Recently, Cardiology Journal published an expert opinion on hospital management of patients with acute coronary syndrome (ACS). The former management has been updated to provide practical advice to emergency medical teams.
ACS diagnosis: resting 12-lead ECG or first-line diagnostic tool span>
1. Emergency Medical Team
The emergency medical team should be responsible for the early diagnosis, triage, transport, and treatment of patients with ACS. In order to improve the quality of care and reduce treatment delay, early diagnosis and risk stratification of ACS should be carried out as soon as possible. Professional ambulance personnel (at least one person with advanced life support training) and equipment (eg, electrocardiographs and defibrillators) facilitate the effective management of patients with ACS. All personnel in the ambulance should be trained to recognize symptoms of ACS, record and transmit electrocardiograms; and administer oxygen, pain relief, or basic life support when necessary.
ACS may be associated with a variety of symptoms, including persistent ischemia or mechanical complications such as severe mitral valve Cardiac arrest, electrical or hemodynamic instability due to cardiogenic shock. The main incentive for the diagnosis and treatment of patients with suspected ACS is acute chest discomfort, which mainly includes pain, pressure, tightness, and burning. In addition to this, patients may present with similar symptoms of chest pain such as dyspnea, upper abdominal pain, or pain in the left arm.
2. ECG< /p>
resting 12-lead ECG can be used as a first-line diagnostic tool for patients with suspected ACS, and it is recommended to perform it within 10 minutes after the first medical contact before hospital , and explained by a qualified physician (support available through telehealth services).
Persistent ST-segment elevation in two adjacent leads is considered a persistent MI (infarct artery occlusion). ) is one of the best diagnostic indicators. If the standard leads cannot be determined, an ECG can be recorded in leads V7-V9 or V3R and V4R, which represent left circumflex occlusion or right ventricular myocardial infarction, respectively. The characteristic ECG features of NSTE-ACS include ST-segment depression, transient ST-segment elevation, and T wave changes, although >30% of patients may have a normal ECG.
Patients with an initial diagnosis of ACS should undergo immediate ECG monitoring to detect life-threatening arrhythmias. Immediate defibrillation when indicated.
Patients with ACS are highly unstable, so even patients with newly diagnosed ACS are not suitable for immediate coronary angiography and PCI, should also be transferred to a PCI-qualified center (regardless of ECG changes). At the first medical contact, a teleconsultation should be conducted and the patient’s 12-lead ECG and associated clinical data should be transmitted to the center to which they need to be transported.
Chest Pain Management: Morphine as Coronary Opener The first choice for analgesic therapy
Coronary revascularization is a The most effective analgesic strategy for acute myocardial ischemia. Patients with STEMI or NSTE-ACS who have recurrent or intractable chest pain despite medical treatment can be treated with immediate invasive treatment.
In order to relieve the pain of ACS patients before culprit cannulation, a fast-acting, potent antiseptic can be used. Pain medication, morphine can be the first choice. When using morphine, the dose and time of administration should be recorded and the medical staff informed. In addition, opioids should be avoided routinely in patients with ACS and should only be used in selected patients with refractory chest pain. If the patient requires analgesia, discontinuation of morphine or routine switching to fentanyl or acetaminophen is not recommended.
In view of the potentially detrimental effects of oxygen inhalation in patients with uncomplicated MI, only oxygen saturation ( SaO2) <90% of hypoxic patients.
Antiplatelet therapy in patients with ACS
Dual antiplatelet therapy (DAPT) containing aspirin and a P2Y12 receptor inhibitor is still an option in ACS patients Standard treatment strategies.
1. Aspirin< /p>
In patients with ACS without contraindications, oral fast-absorbing aspirin (150-300 mg) can be used for treatment; if oral preparations are not available, intravenous aspirin can be used 75-250 mg aspirin.
Aspirin should be given after first medical exposure; thereafter all patients should be given 75-100 mg/day long-term treatment with aspirin.
2.P2Y12 receptor inhibitors< /span>
Currently, commonly used P2Y12 receptor inhibitors include clopidogrel, prasugrel, ticagrelor and Cangrelor (intravenous). When initiating these P2Y12 receptor inhibitors, the contraindications should be identified first.
In clinical practice, a large proportion of ACS patients require long-term oral anticoagulation therapy. Concomitant DAPT was associated with a 2-3-fold increased risk of bleeding complications compared with anticoagulation alone. Ticagrelor or prasugrel are not recommended as part of triple antithrombotic therapy (III, C), and clopidogrel is the only P2Y12 receptor inhibitor that can be used in combination with oral anticoagulants. In patients with moderate to severe stent thrombosis risk, dual antithrombotic therapy (oral anticoagulant + ticagrelor orLagre) benefit (IIb, C).
Intravenous cangrelor has a rapid onset of action and may be used as an ACS in patients requiring urgent invasive treatment Preferred P2Y12 receptor inhibitors. Cangrelor can be considered in patients who are not pretreated with a P2Y12 receptor inhibitor at the time of PCI or who cannot absorb oral medications.
(1) Application of P2Y12 receptor inhibitors in STEMI patients span>
Saving more myocardium is the main goal of STEMI therapy. Timely diagnosis and transport to the cath lab, and rapid opening of the culprit vessel to achieve reperfusion therapy are crucial for the treatment of STEMI patients.
At present, primary PCI is still the main method of coronary revascularization in STEMI patients. According to ESC guidelines, prehospital thrombolytic therapy can be considered when STEMI is diagnosed with PCI-mediated reperfusion therapy for more than 120 minutes.
In the treatment of STEMI, the appropriate P2Y12 receptor inhibitor can be selected according to the risk of ischemia and bleeding. agent. However, there are no randomized controlled trials to confirm when antiplatelet therapy is optimal in patients with STEMI, and available data suggest early initiation of P2Y12 receptor inhibitor therapy (to obtain effective platelet suppression at the time of PCI), especially in hospital settings P2Y12 receptor inhibitors are considered safe when administered prior to administration.
In patients not receiving P2Y12 receptor inhibitors, intravenous cangrelor (IV) can be administered prior to PCI. Push 30 mg/kg, followed by 4 mg/kg/min for ≥ 2 hours or until the end of surgery) for treatment (IIb, A).
If active bleeding, mechanical complications of myocardial infarction, acute aortic dissection, or other For comorbidities of emergency surgery, prehospital DAPT should be avoided.
(2) Application of P2Y12 receptor inhibitors in NSTE-ACS patients
Emergency coronary reperfusion therapy is the mainstay of treatment for STEMI, but In NSTE-ACS patients, the indications and recommended duration of invasive procedures or treatments depend primarily on risk stratification. The importance of risk stratification in decision-making has also been highlighted by the results of randomized controlled trials and their meta-analyses, which only support routine invasive strategies in very high-risk and high-risk patients. The ESC guidelines also recommend immediate invasive treatment strategies (<2h) in very high-risk NSTE-ACS patients.
Similar to STEMI patients, except for patients with contraindications (such as high bleeding risk), NSTE-ACS is also recommended The patient underwent DAPT (I, A). The 2020 ESC NSTE-ACS Guidelines recommend pretreatment with P2Y12 receptor inhibitors in NSTE-ACS patients who are not at high risk of bleeding and who are not planned for early invasive treatment (IIb, C). This guideline does not recommend routine preconditioning with P2Y12 receptor inhibitors in NSTE-ACS patients with unknown coronary structure and planning an early invasive treatment strategy (III, A).
Efficacy of routine prehospital administration of P2Y12 receptor inhibitors in NSTE-ACS patients, available evidence provides Conflicting results have been reported, so routine prehospital treatment with P2Y12 receptor inhibitors is not recommended. However, even if early P2Y12 receptor inhibitors are associated with increased bleeding risk, in-hospital administration of ticagrelor prior to coronary angiography is reasonable after individualized assessment in selected patients with NSTE-ACS.
3. Antiplatelet therapy after ACS
Except for patients with contraindications, all patients after ACS should undergo 12-month DAPT (I, A ). Given the differences in ischemia and bleeding risk, adverse event rates, comorbidities, and concomitant drug use in different patients, the duration of DAPT treatment may be shortened or prolonged in specific clinical situations.
For patients with high ischemic risk and no bleeding risk, a second aspirin should be considered. long-term secondary prevention with antithrombotic drugs (IIa, A). This strategy may also be considered in patients with intermediate ischemic risk and low bleeding risk (IIb, A).
After 12 months of DAPT, some ACS patients continued on aspirin and P2Y12 receptor inhibitors benefit (no or brief interruption of treatment).
In addition, ≥2 years after ACS and/or ≥1 year of DAPT discontinuation, and polyvascular beds In patients with atherosclerosis, if dual antithrombotic therapy is indicated, aspirin combined with rivaroxaban (2.5 mg b.i.d.) may be a better choice.
Conclusion
At present, DAPT consisting of aspirin and P2Y12 receptor inhibitors is still the main treatment strategy for ACS. ESC guidelines recommend that all patients with ACS should be treated with P2Y12 receptor inhibitors, except for patients with contraindications (such as high risk of bleeding).
Although there are limited data on the optimal timing of initiation of P2Y12 receptor inhibitors, current consensus is Early administration of effective P2Y12 receptor inhibitors and aspirin and heparin is crucial for the treatment of all STEMI patients.
For patients with NSTE-ACS, the 2020 ESC NSTE-ACS Management Guidelines do not recommend Routine preconditioning with a P2Y12 receptor inhibitor in unknown patients planning for PCI (III, A). However, adequate antiplatelet effects are required for PCI, so in the absence of fast-acting IV cangrelor, a loading dose of ticagrelor in the hospital prior to coronary angiography is reasonable after individualized assessment of.
Ticagrelor reduces adverse cardiovascular outcomes, including death, in ACS patients undergoing CABG Event risk, but not increased CABG-related bleeding risk.
In the perioperative period, in addition to DAPT, ACS patients should also receive anticoagulation therapy. (70-100 U/kg) or the only anticoagulant available for paramedics and emergency medical teams.
Pain management should be an important part of emergency care for patients with ACS. Intravenous morphine remains the standard of care strategy for STEMI patients. When deciding to use morphine, it is important to identify unnecessary interactions between morphine and antiplatelet drugs, and to identify the most effective analgesic strategy in patients with ACS as emergency revascularization.
In the prehospital phase, patients with ACS may vomit, especially when taking morphine. This may decrease the rate of absorption of antiplatelet drugs. At this point, the time from taking the drug to vomiting should be recorded and look for the presence of tablets in the vomit. Patients should also consult their doctor about taking additional doses of antiplatelet drugs.
In general, for all STEMI patients, an ECG should be Consult an experienced cardiologist for prehospital administration of aspirin and a loading dose of a P2Y12 inhibitor. In selected patients with NSTE-ACS, in-hospital administration of P2Y12 inhibitors is reasonable.
Anterior management algorithm of patients >
Yimaitong compiled from: Jacek Kubica , Piotr Adamski , Jerzy R. Ł adny, et al. Pre-hospital treatment of patients with acute coronary syndrome: Recommendations for medical emergency teams. Expert position update 2022. Cardiology Journal. 2022; 29(4): 540-552. DOI: 10.5603/CJ.a2022.0026.