: 0.08 to 0.15] versus 0.09 [IQR: 0.07 to 0.14], respectively (P = 0.026). Intracoronary tirofiban was associated with a higher change in LVEDV compared with intravenous group (- 10.2% [IQR: - 13.7% to - 2.6%] versus 1.3% [IQR: - 5.6% to 6.1%], p < 0.001). Intracoronary tirofiban application showed no benefit on the occurrence of major adverse cardiovascular events during follow-up compared to intravenous administration. This CMR study in ST-segment-elevation myocardial infarction patients showed a benefit in MVO and left ventricular remodeling for intracoronary tirofiban administration compared to intravenous administration in patients undergoing PCI.

Trends of Use and Outcomes Associated With Glycoprotein-IIb/IIIa Inhibitors in Patients With Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention

Background: Glycoprotein IIb/IIIa inhibitors (GPIs) are a treatment option in the management of acute coronary syndromes (ACSs). Evidence supporting the use of GPIs predates trials establishing the benefits of P2Y12 inhibitors, routine early invasive therapy, and thrombectomy devices in patients with ACS. Objective: The aim of this study was to determine trends in GPI use and their associated outcomes in contemporary practice. Methods: We assessed GPI use in patients with ACS undergoing percutaneous coronary intervention (PCI) from the Melbourne Interventional Group registry (2005-2013). The primary endpoint was the 30-day incidence of major adverse cardiovascular events (MACE). The safety endpoint was in-hospital major bleeding. Results: GPIs were used in 40.5% of 12 357 patients with ACS undergoing PCI. GPI use decreased over the study period (P for trend <0.0001). Patients were more likely to receive GPIs if they were younger, presented with a ST-elevation myocardial infarction (STEMI), had more complex (B2/C-type) lesions, and when thrombectomy devices were used (all P < 0.0001). MACE were higher in patients receiving GPI (4.9% vs 4.1%, P = 0.03). Propensity score matching revealed no difference in 30-day mortality and 30-day MACE (odds ratio [OR] = 1.00; 95% CI = 0.99-1.004 and OR = 1.01; 95% CI = 0.99-1.02, respectively). GPI use was associated with more bleeding complications (3.6% vs 1.8%, P < 0.0001). Conclusion and Relevance: GPI use in ACS patients undergoing PCI has declined, and use appears to be dictated by ACS type and lesion complexity, as opposed to high-risk comorbidities. GPI use was associated with a doubling in bleeding complications.

Platelet Function and Risk of Bleeding in Patients With Acute Coronary Syndrome Following Tirofiban Infusion

Aim: To assess platelet (PLT) function and bleeding risks in patients with acute coronary syndrome after tirofiban infusion.

Methods: Patients diagnosed with acute coronary syndrome from May 2016 to February 2018 in the Department of Cardiac Intensive Care Unit, Zhongshan Hospital, were enrolled. They were symmetrically allocated into two groups: tirofiban treatment group or control group (without tirofiban treatment). Blood samples were collected 24 h postoperation for the evaluation of antiplatelet effect of tirofiban. We applied thromboelastography to detect on-treatment PLT reactivity and conducted laboratory tests to assess the risk of bleeding following tirofiban treatment. After discharge, telephone follow-up and outpatient interview were carried out. The primary clinical endpoint was major adverse cardiovascular events, including cardiovascular death, cardiovascular mortality, myocardial infarction, and revascularization for the targeted vascular lesion.

Results: There were a total of 196 patients with acute coronary syndrome after screening with the inclusion criteria and the exclusion criteria. Ninety-eight patients were assigned to receive either tirofiban treatment or control treatment. Patients treated with tirofiban had more coronary lesions and stents implanted compared with the control group (P = 0.000). After tirofiban infusion, inhibition of platelet aggregation induced by thromboxane A₂ and adenosine diphosphate was significantly higher compared to patients without tirofiban infusion (80.3% ± 19.6% vs. 72.6% ± 13.0%, P = 0.002; and 81.0% ± 19.8% vs. 75.4% ± 12.4%, P = 0.020, respectively). There was no significant difference in the reduction of hemoglobin (Hb), hematocrit (Hct), and PLT after administration of tirofiban, compared with baseline (P > 0.05). In addition, no significant differences were identified between the two groups with respect to Hb, Hct, and PLT after tirofiban infusion. However, C-reactive protein level, referred to as an inflammation marker, was significantly lowered after infusion tirofiban compared with the control group (11.9 ± 14.2 vs. 17.9 ± 21.2, P = 0.020). During the 1-year follow-up, the incidence rate of major adverse cardiovascular events remains indiscriminate between the two groups (P = 0.208). The assessments of cardiac biomarkers showed that tirofiban could decrease incidence of procedural myocardial infarction (odds ratio [OR] = 0.250, 95% confidence interval [CI] = 0.067–0.925, P = 0.027). At follow-up, the morbidity of left atrial dilation in tirofiban-treated patients, defined as enlargement of left atrial diameter >40mm, was lower compared to the control group (OR = 0.533, 95% CI = 0.301–0.945, P = 0.031).

Conclusion: Tirofiban infusion could decrease PLT activation in patients with acute coronary syndrome without increasing the risk of bleeding. As a concomitant medication, tirofiban shows no benefit in reducing the occurrence of major adverse cardiovascular events.

Cangrelor With and Without Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

Cangrelor, an intravenous, reversible P2Y₁₂ antagonist, is approved for use in patients undergoing percutaneous coronary intervention (PCI).

OBJECTIVES

This study sought to evaluate the efficacy and safety of cangrelor compared with clopidogrel in subgroups that did and did not receive glycoprotein IIb/IIIa inhibitors (GPIs).

METHODS

This pooled, patient-level analysis of the 3 CHAMPION (Cangrelor versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition) trials analyzed all randomized patients who underwent PCI and received the study drug (n = 24,902). Only bailout/rescue GPI use was permitted, except in CHAMPION PCI, in which routine or bailout/rescue GPI use was at the site investigator's discretion. The primary efficacy endpoint was the composite of all-cause mortality, myocardial infarction, ischemia-driven revascularization, or stent thrombosis at 48 h after randomization.

RESULTS

Overall, 3,173 patients (12.7%) received a GPI, most commonly eptifibatide (69.4%). Despite variation in indications for GPIs, baseline characteristics were well balanced between the cangrelor and clopidogrel arms in subsets receiving and not receiving GPIs. Rates of the primary composite endpoint were lower with cangrelor compared with clopidogrel in patients who did (4.9% vs. 6.5%; odds ratio [OR]: 0.74; 95% confidence interval [CI]: 0.55 to 1.01) or did not receive a GPI (3.6% vs. 4.4%; OR: 0.82; 95% CI: 0.72 to 0.94; P_int = 0.55). Cangrelor did not increase the primary safety endpoint, GUSTO-defined severe/life-threatening bleeding, in patients who did (0.4% vs. 0.5%; OR: 0.71; 95% CI: 0.25 to 1.99) or did not receive GPIs (0.2% vs. 0.1%; OR: 1.56; 95% CI: 0.80 to 3.04; P_int = 0.21). GPI use was associated with increased risk of bleeding in both treatment arms.

CONCLUSIONS

Cangrelor's efficacy in reducing ischemic complications in patients undergoing PCI was maintained irrespective of GPI administration. GPI use was associated with substantially higher bleeding rates, regardless of the randomization to cangrelor or clopidogrel. (A Clinical Trial to Demonstrate the Efficacy of Cangrelor [PCI]: NCT00305162; Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition [PLATFORM]: NCT00385138; A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI] [CHAMPION PHOENIX] [CHAMPION]: NCT01156571).

Impact of Glycoprotein IIb/IIIa Inhibition in Contemporary Percutaneous Coronary Intervention for Acute Coronary Syndromes: Insights From the National Cardiovascular Data Registry

OBJECTIVES

This study investigates the effects of glycoprotein IIb/IIIa inhibitors (GPIs) on outcomes after percutaneous coronary intervention (PCI).

BACKGROUND

Ischemic complications are reduced after PCI when a GPI is added to heparin. However, there are limited data on the safety and efficacy in contemporary PCI.

METHODS

We used the National Cardiovascular Data Registry CathPCI Registry data to assess the association between GPI use and PCI outcomes for acute coronary syndrome between July 2009 and September 2011. The primary outcome was all-cause in-hospital mortality. The secondary outcome was major bleeding. To adjust for potential bias, we used multivariable logistic regression, propensity-matched (PM) analysis, and instrumental variable analysis (IVA).

RESULTS

There were 970,865 patients included; 326,283 (33.6%) received a GPI. Unadjusted mortality and major bleeding were more common with a GPI (2.4% vs. 1.4% and 3.7% vs. 1.5%, respectively; p < 0.001 for both). In contrast, GPI use was associated with lower mortality on adjusted analyses; relative risks range from 0.72 (95% confidence interval [CI]: 0.50 to 0.97) with IVA to 0.90 (95% CI: 0.86 to 0.95) with PM. The association of GPI use with bleeding remained in adjusted analyses (multivariable relative risk: 1.93, 95% CI: 1.83 to 2.04; PM relative risk: 1.83, 95% CI: 1.74 to 1.92; and IVA relative risk: 1.53, 95% CI: 1.27 to 2.13). Subgroup analysis revealed enhanced risk reduction with ST-segment elevation myocardial infarction, high predicted mortality, and heparin-based anticoagulation.

CONCLUSIONS

In unselected acute coronary syndrome patients undergoing PCI, GPI use was associated with reduced in-hospital mortality and increased bleeding. In the modern era of PCI, there may still be a role for the judicious use of GPIs.

Why we need intravenous antiplatelet agents

Oral ADP-receptor antagonists combined with aspirin are the standard for dual antiplatelet therapy (DAPT) during percutaneous coronary intervention (PCI). However, the oral route of administration of ADP-receptor antagonists leaves them vulnerable to unpredictable and often inadequate platelet inhibition at the time of PCI, while their prolonged effects often lead to the decision not to load them prior to PCI. Intravenous antiplatelet agents, including glycoprotein IIb/IIIa inhibitors (GPI) and cangrelor, a reversible P2Y12 inhibitor, address these shortcomings. In June 2015, the US FDA approved cangrelor for the prevention of thrombotic events associated with coronary stenting. This review examines the current state of peri-PCI DAPT and demonstrates that the selective use of GPIs and intravenous ADP-antagonist agents reduces the risk of periprocedural thrombosis.

Clinical and Angiographic Predictors of Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction

PURPOSE

We aimed to discover clinical and angiographic predictors of microvascular dysfunction using the index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

We enrolled 113 patients with STEMI (age, 56±11 years; 95 men) who underwent primary percutaneous coronary intervention (PCI). The IMR was measured with a pressure sensor/thermistor-tipped guidewire after primary PCI. The patients were divided into three groups based on IMR values: Low IMR [<18 U (12.9±2.6 U), n=38], Mid IMR [18-31 U (23.9±4.0 U), n=38], and High IMR [>31 U (48.1±17.1 U), n=37].

RESULTS

The age of the Low IMR group was significantly lower than that of the Mid and High IMR groups. The door-to-balloon time was <90 minutes in all patients, and it was not significantly different between groups. Meanwhile, the symptom-onset-to-balloon time was significantly longer in the High IMR group, compared to the Mid and Low IMR groups (p<0.001). In the high IMR group, the culprit lesion was found in a proximal location significantly more often than in a non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of a high IMR (p=0.013 and p=0.003, respectively).

CONCLUSION

Our data suggest that age and symptom-onset-to-balloon time might be the major predictors of microvascular dysfunction in STEMI patients with a door-to-balloon time of <90 minutes.