Opioids and ST Elevation Myocardial Infarction: A Systematic Review

Impact of prehospital opioid dose on angiographic and clinical outcomes in acute coronary syndromes

BACKGROUND

An adverse interaction whereby opioids impair and delay the gastrointestinal absorption of oral P2Y₁₂ inhibitors has been established, however the clinical significance of this in acute coronary syndrome (ACS) is uncertain. We sought to characterise the relationship between prehospital opioid dose and clinical outcomes in patients with ACS.

METHODS

Patients given opioid treatment by emergency medical services (EMS) with ACS who underwent percutaneous coronary intervention (PCI) between 1 January 2014 and 31 December 2018 were included in this retrospective cohort analysis using data linkage between the Ambulance Victoria, Victorian Cardiac Outcomes Registry and Melbourne Interventional Group databases. Patients with cardiogenic shock, out-of-hospital cardiac arrest and fibrinolysis were excluded. The primary end point was the risk-adjusted odds of 30-day major adverse cardiac events (MACE) between patients who received opioids and those that did not.

RESULTS

10 531 patients were included in the primary analysis. There was no significant difference in 30-day MACE between patients receiving opioids and those who did not after adjusting for key patient and clinical factors. Among patients with ST-elevation myocardial infarction (STEMI), there were significantly more patients with thrombolysis in myocardial infarction (TIMI) 0 or 1 flow pre-PCI in a subset of patients with high opioid dose versus no opioids (56% vs 25%, p<0.001). This remained significant after adjusting for known confounders with a higher predicted probability of TIMI 0/1 flow in the high versus no opioid groups (33% vs 11%, p<0.001).

CONCLUSIONS

Opioid use was not associated with 30-day MACE. There were higher rates of TIMI 0/1 flow pre-PCI in patients with STEMI prescribed opioids. Future prospective research is required to verify these findings and investigate alternative analgesia for ischaemic chest pain.

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.

Association between pre-hospital chest pain severity and myocardial injury in ST elevation myocardial infarction: A post-hoc analysis of the AVOID study

BACKGROUND

We sought to determine if an association exists between prehospital chest pain severity and markers of myocardial injury.

METHODS AND RESULTS

Patients with confirmed ST elevation myocardial infarction (STEMI) treated by emergency medical services were included in this retrospective cohort analysis of the AVOID study. The primary endpoint was the association of pre-hospital initial chest pain severity, cardiac biomarkers and infarct size based on cardiac magnetic resonance imaging. Groups were categorized based on moderate to severe chest pain (numerical rating scale pain ≥ 5/10) or less than moderate severity to compare procedural and clinical outcomes. 414 patients were included in the analysis. There was a weak correlation between initial pre-hospital chest pain severity and peak creatine kinase (r = 0.16, p = 0.001) and peak cardiac troponin I (r = 0.14, p = 0.005). Both were no longer significant after adjusting for known confounders. There was no association between moderate to severe chest pain on arrival and major adverse cardiac events at 6 months (20% vs. 14%, p=0.12). There was a weak correlation between history of ischemic heart disease (r = 0.16, p = 0.001), percutaneous coronary intervention (r = 0.16, p = 0.001), left anterior descending artery (r = 0.12, p = 0.012) as the culprit vessel and a weak negative correlation between age (r = -0.14, p = 0.039) and chest pain.

CONCLUSION

Only a weak association between pre-hospital chest pain severity and markers of myocardial injury was identified, supporting more judicious use of opioid analgesia with a focus on patient comfort.

Effects of lignocaine vs. opioids on antiplatelet activity of ticagrelor: the LOCAL trial

AIMS

We assessed the impact of intravenous fentanyl and lignocaine on the pharmacokinetics and pharmacodynamics of ticagrelor in patients with unstable angina and non-ST-elevation myocardial infarction and their procedural analgesic efficacy and safety.

METHODS AND RESULTS

Seventy patients undergoing coronary angiography with ticagrelor loading were included in the pharmacokinetic and pharmacodynamic analyses of this randomized trial. Plasma ticagrelor levels 2 h post-loading dose were significantly lower in the fentanyl arm than in the lignocaine treatment arm (598 vs. 1008 ng/mL, P = 0.014). The area under the plasma-time curves for ticagrelor (1228 vs. 2753 ng h/mL, P < 0.001) and its active metabolite (201 vs. 447 ng h/mL, P = 0.001) were both significantly lower in the fentanyl arm. Expression of activated platelet glycoprotein IIb/IIIa receptor (2829 vs. 1426 mean fluorescence intensity, P = 0.006) and P-selectin (439 vs. 211 mean fluorescence intensity, P = 0.001) was significantly higher at 60 min in the fentanyl arm. A higher proportion of patients had high on-treatment platelet reactivity in the fentanyl arm at 60 min using the Multiplate Analyzer (41% vs. 9%, P = 0.002) and 120 min using the VerifyNow (30% vs. 3%, P = 0.003) and VASP (37% vs. 6%, P = 0.002) assays. Both drugs were well tolerated with a high level of patient satisfaction.

CONCLUSIONS

Unlike fentanyl, lignocaine does not impair the bioavailability or delay the antiplatelet effect of ticagrelor. Both drugs were well tolerated and effective with a high level of patient satisfaction for procedural analgesia. Routine procedural analgesia during percutaneous coronary intervention should be reconsidered and if performed, lignocaine is a beneficial alternative to fentanyl.

An open-label, non-inferiority randomized controlled trial of lidocAine Versus Opioids In MyocarDial Infarction study (AVOID-2 study) methods paper

Background There is increasing evidence that opioids interfere with the oral bioavailability of P2Y₁₂ inhibitors leading to delayed onset of antiplatelet effects. Several strategies have been proposed to mitigate this interaction including utilizing alternative analgesic agents in the management of ischemic chest pain. Methods The lidocAine Versus Opioids In MyocarDial Infarction (AVOID-2) study is a phase II, pre-hospital, open-label, non-inferiority, randomized controlled trial conducted by Ambulance Victoria and Monash University in metropolitan Melbourne, Victoria, Australia. The purpose of the study is to compare the analgesic effect (reduction in pain by arrival to hospital) and safety (e.g. adverse drug reactions) (co-primary endpoints) of intravenous lidocaine versus intravenous fentanyl in 300 adult patients attended by ambulance with suspected ST-elevation myocardial infarction (STEMI). Secondary endpoints and a cardiac magnetic resonance imaging (MRI) sub-study will also compare infarct size between these two groups. Conclusions The evaluation of alternative analgesic agents in the management of acute coronary syndromes is urgently needed to manage the opioid-P2Y₁₂ inhibitor interaction. The results of this trial will have significant implications on the emergency management of acute coronary syndromes internationally.

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.

Mitochondria as a therapeutic target for cardiac ischemia‑reperfusion injury (Review)

Acute myocardial infarction is the leading cause of cardiovascular-related mortality and chronic heart failure worldwide. As regards treatment, the reperfusion of ischemic tissue generates irreversible damage to the myocardium, which is termed 'cardiac ischemia-reperfusion (IR) injury'. Due to the large number of mitochondria in cardiomyocytes, an increasing number of studies have focused on the roles of mitochondria in IR injury. The primary causes of IR injury are reduced oxidative phosphorylation during hypoxia and the increased production of reactive oxygen species (ROS), together with the insufficient elimination of these oxidative species following reperfusion. IR injury includes the oxidation of DNA, incorrect modifications of proteins, the disruption of the mitochondrial membrane and respiratory chain, the loss of mitochondrial membrane potential (∆Ψm), Ca²⁺ over-load, mitochondrial permeability transition pore formation, swelling of the mitochondria, and ultimately, cardiomyocyte necrosis. The present review article discusses the molecular mechanisms of IR injury, and summarizes the metabolic and dynamic changes occurring in the mitochondria in response to IR stress. The mitochondria are strongly recommended as a target for the development of therapeutic agents; however, the appropriate use of agents remains a challenge.

Prehospital opioid dose and myocardial injury in patients with ST elevation myocardial infarction

OBJECTIVE

To characterise the relationship between opioid dose and myocardial infarct size in patients with ST elevation myocardial infarction (STEMI).

METHODS

Patients given opioid treatment by emergency medical services with confirmed STEMI were included in this secondary, retrospective cohort analysis of the Air versus Oxygen in Myocardial Infarction (AVOID) study. Patients with cardiogenic shock were excluded. The primary endpoint was comparison of cardiac biomarkers as a measure of infarct size based on opioid dose (low ≤8.75 mg, intermediate 8.76-15 mg and high >15 mg of intravenous morphine equivalent dose).

RESULTS

422 patients were included in the analysis. There was a significantly higher proportion of patients with Thrombolysis in Myocardial Infarction (TIMI) 0 or 1 flow pre-percutaneous coronary intervention (PCI) (94% vs 81%, p=0.005) and greater use of thrombus aspiration catheters (59% vs 30%, p<0.001) in the high compared with low-dose opioid group. After adjustment for potential confounders, every 1 mg of intravenous morphine equivalent dose was associated with a 1.4% (95% CI 0.2%, 2.7%, p=0.028) increase in peak creatine kinase; however, this was no longer significant after adjustment for TIMI flow pre-PCI.

CONCLUSIONS

Our study suggests no benefit of higher opioid dose and a dose-dependent signal between opioid dose and increased myocardial infarct size. Prospective randomised controlled trials are required to establish causality given that this may also be explained by patients with a greater ischaemic burden requiring higher opioid doses due to more severe pain. Future research also needs to focus on strategies to mitigate the opioid-P2Y12 inhibitor interaction and non-opioid analgesia to treat ischaemic chest pain.

Analgesia in acute ischemic chest pain

Analgesics, particularly opioids, have been routinely used in the emergency treatment of ischemic chest pain for a long time. In the past two decades; however, several studies have raised the possibility of the harmful effects of opioid administration. In 2014, the American Heart Association (AHA)/American College of Cardiology Foundation (ACCF) changed the guidelines regarding the use of opioids from class IC to class IIb for non-ST elevation acute coronary syndrome. And in 2015, the European Society of Cardiology (ESC) guidelines incidentally noted the side effects of opioids. In ST-segment elevation myocardial infarction, both ESC and AHA/ACCF still recommend the use of opioids. Given the need for adequate pain relief in ischemic chest pain in the emergency setting, it is necessary to understand the adverse effects of analgesia, while still providing sufficiently potent options for analgesia. The primary purpose of this review is to quantify the effects of analgesics commonly used in the prehospital and emergency department in patients with ischemic chest pain.

The Association Between Potential Opioid-Related Adverse Drug Events and Outcomes in Total Knee Arthroplasty: A Retrospective Study

INTRODUCTION

Characterization of the clinical and economic impact of opioid-related adverse drug events (ORADEs) after total knee arthroplasty (TKA) may guide provider and hospital system approach to managing postoperative pain after TKA. Our analysis quantifies the rate of potential ORADEs after TKA, the impact of potential ORADEs on length of stay (LOS) and hospital revenue, as well as their association with specific patient risk factors and comorbid clinical conditions.

METHODS

We conducted a retrospective study using the Centers for Medicare and Medicaid Services administrative database to analyze Medicare discharges involving two knee replacement surgery diagnosis-related groups (DRGs) in order to identify potential ORADEs. The impact of potential ORADEs on mean hospital LOS and hospital revenue was analyzed.

RESULTS

The potential ORADE rate in patients who underwent TKA was 25,523 out of 316,858 records analyzed (8.0%). The mean LOS for patients who experienced a potential ORADE was 1.04 days longer than those without an ORADE. The mean hospital revenue per day with a potential ORADE was $1334 (USD) less than without an ORADE. Potential ORADEs were significantly associated with poor patient outcomes such as pneumonia, septicemia, and shock.

CONCLUSION

Potential ORADEs in TKA are associated with longer hospitalizations, decreased hospital revenue, and poor patient outcomes. Certain risk factors may predispose patients to experiencing an ORADE, and thus perioperative pain management strategies that reduce the frequency of ORADEs particularly in at-risk patients can improve patient satisfaction and increase hospital revenue following TKAs.