Ticagrelor versus clopidogrel after fibrinolytic therapy in patients with ST-elevation myocardial infarction: Rationale and design of the ticagrelor in patients with ST elevation myocardial infarction treated with thrombolysis (TREAT) trial

Beyond Traditional Pain Relief: A Review of Alternative Analgesics in Myocardial Infarction Patient Management

While morphine is the recommended first-line treatment for pain management in patients with acute coronary syndrome, recent studies have raised concerns about its association with adverse outcomes. Morphine has been found to cause delayed antiplatelet effects, decreased ticagrelor absorption, increased platelet reactivity, and compromised efficacy of dual antiplatelet therapy (DAPT). Alternative analgesics, such as lidocaine, fentanyl, and acetaminophen, have begun to emerge as viable alternatives, each with unique mechanisms and potential benefits. Lidocaine is demonstrated to have superior effects in reducing microvascular obstruction and fewer adverse events compared to fentanyl, despite being less effective in pain reduction. Fentanyl, which shows rapid onset and powerful analgesic properties, may interfere with ticagrelor absorption, potentially affecting platelet inhibition. Acetaminophen, a centrally acting analgesic, emerges as a safer alternative with comparable pain relief efficacy and minimal side effects. The results of multiple clinical trials emphasize the significance of customizing pain management approaches to match individual patient profiles and achieving the optimal balance between pain relief and potential adverse outcomes.

Morphine and clinical outcomes in patients with ST segment elevation myocardial infarction treated with fibrinolytic and antiplatelet therapy: Insights from the TREAT trial

BACKGROUND

Morphine is commonly used to relieve pain, anxiety and dyspnea in STEMI but it lowers blood pressure and delays the activity of oral antiplatelet agents. The impact of morphine on clinical outcomes remains unknown. This analysis was performed to determine if morphine use was associated with increased risk of adverse clinical events among STEMI patients treated with fibrinolytic therapy and clopidogrel or ticagrelor.

METHODS

In the Ticagrelor in Patients with ST Elevation Myocardial Infarction Treated with Pharmacological Thrombolysis (TREAT) study, 3799 STEMI patients treated with fibrinolysis were randomized to receive clopidogrel or ticagrelor. Morphine use was left to the discretion of the treating physicians. In this pre-specified analysis, we evaluated clinical outcomes based on the use and timing of morphine administration. Outcomes were stratified by randomized treatment group. Multivariable analysis was performed using Inverse Probability Treatment Weighting (IPTW) weighting.

RESULTS

Morphine was used in 53% of patients. After adjustment using IPTW weighting, morphine use was associated with higher hazard of reinfarction at 7 days (HR 4.9, P = .0006) and 30 days (HR 1.7, P = .04), and lower hazard of major bleeding (HR 0.37, P = .006). There was no significant difference in mortality at any time point.

CONCLUSIONS

Among patients with STEMI treated with fibrinolytic therapy, morphine use was associated with a higher risk of early reinfarction and a lower risk of major bleeding but no difference in mortality.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02298088.

Effects of Ticagrelor and Clopidogrel on Coronary Microcirculation in Patients with Acute Myocardial Infarction

Introduction

Clopidogrel has been demonstrated to be effective in improving coronary microcirculation (CM) among patients with ST-elevation myocardial infarction (STEMI) treated with fibrinolytics. Ticagrelor is a more potent adenosine diphosphate (ADP) receptor blocker proven to be superior to clopidogrel among patients with acute coronary syndromes. The present study aimed to compare the effects of ticagrelor and clopidogrel on CM in patients with STEMI treated with fibrinolytics.

Methods

The present study prospectively included 48 patients participating in the TREAT trial, which randomly assigned patients with STEMI undergoing fibrinolysis to ticagrelor versus clopidogrel. The primary endpoint of this study was the evaluation of the CM using the global myocardial perfusion score index (global MPSI) obtained by myocardial contrast echocardiography (MCE). Platelet aggregation to ADP was evaluated by Multiplate® and expressed as area under the curve (AUC).

Results

The global MPSI demonstrated no differences between the groups [mean 1.4 (1.2–1.5) in the ticagrelor group and 1.2 (1.2–1.5) in the clopidogrel group (p = 0.41)]. Platelet aggregability was lower in the ticagrelor group (18.1 ± 9.7 AUC), compared to the clopidogrel group (26.1 ± 12.5 AUC, p = 0.01).

Conclusion

We found no improvement in coronary microcirculation with ticagrelor compared to clopidogrel among patients with STEMI treated with fibrinolytics, despite the fact that platelet aggregation to ADP was lower with ticagrelor.

Clinical Trials Registration

NCT03104062.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02061-0.

[The Bleeding Safety of Ticagrelor in Patients With ST-Elevation Acute Coronary Syndrome Treated With Fibrinolytic Therapy]

Aim      To compare hemorrhagic safety of ticagrelor and clopidogrel in patients with ST-segment elevation acute coronary syndrome (STEACS) after thrombolytic therapy (TLT).Material and methods  This nonrandomized study included 183 patients followed up for 30 days. Hemorrhagic safety was compared in a group of patients with STEACS (n=71) after a thrombolytic treatment with alteplase and early ticagrelor treatment (180 mg followed by switching to 90 mg twice daily) and in a group of patients (n=112) with STEACS receiving TLT with alteplase and clopidogrel (loading dose, 600 mg followed by switching to 75 mg daily). Primary endpoint was hemorrhage associated with TLT; patients were followed up for 30 days.Results During the follow-up period, TLT-associated hemorrhages were observed in 11.3% of patients in the ticagrelor treatment group and in 10.7% of patients in the clopidogrel treatment group (p=0.9; odds ratio, 1.06 at 95 % confidence interval, from 0.41 to 2.73). Intracranial hemorrhages and fatal hemorrhages were absent in both groups.Conclusion      There were no significant differences in hemorrhagic safety between patients with STEACS after the TLT treatment with alteplase and early treatment with ticagrelor or clopidogrel.

2019 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Guidelines on the Acute Management of ST-Elevation Myocardial Infarction: Focused Update on Regionalization and Reperfusion

Rapid reperfusion of the infarct-related artery is the cornerstone of therapy for the management of acute ST-elevation myocardial infarction (STEMI). Canada's geography presents unique challenges for timely delivery of reperfusion therapy for STEMI patients. The Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology STEMI guideline was developed to provide advice regarding the optimal acute management of STEMI patients irrespective of where they are initially identified: in the field, at a non-percutaneous coronary intervention-capable centre or at a percutaneous coronary intervention-capable centre. We had also planned to evaluate and incorporate sex and gender considerations in the development of our recommendations. Unfortunately, inadequate enrollment of women in randomized trials, lack of publication of main outcomes stratified according to sex, and lack of inclusion of gender as a study variable in the available literature limited the feasibility of such an approach. The Grading Recommendations, Assessment, Development, and Evaluation system was used to develop specific evidence-based recommendations for the early identification of STEMI patients, practical aspects of patient transport, regional reperfusion decision-making, adjunctive prehospital interventions (oxygen, opioids, antiplatelet therapy), and procedural aspects of mechanical reperfusion (access site, thrombectomy, antithrombotic therapy, extent of revascularization). Emphasis is placed on integrating these recommendations as part of an organized regional network of STEMI care and the development of appropriate reperfusion and transportation pathways for any given region. It is anticipated that these guidelines will serve as a practical template to develop systems of care capable of providing optimal treatment for a wide range of STEMI patients.

Use of ticagrelor alongside fibrinolytic therapy in patients with ST-segment elevation myocardial infarction: Practical perspectives based on data from the TREAT study

Primary percutaneous coronary intervention (PCI) is the preferred reperfusion method in patients with ST-segment elevation myocardial infarction (STEMI). In patients with STEMI who cannot undergo timely primary PCI, pharmacoinvasive treatment is recommended, comprising immediate fibrinolytic therapy with subsequent coronary angiography and rescue PCI if needed. Improving clinical outcomes following fibrinolysis remains of great importance for the many patients globally for whom rapid treatment with primary PCI is not possible. For patients with acute coronary syndrome who underwent primary PCI, the PLATO trial demonstrated superior efficacy of ticagrelor relative to clopidogrel. Results in the predefined subgroup of patients with STEMI were consistent with the overall PLATO trial. Patients who received fibrinolytic therapy in the 24 hours before randomization were excluded from PLATO, and there is thus a lack of data on the safety of using ticagrelor in conjunction with fibrinolytic therapy in the first 24 hours after STEMI. The TREAT study addresses this knowledge gap; patients with STEMI who had symptom onset within the previous 24 hours and had received fibrinolytic therapy (of whom 89.4% had also received clopidogrel) were randomized to treatment with ticagrelor or clopidogrel (median time between fibrinolysis and randomization: 11.5 hours). At 30 days, ticagrelor was found to be non-inferior to clopidogrel for the primary safety outcome of Thrombolysis in Myocardial Infarction (TIMI)-defined first major bleeding. Considering together the results of the PLATO and TREAT studies, initiating or switching to treatment with ticagrelor within the first 24 hours after STEMI in patients receiving fibrinolysis is reasonable.

Ticagrelor vs Clopidogrel After Fibrinolytic Therapy in Patients With ST-Elevation Myocardial Infarction: A Randomized Clinical Trial

Importance

The bleeding safety of ticagrelor in patients with ST-elevation myocardial infarction treated with fibrinolytic therapy remains uncertain.

Objective

To evaluate the short-term safety of ticagrelor when compared with clopidogrel in patients with ST-elevation myocardial infarction treated with fibrinolytic therapy.

Design, Setting and Participants

We conducted a multicenter, randomized, open-label with blinded end point adjudication trial that enrolled 3799 patients (younger than 75 years) with ST-segment elevation myocardial infarction receiving fibrinolytic therapy in 152 sites from 10 countries from November 2015 through November 2017. The prespecified upper boundary for noninferiority for bleeding was an absolute margin of 1.0%.

Interventions

Patients were randomized to ticagrelor (180-mg loading dose, 90 mg twice daily thereafter) or clopidogrel (300-mg to 600-mg loading dose, 75 mg daily thereafter). Patients were randomized with a median of 11.4 hours after fibrinolysis, and 90% were pretreated with clopidogrel.

Main Outcomes and Measures

The primary outcome was thrombolysis in myocardial infarction (TIMI) major bleeding through 30 days.

Results

The mean (SD) age was 58.0 (9.5) years, 2928 of 3799 patients (77.1%) were men, and 2177 of 3799 patients (57.3%) were white. At 30 days, TIMI major bleeding had occurred in 14 of 1913 patients (0.73%) receiving ticagrelor and in 13 of 1886 patients (0.69%) receiving clopidogrel (absolute difference, 0.04%; 95% CI, -0.49% to 0.58%; P < .001 for noninferiority). Major bleeding defined by the Platelet Inhibition and Patient Outcomes criteria and by the Bleeding Academic Research Consortium types 3 to 5 bleeding occurred in 23 patients (1.20%) in the ticagrelor group and in 26 patients (1.38%) in the clopidogrel group (absolute difference, -0.18%; 95% CI, -0.89% to 0.54; P = .001 for noninferiority). The rates of fatal (0.16% vs 0.11%; P = .67) and intracranial bleeding (0.42% vs 0.37%; P = .82) were similar between the ticagrelor and clopidogrel groups, respectively. Minor and minimal bleeding were more common with ticagrelor than with clopidogrel. The composite of death from vascular causes, myocardial infarction, or stroke occurred in 76 patients (4.0%) treated with ticagrelor and in 82 patients (4.3%) receiving clopidogrel (hazard ratio, 0.91; 95% CI, 0.67-1.25; P = .57).

Conclusions and Relevance

In patients younger than 75 years with ST-segment elevation myocardial infarction, delayed administration of ticagrelor after fibrinolytic therapy was noninferior to clopidogrel for TIMI major bleeding at 30 days.

Trial Registration

clinicaltrials.gov Identifier: NCT02298088.