Antithrombotic therapy for patients with STEMI undergoing primary PCI

Elevated Leukocyte Count and Platelet-Derived Thrombogenicity Measured Using the Total Thrombus-Formation Analysis System in Patients with ST-Segment Elevation Myocardial Infarction

AIMS

High platelet-derived thrombogenicity during the acute phase of ST-segment elevation myocardial infarction (STEMI) is associated with poor outcomes; however, the associated factors remain unclear. This study aimed to examine whether acute inflammatory response after STEMI affects platelet-derived thrombogenicity.

METHODS

This retrospective observational single-center study included 150 patients with STEMI who were assessed for platelet-derived thrombogenicity during the acute phase. Platelet-derived thrombogenicity was assessed using the area under the flow-pressure curve for platelet chip (PL-AUC), which was measured using the total thrombus-formation analysis system (T-TAS). The peak leukocyte count was evaluated as an acute inflammatory response after STEMI. The patients were divided into two groups: the highest quartile of the peak leukocyte count and the other three quartiles combined.

RESULTS

Patients with a high peak leukocyte count (＞15,222/mm3; n=37) had a higher PL-AUC upon admission (420 [386-457] vs. 385 [292-428], p=0.0018), higher PL-AUC during primary percutaneous coronary intervention (PPCI) (155 [76-229] vs. 96 [29-170], p=0.0065), a higher peak creatine kinase level (4200±2486 vs. 2373±1997, p＜0.0001), and higher PL-AUC 2 weeks after STEMI (119 [61-197] vs. 88 [46-122], p=0.048) than those with a low peak leukocyte count (≤ 15,222/mm3; n=113). The peak leukocyte count after STEMI positively correlated with PL-AUC during primary PPCI (r=0.37, p＜0.0001). A multivariable regression analysis showed the peak leukocyte count to be an independent factor for PL-AUC during PPCI (β=0.26, p=0.0065).

CONCLUSIONS

An elevated leukocyte count is associated with high T-TAS-based platelet-derived thrombogenicity during the acute phase of STEMI.

Cardiovascular outcomes of sodium-glucose Co-transporter 2 inhibitors use after myocardial infarction: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Patients who had acute myocardial infarction are at high risk of negative cardiac outcomes and previous SGLT2i landmark trials excluded these patients. It therefore remains unclear if SGLT2i is safe and confers beneficial cardiovascular outcomes after acute myocardial infarction.

METHODS

We systematically reviewed randomized controlled trials that evaluated the outcomes of adding SGLT2i to conventional post-myocardial infarction care. Random-effects model meta-analysis via RevMan 5.4 was done on data extracted from pooled 11,204 patients.

RESULTS

SGLT2i use after acute myocardial infarction was significantly associated with reduced heart failure hospitalization (OR: 0.77, 95%CI: 0.62-0.96, p=0.02), but was not associated with a reduction in all-cause mortality (OR: 1.05, 95%CI: 0.77-1.43, p=0.75), cardiac-related death (OR: 1.04, 95%CI: 0.83-1.30, p=0.76), or major adverse cardiac events (OR: 0.90, 95%CI: 0.77-1.05, p=0.18).

CONCLUSION

SGLT2 inhibitor therapy after acute myocardial infarction is safe and is associated with a reduced risk of heart failure hospitalization, but not with all-cause mortality.

Targeted next-generation sequencing panel to investigate antiplatelet adverse reactions in acute coronary syndrome patients undergoing percutaneous coronary intervention with stenting

Antiplatelet therapy, the gold standard of care for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI), is one of the therapeutic approaches most associated with the development of adverse drug reactions (ADRs). Although numerous studies have shown that pharmacological intervention based on a limited number of high-evidence variants (primarily CYP2C19*2 and *3) can reduce the incidence of major adverse cardiovascular events (MACEs), ADRs still occur at variable rates (10.1 % in our case) despite personalized therapy. This study aimed to identify novel genetic variants associated with the endpoint of MACEs 12 months after PCI by designing and analyzing a targeted gene panel. We sequenced 244 ACS-PCI-stent patients (109 with event and 135 without event) and 99 controls without structural cardiovascular disease and performed an association analysis to search for unexpected genetic variants. No single nucleotide polymorphisms reached genomic significance after correction, but three novel variants, including ABCA1 (rs2472434), KLB (rs17618244), and ZNF335 (rs3827066), may play a role in MACEs in ACS patients. These genetic variants are involved in regulating high-density lipoprotein levels and cholesterol deposition, and as they are regulatory variants, they may affect the expression of nearby lipid metabolism-related genes. Our findings suggest new targets (both at the gene and pathway levels) that may increase susceptibility to MACEs, but further research is needed to clarify the role and impact of the identified variants before these findings can be incorporated into the therapeutic decision-making process.

Intravenous antiplatelet therapy in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention : A report from the INVEST-STEMI group

The use of intravenous antiplatelet therapy during primary percutaneous coronary intervention (PPCI) is not fully standardized. The aim is to evaluate the effectiveness and safety of periprocedural intravenous administration of cangrelor or tirofiban in a contemporary ST-segment elevation myocardial infarction (STEMI) population undergoing PPCI. This was a multicenter prospective cohort study including consecutive STEMI patients who received cangrelor or tirofiban during PPCI at seven Italian centers. The primary effectiveness measure was the angiographic evidence of thrombolysis in myocardial infarction (TIMI) flow < 3 after PPCI. The primary safety outcome was the in-hospital occurrence of BARC (Bleeding Academic Research Consortium) 2-5 bleedings. The study included 627 patients (median age 63 years, 79% males): 312 received cangrelor, 315 tirofiban. The percentage of history of bleeding, pulmonary edema and cardiogenic shock at admission was comparable between groups. Patients receiving cangrelor had lower ischemia time compared to tirofiban. TIMI flow before PPCI and TIMI thrombus grade were comparable between groups. At propensity score-weighted regression analysis, the risk of TIMI flow < 3 was significantly lower in patients treated with cangrelor compared to tirofiban (adjusted OR: 0.40; 95% CI: 0.30-0.53). The risk of BARC 2-5 bleeding was comparable between groups (adjusted OR:1.35; 95% CI: 0.92-1.98). These results were consistent across multiple prespecified subgroups, including subjects stratified for different total ischemia time, with no statistical interaction. In this real-world multicenter STEMI population, the use of cangrelor was associated with improved myocardial perfusion assessed by coronary angiography after PPCI without increasing clinically-relevant bleedings compared to tirofiban.

Efficacy and safety of cangrelor as compared to ticagrelor in patients with ST-elevated myocardial infarction (STEMI): a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to compare the efficacy and safety of cangrelor as compared to ticagrelor in patients with ST-elevated myocardial infarction (STEMI) who underwent percutaneous intervention.

METHODS

PubMed, Embase, Scopus, Web of Science, Cochrane CENTRAL, and ClinicalTrials.gov databases were searched for relevant head-on-comparison or swapping studies. The primary outcome was the rate of high platelet reactivity (HPR) at specific time intervals after stopping cangrelor infusion during the first 24 h. Secondary outcomes were the risks of thrombosis, all-cause mortality and bleeding. Pooled odds ratios (ORs) were calculated using random-effects models.

RESULTS

A total of 1018 studies were screened and eight were included in the analysis. There were four head-on-comparison studies and four swapping studies. There was no significant difference in the proportion of patients achieving a high platelet reactivity in swapping studies [OR, 0.71 (95% CI 0.04, 13.87), p = 0.82, i2 = 88%]. In head-on-comparison studies, PRU from Fig. 2B shows there was no significant reduction in high platelet reactivity [mean difference - 77.83 (95% CI - 238.84, 83.18), p < 0.001, i2 = 100%]. PRU results from (Fig. 2C) show a mean difference of 7.38 (95% CI - 29.74, 44.51), p < 0.001, i2 = 97%. There was no significant difference in the risks of thrombosis [OR, 0.91 (95% CI 0.20, 4.13), p = 0.81, i2 = 0%], all-cause mortality [OR, 3.52 (95% CI 0.44, 27.91), p = 0.24, i2 = 26%] and bleeding [OR, 0.89 (95% CI 0.37, 2.17), p = 0.93, i2 = 0%] between the two groups as revealed in the head-on-comparison studies.

CONCLUSION

The efficacy and safety profiles of cangrelor and ticagrelor were similar in patients with STEMI.

Risk of Bleeding Among Cangrelor-Treated Patients Administered Upstream P2Y12 Inhibitor Therapy: The CAMEO Registry

Background

Little is known about the bleeding risk associated with cangrelor use in patients with myocardial infarction (MI) who are exposed to an oral P2Y12 inhibitor before coronary angiography.

Methods

Cangrelor in Acute MI: Effectiveness and Outcomes (CAMEO) is an observational registry studying platelet inhibition for patients with MI. Upstream oral P2Y12 inhibition was defined as receipt of an oral P2Y12 inhibitor within 24 hours before hospitalization or in-hospital before angiography. Among cangrelor-treated patients, we compared bleeding after cangrelor use through 7 days postdischarge between patients with and without upstream oral P2Y12 inhibitor exposure.

Results

Among 1802 cangrelor-treated patients with MI, 385 (21.4%) received upstream oral P2Y12 inhibitor treatment. Of these, 101 patients (33.8%) started cangrelor within 1 hour, 103 (34.4%) between 1 and 3 hours, and 95 (31.8%), >3 hours after in-hospital oral P2Y12 inhibitor administration; the remaining received an oral P2Y12 inhibitor before hospitalization. There was no statistically significant difference in rates of bleeding among cangrelor-treated patients with and without upstream oral P2Y12 inhibitor exposure (6.5% vs 8.8%; adjusted odds ratio [OR], 0.62; 95% CI, 0.38-1.01). Bleeding was observed in 5.0%, 10.7%, and 3.2% of patients treated with cangrelor <1, 1 to 3, and >3 hours after the last oral PY12 inhibitor dose, respectively; bleeding rates were not statistically different between groups (1-3 hours vs <1 hour: adjusted OR, 2.70; 95% CI, 0.87-8.32; >3 hours vs <1 hour: adjusted OR, 0.65; 95% CI, 0.15-2.85).

Conclusions

Bleeding risk was not observed to be significantly higher after cangrelor treatment in patients with and without upstream oral P2Y12 inhibitor exposure.

Bivalirudin in acute coronary syndromes

INTRODUCTION

Bivalirudin, a bivalent direct thrombin inhibitor, has been developed to reduce bleeding without any trade-off in thrombotic events in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI).

AREAS COVERED

Despite showing a superior safety profile compared with unfractionated heparin (UFH), bivalirudin is not considered the anticoagulant of choice in ACS patients undergoing PCI, mainly because of an increased rate of acute stent thrombosis (ST) shown by several randomized controlled trials (RCTs), in addition to limited availability in certain countries and increased costs. However, RCTs on bivalirudin have been characterized by several confounding factors hindering the interpretation of its safety and efficacy compared with UFH among the spectrum of ACS patients. Furthermore, a significant body of evidence has demonstrated that the risk of acute ST can be mitigated by a full-dose infusion regimen following PCI, without compromising the favorable safety profile compared to UFH.

EXPERT OPINION

In light of the increased understanding of the prognostic relevance of bleeding events and the excellent safety profile of bivalirudin, recent trial evidence may allow for this anticoagulant agent to reemerge and have a more prominent role in the management of ACS patients undergoing PCI.

Dual Antiplatelet Therapy with Parenteral P2Y12 Inhibitors: Rationale, Evidence, and Future Directions

Dual antiplatelet therapy (DAPT), consisting of the combination of aspirin and an inhibitor of the platelet P2Y₁₂ receptor for ADP, remains among the most investigated treatments in cardiovascular medicine. While a substantial amount of research initially stemmed from the observations of late and very late stent thrombosis events in the first-generation drug-eluting stent (DES) era, DAPT has been recently transitioning from a purely stent-related to a more systemic secondary prevention strategy. Oral and parenteral platelet P2Y₁₂ inhibitors are currently available for clinical use. The latter have been shown to be extremely suitable in drug-naïve patients with acute coronary syndrome (ACS), mainly because oral P2Y₁₂ inhibitors are associated with delayed efficacy in patients with STEMI and because pre-treatment with P2Y₁₂ inhibitors is discouraged in NSTE-ACS, and in patients with recent DES implantation and in need of urgent cardiac and non-cardiac surgery. More definitive evidence is needed, however, about optimal switching strategies between parenteral and oral P2Y₁₂ inhibitors and about newer potent subcutaneous agents that are being developed for the pre-hospital setting.

Cangrelor in Patients With Coronary Artery Disease Pretreated With Ticagrelor: The Switching Antiplatelet (SWAP)-5 Study

BACKGROUND

There are no studies specifically designed to rule out a drug-drug interaction (DDI) when cangrelor is used among patients who have been pretreated with ticagrelor.

OBJECTIVES

This study sought to rule out a DDI among cangrelor-treated patients who have been pretreated with ticagrelor.

METHODS

In this prospective, randomized, double-blind, placebo-controlled, crossover, pharmacokinetic (PK) and pharmacodynamic (PD) study, patients with coronary artery disease (N = 20) were pretreated with a 180-mg ticagrelor loading dose and after 1 hour randomized to placebo or cangrelor (bolus and infusion for 2 hours). Patients crossed over after 1 to 4 weeks of washout. PK analysis included ticagrelor plasma levels and its active metabolite. PD assessments included VerifyNow P2Y₁₂ reaction units (PRU), light transmittance aggregometry, vasodilator-stimulated phosphoprotein, and Total Thrombus-Formation Analysis System. PK/PD assessments were performed at 7 time points.

RESULTS

Compared with placebo, adding cangrelor to patients pretreated with ticagrelor resulted in a significant reduction in PRU at 30 minutes and 1 hour after starting infusion. At 2 hours after stopping cangrelor/placebo infusion, PRU were low and similar in both groups (16.9 vs 12.6; mean difference: 4.3; 95% CI: -28.6 to 37.3), meeting the noninferiority primary endpoint (predefined noninferiority margin 45 PRU). Consistent findings were shown with all PD assays. PK tracked PD findings with no differences between groups in plasma levels of ticagrelor and its metabolite.

CONCLUSIONS

Compared with placebo, the use of cangrelor in patients pretreated with ticagrelor results in enhanced platelet inhibition with no differences in PK/PD profiles after discontinuation of drug infusion indicating the absence of a DDI. (PD and PK Profiles of Switching Between Cangrelor and Ticagrelor Following Ticagrelor Pre-treatment [SWAP-5]; NCT04634162).

Analgesic drug use in patients with STEMI: Current perspectives and challenges

Therapy for patients with ST-elevation myocardial infarction (STEMI) has been a controversial topic since the introduction of thrombolytic agents in the 1980s. The use of morphine, fentanyl and lidocaine has increased substantially during this period. However, there is still limited evidence on their advantages and limitations. In this review, the clinical application, as well as future considerations of morphine, fentanyl and lidocaine in patients with ST segment elevation myocardial infarction were discussed.

Intracoronary bolus of glycoprotein IIb/IIIa inhibitor as bridging or adjunctive strategy to oral P2Y12 inhibitor load in the modern setting of ST-elevation myocardial infarction

BACKGROUND

In the acute management of ST-elevation myocardial infarction (STEMI), glycoprotein IIb/IIIa inhibitors (GPIs) bolus not followed by intravenous infusion is potentially advantageous given their fast onset and offset of action, but clinical evidence in a contemporary setting is limited.

METHODS

We collected data from consecutive STEMI patients admitted to the cardiac catheterization laboratory of the IRCCS A. Gemelli University Polyclinic Foundation from October 2017 to September 2019.

RESULTS

Out of 423 consecutive STEMI patients, 297 met the inclusion and exclusion criteria and were included in the study. Of them, 107/297 (36%) received an intracoronary GPI bolus-only during primary percutaneous coronary intervention (PPCI) not followed by intravenous infusion and 190/297 (64%) received standard antithrombotic therapy. Of the 107 GPI-treated, 22/107 (21%) had P2Y<inf>12</inf> inhibitor pretreatment (adjunctive strategy) and 85/107 (79%) did not (bridging strategy). During hospital staying, there was no difference in the primary safety endpoint of TIMI major+minor bleeding (P=0.283), TIMI major (P=0.267) or TIMI minor (P=0.685) bleeding between groups. No stroke event occurred in the GPI group. Despite patients receiving GPI having a significantly higher intraprocedural ischemic burden, no significant differences were found in the efficacy outcomes between groups. Consistent findings were observed for patients receiving GPIs bolus before (bridging strategy) or after (adjunctive strategy) P2Y<inf>12</inf> inhibitors, compared to those receiving standard therapy. Multivariate logistic regression analyses did not find any independent predictors significantly associated to the primary and secondary composite endpoints.

CONCLUSIONS

In a contemporary real-world population of STEMI patients undergoing PPCI, the use of intracoronary GPIs bolus-only in selected patients at high ischemic risk is safe and could represent a useful antithrombotic strategy both in those pretreated and in those naïve to P2Y<inf>12</inf> inhibitors.

Targeted delivery of nanomedicines for promoting vascular regeneration in ischemic diseases

Ischemic diseases, the leading cause of disability and death, are caused by the restriction or blockage of blood flow in specific tissues, including ischemic cardiac, ischemic cerebrovascular and ischemic peripheral vascular diseases. The regeneration of functional vasculature network in ischemic tissues is essential for treatment of ischemic diseases. Direct delivery of pro-angiogenesis factors, such as VEGF, has demonstrated the effectiveness in ischemic disease therapy but suffering from several obstacles, such as low delivery efficacy in disease sites and uncontrolled modulation. In this review, we summarize the molecular mechanisms of inducing vascular regeneration, providing the guidance for designing the desired nanomedicines. We also introduce the delivery of various nanomedicines to ischemic tissues by passive or active targeting manner. To achieve the efficient delivery of nanomedicines in various ischemic diseases, we highlight targeted delivery of nanomedicines and controllable modulation of disease microenvironment using nanomedicines.

Current and Future Insights for Optimizing Antithrombotic Therapy to Reduce the Burden of Cardiovascular Ischemic Events in Patients with Acute Coronary Syndrome

The pharmacological treatment strategies for acute coronary syndrome (ACS) in recent years are constantly evolving to develop more potent antithrombotic agents, as reflected by the introduction of more novel P2Y₁₂ receptor inhibitors and anticoagulants to reduce the ischemic risk among ACS patients. Despite the substantial improvements in the current antithrombotic regimen, a noticeable number of ACS patients continue to experience ischemic events. Providing effective ischemic risk reduction while balancing bleeding risk remains a clinical challenge. This updated review discusses the currently approved and widely used antithrombotic agents and explores newer antithrombotic treatment strategies under development for the initial phase of ACS.

Comprehensive safety profile evaluation of bivalirudin in Chinese ST-segment elevation myocardial infarction patients receiving percutaneous coronary intervention: a prospective, multicenter, intensive monitoring study

Background

This prospective, multi-center, intensive monitoring study aimed to systematically assess the occurrence of adverse events (AEs) and adverse drug reactions (ADRs), especially thrombocytopenia and bleeding, as well as their risk factors in Chinese ST-segment elevation myocardial infraction (STEMI) patients receiving bivalirudin as anticoagulant for percutaneous coronary intervention (PCI).

Methods

In total, 1244 STEMI patients undergoing PCI and receiving bivalirudin as anticoagulant were enrolled in the present study. Safety data were collected from hospital admission to 72 h after bivalirudin administration; in addition, patients were further followed up at the 30th day with safety data collected at that time.

Results

AEs, severe AEs, ADRs and severe ADRs were reported in 224 (18.0%), 15 (1.2%), 49 (3.9%) and 5 (0.4%) patients, respectively. Importantly, 4 (0.3%) patients were submitted to hospitalization and 6 (0.5%) patients died due to AEs, while 1 (0.1%) patient was submitted to hospitalization but no (0.0%) patient died due to ADRs. Meanwhile, thrombocytopenia and bleeding occurred in 24 (1.9%) and 21 (1.7%) patients, respectively. Further multivariate logistic analysis identified several important independent factors related to AEs, ADRs, thrombocytopenia or bleeding, which included history of cardiac surgery and renal function impairment, high CRUSADE risk stratification, elective operation and combination with glycoprotein IIb/IIIa inhibitors. Moreover, 4 multivariate models were constructed based on the above-mentioned factors, which all showed acceptable predictive value for AEs, ADRs, thrombocytopenia and bleeding, respectively.

Conclusion

Bivalirudin is a well-tolerant anticoagulant in Chinese STEMI patients undergoing PCI procedure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02716-4.

Prasugrel-based De-Escalation of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention in Patients With STEMI

BACKGROUND AND OBJECTIVES

De-escalation of dual-antiplatelet therapy through dose reduction of prasugrel improved net adverse clinical events (NACEs) after acute coronary syndrome (ACS), mainly through the reduction of bleeding without an increase in ischemic outcomes. Whether the benefits of de-escalation are sustained in highly thrombotic conditions such as ST-elevation myocardial infarction (STEMI) is unknown. We aimed to assess the efficacy and safety of de-escalation therapy in patients with STEMI or non-ST-segment elevation ACS (NSTE-ACS).

METHODS

This is a pre-specified subgroup analysis of the HOST-REDUCE-POLYTECH-ACS trial. ACS patients were randomized to prasugrel de-escalation (5 mg daily) or conventional dose (10 mg daily) at 1-month post-percutaneous coronary intervention. The primary endpoint was a NACE, defined as a composite of all-cause death, non-fatal myocardial infarction, stent thrombosis, clinically driven revascularization, stroke, and bleeding events of grade ≥2 Bleeding Academic Research Consortium (BARC) criteria at 1 year.

RESULTS

Among 2,338 patients included in the randomization, 326 patients were diagnosed with STEMI. In patients with NSTE-ACS, the risk of the primary endpoint was significantly reduced with de-escalation (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.48-0.89; p=0.006 for de-escalation vs. conventional), mainly driven by a reduced bleeding. However, in those with STEMI, there was no difference in the occurrence of the primary outcome (HR, 1.04; 95% CI, 0.48-2.26; p=0.915; p for interaction=0.271).

CONCLUSIONS

Prasugrel dose de-escalation reduced the rate of NACE and bleeding, without increasing the rate of ischemic events in NSTE-ACS patients but not in STEMI patients.

Genotype-Guided Use of P2Y12 Inhibitors: A Review of Current State of the Art

The pharmacodynamics of the purinergic receptor type Y, subtype 12 (P2Y12) inhibitors has evolved. Our understanding of the metabolism of P2Y12 inhibitors has revealed polymorphisms that impact drug metabolism and antiplatelet efficacy, leading to genetic testing guided therapy. In addition, assays of platelet function and biochemistry have provided insight into our understanding of the efficacy of "antiplatelet" therapy, identifying patients with high or low platelet reactivity on P2Y12 therapy. Despite the data, the implementation of these testing modalities has not gained mainstream adoption across hospital systems. Given differences in potency between the three clinically available P2Y12 inhibitors, the balance between thrombotic and bleeding complications must be carefully considered, especially for the large proportion of patients at higher risk for bleeding. Here we review the current data for genetic and functional testing, risk assessment strategies, and guidelines for P2Y12 inhibitors guided therapy.

Frequency, Etiology, and Impact of Unplanned Repeat Coronary Angiography After ST-Elevation Myocardial Infarction

Unplanned repeat coronary angiography (CAG) after balloon angioplasty for ST-elevation myocardial infarction (STEMI) was common before the advent of coronary stenting. Limited data are available regarding the role of unplanned repeat CAG in contemporary percutaneous coronary intervention (PCI) for STEMI. Therefore, we analyzed a large, 2-center prospective STEMI registry (January 2011 to June 2020) stratified by the presence or absence of unplanned repeat CAG during index hospitalization. Patients with planned CAG for staged PCI or experimental drug administration were excluded. Among 3,637 patients with STEMI, 130 underwent unplanned repeat CAG (3.6%) during index hospitalization. These patients were more likely to have cardiogenic shock (16% vs 9.8%, p = 0.021), left anterior descending culprit (44% vs 31%, p <0.001), lower left ventricular ejection fraction (45% vs 52%, p <0.001), and higher peak troponin levels (22 vs 8 ng/ml, p <0.001) than those without repeat CAG. At repeat CAG, 80 patients had a patent stent (62%) including 65 requiring no further intervention (50%) and 15 who underwent intervention on a nonculprit lesion (12%). Only 32 patients had stent thrombosis (25%). Repeat CAG was associated with a higher incidence of recurrent MI (19% vs 0%, p <0.001) and major bleeding (12% vs 4.5%, p <0.001), yet similar in-hospital mortality (7% vs 6.4%, p = 0.93) than those without repeat CAG. In conclusion, in the era of contemporary PCI for STEMI, unplanned repeat CAG during index hospitalization was infrequent and more commonly observed in patients with left anterior descending culprit in the presence of significant left ventricular dysfunction or shock and was associated with higher in-hospital recurrent myocardial infarction and major bleeding complications.

Toll-like receptor 4 activation in platelets from myocardial infarction patients

INTRODUCTION

Platelet toll-like receptor 4 (TLR4) is overexpressed in patients with myocardial infarction (MI) but it remains to elucidate if it is activated and the potential trigger.

METHODS

Serum levels of lipopolysaccharides (LPS) and platelet aggregation (PA) by collagen alone or in combination with a TLR4 inhibitor (TLR4i) were studied ex vivo in platelets from 40 MI patients and 40 controls matched for age, sex and atherosclerotic risk factors; platelet TIR domain-containing adaptor protein (TIRAP) and TIRAP-MyD88 interaction were also investigated by western blot and co-immunoprecipitation, respectively. In vitro experiments were conducted to see if LPS triggers platelet TIRAP phosphorylation.

RESULTS

Serum LPS was significantly higher in patients compared to controls (29.5±7.1 vs 16.2±3.8 pg/mL; p<0.001). Collagen-stimulated platelets from MI pre-treated with TLR4i showed a significant decrease of PA compared to platelets stimulated with collagen. Ex vivo study showed that TIRAP phosphorylation as well as TIRAP-MyD88 co-immunoprecipitation were higher in patients compared to controls. In vitro study showed that LPS, at concentrations like those found in MI, dose-dependently activated TIRAP and amplified the platelet response to the agonist, an effect blunted by TLR4i.

CONCLUSION

The study provides evidence that in MI patients platelet TLR4 is activated and suggests circulating LPS as potential trigger.

Efficacy and safety of next-generation tick transcriptome-derived direct thrombin inhibitors

Despite their limitations, unfractionated heparin (UFH) and bivalirudin remain standard-of-care parenteral anticoagulants for percutaneous coronary intervention (PCI). We discovered novel direct thrombin inhibitors (DTIs) from tick salivary transcriptomes and optimised their pharmacologic activity. The most potent, ultravariegin, inhibits thrombin with a K_i of 4.0 pM, 445-fold better than bivalirudin. Unexpectedly, despite their greater antithrombotic effect, variegin/ultravariegin demonstrated less bleeding, achieving a 3-to-7-fold wider therapeutic index in rodent thrombosis and bleeding models. When used in combination with aspirin and ticagrelor in a porcine model, variegin/ultravariegin reduced stent thrombosis compared with antiplatelet therapy alone but achieved a 5-to-7-fold lower bleeding time than UFH/bivalirudin. Moreover, two antibodies screened from a naïve human antibody library effectively reversed the anticoagulant activity of ultravariegin, demonstrating proof-of-principle for antidote reversal. Variegin and ultravariegin are promising translational candidates for next-generation DTIs that may reduce peri-PCI bleeding in the presence of antiplatelet therapy.

STEMI care 2021: Addressing the knowledge gaps

Tremendous progress has been made in the treatment of ST-segment elevation myocardial infarction (STEMI), the most severe and time-sensitive acute coronary syndrome. Primary percutaneous coronary intervention (PCI) is the preferred method of reperfusion, which has stimulated the development of regional STEMI systems of care with standardized protocols designed to optimize care. However, challenges remain for patients with cardiogenic shock, out-of-hospital cardiac arrest, an expected delay to reperfusion (>120 min), in-hospital STEMI, and more recently, those with Covid-19 infection. Ultimately, the goal is to provide timely reperfusion with primary PCI coupled with the optimal antiplatelet and anticoagulant therapies. We review the challenges and provide insights into the remaining knowledge gaps for contemporary STEMI care.

Effects of Heparin and Bivalirudin on Thrombin-Induced Platelet Activation: Differential Modulation of PAR Signaling Drives Divergent Prothrombotic Responses

Heparin and bivalirudin are widely used as anticoagulants in the setting of acute thrombosis. In this study, we investigated how these drugs affect the ability of thrombin to generate a prothrombotic platelet response via activation of the protease-activated receptors (PARs) 1 and 4. We examined the effects of heparin/antithrombin and bivalirudin on PAR1- and PAR4-mediated intracellular calcium mobilization, aggregation, α-granule release, and procoagulant membrane exposure in platelets exposed to thrombin concentrations likely to be encountered in the thrombus microenvironment during thrombosis. At physiological antithrombin levels, heparin treatment resulted in complete and sustained inhibition of thrombin-induced PAR4-mediated platelet activation, but transient PAR1 signaling was sufficient to elicit significant α-granule release and platelet aggregation. In contrast, bivalirudin treatment resulted in rapid and profound inhibition of signaling from both PAR receptors, followed by a delayed phase of PAR4-mediated platelet activation, resulting in a robust prothrombotic response. Combination treatment with bivalirudin and subtherapeutic concentrations of heparin completely inhibited the residual platelet activation observed with single drug treatment at all time-points. Our results show that heparin and bivalirudin have different and complementary inhibitory effects on the activation of PAR1 and PAR4 by thrombin.

Crushed/chewed administration of potent P2Y12 inhibitors in ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: Systematic review and meta-analysis

Crushed or chewed potent P2Y₁₂ inhibitors are commonly used in the hope of bridging the gap of platelet inhibition in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). The study aimed to investigate the efficacy and safety of this alternative oral administration strategy by performing a meta-analysis of available randomized clinical trials (RCTs). PubMed, Embase, the Cochrane Library and Web of Science medical literature databases were searched for RCTs comparing crushed/chewed vs. integral administration of loading dose potent P2Y₁₂ inhibitors in patients with STEMI undergoing pPCI with no language restrictions from inception to January 20th, 2021. The primary efficacy endpoints of high on treatment platelet reactivity (HPR) and P2Y₁₂ reaction units (PRU) at 1 hour together with safety and additional clinical endpoints were evaluated by pooled odds ratio (OR) or mean differences (MD) with 95% confidence intervals (95% CI). A total of 973 patents in six RCTs were eligible for analysis, while 876 patients present baseline and procedural characteristics. HPR and PRU at 1 hour were significantly reduced in the group receiving crushed/chewed P2Y₁₂ inhibitors compared with integral tablets (OR 0.28, 95% CI 0.16 to 0.49, P < .0001; MD -60.62, 95% CI -97.06 to -24.19, P = .001, respectively). Safety endpoints of major bleeding (OR 0.54, 95% CI 0.11 to 2.73, P = .46) and any bleeding (OR 0.84, 95% CI 0.43 to 1.64, P = .61), as well as additional clinical endpoints of cardiovascular death, myocardial infarction, and stroke were not affected by the oral administration strategy. In STEMI patients undergoing pPCI, crushed or chewed administration of potent P2Y₁₂ inhibitors are associated with enhanced early platelet inhibition and appear to be safe. The clinical profile transformed from this pharmacodynamic benefit need to be determined by further researches.

Cangrelor: Clinical Data, Contemporary Use, and Future Perspectives

Cangrelor is the only currently available intravenous platelet P2Y₁₂ receptor inhibitor. It is characterized by potent, predictable, and rapidly reversible antiplatelet effects. Cangrelor has been tested in the large CHAMPION (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition) program, where it was compared with different clopidogrel regimens, and it is currently indicated for use in patients with coronary artery disease undergoing percutaneous coronary intervention. However, the uptake of cangrelor use varies across the globe and may also include patients with profiles different from those enrolled in the registration trials. These observations underscore the need to fully examine the safety and efficacy of cangrelor in postregistration studies. There are several ongoing and planned studies evaluating the use of cangrelor in real‐world practice which will provide important insights to this extent. The current article provides a review on the pharmacology, clinical studies, contemporary use of cangrelor in real‐world practice, a description of ongoing studies, and futuristic insights on potential strategies on how to improve outcomes of patients undergoing percutaneous coronary intervention.

Feasibility and safety of cangrelor in patients with suboptimal P2Y12 inhibition undergoing percutaneous coronary intervention: rationale of the Dutch Cangrelor Registry

BACKGROUND

Despite the advances of potent oral P2Y12 inhibitors, their onset of action is delayed, which might have a negative impact on clinical outcome in patients undergoing percutaneous coronary intervention (PCI). Trials conducted in the United States of America have identified cangrelor as a potent and rapid-acting intravenous P2Y12 inhibitor, which has the potential of reducing ischemic events in these patients without an increase in the bleeding. As cangrelor is rarely used in The Netherlands, we conducted a nationwide registry to provide an insight into the use of cangrelor in the management of patients with suboptimal platelet inhibition undergoing (primary) PCI (the Dutch Cangrelor Registry).

STUDY DESIGN

The Cangrelor Registry is a prospective, observational, multicenter, single-arm registry with cangrelor administered pre-PCI in: (1) P2Y12 naive patients with ad-hoc PCI, (2) patients with STEMI/NSTEMI with suboptimal P2Y12 inhibition including (3) stable resuscitated/defibrillated patients with out-of-hospital cardiac arrest (OHCA) due to acute ischemia and (4) STEMI/NSTEMI patients with a high thrombotic burden. Primary endpoint is 48 h Net Adverse Clinical Events (NACE), which is a composite endpoint of all-cause death, recurrent myocardial infarction (MI), target vessel revascularization (TVR), stroke, stent thrombosis (ST) and BARC 2-3-5 bleeding. The Dutch Cangrelor Registry will assess the feasibility and safety of cangrelor in patients with suboptimal P2Y12 inhibition undergoing (primary) PCI in the setting of acute coronary syndrome (ACS) and stable coronary artery disease (CAD) in the Netherlands.

Pharmacodynamic Effects of Pre-Hospital Administered Crushed Prasugrel in Patients With ST-Segment Elevation Myocardial Infarction

OBJECTIVES

This study sought to compare the pharmacodynamic effects of pre-hospitally administered P2Y₁₂ inhibitor prasugrel in crushed versus integral tablet formulation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI).

BACKGROUND

Early dual antiplatelet therapy is recommended in STEMI patients. Yet, onset of oral P2Y₁₂ inhibitor effect is delayed and varies according to formulation administered.

METHODS

The COMPARE CRUSH (Comparison of Pre-hospital Crushed Versus Uncrushed Prasugrel Tablets in Patients With STEMI Undergoing Primary Percutaneous Coronary Interventions) trial randomized patients with suspected STEMI to crushed or integral prasugrel 60-mg loading dose in the ambulance. Pharmacodynamic measurements were performed at 4 time points: before antiplatelet treatment, at the beginning and end of pPCI, and 4 h after study treatment onset. The primary endpoint was high platelet reactivity at the end of pPCI. The secondary endpoint was impact of platelet reactivity status on markers of coronary reperfusion.

RESULTS

A total of 441 patients were included. In patients with crushed prasugrel, the occurrence of high platelet reactivity at the end of pPCI was reduced by almost one-half (crushed 34.7% vs. uncrushed 61.6%; odds ratio [OR] = 0.33; 95% confidence interval [CI] = 0.22 to 0.50; p < 0.01). Platelet reactivity <150 P2Y₁₂ reactivity units at the beginning of coronary angiography correlated with improved Thrombolysis In Myocardial Infarction flow grade 3 in the infarct artery pre-pPCI (OR: 1.78; 95% CI: 1.08 to 2.94; p = 0.02) but not ST-segment resolution (OR: 0.80; 95% CI: 0.48 to 1.34; p = 0.40).

CONCLUSIONS

Oral administration of crushed compared with integral prasugrel significantly improves platelet inhibition during the acute phase in STEMI patients undergoing pPCI. However, a considerable number of patients still exhibit inadequate platelet inhibition at the end of pPCI, suggesting the need for alternative agents to bridge the gap in platelet inhibition.

Low-grade endotoxaemia enhances artery thrombus growth via Toll-like receptor 4: implication for myocardial infarction

AIMS

Low-grade endotoxaemia is detectable in human circulation but its role in thrombosis is still unclear.

METHODS AND RESULTS

We measured serum lipopolysaccharide (LPS) concentration, soluble P-selectin (sP-selectin), a marker of platelet activation, and zonulin, a marker of gut permeability, in peripheral circulation, coronary thrombi, and intracoronary blood of patients with ST-elevation myocardial infarction (STEMI, n = 50) and stable angina (SA) (n = 50), respectively, and in controls (n = 50). Experimental study was carried out in mice to assess if Escherichia coli-LPS (E. coli-LPS) possess thrombotic property. Coronary thrombi from STEMI showed higher concentrations of LPS, sP-selectin vs. intracoronary blood of SA and peripheral blood of controls (P < 0.001). Zonulin was higher in STEMI compared to the other two groups [4.57 (3.34-5.22); 2.56 (0.41-4.36); 1.95 (1.22-2.65) ng/mL; P < 0.001] and correlated with LPS (Rs = 0.585; P < 0.001). Escherichia coli DNA was positive in 34% of STEMI vs. 12% of SA and 4% of controls (P < 0.001). In a subgroup of 12 STEMI, immunohistochemical analysis of coronary thrombi showed positivity for leucocyte Toll-like receptor 4 (TLR4), cathepsin G, and LPS from E. coli in 100%, 80%, and 25% of samples, respectively. E. coli-LPS injected in mice to reach LPS concentrations like those detected in coronary thrombi was associated with enhanced artery thrombosis and platelet activation, an effect blunted by TLR4 inhibitor co-administration. In vitro study demonstrated that LPS from E. coli enhanced platelet aggregation via TLR4-mediated leucocyte cathepsin G activation.

CONCLUSION

ST-elevation myocardial infarction patients disclose an enhanced gut permeability that results in LPS translocation in human circulation and eventually thrombus growth at site of artery lesion via leucocyte-platelet interaction.

Tackling the gap in platelet inhibition with oral antiplatelet agents in high-risk patients undergoing percutaneous coronary intervention

Introduction: Oral P2Y₁₂ inhibitors represent the mainstay therapy for the prevention of thrombotic complications in patients presenting with an acute coronary syndrome and/or undergoing percutaneous coronary intervention (PCI). However, the onset of antiplatelet action of the oral P2Y₁₂ inhibitors is affected by their need to be absorbed in the gastrointestinal (GI) tract before becoming systemically available.Areas covered: Following oral intake of P2Y₁₂ inhibitors, the timeframe required for GI absorption leads to a window of inadequate antiplatelet protection during which patients are at increased thrombotic risk. The onset of action of the oral P2Y₁₂ inhibitors is even further delayed in high-risk patients, underscoring the need to define strategies to bridge the gap in platelet inhibitory effects following their intake.Expert opinion: Multiple mechanisms may impair GI absorption leading to a delay in the onset of action of oral P2Y₁₂ inhibitors. Several strategies have been tested to overcome the gap in platelet inhibition in high-risk patients undergoing PCI. These include administration of crushed or chewed tablets to improve the dissolution rate and use of opioid receptor antagonists or metoclopramide to counteract impairment of gastric motility induced by opioids. However, intravenous antiplatelet therapies represent the most effective strategy to bridge such gap in platelet inhibition.

A meta-analysis and cost-minimization analysis of bivalirudin versus heparin in high-risk patients for percutaneous coronary intervention

This meta‐analysis was performed to compare the safety, efficacy, and pharmacoeconomic of bivalirudin versus heparin in high‐risk patients for percutaneous coronary interventions (PCI). Earlier meta‐analysis comparing bivalirudin and heparin during PCI demonstrated that bivalirudin caused less bleeding with more stent thrombosis. However, little data were available on the safety of bivalirudin versus heparin in high‐risk patients for PCI. Thus, we performed a meta‐analysis to evaluate the efficacy and safety in the “high‐risk” patients. A systematic search of electronic databases was conducted up to July 30, 2020. The Cochrane Risk of Bias assessment tool was used to assess the quality of included studies. The primary outcomes were all‐cause death and major adverse cardiac events (MACE); secondary outcomes were major and minor bleeding, followed by a cost‐minimization analysis comparing bivalirudin and heparin using a local drug and medical costs reported in China. Subgroup analysis was based on the type of disease of the high‐risk population. Finally, a total of 10 randomized controlled trials involved 42,699 patients were collected. The Cochrane Risk of Bias Tool was employed to appraise the research quality. No significant difference was noted between bivalirudin and heparin regarding all‐cause death and MACE. However, subgroup analysis showed that bivalirudin caused less major bleeding in female (OR:0.65, 95% CI:0.53–0.79), diabetes (OR:0.55, 95%CI:0.42–0.73), and CKD (OR:0.59, 95%CI:0.63–1.65). The scatterers of the included literature were approximately symmetrical, and no research was outside the funnel plot. Additionally, cost‐minimization analysis showed that heparin was likely to represent a cost‐effective option compared with bivalirudin in China, with potential savings of 2129.53 Chinese Yuan (CNY) per patient for one PCI. Overall, the meta‐analysis showed that although bivalirudin appeared to have a lower risk of major bleeding rate, the overall effectiveness and safety between the two groups showed no significant difference in high‐risk patients for PCI. But the results of the cost‐minimization analysis showed that heparin could be a potential cost‐saving drug than bivalirudin in patients for PCI in China.

Use of the VerifyNow point of care assay to assess the pharmacodynamic effects of loading and maintenance dose regimens of prasugrel and ticagrelor

Prasugrel and ticagrelor are potent oral platelet P2Y₁₂ inhibitors and are recommended over clopidogrel in patients with acute coronary syndrome (ACS). Oral platelet P2Y₁₂ inhibitors are characterized by varying degrees of pharmacodynamic response profiles as assessed by a variety of commercially available assays. Because of its ease of use, rapid turnaround times and ability to provide results specific to P2Y₁₂ inhibitory effects, VerifyNow has emerged as one of the most commonly utilized platelet function assays. However, reference ranges with VerifyNow have been reported mainly for clopidogrel and there has not yet been any study specifically conducted to provide the expected on treatment reference ranges following administration of prasugrel and ticagrelor. This was a prospective single center investigation conducted in 120 patients with ACS who were treated with prasugrel or ticagrelor as per standard of care. Patients who underwent percutaneous coronary interventions (PCI) were treated with a loading dose of prasugrel (60 mg) or ticagrelor (180 mg), and patients who were on maintenance therapy were taking prasugrel (10 mg qd or 5 mg qd) or ticagrelor (90 mg bid). Platelet function testing was performed using the VerifyNow™ PRUTest™. The overall range of PRUTest values was lower than that observed in studies of patients treated with clopidogrel. The use of a maintenance dose regimen had a wider range of PRUTest values compared to the use of a loading dose for both prasugrel (1–179 vs. 2–128) and ticagrelor (1–196 vs. 1–177). The average PRUTest values in patients on prasugrel and ticagrelor maintenance dosing were 20% and 9% higher those observed in patients treated with a loading dose. PRUTest results following loading dose administration were very similar between drugs, but were 20% higher with prasugrel compared with ticagrelor during maintenance dosing. This study establishes expected PRUTest ranges for patients taking loading and maintenance doses of prasugrel and ticagrelor.

Clinical Trial Registrationhttp://www.clinicaltrials.gov Unique Identifier: NCT04492423, registered July 2020 retrospectively registered.

Ticagrelor or Prasugrel in Patients With ST-Segment–Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background:

Data on the comparative efficacy and safety of ticagrelor versus prasugrel in patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention are limited. We assessed the efficacy and safety of ticagrelor versus prasugrel in a head-to-head comparison in patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Methods:

In this prespecified subgroup analysis, we included 1653 patients with ST-segment–elevation myocardial infarction randomized to receive ticagrelor or prasugrel in the setting of the ISAR REACT-5 trial (Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 5). The primary end point was the incidence of death, myocardial infarction, or stroke at 1 year after randomization. The secondary end point was the incidence of bleeding defined as BARC (Bleeding Academic Research Consortium) type 3 to 5 bleeding at 1 year after randomization.

Results:

The primary end point occurred in 83 patients (10.1%) in the ticagrelor group and in 64 patients (7.9%) in the prasugrel group (hazard ratio, 1.31 [95% CI, 0.95–1.82]; P =0.10). One-year incidence of all-cause death (4.9% versus 4.7%; P =0.83), stroke (1.3% versus 1.0%; P =0.46), and definite stent thrombosis (1.8% versus 1.0%; P =0.15) did not differ significantly in patients assigned to ticagrelor or prasugrel. One-year incidence of myocardial infarction (5.3% versus 2.8%; hazard ratio, 1.95 [95% CI, 1.18–3.23]; P =0.010) was higher with ticagrelor than with prasugrel. BARC type 3 to 5 bleeding occurred in 46 patients (6.1%) in the ticagrelor group and in 39 patients (5.1%) in the prasugrel group (hazard ratio, 1.22 [95% CI, 0.80–1.87]; P =0.36).

Conclusions:

In patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention, there was no significant difference in the primary end point between prasugrel and ticagrelor. Ticagrelor was associated with a significant increase in the risk for recurrent myocardial infarction.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01944800.

Effect of Prehospital Crushed Prasugrel Tablets in Patients With ST-Segment–Elevation Myocardial Infarction Planned for Primary Percutaneous Coronary Intervention

Background:

Early treatment with a potent oral platelet P2Y 12 inhibitor is recommended in patients presenting with ST-segment–elevation myocardial infarction scheduled to undergo primary percutaneous coronary intervention (pPCI). The impact on coronary reperfusion of crushed P2Y 12 inhibitor tablets, which lead to more prompt and potent platelet inhibition, is unknown.

Methods:

We conducted a randomized controlled, multicenter trial in the Netherlands, enrolling patients with ST-segment–elevation myocardial infarction scheduled to undergo pPCI. Patients were randomly allocated to receive in the ambulance, before transfer, a 60-mg loading dose of prasugrel either as crushed or integral tablets. The independent primary end points were thrombolysis in myocardial infarction (TIMI) 3 flow in the infarct-related artery at initial coronary angiography, and complete (≥70%) ST-segment resolution 1 hour after pPCI. The safety end points were TIMI major and Bleeding Academic Research Consortium ≥3 bleedings. Secondary end points included platelet reactivity and ischemic outcomes.

Results:

A total of 727 patients were assigned to either crushed or integral tablets of prasugrel loading dose. The median time from study treatment to wire-crossing during pPCI was 57 (47–70) minutes. The primary end point TIMI 3 flow in the infarct-related artery before pPCI occurred in 31.0% in the crushed group versus 32.7% in the integral group (odds ratio, 0.92 [95% CI, 0.65–1.30], P =0.64). Complete ST-segment resolution 1 hour after pPCI was present in 59.9% in the crushed group versus 57.3% in the integral group (odds ratio, 1.11 [95% CI, 0.78–1.58], P =0.55). Platelet reactivity at the beginning of pPCI, measured as P2Y 12 reactivity unit, differed significantly between groups (crushed, 192 [132–245] versus integral, 227 [184–254], P ≤0.01). TIMI major and Bleeding Academic Research Consortium ≥3 bleeding occurred in 0% in the crushed group versus 0.8% in the integral group, and in 0.3% in the crushed group versus 1.1% in the integral group, respectively. There were no differences observed between groups regarding ischemic events at 30 days.

Conclusions:

Prehospital administration of crushed prasugrel tablets does not improve TIMI 3 flow in the infarct-related artery before pPCI or complete ST-segment resolution 1 h after pPCI in patients presenting with ST-segment–elevation myocardial infarction scheduled for pPCI.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03296540.

Frequency of Thrombolysis in Myocardial Infarction III Flow in Patients With Primary Percutaneous Coronary Intervention: Not All Culprit Vessels Are Completely Occluded in ST Elevation Myocardial Infarction

Background

ST elevation myocardial infarction (STEMI) is classically characterized by total occlusion of the culprit coronary artery. However during primary percutaneous coronary intervention (PCI) thrombolysis in myocardial infarction (TIMI) 0 flow is not observed in all patients' culprit arteries in angiographic views. This study was conducted to find out the frequency of TIMI flow in acute STEMI patients in view of the above concept. The aim of this study was to evaluate the frequency of pre-procedural TIMI III flow in those patients who underwent primary PCI for acute STEMI in a public sector hospital in Karachi, Pakistan.

Methodology

This study is an audit of already saved data in the catheterization laboratory of the National Institute of Cardiovascular Diseases (NICVD), Karachi, that was collected prospectively from January 2016 to December 2018. These data were collected after taking consent from those patients who presented to hospital within 12 hours of symptoms and underwent primary PCI. Data were entered and analyzed on Statistical Package for the Social Sciences (SPSS) version 19 (IBM Corp., Armonk, NY, USA).

Results

A total of 8018 patients were included in this study who presented with STEMI and underwent primary PCI. Out of them 80.9% were males. Hypertension was the leading risk factor in 54.1% (4340) of patients. TIMI III flow was present in 11.4% of patients before primary PCI, while TIMI 0, I and II flow were present in 57.1%, 15.1%, and 16.3% of patients respectively (p<0.001). Fourteen percent of patients with TIMI III flow were of age group 51 to 60 years. Among those who had TIMI III flow, 11.2% were those with door to balloon time of <90 minutes. In 11% of cases, left anterior descending (LAD) artery had TIMI III flow as compared to other vessels (p<0.001). The length of the lesion was significantly smaller in patients who had TIMI III flow compared to those who had TIMI 0-II flow.

Conclusions

This study revealed that not all patients with acute STEMI had totally occluded culprit coronary artery but some of them had angiographic TIMI I-III flow in the infarct-related artery. Further studies are needed to find the reason for re-establishment of flow in the culprit vessel in STEMI patients before PCI.

Impact of opioids on P2Y12 receptor inhibition in patients with ST-elevation myocardial infarction who are pre-treated with crushed ticagrelor: Opioids aNd crushed Ticagrelor In Myocardial infarction Evaluation (ON-TIME 3) trial

Aims

Platelet inhibition induced by P2Y₁₂ receptor antagonists in patients with ST-elevation myocardial infarction (STEMI) can be affected by concomitant use of opioids. The aim of this trial was to examine the effect of intravenous (iv) acetaminophen compared with iv fentanyl on P2Y₁₂ receptor inhibition in patients with STEMI.

Methods and results

The Opioids aNd crushed Ticagrelor In Myocardial infarction Evaluation (ON-TIME 3) trial randomized 195 STEMI patients who were scheduled to undergo primary percutaneous coronary intervention (PCI) and were pre-treated with crushed ticagrelor to iv acetaminophen (N = 98) or iv fentanyl (N = 97) in the ambulance. The primary endpoint, consisting of the level of platelet reactivity units (PRU) measured immediately after primary PCI, was not significantly different between the study arms [median PRU 104 (IQR 37–215) vs. 175 (63–228), P = 0.18]. However, systemic levels of ticagrelor were significantly higher in the acetaminophen arm at the start of primary PCI [151 ng/mL (32–509) vs. 60 ng/mL (13–206), P = 0.007], immediately after primary PCI [326 ng/mL (94–791) vs. 115 ng/mL (38–326), P = 0.002], and at 1 h after primary PCI [488 ng/mL (281–974) vs. 372 ng/mL (95–635), P = 0.002]. Acetaminophen resulted in the same extent of pain relief when compared with fentanyl [reduction of 3 points on 10-step-pain scale before primary PCI (IQR 1–5)] in both study arms (P = 0.67) and immediately after PCI [reduction of 5 points (3–7); P = 0.96].

Conclusion

The iv acetaminophen in comparison with iv fentanyl was not associated with significantly lower platelet reactivity in STEMI patients but resulted in significantly higher ticagrelor plasma levels and was effective in pain relief.

Molecular Drivers of Platelet Activation: Unraveling Novel Targets for Anti-Thrombotic and Anti-Thrombo-Inflammatory Therapy

Cardiovascular diseases (CVDs) are the leading cause of death globally-partly a consequence of increased population size and ageing-and are major contributors to reduced quality of life. Platelets play a major role in hemostasis and thrombosis. While platelet activation and aggregation are essential for hemostasis at sites of vascular injury, uncontrolled platelet activation leads to pathological thrombus formation and provokes thrombosis leading to myocardial infarction or stroke. Platelet activation and thrombus formation is a multistage process with different signaling pathways involved to trigger platelet shape change, integrin activation, stable platelet adhesion, aggregation, and degranulation. Apart from thrombotic events, thrombo-inflammation contributes to organ damage and dysfunction in CVDs and is mediated by platelets and inflammatory cells. Therefore, in the past, many efforts have been made to investigate specific signaling pathways in platelets to identify innovative and promising approaches for novel antithrombotic and anti-thrombo-inflammatory strategies that do not interfere with hemostasis. In this review, we focus on some of the most recent data reported on different platelet receptors, including GPIb-vWF interactions, GPVI activation, platelet chemokine receptors, regulation of integrin signaling, and channel homeostasis of NMDAR and PANX1.

A Novel Anti-Coagulative Nanocomplex in Delivering miRNA-1 Inhibitor Against Microvascular Obstruction of Myocardial Infarction

Great progress has been made in miRNA nanodelivery for the treatment of myocardial infarction (MI). However, miRNA nanodelivery within the infarct is impeded by microvascular obstruction as a local circulatory disorder caused by microthrombus formation in microvessels. Knowing that low molecular weight heparin (LMWH) can effectively prevent microthrombus formation in microcirculation, it is hypothesized whether surface modification of the nanocarrier with LMWH can overcome microvascular obstruction in the infarct area for better miRNA delivery. Herein, a novel nanocomlex consisting of dendrigraft poly-l-lysine (DGL)-loaded miR-1 inhibitor as the core to decrease apoptosis of cardiomyocytes and LMWH as the shell to overcome microvascular obstruction of the infarct area is developed. The results show that this anti-coagulative nanocomlex is able to reduce microthrombus formation in microvessels and inhibit blood-coagulation factor Xa, thereby overcoming microvascular obstruction in the infarct area. In addition, it further enhances the uptake of miR-1 inhibitor within the infarct and decreases myocardiocyte apoptosis, thus improving the cardiac function and attenuating the myocardial fibrosis. In conclusion, modification of DGL-loaded miR-1 inhibitor with LMWH helps overcome microvascular obstruction in delivering the drug to the infarct area, thus providing a promising therapeutic strategy for achieving a better therapeutic outcome of MI.

Ischemic Versus Bleeding Outcomes After Percutaneous Coronary Interventions in Patients With High Bleeding Risk

Patients undergoing percutaneous coronary intervention (PCI) often have high-bleeding-risk (HBR) factors. Dual antiplatelet therapy (DAPT) further increases this risk of bleeding. We sought to compare clinical outcomes according to presence or absence of HBR factors in patients with elevated ischemic risk (DAPT score ≥ 2) undergoing PCI. We evaluated all patients undergoing PCI at MedStar Washington Hospital Center (January 2009 to July 2018) with DAPT score ≥2, which is associated with elevated risk of ischemic events. Patients were categorized as HBR group (HBR score ≥1) or low-bleeding-risk (LBR) group (HBR score = 0). Outcomes included major adverse cardiac events such as target vessel revascularization, stent thrombosis, death, and bleeding events at 30 days, 6 months, 1 year, and 2 years. The final cohort consisted of 7,499 patients: 3,949 patients had LBR features, and 3,550 patients had HBR features. The 2 groups were different at baseline, with HBR patients being older and having a higher prevalence of congestive heart failure and renal dysfunction than the LBR group. The mean DAPT score was 2.96±1.1 for the LBR group and 3.7±1.4 for the HBR group (p <0.001). During follow-up at 30 days, 6 months, and 1 and 2 years, the rates of target vessel revascularization and stent thrombosis were not significantly different between the 2 groups. Bleeding events and all-cause mortality were significantly more frequent in the HBR group than in the LBR group. In conclusion, patients undergoing PCI often have pre-existing risk factors that predispose them to ischemic and bleeding complications. Prolonged duration of DAPT to mitigate ischemic events could lead to a disproportionate increase in bleeding events, especially in HBR patients.

COMPARison of pre-hospital CRUSHed vs. uncrushed Prasugrel tablets in patients with STEMI undergoing primary percutaneous coronary interventions: Rationale and design of the COMPARE CRUSH trial

BACKGROUND

Dual antiplatelet therapy constitutes the cornerstone of medical treatment in patients with ST elevation myocardial infarction (STEMI). However, oral antiplatelet agents, such as prasugrel or ticagrelor, are characterized by slow gastrointestinal drug absorption in the acute phase of STEMI, leading to decreased bioavailability and therefore delayed onset of platelet inhibition. Evidence suggests that administration of crushed tablets of the P2Y₁₂ inhibitor prasugrel improves drug absorption and achieves earlier antiplatelet effects in STEMI patients undergoing primary percutaneous coronary intervention (PCI). However, the clinical implications of these pharmacokinetic and pharmacodynamic findings are unknown.

HYPOTHESIS

The present study is designed to test the hypothesis that patients presenting with STEMI planned for primary PCI will have improved markers of optimal reperfusion and clinical outcomes by prehospital administration of crushed tablets of prasugrel loading dose.

STUDY DESIGN

COMPARE CRUSH (NCT03296540) is a randomized trial in a regionally organized ambulance care setting evaluating the efficacy and safety of pre-hospital loading dose with prasugrel crushed tablets versus integral tablets in approximately 674 patients presenting with STEMI planned for primary PCI. The independent primary endpoints are percentage of patients reaching thrombolysis in myocardial infarction (TIMI) flow grade 3 in the infarct-related artery at initial angiography, or achieving ≥70% ST-segment elevation resolution at 1 hour post-PCI. Secondary clinical endpoints are death, myocardial infarction, revascularization, and stent thrombosis followed up to 1 year. Moreover, the primary safety endpoint is bleeding events assessed at 48 hours.

CONCLUSIONS

The COMPARE CRUSH trial will assess whether prehospital administration of loading dose prasugrel in form of crushed tablets - which is expected to provide faster platelet inhibition compared to standard treatment with integral tablets - results in improved reperfusion and clinical outcomes. RCT# NCT03296540.

Platelet-Derived Thrombogenicity Measured by Total Thrombus-Formation Analysis System in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Prompt and potent antiplatelet effects are important aspects of management of ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). We evaluated the association between platelet-derived thrombogenicity during PPCI and enzymatic infarct size in STEMI patients.Methods and Results:Platelet-derived thrombogenicity was assessed in 127 STEMI patients undergoing PPCI by: (1) the area under the flow-pressure curve for the PL-chip (PL₁₈-AUC₁₀) using the total thrombus-formation analysis system (T-TAS); and (2) P2Y₁₂reaction units (PRU) using the VerifyNow system. Patients were divided into 2 groups (High and Low) based on median PL₁₈-AUC₁₀during PPCI. PRU levels during PPCI were suboptimal in both the High and Low PL₁₈-AUC₁₀groups (median [interquartile range] 266 [231-311] vs. 272 [217-317], respectively; P=0.95). The percentage of final Thrombolysis in Myocardial Infarction (TIMI) 3 flow was lower in the High PL₁₈-AUC₁₀group (75% vs. 90%; P=0.021), whereas corrected TIMI frame count (31.3±2.5 vs. 21.0±2.6; P=0.005) and the incidence of slow-flow/no-reflow phenomenon (31% vs. 11%, P=0.0055) were higher. The area under the curve for creatine kinase (AUC_CK) was greater in the High PL₁₈-AUC₁₀group (95,231±7,275 IU/L h vs. 62,239±7,333 IU/L h; P=0.0018). Multivariate regression analysis identified high PL₁₈-AUC₁₀during PPCI (β=0.29, P=0.0006) and poor initial TIMI flow (β=0.37, P<0.0001) as independent determinants of AUC_CK.

CONCLUSIONS

T-TAS-based high platelet-derived thrombogenicity during PPCI was associated with enzymatic infarct size in patients with STEMI.

Choice of access site and type of anticoagulant in acute coronary syndromes with advanced Killip class or out-of-hospital cardiac arrest

INTRODUCTION AND OBJECTIVES

Patients who are vulnerable to hemodynamic or electrical disorders (VP) are often excluded from clinical trials and data on the optimal access-site or antithrombotic treatment are limited. We assessed outcomes of transradial vs transfemoral access and bivalirudin vs unfractionated heparin (UFH) in VP with acute coronary syndrome undergoing invasive management.

METHODS

The MATRIX trial randomized 8404 patients to radial or femoral access and 7213 patients to bivalirudin or UFH. Among them, 934 (11.1%) were deemed VP due to advanced Killip class (n = 808), cardiac arrest (n = 168), or both (n = 42). The 30-day coprimary outcomes were major adverse cardiovascular and cerebrovascular events (MACE: death, myocardial infarction, or stroke) and net adverse clinical events (NACE: MACE or major bleeding).

RESULTS

MACE and NACE were similarly reduced with radial vs femoral access in VP and non-VP. Transradial access was also associated with consistent relative benefits in all-cause and cardiovascular mortality or Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding with greater absolute benefits in VP. The effects of bivalirudin vs UFH on MACE and NACE were consistent in VP and non-VP. Bivalirudin was associated with lower all-cause and cardiovascular mortality in VP but not in non-VP, with borderline interaction testing. Bivalirudin reduced bleeding in both VP and non-VP with a larger absolute benefit in VP.

CONCLUSIONS

In acute coronary syndrome patients undergoing invasive management, the effects of randomized treatments were consistent in VP and non-VP, but absolute risk reduction with radial access and bivalirudin were greater in VP, with a 5- to 10-fold lower number needed to treat for benefits. Trial registry number: NCT01433627.

Novel use of a stent graft for uncontrollable intraprocedural stent thrombosis in a patient with acute myocardial infarction

We report the case of a patient who developed uncontrollable intraprocedural stent thrombosis (IPST) during an emergent percutaneous coronary intervention for acute myocardial infarction that was mitigated only by covering the culprit lesion with a stent graft. Although several factors can induce stent thrombosis, IPST was likely a result of intrastent plaque protrusion in this patient. This is the first case report on the use of stent graft implantation as an effective bailout procedure for uncontrolled IPST. The findings described in this case study warrant the adoption of stent grafts for the complete sealing of plaque protrusion in lesions.

Platelet Inhibition With Cangrelor and Crushed Ticagrelor in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

The platelet inhibitory effects induced by oral P2Y₁₂ receptor antagonists are delayed in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (P-PCI). In turn, this leads to a gap in platelet inhibition, exposing patients to an increased risk of early thrombotic complications and underscoring the need to define strategies associated with more effective platelet inhibition in the peri-primary percutaneous coronary intervention period. Cangrelor is an intravenous P2Y₁₂ inhibitor with prompt and potent antiplatelet effects. However, to date, there are limited data on the effects of cangrelor used in combination with ticagrelor in patients undergoing primary percutaneous coronary intervention. Moreover, questions have emerged on the potential for drug-drug interactions during the transition from cangrelor to oral P2Y₁₂ inhibitors.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled pharmacodynamic study conducted in patients undergoing primary percutaneous coronary intervention (n=50) who were randomized to treatment with either cangrelor or matching placebo (bolus followed by 2-hour infusion). All patients received ticagrelor 180-mg loading dose administered as crushed tablets at the time of cangrelor/placebo bolus administration. Pharmacodynamic analyses were performed at 8 time points. Pharmacodynamic effects were measured as P2Y₁₂ reaction units by VerifyNow and platelet reactivity index by vasodilator-stimulated phosphoprotein.

RESULTS

Compared with placebo, cangrelor was associated with reduced P2Y₁₂ reaction units as early as 5 minutes after bolus, which persisted during the entire duration of drug infusion, including at 30 minutes (63 [32-93] versus 214 [183-245]; mean difference, 152 [95% CI, 108-195]; P<0·001; primary end point). Parallel findings were shown with platelet reactivity index. Accordingly, high on-treatment platelet reactivity rates were reduced with cangrelor. After discontinuation of cangrelor/placebo infusion, there were no differences in levels of platelet reactivity between groups, ruling out a drug-drug interaction when cangrelor and ticagrelor are concomitantly administered.

CONCLUSIONS

In patients undergoing primary percutaneous coronary intervention, cangrelor is an effective strategy to bridge the gap in platelet inhibition associated with the use of oral P2Y₁₂ inhibition induced by ticagrelor. Ticagrelor can be administered as a crushed formulation concomitantly with cangrelor without any apparent drug-drug interaction. The clinical implications of these pharmacodynamic findings warrant investigation in an adequately powered clinical trial.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03247738.

Short-term efficacy of ticagrelor in acute ST-segment elevation myocardial infarction patients undergoing an emergency percutaneous coronary intervention

In total, 97 acute ST-segment elevation myocardial infarction (STEMI) patients who received an emergency percutaneous coronary intervention (PCI) were enrolled and divided into a ticagrelor group and a clopidogrel group. Thrombolysis in myocardial infarction (TIMI) blood flow and the corrected TIMI frame count (CTFC) were used to assess the blood perfusion of culprit vessels. Thromboelastography (TEG) was used to evaluate the antiplatelet effect of drugs. The results showed that the incidence of TIMI grade III blood flow in the ticagrelor group was significantly higher than that in the clopidogrel group. The CTFC in the anterior descending, circumflex, and right coronary arteries was statistically significantly lower in the ticagrelor group as compared with that in the clopidogrel group. At 2 h and 7 d postdrug treatment, the adenosine diphosphate-induced platelet inhibition rate (ADP%) in the ticagrelor group increased significantly as compared with that in the clopidogrel group, and the platelet aggregation rate of the ADP pathway (MA_ADP) decreased significantly in the ticagrelor group versus that in the clopidogrel group. In conclusion, ticagrelor significantly improved TIMI blood flow and had a better antiplatelet effect than clopidogrel in STEMI patients undergoing an emergency PCI.

Effects of Methylnaltrexone on Ticagrelor-Induced Antiplatelet Effects in Coronary Artery Disease Patients Treated With Morphine

OBJECTIVES

The aim of this study was to assess if intravenous methylnaltrexone can counteract the effects of morphine on the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of ticagrelor.

BACKGROUND

Morphine delays the onset of action of oral P2Y₁₂ receptor inhibitors, including ticagrelor, by inhibiting gastric emptying and leading to delayed drug absorption. Methylnaltrexone is a peripheral opioid receptor antagonist that has the potential to prevent opioid-induced peripherally mediated side effects (e.g., gastric emptying inhibition) without affecting analgesia.

METHODS

In this prospective, randomized, double-blind, placebo-controlled, crossover study, aspirin-treated patients with stable coronary artery disease (n = 30) were randomized to receive methylnaltrexone (0.3 mg/kg intravenous) or matching placebo. After methylnaltrexone or placebo administration, all patients received morphine (5 mg intravenous). This was followed 15 min later by a 180-mg loading dose of ticagrelor. Patients crossed over to the alternative study treatment after 7 ± 2 days of washout. PK and PD assessments were performed at 12 time points (6 pre- and 6 post-crossover). PK analysis included measurement of plasma levels of ticagrelor and its major active metabolite (AR-C124910XX). PD assessments included VerifyNow P2Y₁₂, light transmittance aggregometry, and vasodilator-stimulated phosphoprotein.

RESULTS

Only marginal changes in plasma levels of ticagrelor (and its major active metabolite) were observed with ticagrelor: maximum plasma concentration and area under the plasma concentration versus time curve from time 0 to the last measurable concentration were 38% and 30% higher, respectively, in patients receiving methylnaltrexone compared with those receiving placebo, but no differences in time to maximum plasma concentration were observed. There were no differences in P2Y₁₂ reaction units by VerifyNow P2Y₁₂ between groups at each time point, including 2 h (the primary endpoint; p = 0.261). Similarly, there were no differences in PD markers assessed by light transmittance aggregometry and vasodilator-stimulated phosphoprotein.

CONCLUSIONS

In patients with coronary artery disease receiving morphine, intravenous administration of the peripheral opioid receptor antagonist methylnaltrexone leads to only marginal changes in plasma levels of ticagrelor and its major metabolite, without affecting levels of platelet reactivity. (Effect of Methylnaltrexone on the PK/PD Profiles of Ticagrelor in Patients Treated With Morphine; NCT02403830).

Role of oral anticoagulant therapy for secondary prevention in patients with stable atherothrombotic disease manifestations

Coronary artery disease and peripheral arterial disease are strong predictors of risk for a future ischemic event. Despite the utilization of effective secondary prevention strategies, the prevalence of ischemic recurrences remains high, underscoring the need for effective secondary prevention antithrombotic treatment regimens. To date, most of the tested approaches have been with the use of antiplatelet therapies, used either individually or in combination. However, most recent findings support the potential role of oral anticoagulant therapy in addition to antiplatelet therapy to reduce the risk of ischemic recurrences. This approach has been tested in both acute and stable settings of patients with cardiovascular disease manifestations. The present manuscript provides an overview on the rationale and clinical trial updates on the role of oral anticoagulant therapy, in particular rivaroxaban used at the so-called vascular protection dose, in adjunct to antiplatelet therapy (i.e. aspirin), a strategy known as dual pathway inhibition, for secondary prevention of ischemic recurrences in patients with stable atherosclerotic disease manifestations.