Comparison of double (360 mg) ticagrelor loading dose with standard (60 mg) prasugrel loading dose in ST-elevation myocardial infarction patients: the Rapid Activity of Platelet Inhibitor Drugs (RAPID) primary PCI 2 study

Strategies to optimize initial P2Y12 inhibitor therapy in STEMI patients

INTRODUCTION

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is the standard of care for patients who undergo percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI). Though this regimen reduces rates of ischemic events in patients with STEMI, the optimal strategy for P2Y12 administration in STEMI patients is still evolving.

PURPOSE

The purpose of this review is to summarize current evidence on optimal use of ticagrelor and prasugrel in the acute phase of STEMI.

SUMMARY

Due to high platelet activity in the acute setting of STEMI and PCI, adequate and rapid platelet inhibition is important. Strategies of increased ticagrelor/prasugrel loading dose or earlier administration in STEMI have not been successful in closing this platelet inhibition gap. Potential strategies for improving ticagrelor/prasugrel use early in STEMI include bridging with intravenous antiplatelet agents or crushed or chewed administration.

CONCLUSION

Oral ticagrelor/prasugrel given before or immediately after STEMI PCI is usually sufficient to prevent thrombotic complications. When faster platelet inhibition is desired, or oral administration is compromised by inability to swallow tablets, crushing/chewing ticagrelor/prasugrel tablets is an alternative to intravenous P2Y12 inhibitor therapy.

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.

Dual Antiplatelet Therapy with 3rd Generation P2Y12 Inhibitors in STEMI Patients: Impact of Body Mass Index on Loading Dose-Response

PURPOSE

This study aims to assess the association between body mass index (BMI) and platelet reactivity in STEMI patients treated with oral 3rd generation P2Y12 inhibitors.

METHODS

Overall, 429 STEMI patients were enrolled in this study. Patients were divided into two groups according to BMI (BMI < 25 vs ≥ 25 kg/m2). A propensity score matching (1:1) was performed to balance potential confounders in patient baseline characteristics. Platelet reactivity was assessed by VerifyNow at baseline and after 3rd generation P2Y12 inhibitor (ticagrelor or prasugrel) loading dose (LD). Blood samples were obtained at baseline (T0), 1 h (T1), 2 h (T2), 4-6 h (T3), and 8-12 h (T4) after the LD. High on-treatment platelet reactivity (HTPR) was defined as a platelet reactivity unit value ≥ 208 units.

RESULTS

After propensity score matching, patients with BMI ≥ 25 had similar values of baseline platelet reactivity, while they had higher level of platelet reactivity at 1 and 2 h after the LD and higher rate of HRPT. Furthermore, multivariate analysis demonstrated that BMI ≥ 25 was an independent predictor of HTPR at 2 h (OR 2.01, p = .009). Conversely, starting from 4 h after the LD, platelet reactivity values and HRPT rates were comparable among the two study groups.

CONCLUSIONS

A BMI ≥ 25 kg/m2 is associated with delayed pharmacodynamic response to oral 3rd generation P2Y12 inhibitor LD, and it is a strong predictor of HTPR in STEMI patients treated by dual antiplatelet therapy with ticagrelor or prasugrel.

Timing, Selection, Modulation, and Duration of P2Y12 Inhibitors for Patients With Acute Coronary Syndromes Undergoing PCI

Dual antiplatelet therapy with aspirin and the oral P2Y₁₂ inhibitor clopidogrel as the cornerstone of treatment for patients with an acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) was firstly established in 2001. Soon thereafter, the newer-generation P2Y₁₂ inhibitors prasugrel and ticagrelor became commercially available. The clinical management of ACS patients undergoing PCI has evolved significantly in the last 2 decades, with a shift toward more rapid invasive management, broader use of drug-eluting stents, and the increasing recognition that major bleeding due to antiplatelet therapy is detrimental. In this ever-changing scenario, numerous studies have addressed 4 main questions regarding P2Y₁₂ inhibition in ACS patients undergoing PCI: timing, selection, modulation, and duration. This paper reviews the latest evidence surrounding these topical questions, with a focus on efficacy and safety data, practice guidelines, and residual areas of uncertainty.

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.

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.

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.

Pharmacokinetic Modeling of Morphine's Effect on Plasma Concentrations of Ticagrelor and Its Metabolite in Healthy Volunteers

This study aimed to build a mathematical model describing the pharmacokinetics of ticagrelor and its active metabolite (AR-C124910XX) in a stable setting with concomitant administration of morphine. The model consists of a set of four differential equations prepared upon the available knowledge regarding the biological processes in the pharmacokinetics of ticagrelor. The set of equations was solved numerically using the Runge–Kutta method. The data were obtained in a double-blind, randomized, placebo-controlled, crossover trial. Twenty-four healthy volunteers received a 180-mg ticagrelor loading dose together with either 5-mg morphine or placebo. Blood samples were analyzed with liquid chromatography–tandem mass spectrometry to assess plasma concentrations of ticagrelor and AR-C124910XX before ticagrelor loading dose and after that 1, 2, 3, 4, and 6 h. The model allowed us to reproduce the experimental results accurately and led us to conclusions consistent with clinical observations that morphine delays the time of maximum drug concentration and that the morphine effect occurs due to decreased gastrointestinal motility. Based on the model, we were able to predict the effect of drug dose on receptor blocking efficacy.

Predicting 30-day mortality after ST elevation myocardial infarction: Machine learning- based random forest and its external validation using two independent nationwide datasets

BACKGROUND

Various prognostic models for mortality prediction following ST-segment elevation myocardial infarction (STEMI) have been developed over the past two decades. Our group has previously demonstrated that machine learning (ML)-based models can outperform known risk scores for 30-day mortality post-STEMI. The study aimed to redevelop an ML-based random forest prediction model for 30-day mortality post-STEMI and externally validate it on a large cohort.

METHODS

This was a retrospective, supervised learning, data mining study developed on the Acute Coronary Syndrome Israeli Survey (ACSIS) registry and the Myocardial Ischemia National Audit Project (MINAP) for external validation. Patients included received reperfusion therapy for STEMI between 2006 and 2016. Discrimination and calibration performances were assessed for two developed models and compared with the Global Registry of Acute Cardiac Events (GRACE) score.

RESULTS

The ACSIS cohort (2,782 included /15,212 total) and MINAP cohort (22,693 included/735,000 total) were significantly different in most variables, yet similar in 30-day mortality rate (4.3-4.4%). Random forest models were developed on the ACSIS cohort with a full model including all 32 variables and a simple model including the 10 most important ones. Features' importance was calculated using the varImp function measuring how much each feature contributes to the data's homogeneity. Applying the optimized models on the MINAP validation cohort showed high discrimination of area under the curve (AUC) = 0.804 (0.786-0.822) for the full model, and AUC = 0.787 (0.748-0.780) using the simple model, compared with the GRACE risk score discrimination of AUC = 0.764 (0.748-0.780). All models were not well calibrated for the MINAP data. Following Platt scaling on 20% of the MINAP data, the random forest models calibration improved while the GRACE calibration did not change.

CONCLUSIONS

The random forest predictive model for 30-day mortality post STEMI, developed on the ACSIS national registry, has been validated in the MINAP large external cohort and can be applied early at admission for risk stratification. The model performed better than the commonly used GRACE score. Furthermore, to the best of our knowledge, this is the first externally validated ML-based model for STEMI.

Prehospital Adenosine Diphosphate Receptor Blocker Use, Culprit Artery Flow, and Mortality in STEMI: The MADDEC Study

BACKGROUND AND OBJECTIVE

The newer adenosine diphosphate (ADP) receptor blockers ticagrelor and prasugrel are superior to clopidogrel in the long-term management of acute coronary syndrome (ACS). We evaluated the acute performance (prehospital loading) of these ADP receptor blockers in a primary percutaneous coronary intervention (PCI) for an ST-elevation myocardial infarction (STEMI).

METHODS

In a retrospective, single-center registry study, data on all STEMI patients admitted for their first primary PCI between January 2007 and April 2020 were analyzed (n = 3218). The three ADP receptor blockers were mainly used during consecutive periods (clopidogrel 2007-2010, prasugrel 2011-2014, and ticagrelor 2014-2020), and were compared with risk factor-adjusted multivariate logistic regression for acute 3- and 7-day mortality and culprit artery flow before and after PCI.

RESULTS

Of the 3218 total patients, 47.6% (n = 1532) were treated with ticagrelor, 22.1% (n = 711) were treated with prasugrel, and 30.3% (n = 975) were treated with clopidogrel. The use of ticagrelor or prasugrel as opposed to clopidogrel was associated with better culprit artery flow before PCI (odds ratio [OR] 1.21 for moderate or good flow, 95% confidence interval [CI] 1.03-1.42, p = 0.022), as well as lower acute mortality (OR 0.66 for 3-day mortality, 95% CI 0.46-0.95, p = 0.025; and OR 0.71 for 7-day mortality, 95% CI 0.52-0.98, p = 0.039). The results in regard to acute mortality were highlighted among patients with short treatment delays (disappearing with longer treatment delays; p < 0.05 for interaction).

CONCLUSIONS

The newer ADP receptor blockers are associated with lower mortality and better culprit artery flow at presentation when compared with clopidogrel. There are no significant differences between the two newer drugs. As the drugs were mainly used during three consecutive periods, unmeasured confounding related to the development of cardiac care and changes in the population may contribute to the results.

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.

Not-high before-treatment platelet reactivity in patients with STEMI: prevalence, clinical characteristics, response to therapy and outcomes

Platelet reactivity (PR) has been indicated as a pathophysiological key element for ST-Elevation Myocardial Infarction (STEMI) development. Patients with not-high before-treatment platelet reactivity (NHPR) have been poorly studied so far. The aim of this study is to investigate the prevalence, clinical characteristics, response to therapy and outcomes of baseline prior to treatment NHPR among patients with STEMI undergoing primary PCI.We analyzed the data from 358 STEMI patients with assessment of PR by VerifyNow before P2Y₁₂ inhibitor loading dose (LD). Blood samples were obtained at baseline, and after 1 hour, 2 hours, 4-6 hours and 8-12 hours after LD. High platelet reactivity (HPR) was defined as Platelet Reactivity Unit values ≥208, while patients with values <208 at baseline were defined as having NHPR.Overall, 20% patients had NHPR. Age and male gender both resulted independent predictors of NHPR, even after propensity score adjustment. The percentage of inhibition of PR after ticagrelor or prasugrel LD was similar between HPR and NHPR patients at each time point. However, patients with HPR showed worse in-hospital clinical outcomes, and the composite adverse outcome endpoint of death, reinfarction, stroke, acute kidney injury or heart failure was significantly higher (10.0% vs 1.4%; p = .017) as compared with the NHPR group.In conclusion, a significant proportion of patients presenting with STEMI has a baseline NHPR that is associated with better in-hospital outcomes as compared with patients with HPR. Further studies are needed to better elucidate the potential therapeutic implications of NHPR in terms of secondary prevention.

Bridging the gap: Current and future insights for improving suboptimal platelet inhibition in STEMI

Antiplatelet therapy is one of the cornerstones in the acute treatment of patients with ST-elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention (PCI). However, hemodynamic changes and delayed intestinal absorption of P2Y₁₂ inhibitors leads to a delay in the onset of antiplatelet effects resulting in a gap of platelet inhibition. Several strategies have been proposed to bridge this gap, such as pre-hospital administration of antiplatelet therapy, higher loading doses of P2Y₁₂ inhibitors, crushing or chewing tablets, subcutaneous or intravenous administration of platelet inhibitors, or use of pain relievers alternative to opioids that do not delay intestinal absorption of oral platelet inhibitors. These strategies may improve platelet inhibition with the goal of optimizing clinical outcomes in the acute phase of STEMI. In this review we present current and future insights for bridging the gap in platelet inhibition in STEMI patients undergoing primary PCI.

Meta-analysis Comparing Outcomes of Type 2 Myocardial Infarction and Type 1 Myocardial Infarction With a Focus on Dual Antiplatelet Therapy

BACKGROUND

There are important knowledge gaps in type 2 myocardial infarction (T2MI). Our primary objective was to compare the outcomes of patients with T2MI with those of patients with type 1 myocardial infarction (T1MI). Our secondary objective was to determine whether randomized controlled trials (RCTs) evaluating dual antiplatelets (DAPTs) have explicitly included patients with T2MI.

METHODS

We performed a meta-analysis comparing outcomes of patients with T2MI with patients with T1MI and a separate systematic review to evaluate the inclusion of T2MI in RCTs evaluating DAPT. There were 19 cohorts enrolling 48,829 patients (40,604 with T1MI and 5361 with T2MI) and 51 RCTs enrolling 188,132 patients with acute coronary syndrome.

RESULTS

Patients with T2MI had approximately 2-fold increases in unadjusted odds of long-term mortality compared with patients with T1MI (odds ratio, 2.47; 95% confidence interval, 2.06-2.96; P < 0.0001) and a 45% increase in adjusted odds of long-term mortality (odds ratio, 1.45; 95% confidence interval, 1.25-1.69; P < 0.0001, respectively). There was no published evaluation of efficacy, effectiveness, and safety of DAPT in patients with T2MI.

CONCLUSION

Patients with T2MI are at increased risk of adjusted all-cause long-term mortality compared with patients with T1MI. The role of DAPT remains unclear in T2MI.

Impact of Preadmission Morphine on Reinfarction in Patients With ST-Elevation Myocardial Infarction Treated With Percutaneous Coronary Intervention: A Meta-Analysis

Opiates are the traditional analgesics used in patients with ST-elevation myocardial infarction (STEMI). Pharmacodynamic studies indicate that opiates delay the absorption of orally administered P2Y₁₂ inhibitors and the onset of platelet inhibition. Whether these negative effects on platelet inhibition have an impact on clinical outcomes is unclear. A systematic review and meta-analysis was performed searching PubMed, MEDLINE, and Cochrane Central Register of Controlled Trials to identify studies comparing morphine and no-morphine treatment in STEMI patients undergoing primary percutaneous coronary intervention. The primary end point was the occurrence of in-hospital myocardial infarction, and secondary end points were in-hospital stroke and death. Four observational studies were identified, including 3,220 patients with STEMI. Morphine-treated patients had a higher unadjusted rate of reinfarction compared with patients not receiving morphine (1.5% vs. 0.67%, odds ratio (OR) 2.41; 95% confidence interval (CI), 1.11-5.21; P = 0.03). Unadjusted mortality rate was lower in morphine-treated patients (1.7% vs. 4.2%, OR 0.43, 95% CI, 0.23-0.81; P = 0.009). Exclusion of the study with baseline differences between groups showed more frequent reinfarction in the morphine group, but this was no longer statistically significant (1.3% vs. 0.5%, OR 2.02; 95% CI, 0.39-10.43; P = 0.40). There was no difference in stroke according to morphine treatment. Patients pretreated with morphine appear to have a higher rate of reinfarction than patients not receiving morphine. This may be attributable to opiate-related delay in P2Y₁₂ inhibitor absorption and resultant delay in onset of platelet inhibition. These concerning findings indicate the need for prospective, randomized trials to assess the impact of opiates on clinical outcomes in STEMI.

Prasugrel vs. Ticagrelor for Acute Coronary Syndrome Patients Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

BACKGROUND

The newer P2Y₁₂ inhibitors have better efficacy than clopidogrel. However, whether ticagrelor or prasugrel have a better comparative safety and efficacy profile, especially in the long-term, remains inconclusive.

OBJECTIVE

We compared prasugrel and ticagrelor in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

METHODS

MEDLINE and the Cochrane library were queried for randomized controlled trials (RCTs) or observational studies comparing prasugrel with ticagrelor in patients with ACS undergoing PCI. Random-effects pooling was used to calculate odds ratios (ORs) with 95% confidence intervals (CI). Analyses were stratified by duration of follow-up (short term [≤ 3 months] and long term [≥ 1 year]) and study design.

RESULTS

In total, 14 studies (six RCTs, eight observational studies), including 40,188 patients, met eligibility criteria. Pooled analysis did not indicate that prasugrel significantly decreased all-cause mortality compared with ticagrelor in the short term (OR 0.49; 95% CI 0.20-1.20; p = 0.11) or long term (OR 0.74; 95% CI 0.48-1.15; p = 0.38). Pooled observational studies showed significantly lower long-term all-cause mortality (OR 0.63; 95% CI 0.43-0.92; p = 0.02) and short-term stent thrombosis (OR 0.46; 95% CI 0.28-0.75; p = 0.002) with prasugrel. No significant difference was observed in the risk of nonfatal myocardial infarction, ischemic stroke, bleeding, or repeat revascularization between the two groups. Results remained similar after stratification according to follow-up and study design.

CONCLUSIONS

The present analysis suggests that prasugrel might have a better efficacy profile than ticagrelor in patients with ACS undergoing PCI. However, this advantage was only seen in pooled observational studies and is likely to be affected by selection bias.

Machine learning for prediction of 30-day mortality after ST elevation myocardial infraction: An Acute Coronary Syndrome Israeli Survey data mining study

BACKGROUND

Risk scores for prediction of mortality 30-days following a ST-segment elevation myocardial infarction (STEMI) have been developed using a conventional statistical approach.

OBJECTIVE

To evaluate an array of machine learning (ML) algorithms for prediction of mortality at 30-days in STEMI patients and to compare these to the conventional validated risk scores.

METHODS

This was a retrospective, supervised learning, data mining study. Out of a cohort of 13,422 patients from the Acute Coronary Syndrome Israeli Survey (ACSIS) registry, 2782 patients fulfilled inclusion criteria and 54 variables were considered. Prediction models for overall mortality 30days after STEMI were developed using 6 ML algorithms. Models were compared to each other and to the Global Registry of Acute Coronary Events (GRACE) and Thrombolysis In Myocardial Infarction (TIMI) scores.

RESULTS

Depending on the algorithm, using all available variables, prediction models' performance measured in an area under the receiver operating characteristic curve (AUC) ranged from 0.64 to 0.91. The best models performed similarly to the Global Registry of Acute Coronary Events (GRACE) score (0.87 SD 0.06) and outperformed the Thrombolysis In Myocardial Infarction (TIMI) score (0.82 SD 0.06, p<0.05). Performance of most algorithms plateaued when introduced with 15 variables. Among the top predictors were creatinine, Killip class on admission, blood pressure, glucose level, and age.

CONCLUSIONS

We present a data mining approach for prediction of mortality post-ST-segment elevation myocardial infarction. The algorithms selected showed competence in prediction across an increasing number of variables. ML may be used for outcome prediction in complex cardiology settings.

Comparison of the effects of P2Y12 receptor antagonists on platelet function and clinical outcomes in patients undergoing Primary PCI: A substudy of the HEAT-PPCI trial

AIMS

The HEAT-PPCI trial compared bivalirudin and unfractionated heparin in patients undergoing primary percutaneous coronary intervention (PPCI). The aim of this study was to report pre-specified, secondary analyses comparing the effects of P2Y12 inhibiting agents on platelet reactivity and clinical events.

METHODS AND RESULTS

All patients received preprocedural oral antiplatelet therapy. During the early stages of the trial, the P2Y12 inhibitor of choice was prasugrel with some use of clopidogrel. Later, routine therapy switched to ticagrelor. For cases performed during working hours, multiple electrode aggregometry (MEA) was used to assess ADP-induced platelet aggregation at the end of the index procedure. The effect of P2Y12 inhibitors on the primary efficacy (major adverse cardiac events [MACE]) and safety (major bleeding) outcomes was assessed in all patients. Multiple logistic regression was used to adjust for differences in baseline characteristics. With MEA data from 469 patients, prasugrel therapy resulted in significantly greater suppression of ADP-induced platelet aggregation at 40 U (23, 78) (median; interquartile range [IQR]) when compared against ticagrelor 75 U (41, 100.75); p<0.001 or clopidogrel 79 U (56, 96); p<0.001. In the entire study population (N=1,803), prasugrel therapy was associated with significantly fewer MACE (26/497; 5.2%) in comparison to ticagrelor (83/1,123; 7.4%) or clopidogrel (18/183; 9.8%); odds ratio (OR) 0.64, confidence interval (CI): 0.41-0.99, p=0.045. For major bleeding, there were no significant differences among the three groups - clopidogrel (3/183; 1.6%), prasugrel (13/497; 2.6%) and ticagrelor (43/1,123; 3.8%); OR 0.73, CI: 0.39-1.35, p=0.31. Patients treated with clopidogrel had more high-risk features and clopidogrel use was more common as an alternative to prasugrel. After adjustment, there were no significant differences in the rates of MACE (OR 0.70, CI: 0.41-1.21, p=0.20) or major bleeding (OR 0.80, CI: 0.41-1.60, p=0.53).

CONCLUSIONS

In HEAT-PPCI, patients who received prasugrel (rather than clopidogrel or ticagrelor) had significantly greater suppression of ADP-induced platelet aggregation at the end of the procedure. After adjustment for differences in baseline characteristics, there were no significant differences in ischaemic or bleeding outcomes among the antiplatelet therapies.

Crushed sublingual versus oral ticagrelor administration strategies in patients with unstable angina

Oral administration of crushed ticagrelor tablets turned out to be an efficacious method that improves its pharmacokinetics and pharmacodynamics. This strategy, however, is unlikely to eliminate the drug-drug interaction in patients receiving intravenous morphine, as the impairment of the P2Y12 inhibitor absorption related to decreased propulsive motility of the gastro-intestinal tract is the most likely mechanism of interaction. Thus, we designed a pharmacokinetic and pharmacodynamic study setting the feasibility of platelet inhibition with a loading dose of ticagrelor given as crushed tablets sublingually compared with two other ticagrelor loading dose administration strategies: integral tablet given orally and crushed tablet given orally in patients with unstable angina. Ticagrelor and its metabolite AR-C124900XX plasma concentration was evaluated in nine time points (time frame of 6 hours) using liquid chromatography coupled with mass spectrometry; platelet reactivity was evaluated using multiple electrode aggregometry. The area under the plasma concentration-time curve for ticagrelor and AR-C124900XX was significantly higher in patients treated with crushed tablets given orally compared with crushed tablets given sublingually only within the first hour after loading dose (936.9 ± 898.0 vs 368.0 ± 422.4, p=0.042 and 103.4 ± 120.8 vs 31.3 ± 43.9, p=0.031, respectively). Moreover, we showed significantly stronger platelet inhibition in patients receiving crushed ticagrelor orally vs. sublingually at 30 and 45 min after the loading dose (p=0.024 and p=0.016, respectively). Therefore, the administration strategy of ticagrelor determines the pharmacokinetic and pharmacodynamic profile of both ticagrelor and its active metabolite AR-C124900XX.

Bivalirudin for acute coronary syndromes: premises, promises and doubts

Bivalirudin is a valuable anticoagulant option in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention. Advantages over heparin as a parenteral anticoagulant include more predictable pharmacokinetics and pharmacodynamics, shorter half-life, no need for cofactors, some degree of antiplatelet effect, and the ability to inhibit clot-bound thrombin. Clinical evidence supporting the use of bivalirudin over heparin in current ACS guidelines, however, derives mostly from early randomised trials that may no longer reflect current management patterns, now including the use of oral antiplatelet agents more potent than clopidogrel (i.e. prasugrel or ticagrelor) and a broader implementation of strategies to reduce bleeding (i.e. radial access for percutaneous coronary intervention, and use of glycoprotein IIb/IIIa inhibitors only in bailout situations). Defining the fine balance between bivalirudin efficacy and safety over heparins in the context of other antithrombotic treatments remains a challenge in clinical practice, particularly in a fast-evolving scenario, such as ACS, where numerous new trials have been presented in very recent times. Here we provide an up-to-date overview of the evidence on the use of bivalirudin in ACS, with focus on new data, open issues, and future directions.

P2Y12 Receptor Antagonists and Morphine: A Dangerous Liaison?

P2Y12 receptor antagonists, concurrently administered with aspirin in what has come to be commonly called dual antiplatelet therapy, are a mainstay of treatment for patients with acute coronary syndromes. Morphine, on the contrary, is a commonly used drug in the acute phase of acute coronary syndromes to relieve pain-with the added potential benefit of attenuating acutely raised sympathetic tone. In current guidelines, though, morphine is recommended with decreasing strength of recommendation. One reason is that it raises concern regarding the potentially significant interaction with antiplatelet agents, leading to impaired inhibition of platelet activation. In any case, it is still considered a mandatory part of the inventory of available medications in prehospital acute myocardial infarction management. The goal of the present review is to present published evidence on morphine and its potential interactions with P2Y12 receptor antagonists, as well as on the central issue of whether such interactions may underlie clinically significant effects on patient outcomes.

Intracoronary high-dose bolus tirofiban administration during complex coronary interventions: A United States-based case series

The GP IIb/IIIa inhibitors (GPIs) rapidly provide therapeutic levels of platelet aggregation inhibition and serve as adjunct pharmacotherapy to oral P2Y12 inhibitors that exhibit a significant delay in onset of action for patients with Acute Coronary Syndrome (ACS). Intracoronary (IC) administration of the high dose bolus (HDB) tirofiban has not been extensively studied. Compared to intravenous delivery, IC administration can lead to higher local drug concentration and, therefore, provide instantaneous disruption of platelet aggregation in the culprit vessel. This report describes the successful resolution of thrombus using IC HDB tirofiban in 7 high-risk coronary interventions with complications such as recurrent thrombosis and cardiogenic shock in ACS patients. This report represents the first case series of IC HDB tirofiban performed in North America and suggests that IC HDB tirofiban may represent an effective and safe strategy to achieve rapid thrombus resolution in ACS patients.

Pretreatment with Antiplatelet Agents in the Setting of Percutaneous Coronary Intervention: When and Which Drugs?

Administering antiplatelet agents before coronary angiography to patients referred to elective or urgent percutaneous coronary intervention (PCI) requires a careful evaluation of advantages and disadvantages associated with platelet inhibition to avoid overtreatment on one side and undertreatment on the other. The delicate balance between ischemic protection and bleeding demands the ability to undertake risk stratification and individualized decisions, which is particularly challenging in the setting of ad hoc PCI and urgent procedures. This review analyzes the current evidence on pretreatment with oral and intravenous P2Y₁₂ inhibitors in patients undergoing coronary angiography with intent to undergo PCI.

Crushed Versus Integral Tablets of Ticagrelor in ST-Segment Elevation Myocardial Infarction Patients: A Randomized Pharmacokinetic/Pharmacodynamic Study

OBJECTIVE

The objective of this study was to assess the pharmacokinetic and pharmacodynamic behavior of ticagrelor administered either as crushed (in the semi-upright sitting position) or as integral (in the supine position) tablets in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI).

METHODS

We randomized 20 patients to ticagrelor 180 mg either as 2 integral tablets administered in the supine position (standard administration) or as 2 tablets crushed and dispersed, administered in the semi-upright sitting position. Blood samples were drawn for pharmacokinetic and pharmacodynamic assessment at randomization (0 h) and at 0.5, 1, 2, and 4 h.

RESULTS

At 1 h, ticagrelor plasma exposure and area under the plasma concentration-time curve from time zero to 1 h (AUC1) (co-primary endpoints) were higher in the crushed versus integral tablets group (median 586 vs. 70.1 ng/mL and 234 vs. 24.4 ng·h/mL, respectively), with a ratio of adjusted geometric means (95% confidence interval [CI]) of 12.67 (2.34-68.51) [p = 0.005] and 19.28 (3.51-106.06) [p = 0.002], respectively. Time to maximum plasma concentration was shorter in the crushed versus integral tablets group (median 2 vs. 4 h), with a ratio of adjusted geometric means (95% CI) of 0.69 (0.49-0.97) [p = 0.035]. Parallel findings were observed with AR-C124910XX (active metabolite). Platelet reactivity (VerifyNow(®)) at 1 h was lower with crushed versus standard administration with least squares estimates mean difference (95% CI) of 92 (-158.4 to 26.6) P2Y12 reaction units (p = 0.009).

CONCLUSIONS

In patients with STEMI undergoing primary PCI, ticagrelor crushed tablets administered in the semi-upright sitting position seems to lead to a faster-compared with standard administration-absorption, with stronger antiplatelet activity within the first hour.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02046486.

New directions for pharmacotherapy in the treatment of acute coronary syndrome

INTRODUCTION

Acute coronary syndromes (ACS) are one of the leading causes of death worldwide. Several landmark trials, followed by a widespread introduction of new agents, have significantly improved ACS outcomes in recent years. However, despite the use of contemporary therapy, a substantial number of ACS patients continue to suffer from cardiovascular events. Areas covered: The aim of this review was to summarize available data on innovative drugs and pharmacological strategies that have potential to amend the current ACS therapy. We present the results of recent large clinical trials, as well as insights from ongoing phase III and phase IV studies, exploring the value of new strategies for the improvement of outcomes in ACS. Expert opinion: More potent platelet inhibition, more profound lipid reduction and possibly anti-inflammatory action are considered to have potential to further reduce the rates of adverse cardiovascular and thrombotic events in ACS patients. 'Hit fast, hit hard' approach regarding novel antiplatelet and lipid-lowering therapy seems attractive, but it has to be considered that these strategies may be associated with increased adverse events rate. Introduction of cangrelor and ezetimibe, and potentially future recognition of proprotein convertase subtilisin/kexin type 9 antibodies, are likely to alter the landscape of ACS pharmacotherapy.

Impact of Escalating Loading Dose Regimens of Ticagrelor in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: Results of a Prospective Randomized Pharmacokinetic and Pharmacodynamic Investigation

OBJECTIVES

The goal of this study was to assess the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of escalating ticagrelor loading dose (LD) regimens in primary percutaneous coronary intervention (PPCI).

BACKGROUND

Patients with ST-segment elevation myocardial infarction undergoing PPCI frequently have suboptimal platelet inhibition in the early hours after ticagrelor LD. The use of high ticagrelor LD regimens has been hypothesized to optimize platelet inhibition in PPCI.

METHODS

This was a prospective, randomized study of escalating ticagrelor LD regimens (180 mg, 270 mg, or 360 mg) in PPCI (N = 52). PK/PD analyses were performed before and 30 min, 1, 2, 4, 8, and 24 h post-LD. PK assessments included exposure to ticagrelor and its metabolite (AR-C124910XX). PD assessments included P2Y12 reaction units (PRU) measured by VerifyNow P2Y12 and platelet reactivity index (PRI) measured by vasodilator-stimulated phosphoprotein (VASP).

RESULTS

Platelet reactivity was elevated during the first 2 h post-LD. There were no differences in PRU between groups during the study time course (p = 0.179). There were no significant differences in PRU levels across groups at all time points, except at 1 h (p = 0.017) where platelet reactivity was lowest with a 270-mg LD. No differences were found between the 180-mg and 360-mg groups (primary endpoint; p > 0.999). High on-treatment platelet reactivity rates were not different across groups, except at 1 hour (p = 0.038). Parallel PD findings were observed with VASP-PRI. PK analysis showed a delay in ticagrelor absorption and generation of AR-C124910XX, irrespective of dose. Although morphine was associated with a delay in ticagrelor PK/PD, it was not an independent predictor of high on-treatment platelet reactivity.

CONCLUSIONS

ST-segment elevation myocardial infarction patients undergoing PPCI frequently exhibit impaired response to ticagrelor in the early hours after drug administration, which cannot be overcome by increasing LD regimens. These PD findings are largely attributed to an impaired PK profile, indicating a delay in drug absorption compared with that reported in stable clinical settings. (High Ticagrelor Loading Dose in STEMI; NCT01898442).

Reviewing the controversy surrounding pre-treatment with P2Y12 inhibitors in acute coronary syndrome patients

Pretreatment with oral P2Y12 inhibitors occurs each time clopidogrel, prasugrel, ticagrelor are given to patients with suspected coronary artery disease before definition of the coronary anatomy. In acute coronary syndromes, the practice of administering oral P2Y12 inhibitors upstream has been the object of significant controversy in recent years, following the publication of two trials of pretreatment in non-ST-segment elevation acute coronary syndromes and ST-segment elevation myocardial infarction, respectively. The introduction in the market of cangrelor - the first intravenous P2Y12 inhibitor - represents a new opportunity but also a new challenge for clinicians. This article reviews current recommendations and supporting evidence surrounding pretreatment with oral and intravenous P2Y12 inhibitors in patients with acute coronary syndromes.

Crushed Prasugrel Tablets in Patients With STEMI Undergoing Primary Percutaneous Coronary Intervention: The CRUSH Study

BACKGROUND

Platelet inhibitory effects induced by oral P2Y12 receptor antagonists are delayed in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI), which may be attributed to impaired absorption affecting drug pharmacokinetics (PK) and pharmacodynamics (PD). Crushing tablets has been suggested to lead to more favorable PK/PD profiles. To date, no studies have investigated the PK/PD effects of crushing prasugrel.

OBJECTIVES

This study sought to determine whether crushing prasugrel is associated with more favorable drug bioavailability and platelet inhibitory effects compared with whole tablets in STEMI patients undergoing PPCI.

METHODS

Our prospective, randomized, open-label study assessed STEMI patients undergoing PPCI (n = 52) who were treated with a prasugrel 60-mg loading dose (LD) either as whole or crushed tablets. PK/PD analyses were performed at 7 time points. PD effects were measured as P2Y12 reaction units and platelet reactivity index, and PK by plasma levels of prasugrel's active metabolite.

RESULTS

Compared with whole tablets, crushed prasugrel led to reduced P2Y12 reaction units by 30 min post-LD, which persisted at 1, 2 (164 vs. 95; least square mean difference = 68; 95% confidence interval: 10 to 126; primary endpoint), and 4 h post-LD. Significant differences were no longer present at 6 h post-LD. Parallel findings were shown with platelet reactivity index. Accordingly, high on-treatment platelet reactivity rates were reduced with crushed prasugrel. PK analyses showed a >3-fold faster absorption with crushed compared with whole prasugrel.

CONCLUSIONS

In STEMI patients undergoing PPCI, crushed prasugrel leads to faster drug absorption, and consequently, more prompt and potent antiplatelet effects compared with whole tablet ingestion. (Pharmacological Effects of Crushing Prasugrel in STEMI Patients; NCT02212028).

Post-Procedural Bivalirudin Infusion Following Primary PCI to Reduce Stent Thrombosis

BACKGROUND

Prolonging infusions may abrogate the acute stent thrombosis (ST) associated with bivalirudin use during primary PCI but at an increased cost. We hypothesized that continuing the bivalirudin infusion commenced during the procedure at the PCI recommended dose until infusion end would prevent excess early ST.

METHODS

Baseline demographics, procedural data and outcomes were gathered prospectively on 1395 consecutive patients undergoing primary PCI. The choice of bivalirudin versus heparin was at the cardiologist's discretion. Local protocol recommended continuation of the procedural bivalirudin at the PCI dose until infusion end.

RESULTS

Patients' mean age was 62.8 ± 13.1years with 11.4% presenting with shock. The majority of patients underwent PCI using bivalirudin with fewer using heparin (87.7 vs. 12.3%, P < 0.0001). Glycoprotein inhibitor bailout rates were 6.1% with bivalirudin and 36.3% with heparin (P < 0.0001). Calculated on an individual patient basis the median intra-procedure duration of the bivalirudin infusion was 30(IQR 21-43) minutes and post-procedure 49(32-66) minutes. The acute (<24-hours) ST rates were 4/1224 with bivalirudin ± GPI (0.3%) and 0/171 with heparin ± GPI (0%, P = 0.41). The sub-acute (24-hours to 30-days) ST rates were 3/1224 for bivalirudin ± GPI (0.3%) and 2/171 with heparin ± GPI (1.2%, P = 0.11). In total the early (<30-days) ST rates were 7/1224 for bivalirudin ± GPI (0.6%) and 2/171 with heparin ± GPI (1.2%, P = 0.31). Acute ST was significantly more likely to occur in clopidogrel-loaded patients than prasugrel/ticagrelor patients (2.7 vs. 0.5%, P = 0.003).

CONCLUSION

Continuing the bivalirudin infusion commenced during the procedure at the PCI recommended dose until infusion end combined with potent P2 Y12 inhibitors ameliorates excess early stent thrombosis.

Morphine delays and attenuates ticagrelor exposure and action in patients with myocardial infarction: the randomized, double-blind, placebo-controlled IMPRESSION trial

AIMS

The currently available data indicate a drug-drug interaction between morphine and oral P2Y12 receptor inhibitors, when administered together. The aim of this trial was to assess the influence of infused morphine on pharmacokinetics and pharmacodynamics of ticagrelor and its active metabolite (AR-C124910XX) in patients with acute myocardial infarction.

METHODS AND RESULTS

In a single-centre, randomized, double-blind trial, patients were assigned in a 1:1 ratio to receive intravenously either morphine (5 mg) or placebo, followed by a 180 mg loading dose of ticagrelor. Pharmacokinetics was determined with liquid chromatography tandem mass spectrometry and ticagrelor antiplatelet effects were measured with up to three different platelet function tests: vasodilator-stimulated phosphoprotein phosphorylation assay, multiple electrode aggregometry and VerifyNow. The pharmacokinetic and pharmacodynamic assessment was performed in 70 patients (35 in each study group). Morphine lowered the total exposure to ticagrelor and its active metabolite by 36% (AUC(0-12): 6307 vs. 9791 ng h/mL; P = 0.003), and 37% (AUC(0-12): 1503 vs. 2388 ng h/mL; P = 0.008), respectively, with a concomitant delay in maximal plasma concentration of ticagrelor (4 vs. 2 h; P = 0.004). Multiple regression analysis showed that lower AUC(0-12) values for ticagrelor were independently associated with the administration of morphine (P = 0.004) and the presence of ST-segment elevation myocardial infarction (P = 0.014). All three methods of platelet reactivity assessment showed a stronger antiplatelet effect in the placebo group and a greater prevalence of high platelet reactivity in patients receiving morphine.

CONCLUSIONS

Morphine delays and attenuates ticagrelor exposure and action in patients with myocardial infarction. ClinicalTrials.gov Identifier: NCT02217878.

Early P2Y12 inhibition in ST-segment elevation myocardial infarction: Bridging the gap

Rapid and consistent platelet inhibition represents the cornerstone of pharmacologic treatment in the early hours of ST-segment elevation myocardial infarction (STEMI). Oral P2Y12 inhibitors are recommended to be administered as early as possible in patients with STEMI undergoing primary percutaneous coronary intervention. However, a delay in the onset of antiplatelet agent effects has been recently described in the first several hours after oral administration of clopidogrel, prasugrel, and ticagrelor. As a result, primary percutaneous coronary intervention is performed in most cases with P2Y12 inhibition that may be inadequate. Several strategies may be applied in order to "bridge the gap" in platelet inhibition after oral P2Y12 inhibitors in STEMI, such as upstream administration of P2Y12 inhibitors, loading dose modification, use of an intravenous P2Y12 inhibitor, or glycoprotein IIb/IIIa inhibitors' administration. These strategies may further improve clinical outcomes in this high-risk "golden window."

Comparison of Prasugrel and Ticagrelor Antiplatelet Effects in Korean Patients Presenting With ST-Segment Elevation Myocardial Infarction

BACKGROUND

There is insufficient data on the efficacy of prasugrel and ticagrelor in Korean patients with ST-segment elevation myocardial infarction (STEMI).

METHODS AND RESULTS

I n the current double-blind, prospective pilot study, 39 patients with STEMI undergoing primary percutaneous coronary intervention were randomized to receive prasugrel 60 mg loading dose (LD) followed by 10 mg daily maintenance dose (n=19), or ticagrelor 180 mg LD followed by 90 mg twice daily maintenance dose (n=20). We assessed platelet reactivity with the VerifyNow and Vasodilator-Stimulated Phosphoprotein (VASP) P2Y12 assays. Compared to baseline platelet reactivity, both prasugrel and ticagrelor groups achieved similar and significantly lower P2Y12 reaction units (PRU) (259 [IQR: 230 to 281] vs. 28 [12 to 55] for prasugrel; 261 [196 to 286] vs. 43 [11 to 61] for ticagrelor), and platelet reactivity indexes (PRI) (51.2% [39.3 to 61.3] vs. 8.1% [6.1 to 14.7] for prasugrel; 47.5% [38.4 to 50.4] vs. 11.2% [7.1 to 15.5] for ticagrelor, all P values <0.001) at 48 h post-LD. Most patients had low platelet reactivity with 95% PRU values <85 and 82% with PRI <16%.

CONCLUSIONS

Both prasugrel and ticagrelor were effective for platelet inhibition in Korean STEMI patients with almost no patients exhibiting high platelet reactivity at 48 h after the LD. Our finding of a high number of patients with very low platelet reactivity deserves further studies to assess the safety of the drugs (Prasugrel and Ticagrelor in ST-segment Elevation Myocardial Infarction Study, NCT02075125).

Editor's Choice-Chest pain relief in patients with acute myocardial infarction

Chest pain is the prevalent symptom at presentation in patients with acute myocardial infarction (AMI). Despite the complete absence of rigorous studies designed to assess the impact of morphine administration in patients with AMI, clinical practice guidelines strongly recommend morphine for analgesia. However, when using morphine to relieve chest pain in AMI patients, physicians must be aware that hypotension, respiratory depression, vomiting, and delayed onset of action of antiplatelet agents are potential unwanted side effects of the drug. The purpose of this report is to review morphine's clinical and side effects and to propose strategies able to reduce chest pain in AMI patients.

Morphine Is Associated With a Delayed Activity of Oral Antiplatelet Agents in Patients With ST-Elevation Acute Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background—

Morphine is recommended in patients with ST-segment–elevation myocardial infarction, including those undergoing primary percutaneous coronary intervention. Suboptimal antiplatelet effect during and after primary percutaneous coronary intervention is associated with increased thrombotic complications. It was hypothesized a potential drug–drug interaction between morphine and antiplatelet agents. We sought to assess platelet inhibition after a loading dose of the currently recommended antiplatelet agents in ST-segment–elevation myocardial infarction patients according to morphine use.

Methods and Results—

Three hundred patients undergoing primary percutaneous coronary intervention receiving either prasugrel (n=95) or ticagrelor (n=205) loading dose had platelet reactivity assessed by VerifyNow 1, 2, and 4 hours after loading dose. Patients treated with morphine (n=95; 32%) had a higher incidence of vomit (15% versus 2%; P =0.001). P2Y 12 reactivity units 2 hours after the loading dose was 187 (153–221) and 133 (102–165) in patient with and without morphine ( P <0.001); the difference persisted after excluding patients with vomit ( P <0.0001). High residual platelet reactivity (P2Y 12 reactivity units ≥208) at 2 hours was found in 53% and 29% patients with and without morphine ( P <0.001) and without difference between prasugrel and ticagrelor patients. The independent predictors of high residual platelet reactivity at 2 hours were morphine use (odds ratio, 2.91 [1.71–4.97]; P <0.0001) and age (odds ratio, 1.03 [1.01–1.05]; P =0.010). Morphine remained associated with high residual platelet reactivity after propensity score adjustment (c-statistic, 0.68; 95% confidence interval, 0.66–0.70; P =0.879 for Hosmer–Lemeshow test).

Conclusions—

In patients with ST-segment–elevation myocardial infarction, morphine use is associated with a delayed onset of action of the oral antiplatelet agents. This association persisted after adjusting for the propensity to receive morphine and after excluding patients with vomit.