Safety and Effectiveness of Field Nitroglycerin in Patients with Suspected ST Elevation Myocardial Infarction

2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes" incorporates new evidence since the "2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction" and the corresponding "2014 AHA/ACC Guideline for the Management of Patients With Non-ST-Elevation Acute Coronary Syndromes" and the "2015 ACC/AHA/SCAI Focused Update on Primary Percutaneous Coronary Intervention for Patients With ST-Elevation Myocardial Infarction." The "2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes" and the "2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization" retire and replace, respectively, the "2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients With Coronary Artery Disease."

METHODS

A comprehensive literature search was conducted from July 2023 to April 2024. Clinical studies, systematic reviews and meta-analyses, and other evidence conducted on human participants were identified that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Many recommendations from previously published guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes" incorporates new evidence since the "2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction" and the corresponding "2014 AHA/ACC Guideline for the Management of Patients With Non-ST-Elevation Acute Coronary Syndromes" and the "2015 ACC/AHA/SCAI Focused Update on Primary Percutaneous Coronary Intervention for Patients With ST-Elevation Myocardial Infarction." The "2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes" and the "2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization" retire and replace, respectively, the "2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients With Coronary Artery Disease."

METHODS

A comprehensive literature search was conducted from July 2023 to April 2024. Clinical studies, systematic reviews and meta-analyses, and other evidence conducted on human participants were identified that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Many recommendations from previously published guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

[Sublingual and buccal drug administration in medical emergencies]

Drug administration is crucial to achieve effective therapeutic drug outcomes. In medical emergencies, it is particularly convenient to use drugs that could be administered as an alternative to traditional routes (as oral or intravenous routes), that are not always suitable in these situations. Thus, sublingual and buccal routes offer an alternative to traditional routes, when a rapid onset of action is required. The main objective of this narrative review is to summarize the evidence for the use of sublingual and buccal drug administration in medical emergencies. The evidence obtained has been divided into four common scenarios found in the emergency department and intensive care units: cardiovascular emergencies, acute pain, agitation, and epileptic status. Moreover, the main advantages and disadvantages of sublingual and buccal routes are presented, as the future perspectives in the drug delivery field to overcome the limitations of these routes.

Integration of transcriptomics and metabolomics reveals toxicological mechanisms of ZhuRiHeng drop pill in the 180-day repeated oral toxicity study

Background: ZhuRiHeng Drop Pill (ZRH) is a traditional Mongolian medicinal preparation. Despite its long history of use for the treatment of coronary heart disease, there have been few toxicological studies of the safety profile of ZRH. Purpose: In order to comprehensively elucidate the underlying mechanisms behind the observed toxicity of ZRH on rat livers in the 180-day repeated oral toxicity study, we conducted a comprehensive analysis by integrating transcriptomic and metabolomic data. Methods: High-resolution mass spectrometry was conducted to evaluate the constituents of ZRH. For the acute oral toxicity study, mice were administered a dose of 32 g/(kg·d) of ZRH, while rats were instead orally administered 0.934, 1.868, or 3.736 g/(kg·d) of ZRH over a 180-day period in a 180-day repeated oral toxicity study. Conventional index and organ weights/histology were then monitored to detect any potential ZRH treatment-related toxicity. To identify key genes and metabolites involved in ZRH toxicological processes, we performed transcriptomic and metabolomic analyses of liver tissue upon ZRH treatment using RNA-seq techniques, qPCR and liquid chromatography-mass spectrometry analyses. Results: A total of 60 compounds in ZRH were identified and speculated in positive and negative ion modes. Mice in the acute toxicity study exhibited no signs of ZRH-related toxicity. In a protracted oral toxicity investigation spanning 180 days, discernible elevations in liver ratios were noted in both male and female rats across all three dose cohorts, relative to the control group (p < 0.05 or p < 0.01). Upon subjecting to ZRH treatment, our transcriptomic and qPCR analyses unveiled notable upregulation of crucial genes, exemplified by Abcb1b and Cyp2b2, known for theirs involvement in liver drug transport and metabolism function. Furthermore, our untargeted metabolomic analysis provided supplementary insights, revealing significant regulation in pyrimidine metabolism, as well as alanine, aspartate, and glutamate metabolism pathways. Conclusion: Our study unveils a panoramic understanding of the temporal, dosage-specific, and gene dimensions surrounding the metabolic and transcriptional shifts induced by ZRH exposure. As we peer into the future, recommendations emerge for further exploration, encompassing aspects such as time dynamics, dosage considerations, and gene-centric avenues to enhance therapeutic efficacy.

Safety of prehospital intravenous bolus dose nitroglycerin in patients with acute pulmonary edema: A 4-year review

Background

Intravenous nitrates are a primary therapy for hypertensive congestive heart failure (CHF) with acute pulmonary edema (APE) in the hospital setting. Historically, sublingual nitrates are the mainstay of emergency medical services (EMS) pharmacologic therapy for these patients. We aimed to evaluate the safety of prehospital bolus dose intravenous nitroglycerin in patients with APE.

Methods

This is a retrospective evaluation of EMS data between March 15, 2018, and March 15, 2022, where CHF with APE was suspected and bolus-dose intravenous nitroglycerin was administered. Protocol inclusion criteria were hypertension (systolic blood pressure [SBP] >160 mmHg) and acute respiratory distress, with a presumption of decompensated CHF with APE. These patients received 1 mg intravenous nitroglycerin, with the option to repeat once for ongoing distress if the SBP remained >160 mmHg. The primary outcomes were adverse events, defined as hypotension (SBP <90 mmHg), syncope, vomiting, or dysrhythmia.

Results

The final analysis included 235 patients. In patients receiving intravenous bolus nitroglycerin, the median (interquartile range [IQR]) initial and final EMS SBP values decreased from 198 mmHg (180-218) to 168 (148-187), respectively. The median (IQR) pulse decreased from 108 (92-125) to 103 (86-119), and the median oxygen saturation increased from 89% (82-95) to 98% (96-99). Three episodes (1.3%) of asymptomatic hypotension occurred, and none required intervention.

Conclusion

This study supports a favorable safety profile for prehospital bolus-dose intravenous nitroglycerin for decompensated CHF with APE. Blood pressure, heart rate, and oxygen saturation improvements are also demonstrated. Further, prospective studies are needed to confirm these findings.

Arterial Glyceryl Trinitrate in Acute Ischemic Stroke After Thrombectomy for Neuroprotection (AGAIN): A Pilot Randomized Controlled Trial

Although endovascular therapy demonstrates robust clinical efficacy in acute ischemic stroke (AIS), not all stroke patients benefit from successful reperfusion. This study aimed to evaluate the safety, feasibility, and preliminary efficacy of intra-arterial administration of glyceryl trinitrate (GTN) after endovascular recanalization for neuroprotection. This is a prospective randomized controlled study. Eligible patients were randomized to receive 800 μg GTN or the same volume of normal saline through the catheter after recanalization. The primary outcome was symptomatic intracranial hemorrhage (ICH), while secondary outcomes included mortality, functional outcome, infarction volume, complications, and blood nitrate index (NOx). A total of 40 patients were enrolled and randomized with no participants being lost to follow-up. There was no significant difference in the proportion of sICH between GTN and control groups. Additionally, no significant difference was observed in mortality or rates of neurological deterioration and other complications. Favorable trends, while non-significant, were noted in both outcome and imaging for functional independence at 90 days and reduction in final infarct volume (75.0% vs 65.0%; 33.2 vs 38.9 ml) for the GTN group. Moreover, the concentration of blood NOx in the GTN group was significantly higher than in the control group at 2 h after GTN administration (26.2 vs 18.0 μmol/l, p < 0.05). The AGAIN study suggests intra-arterial administration of GTN post-endovascular therapy is safe and feasible and GTN successfully raised NOx levels over controls at 2 h. A multi-center randomized controlled trial with a larger sample size is warranted to determine GTN neoadjuvant efficacy.

Adverse events from nitrate administration during right ventricular myocardial infarction: a systematic review and meta-analysis

BACKGROUND

The current guidelines of the American Heart Association (AHA) and European Society of Cardiology (ESC) recommend that when right ventricular myocardial infarction (RVMI) is present patients are not administered nitrates, due to the risk that decreasing preload in the setting of already compromised right ventricular ejection fraction may reduce cardiac output and precipitate hypotension. The cohort study (n=40) underlying this recommendation was recently challenged by new studies suitable for meta-analysis (cumulatively, n=1050), suggesting that this topic merits systematic review.

METHODS

The protocol was registered on PROSPERO and published in Evidence Synthesis. Six databases were systematically searched in May 2022: PubMed, Embase, MEDLINE Complete, Cochrane CENTRAL Register, CINAHL and Google Scholar. Two investigators independently assessed for quality and bias and extracted data using Joanna Briggs Institute tools and methods. Risk ratios and 95% CIs were calculated, and meta-analysis performed using the random effects inverse variance method.

RESULTS

Five studies (n=1113) were suitable. Outcomes included haemodynamics, GCS, syncope, arrest and death. Arrest and death did not occur in the RVMI group. Meta-analysis was possible for sublingual nitroglycerin 400 μg (2 studies, n=1050) and found no statistically significant difference in relative risk to combined inferior and RVMI at 1.31 (95% CI 0.81 to 2.12, p=0.27), with an absolute effect of 3 additional adverse events per 100 treatments. Results remained robust under sensitivity analysis.

CONCLUSIONS

This review suggests that the AHA and ESC contraindications are not supported by evidence. Key limitations include all studies having concomitant inferior and RVMI, not evaluating beneficial effects and very low certainty of evidence. As adverse events are transient and easily managed, nitrates are a reasonable treatment modality to consider during RVMI on current evidence.

PROSPERO REGISTRATION NUMBER

CRD42020172839.

Arterial Glyceryl Trinitrate in Acute Ischemic Stroke after Thrombectomy for Neuroprotection (AGAIN): Rationale, design and protocol for a prospective randomized controlled trial

BACKGROUND

Although endovascular recanalization therapy demonstrates robust clinical efficacy in acute ischemic stroke (AIS), not all victims of these cerebrovascular accidents can benefit from it and achieve a favorable prognosis after successful reperfusion. Therefore, alternative neuroprotective strategies are urgently needed for AIS patients after vessel recanalization. Nitric oxide (NO) levels are low after AIS and NO donor drugs may be neuroprotective against cerebral ischemia-reperfusion injury. Glyceryl trinitrate (GTN), often used in the clinic as a NO donor, may provide a novel neuroprotective strategy. This rationale, design, and protocol for a prospective pilot study plans to explore the preliminary safety, feasibility, and neuroprotective benefits of Arterial Glyceryl Trinitrate in Acute Ischemic Stroke after Thrombectomy for Neuroprotection (AGAIN).

METHODS

AGAIN, a prospective RCT, is proposed for AIS patients after mechanical thrombectomy. Subjects will be randomly assigned in a 1:1 fashion (n = 40) to either the control group or the intervention group. Participants assigned to the intervention group will be administered 800 μg GTN in the catheter immediately after recanalization, whereas those in the control group will be administered the same volume of normal saline. All participants from either group will be given concurrent treatment with standard of care therapies in accordance with the current guidelines for stroke management. The primary outcome is safety [symptomatic intracranial hemorrhage (ICH), hypotension, neurological deterioration, ICH, fatal ICH, as well as headache, tachycardia, emesis, and seizures], whereas secondary outcomes included changes in poststroke functional outcomes, infarction volumes, and blood nitrate index detection.

DISCUSSIONS

This study is a prospective randomized controlled trial to test the safety and efficacy of intra-arterial GTN in AIS patients after endovascular therapy. The results from this study will give insight for future GTN studies and new neuroprotective strategies for future AIS treatment strategies.

TRIAL REGISTRATION NUMBER

ChiCTR2100045254. Registered on March 21, 2021.

Prehospital Administration of Aspirin and Nitroglycerin for Patients With Suspected Acute Coronary Syndrome ― A Systematic Review ―

Background: Recent guidelines for acute coronary syndrome (ACS) recommend prehospital administration of aspirin and nitroglycerin for ACS patients. However, there is no clear evidence to support this. We investigated the benefits and harms of prehospital administration of aspirin and nitroglycerin by non-physician healthcare professionals in patients with suspected ACS.

Methods and Results: We searched the PubMed database and used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence. Three retrospective studies for aspirin and 1 for nitroglycerin administered in the prehospital setting to patients with acute myocardial infarction were included. Prehospital aspirin administration was associated with significantly lower 30-day and 1-year mortality compared with aspirin administration after arrival at hospital, with odds ratios (OR) of 0.59 (95% confidence interval [CI] 0.35–0.99) and 0.47 (95% CI 0.36–0.62), respectively. Prehospital nitroglycerin administration was also associated with significantly lower 30-day and 1-year mortality compared with no prehospital administration (OR 0.34 [95% CI 0.24–0.50] and 0.38 [95% CI 0.29–0.50], respectively). The certainty of evidence was very low in both systematic reviews.

Conclusions: Our systematic reviews suggest that prehospital administration of aspirin and nitroglycerin by non-physician healthcare professionals is beneficial for patients with suspected ACS, although the certainty of evidence is very low. Further investigation is needed to determine the benefit of the prehospital administration of these agents.

Adverse events after prehospital nitroglycerin administration in a nationwide registry analysis

OBJECTIVE

Nitroglycerin (NTG) is a vasodilator used in the prehospital setting with chest pain patients. Potential adverse effects include hypotension, bradycardia or tachycardia, and mental status change. However, it is unclear which factors, if any, are associated with patients having an adverse event after receiving NTG. The objective of this study was to determine demographic and clinical factors associated with adverse events after prehospital NTG administration.

METHODS

The ESO Data Collaborative (Austin, TX), containing records from 1322 EMS agencies, was queried for 911 encounters where NTG was administered to patients ≥18 years old by EMS. Adverse event outcomes were defined as a new systolic blood pressure (SBP) < 90, heart rate (HR) < 50 or > 120, mean arterial pressure (MAP) < 65, or change in mental status following NTG administration. Descriptive statistics and logistic regression models adjusting for age, sex, race, ethnicity, intravenous (IV) access, and initial vital signs were used to assess for adverse event-related factors.

RESULTS

Among 80,760 encounters, the mean age was 61 (IQR 50-72), with 52% males, 71% white race, and 7% Hispanic ethnicity. Adverse events occurred in 7% of encounters. Adverse events were found to be less common among Black patients (OR = 0.74, 95%CI:0.69-0.80). IV access obtained prior to NTG administration was associated with fewer adverse events (OR = 0.92, 95%CI:0.85-0.99). Increasing age (OR = 1.02, 95%CI:1.01-1.02) and HR (OR = 1.03, 95%CI:1.02-1.03) were associated with increased odds of adverse events while SBP (OR = 0.99, 95%CI:0.98-0.99) was inversely associated.

CONCLUSIONS

Adverse events following prehospital NTG administration were rare, especially in patients with an SBP > 110 and a HR < 100, and less frequent in those with existing IV access. Demographics were not found to be clinically significant.

Adverse events from nitrate administration during right ventricular myocardial infarction: a systematic review protocol

OBJECTIVE

This systematic review will aim to summarize and evaluate the literature describing the evidence regarding adverse events from the administration of nitrates during right ventricular myocardial infarction.

INTRODUCTION

Withholding nitrates in the setting of right ventricular myocardial infarction is currently recommended by the American Heart Association, European Society of Cardiology, and in the Australian Journal of General Practice, due to the risk that decreasing preload in the setting of already compromised right ventricular ejection fraction may reduce cardiac output and precipitate hypotension or exacerbate cardiogenic shock. The original evidence from 1989 underpinning these recommendations displays methodological weaknesses including low sample size and confounding interventions. More recent and comprehensive research from 2014, 2016, 2018, and 2019 conflicts with the conclusions from the 1989 study, suggesting instead that nitrate administration during right ventricular myocardial infarction results in no significant difference in the rate of adverse events. The combination of recommended practice based on 30-year-old evidence and the emergence of recent challenging evidence suggest that this topic merits systematic review.

INCLUSION CRITERIA

The study will include both experimental and observational (descriptive and analytical) study designs that discuss the occurrence of adverse events from the administration of nitrates during a known right ventricular myocardial infarction.

METHODS

Six databases will be systematically searched: the Cochrane CENTRAL Register, PubMed, Embase, MEDLINE Complete, CINAHL, and Google Scholar. Identified studies will be independently assessed for inclusion by two investigators using JBI critical appraisal tools. Data will be extracted for narrative and tabular synthesis.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020172839.