Morphine and Cardiovascular Outcomes Among Patients With Non-ST-Segment Elevation Acute Coronary Syndromes Undergoing Coronary Angiography

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.

Assessing the Impact of Morphine on Adverse Outcomes in ACS Patients Treated with P2Y12 Inhibitors: Insights from Multiple Real-World Evidence

Purpose

Mechanistic studies showed that morphine may impair the antiplatelet effect of P2Y12 inhibitors. However, Several clinical studies with cardiovascular events as an outcome are contradictory, and the broader impact of this drug interaction on additional organ systems remains uncertain. With multisource data, this study sought to determine the effects of morphine interaction with P2Y12 inhibitors on major adverse outcomes comprehensively, and identify the warning indicators.

Patients and Methods

Interaction signals were sought in 187,919 safety reports from the FDA Adverse Event Reporting System (FAERS) database, utilizing reporting odds ratios (repOR). In a cohort of 5240 acute coronary syndrome patients, the analyses were validated, and the biological effects of warning indicators were further studied with Mendelian randomization and mediation analysis.

Results

Potential risk of renal system adverse events in patients cotreated with morphine is significantly higher in FAERS (repOR 4.83, 95% CI 4.42-5.28, false discovery rate adjusted-P =3.55*10-209). The analysis of in-house patient cohorts validated these results with an increased risk of acute kidney injury (adjusted OR: 1.65; 95% CI: 1.20 to 2.26), and we also found a risk of myocardial infarction in patients treated with morphine (adjusted OR: 1.55; 95% CI: 1.14 to 2.11). The Morphine group exhibited diminished Plateletcrit (PCT) levels post-surgery and lower PCT levels were associated with an increased risk of AKI.

Conclusion

The administration of morphine in patients treated with P2Y12 receptor inhibitors should be carefully evaluated. PCT may serve as a potential warning indicator for morphine-related renal injury.

Using machine learning to predict adverse events in acute coronary syndrome: A retrospective study

BACKGROUND

Up to 30% of patients with acute coronary syndrome (ACS) die from adverse events, mainly renal failure and myocardial infarction (MI). Accurate prediction of adverse events is therefore essential to improve patient prognosis.

HYPOTHESIS

Machine learning (ML) methods can accurately identify risk factors and predict adverse events.

METHODS

A total of 5240 patients diagnosed with ACS who underwent PCI were enrolled and followed for 1 year. Support vector machine, extreme gradient boosting, adaptive boosting, K-nearest neighbors, random forest, decision tree, categorical boosting, and linear discriminant analysis (LDA) were developed with 10-fold cross-validation to predict acute kidney injury (AKI), MI during hospitalization, and all-cause mortality within 1 year. Features with mean Shapley Additive exPlanations score >0.1 were screened by XGBoost method as input for model construction. Accuracy, F1 score, area under curve (AUC), and precision/recall curve were used to evaluate the performance of the models.

RESULTS

Overall, 2.6% of patients died within 1 year, 4.2% had AKI, and 4.7% had MI during hospitalization. The LDA model was superior to the other seven ML models, with an AUC of 0.83, F1 score of 0.90, accuracy of 0.85, recall of 0.85, specificity of 0.68, and precision of 0.99 in predicting all-cause mortality. For AKI and MI, the LDA model also showed good discriminating capacity with an AUC of 0.74.

CONCLUSION

The LDA model, using easily accessible variables from in-hospital patients, showed the potential to effectively predict the risk of adverse events and mortality within 1 year in ACS patients after PCI.

Major adverse cardiovascular events and mortality with opioids versus NSAIDs initiation in patients with rheumatoid arthritis

OBJECTIVE

Assess major adverse cardiovascular event (MACE) risk with opioids compared with non-steroidal anti-inflammatory drugs (NSAIDs) in patients with rheumatoid arthritis (RA) METHODS: We conducted a new-user active comparator cohort study among patients with RA within FORWARD, The National Databank for Rheumatic Diseases, with ≥1 year participation between 1998 and 2021. Each opioid initiator was matched to two NSAID initiators by propensity scores (PSs). Patients were followed until the occurrence of the composite endpoint of MACE (myocardial infarction, stroke, heart failure, cardiovascular disease (CVD) death, venous thromboembolism (VTE)) and all-cause mortality. The risk of outcomes was estimated using Cox proportional hazards with adjustment for PS weights and imbalanced covariables.

RESULTS

Among 6866 opioid initiators and 13 689 NSAID initiators, 212 vs 253 MACE (20.6/1000 person-years (PY) vs 18.9/1000 PY) and 144 vs 150 deaths (13.5/1000 PY vs 10.8/1000 PY) occurred, respectively. The risk of MACE with opioids was similar to NSAIDs (HR=1.02, 95% CI 0.85 to 1.22), whereas all-cause mortality with opioids was 33% higher than NSAIDs (HR=1.33, 95% CI 1.06 to 1.67) in PS-weighted models. Among the individual outcomes of MACE, VTE risk tended to be higher in opioid initiators than NSAID initiators (HR=1.41, 95% CI 0.84 to 2.35). Strong opioids had a higher risk for all-cause mortality and VTE than weak opioids compared with NSAIDs suggesting a dose-dependent association.

CONCLUSION

Opioids had similar MACE risk compared with NSAIDs in patients with RA with increased all-cause mortality and likely VTE, which suggests that opioids are not safer than NSAIDs, as clinicians have perceived.

Effects of morphine and P2Y inhibitor amongst patients with acute coronary syndrome: A meta-analysis of comparative studies

BACKGROUND

P2Y inhibitor and morphine are widely used in caring for patients with the acute coronary syndrome (ACS), but there are some concerns about the combination use due to interaction in metabolism. Therefore, this study aimed to examine whether using morphine with antiplatelets in patients with ACS affects the clinical outcomes based on currently available evidence.

METHODS

Three databases were searched for comparative studies on this topic by using relevant keywords of ACS and morphine. Two authors independently extracted study information, mortality, major adverse cardiac event (MACE), major bleeding, and length of hospital stay. Then, they evaluated the quality of evidence independently. Meta-analysis was planned to be conducted in random-effects model. Risk ratio (RR) was used for most outcomes except hospital stay, and Peto odds ratio (POR) was used if there were any zero cells. Pooled estimate was presented with 95% confidence interval (CI).

RESULTS

Fourteen studies (n = 73,033) met eligibility criteria, and there was non-significant difference in mortality between antiplatelet with and without morphine (RR = 1.13, 95%CI: 0.78 to 1.64). Antiplatelet therapy without morphine significantly reduced the risk of MACE (RR = 0.78, 95%CI: 0.67 to 0.89; I-square = 0%), but increased the odds of major bleeding (POR = 1.87, 95%CI: 1.04 to 3.35; I-square = 0%) as compared with the combined use of antiplatelet therapy and morphine.

CONCLUSION

In conclusion, there is no statistically significant difference in mortality in patients with ACS using morphine or not, but clinicians ought to make a trade-off between a lower risk of MACE and a higher risk of major bleeding before adding morphine to antiplatelet therapy.

LidocAine Versus Opioids In MyocarDial infarction: the AVOID-2 randomized controlled trial

AIMS

Opioid analgesia has been shown to interfere with the bioavailability of oral P2Y12 inhibitors prompting the search for safe and effective non-opioid analgesics to treat ischaemic chest pain.

METHODS AND RESULTS

The lidocAine Versus Opioids In MyocarDial infarction trial was a prospective, Phase II, prehospital, open-label, non-inferiority, randomized controlled trial enrolling patients with suspected STEACS with moderate to severe pain [numerical rating scale (NRS) at least 5/10]. Intravenous lidocaine (maximum dose 300 mg) or intravenous fentanyl (up to 50 µg every 5 min) were administered as prehospital analgesia. The co-primary end points were prehospital pain reduction and adverse events requiring intervention. Secondary end points included peak cardiac troponin I, cardiac MRI (cMRI) assessed myocardial infarct size and clinical outcomes to 30 days. A total of 308 patients were enrolled. The median reduction in pain score (NRS) was 4 vs. 3 in the fentanyl and lidocaine arms, respectively, for the primary efficacy end point [estimated median difference -1 (95% confidence interval -1.58, -0.42, P = 0.5 for non-inferiority, P = 0.001 for inferiority of lidocaine)]. Adverse events requiring intervention occurred in 49% vs. 36% of the fentanyl and lidocaine arms which met non-inferiority and superiority favouring lidocaine (P = 0.016 for superiority). No significant differences in myocardial infarct size and clinical outcomes at 30 days were seen.

CONCLUSION

IV Lidocaine did not meet the criteria for non-inferiority with lower prehospital pain reduction than fentanyl but was safe and better tolerated as analgesia in ST-elevation myocardial infarction (STEMI). Future trials testing non-opioid analgesics in STEMI and whether opioid avoidance improves clinical outcomes are needed.

TRIAL REGISTRATION

CTRN12619001521112p.

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.

Comparison of the prevalence of opioid use among U.S. adults with cardiac conditions before and during the COVID-19 pandemic

Limited data are available on the prevalence of prescription opioid use among patients with cardiac conditions who were exposed to increased risks of cardiac events including myocardial failure and cardiac arrest. According to the U.S. National Health Interview Survey, we evaluated the prevalence of opioid use in patients with cardiac conditions who reported prescription opioid use in the past 12 months and 3 months in 2019 and 2020, respectively, and further estimated the prevalence of opioid use for acute pain or chronic pain. We also analyzed the stratified prevalence by demographical characteristics. Our results showed that there was no statistically significant change in the prevalence of opioid use in the past 12 months (26.5% in 2019 vs. 25.7% in 2020) or the past 3 months (66.6% in 2019 vs. 62.5% in 2020) before and during the COVID-19 pandemic. However, there was a significant decline in the prevalence of opioid use for acute pain, from 64.2% (95% confidence interval [CI] 57.6% to 70.3%) in 2019 to 49.6% (95% CI 40.1% to 59.0%) in 2020 (P = 0.012), particularly in the subgroups of men, non-Hispanic white people, adults with education below high school, those with an income-to-poverty ratio ranging from 1.0 to 1.9, and those covered with health insurance. Our findings suggest that monitoring opioid use in the era of living with COVID-19 is important, which will help inform healthcare providers to develop care strategies to reduce health loss for vulnerable individuals.

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.

Evolving therapeutic strategies for patients hospitalized with new or worsening heart failure across the spectrum of left ventricular ejection fraction

Heart failure (HF) is a chronic, progressive, and increasingly prevalent syndrome characterized by stepwise declines in health status and residual lifespan. Despite significant advancements in both pharmacologic and nonpharmacologic management approaches for chronic HF, the burden of HF hospitalization-whether attributable to new-onset (de novo) HF or worsening of established HF-remains high and contributes to excess HF-related morbidity, mortality, and healthcare expenditures. Owing to a paucity of evidence to guide tailored interventions in this heterogeneous group, management of acute HF events remains largely subject to clinician discretion, relying principally on alleviation of clinical congestion, as-needed correction of hemodynamic perturbations, and concomitant reversal of underlying trigger(s). Following acute stabilization, the subsequent phase of care primarily involves interventions known to improve long-term outcomes and rehospitalization risk, including initiation and optimization of disease-modifying pharmacotherapy, targeted use of adjunctive therapies, and attention to contributing comorbid conditions. However, even with current standards of care many patients experience recurrent HF hospitalization, or after admission incur worsening clinical trajectories. These patterns highlight a persistent unmet need for evidence-based approaches to inform in-hospital HF care and call for renewed focus on urgent implementation of interventions capable of ameliorating risk of worsening HF. In this review, we discuss key contemporary and emerging therapeutic strategies for patients hospitalized with de novo or worsening HF.

Balancing thrombosis and bleeding after out-of-hospital cardiac arrest related to acute coronary syndrome: A literature review

Balance between thrombosis and bleeding is now well recognized in patients treated for acute coronary syndrome, with impact on short- and long-term prognosis, including survival. Recent data suggest that patients who are resuscitated after out-of-hospital cardiac arrest related to myocardial infarction are at an even higher risk of bleeding and thrombosis than those with uncomplicated acute coronary syndrome. Delayed enteral absorption of medication due to induced hypothermia and systemic inflammation increases thrombosis risk, whereas transfemoral access site, cardiopulmonary resuscitation manoeuvres and mechanical circulatory support devices increase bleeding risk. In addition, post-resuscitation syndrome and renal or hepatic impairment are potential risk factors for both bleeding and thrombotic complications. There are currently no randomized controlled trials comparing various P₂Y₁₂ inhibitor and/or anticoagulation strategies in the setting of out-of-hospital cardiac arrest, and current practice is largely derived from management of patients with uncomplicated acute coronary syndrome. The aim of this review is therefore to describe the bleeding and thrombosis risk factors in this specific population, and to review recent data on antithrombotic drugs in this patient subset.

2021 Update for the Diagnosis and Management of Acute Coronary Syndromes for the Perioperative Clinician

In this review, recent key publications related to acute coronary syndrome (ACS) are summarized and placed into context of contemporary practice. Landmark trials examining vascular access in ST-elevation myocardial infarction, the management of multivessel disease, acute myocardial infarction and cardiac arrest are discussed. An update in pharmacology for ACS provides updates in major trials relating to P2Y12 inhibitor initiation, deescalation, and use in special populations. Additional updates in the use of lipid-lowering agents and adjunctive medications in ACS are reviewed. Finally, cardiac pathology related to coronavirus disease 2019 (COVID-19), as well as the impact of the COVID-19 global pandemic on the care of patients with ACS, is summarized.

Management strategies for STE-ACS

ABSTRACT

Using guideline-driven interventions, NPs are well suited for management of ST-segment elevation (STE)-acute coronary syndrome (ACS). This second article in a two-part series on ACS management presents an updated overview to help NPs in applying evidence-based interventions while caring for patients with STE-ACS.

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.

Impact of Morphine Treatment With and Without Metoclopramide Coadministration on Myocardial and Microvascular Injury in Acute Myocardial Infarction: Insights From the Randomized MonAMI Trial

Background

Intravenous morphine administration can adversely affect platelet inhibition induced by P2Y₁₂ receptor inhibitors after acute myocardial infarction. In contrast, some evidence suggests that opioid agonists may have cardioprotective effects on the myocardium. The aim of this prospective, randomized MonAMI (Impact of Morphine Treatment With and Without Metoclopramide Coadministration on Platelet Inhibition in Acute Myocardial Infarction) trial was, therefore, to investigate the impact of morphine with or without metoclopramide coadministration on myocardial and microvascular injury.

Methods and Results

Patients with acute myocardial infarction (n=138) were assigned in a 1:1:1 ratio to ticagrelor 180 mg plus: (1) intravenous morphine 5 mg (morphine group); (2) intravenous morphine 5 mg and metoclopramide 10 mg (morphine+metoclopramide group); or (3) intravenous placebo (control group) administered before primary percutaneous coronary intervention. Cardiac magnetic resonance imaging was performed in 104 patients on day 1 to 4 after the index event. Infarct size was significantly smaller in the morphine only group as compared with controls (percentage of left ventricular mass, 15.5 versus 17.9; P=0.047). Furthermore, the number of patients with microvascular obstruction was significantly lower after morphine administration (28% versus 54%; P=0.022) and the extent of microvascular obstruction was smaller (percentage of left ventricular mass, 0 versus 0.74; P=0.037). In multivariable regression analysis, morphine administration was independently associated with a reduced risk for the occurrence of microvascular obstruction (odds ratio, 0.37; 95% CI, 0.14–0.93 [P=0.035]). There was no significant difference in infarct size (P=0.491) and extent (P=0.753) or presence (P=0.914) of microvascular obstruction when comparing the morphine+metoclopramide group with the control group.

Conclusions

In this randomized study, intravenous administration of morphine before primary percutaneous coronary intervention resulted in a significant reduction of myocardial and microvascular damage following acute myocardial infarction. This effect was not observed in the morphine plus metoclopramide group.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02627950.

Comparison of Hospitalization Trends and Outcomes in Acute Myocardial Infarction Patients With Versus Without Opioid Use Disorder

Discrepancies in medical care are well known to adversely affect patients with opioid abuse disorders (OUD), including management and outcomes of acute myocardial infarction (AMI) in patients with OUD. We used the National Inpatient Sample was queried from January 2006 to September 2015 to identify all patients ≥18 years admitted with a primary diagnosis of AMI (weighted N = 13,030; unweighted N = 2,670) and concomitant OUD. Patients using other nonopiate illicit drugs were excluded. Propensity matching (1:1) yielded 2,253 well-matched pairs in which intergroup comparison of invasive revascularization strategies and cardiac outcomes were performed. The prevalence of OUD patients with AMI over the last decade has doubled, from 163 (2006) to 326 cases (2015) per 100,000 admissions for AMI. The OUD group underwent less cardiac catheterization (63.2% vs 72.2%; p <0.001), percutaneous coronary intervention (37.0% vs 48.5%; p <0.001) and drug-eluting stent placement (32.3% vs 19.5%; p <0.001) compared with non-OUD. No differences in in-hospital mortality/cardiogenic shock were noted. Among subgroup of ST-elevation myocardial infarction patients (26.2% of overall cohort), the OUD patients were less likely to receive percutaneous coronary intervention (67.9% vs 75.5%; p = 0.002), drug-eluting stent (31.4% vs 47.9%; p <0.001) with a significantly higher mortality (7.4% vs 4.3%), and cardiogenic shock (11.7% vs 7.9%). No differences in the frequency of coronary bypass grafting were noted in AMI or its subgroups. In conclusion, OUD patients presenting with AMI receive less invasive treatment compared with those without OUD. OUD patients presenting with ST-elevation myocardial infarction have worse in-hospital outcomes with increased mortality and cardiogenic shock.

Challenges of Combining Opioids and P2Y12 Inhibitors in Acute Coronary Syndrome: Should the Future Be Opioid Free?

Morphine has been long recognized as standard of care in the treatment of acute coronary syndrome (ACS) patients; however, its safety has recently been called into question due to a drug interaction with P2Y₁₂ inhibitors. Opioids, given in combination with P2Y₁₂ inhibitors, can reduce antiplatelet effects by slowing gastrointestinal motility and ultimately reducing drug absorption. While there are proposed benefits of opioids in ACS patients, conflicting data regarding clinical outcomes exist. The majority of clinical data slightly favors opioid use in ST-elevation myocardial infarction over non-ST-elevation myocardial infarction, although trends for increased myocardial infarction are present in both settings. Current practice should be aimed at discerning the need for routine opioid use in ACS. Alternative strategies may be needed to overcome these interactions; however, no robust data are currently available to support these treatment options. Future research should be aimed at non-opioid treatment options in ACS, as opioid use remains controversial in this population.

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

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

Prolonged enoxaparin therapy compared with standard-of-care antithrombotic therapy in opiate-treated patients undergoing primary percutaneous coronary intervention

A novel enoxaparin regimen consisting of intra-arterial bolus (0.75 mg/kg) followed by intravenous infusion (0.75 mg/kg/6 hours) has been developed as a possible solution to the delayed absorption of oral P2Y₁₂ inhibitors in opiate-treated ST-elevation myocardial infarction (STEMI) patients undergoing primary angioplasty. We aimed to study the feasibility of this regimen as an alternative to standard-of-care treatment (SOC) with unfractionated heparin ± glycoprotein IIb/IIIa antagonist (GPI). One hundred opiate-treated patients presenting with STEMI and accepted for primary angioplasty were randomized (1:1) to either enoxaparin or SOC. Fifty patients were allocated enoxaparin (median age 61, 40% females) and 49 allocated SOC (median age 62, 22% females). One developed stroke before angiography and was withdrawn. One SOC patient had a gastrointestinal bleed resulting in 1 g drop in hemoglobin and early cessation of GPI infusion. Two enoxaparin patients had transient minor bleeding: one transient gingival bleed and one episode of coffee ground vomit with no hemoglobin drop or hemodynamic instability. Two SOC and no enoxaparin group patients had acute stent thrombosis. These preliminary data support further study of this novel 6-hour enoxaparin regimen in opiate-treated PPCI patients.