Management of Chest Pain in NSTEMI

Immediate Anti-Ischemic Management

• The American College of Cardiology recommends administering aspirin 162-325 mg immediately as a non-enteric formulation for rapid buccal absorption, followed by 75-162 mg daily indefinitely, for patients with NSTEMI presenting with chest pain 1, 2
• The American Heart Association suggests giving sublingual nitroglycerin 0.4 mg every 5 minutes for a total of 3 doses for ongoing ischemic discomfort, and initiating intravenous NTG for the first 48 hours to treat persistent ischemia, heart failure, or hypertension if chest pain persists 1, 3, 4
• The American College of Cardiology recommends administering supplemental oxygen only if arterial saturation is <90%, respiratory distress is present, or other high-risk features for hypoxemia exist 3
• The American Heart Association recommends giving morphine sulfate intravenously for uncontrolled ischemic chest discomfort despite nitroglycerin 3

Monitoring and Environment

• The American Heart Association suggests admitting patients to a monitored unit with continuous ECG monitoring and bed/chair rest for at least 24 hours 3, 5

Anti-Ischemic Medications

• The American College of Cardiology recommends initiating oral beta-blocker therapy within the first 24 hours unless the patient has signs of heart failure, evidence of low-output state, increased risk for cardiogenic shock, or contraindications including PR interval >0.24 seconds, second or third degree heart block, active asthma, or reactive airway disease 3
• The American Heart Association suggests administering ACE inhibitor orally within the first 24 hours if pulmonary congestion is present or LVEF ≤0.40, provided systolic blood pressure ≥100 mmHg 3

Antiplatelet and Anticoagulant Therapy

• The American College of Cardiology recommends continuing aspirin indefinitely 2
• The American Heart Association suggests administering a P2Y12 inhibitor, with the timing depending on the management strategy, and delaying the loading dose until after coronary anatomy is determined for early invasive strategy 2
• The American College of Cardiology recommends administering parenteral anticoagulation to all NSTEMI patients in addition to antiplatelet therapy, with preferred agents including unfractionated heparin, enoxaparin, and fondaparinux 1, 6, 2

Risk Stratification and Management Strategy Selection

• The American College of Cardiology recommends proceeding with an early invasive approach if the patient has refractory angina despite medical therapy, hemodynamic instability, electrical instability, elevated cardiac biomarkers, or a high GRACE/TIMI risk score 6

Critical Medications to Avoid

• The American College of Cardiology recommends avoiding NSAIDs (except aspirin) during hospitalization due to increased risks of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 1, 6

Initial Medication Dosing for NSTEMI in the Emergency Room

Immediate Antiplatelet Therapy

• The American College of Cardiology recommends a loading dose of aspirin 162-325 mg orally, followed by a maintenance dose of 75-100 mg daily, for patients with NSTEMI 7
• The American College of Cardiology suggests that aspirin should be chewed when possible to achieve faster onset of antiplatelet action, and continued indefinitely unless absolute contraindication exists 7
• When using ticagrelor, aspirin maintenance must not exceed 100 mg daily, as higher doses reduce ticagrelor's efficacy, according to the American College of Cardiology 7

P2Y12 Inhibitor Selection and Dosing

• The American College of Cardiology recommends ticagrelor 180 mg loading dose, then 90 mg twice daily maintenance, as first-line treatment for patients proceeding to PCI 7
• The American College of Cardiology suggests prasugrel 60 mg loading dose, then 10 mg daily, as an alternative for patients undergoing PCI with no contraindications 7

Anticoagulation Therapy

• The European Society of Cardiology recommends enoxaparin, fondaparinux, or unfractionated heparin as anticoagulation options, with specific dosing regimens, for patients with NSTEMI 8

Anti-Ischemic Medications

• The American College of Cardiology recommends against the use of nitroglycerin in patients with systolic BP <90 mmHg, heart rate <50 or >100 bpm without heart failure, right ventricular infarction, or recent phosphodiesterase inhibitor use 9
• The American College of Cardiology suggests that beta-blockers should not be given if heart rate <60 bpm, systolic BP <100 mmHg, or moderate-severe LV dysfunction with signs of heart failure 10

Oxygen Therapy

• The American College of Cardiology recommends against routine oxygen administration in uncomplicated NSTEMI without hypoxemia, according to the American Heart Association 11

Medications to AVOID

• The American College of Cardiology recommends that NSAIDs (except aspirin) are absolutely contraindicated in patients with NSTEMI, as they increase mortality, reinfarction, hypertension, heart failure, and myocardial rupture risk 11

Dosing Summary

• The American College of Cardiology recommends a minimum of 12 months of dual antiplatelet therapy, unless bleeding risk outweighs benefit 7

Management of Acute Coronary Syndrome

Introduction to Antiplatelet Therapy

• The American College of Cardiology recommends that all patients with acute coronary syndrome should receive a P2Y12 inhibitor in addition to aspirin to reduce major cardiovascular events 12
• The American Heart Association suggests that aspirin should be administered as soon as possible after presentation, with a dose of 162-325 mg, and that ticagrelor 180 mg should be given at the same time 12
• The dose of aspirin for maintenance should be 75-100 mg daily, and ticagrelor 90 mg twice daily, as recommended by the American College of Cardiology 12

Protocol for Antiplatelet Therapy

• Aspirin should be chewed when possible to allow for faster antiplatelet action, as recommended by the American Heart Association 12, 13
• Ticagrelor blocks the P2Y12 receptor, which is synergistic with aspirin's inhibition of the thromboxane A2 pathway, as described by the American College of Cardiology 12
• The American College of Cardiology recommends that ticagrelor should be used instead of clopidogrel in patients with acute coronary syndrome, due to its greater efficacy, as shown in studies 13, 14

Important Considerations for Antiplatelet Therapy

• When using ticagrelor, the maintenance dose of aspirin should never exceed 100 mg daily, as higher doses reduce the efficacy of ticagrelor and increase the risk of bleeding, as recommended by the American Heart Association 12, 13
• The American College of Cardiology suggests that anticoagulation with enoxaparin, fondaparinux, or unfractionated heparin should be used in all patients with acute coronary syndrome, in addition to antiplatelet therapy 12, 14

Timing of P2Y12 Inhibitor Administration Relative to Diagnostic Cardiac Catheterization

1. Stable Coronary Artery Disease / Elective Diagnostic Catheterization

• Do not give any P2Y12 inhibitor before diagnostic coronary angiography in stable patients; the recommendation is Class III, Level A. (American College of Cardiology/American Heart Association) 15
• Pretreatment with clopidogrel when coronary anatomy is unknown is not recommended (Class III, Level A). (ACC/AHA) 16
• Pretreatment with prasugrel when coronary anatomy is unknown is not recommended (Class III, Level B). (ACC/AHA) 15
• The 2014 ESC/EACTS guideline advises giving 600 mg clopidogrel only after the anatomy is known and preferably ≥2 h before PCI (Class I). (European Society of Cardiology/European Association for Cardio‑Thoracic Surgery) 15
• Pretreatment may be considered (Class IIb) only in patients with a high probability of significant CAD requiring intervention. (ACC/AHA) 17
• Prasugrel must be stopped ≥7 days before planned CABG; clopidogrel must be stopped ≥5 days before surgery. (FDA label) 18

2. ST‑Elevation Myocardial Infarction (Primary PCI)

• A loading dose of a P2Y12 inhibitor should be given as early as possible or at the time of primary PCI (Class I, Level B). (ACC/AHA) 15
• ESC 2014 guideline recommends administering the P2Y12 inhibitor at first medical contact (Class I, Level B). (ESC) 15
• The recommended loading doses are ticagrelor 180 mg or clopidogrel 600 mg. (ESC) 19
• Prasugrel 60 mg may be given promptly but no later than 1 h after PCI once the coronary anatomy is defined (Class I, Level B). (ACC/AHA) 18

3. Non‑ST‑Elevation ACS – Early Invasive Strategy (Planned PCI)

• A loading dose of a P2Y12 inhibitor is recommended for patients in whom PCI is planned (Class I). (ACC/AHA) 18
• Clopidogrel 600 mg should be given as early as possible before or at the time of PCI (Class I, Level B). (ACC/AHA) 18
• Ticagrelor 180 mg should be given as early as possible before or at the time of PCI (Class I, Level B). (ACC/AHA) 18
• Prasugrel 60 mg should be given promptly and no later than 1 h after PCI once the anatomy is known (Class I, Level B). (ACC/AHA) 18

4. Non‑ST‑Elevation ACS – Conservative Strategy (No Immediate Catheterization)

• Clopidogrel or ticagrelor (loading dose followed by maintenance) should be added to aspirin as soon as possible after admission (Class I, Level B). (ACC/AHA) 18
• If recurrent symptoms develop and angiography becomes necessary, continue the P2Y12 inhibitor that was already started. (ACC/AHA) 18

5. Contraindications & Safety Precautions

• Prasugrel is absolutely contraindicated before coronary anatomy is defined in NSTEMI or stable CAD patients (Class III, strong evidence). (ACC/AHA) 15
• Early administration of P2Y12 inhibitors in patients who may require urgent CABG markedly increases bleeding risk; the FDA label warns of substantial bleeding when prasugrel is given before CABG. (FDA label) 18

Premedication Strategies for Coronary Angiography

Antiplatelet Therapy – Aspirin Loading

• All patients scheduled for coronary angiography should receive a rapid‑acting, non‑enteric aspirin loading dose of 162–325 mg immediately, followed by a maintenance dose of 75–100 mg daily (unless already on chronic aspirin). Class I, Level A recommendation (American Heart Association) 20.

P2Y12 Inhibitor Timing According to Clinical Scenario

STEMI – Primary PCI

• Give a loading dose of ticagrelor 180 mg or clopidogrel 600 mg as early as possible before or at the time of primary PCI. Class I, Level A (American College of Cardiology) 21.
• Prasugrel 60 mg may be administered promptly but must not be given later than 1 hour after PCI once the coronary anatomy is defined. Class I, Level A (American College of Cardiology) 22.

NSTEMI / Unstable Angina – Early Invasive Strategy

• Administer clopidogrel 600 mg or ticagrelor 180 mg as early as possible before diagnostic angiography. Class I, Level A (American Heart Association) 20.
• For high‑risk patients, an intravenous GP IIb/IIIa inhibitor (eptifibatide or tirofiban) may be given before the procedure. Class IIa, Level B (American Heart Association) 23.

CABG Bleeding‑Risk Considerations

• Pre‑procedure clopidogrel creates a 5–7 day delay for urgent coronary‑artery bypass grafting (CABG) due to excess bleeding risk. Class I, Level B (American College of Cardiology) 24.
• Pre‑procedure prasugrel creates a 7‑day delay for urgent CABG. Class I, Level B (American College of Cardiology) 25.

Anticoagulation Therapy for Angiography with Planned or Possible PCI

• Parenteral anticoagulation is recommended for all patients undergoing coronary angiography when PCI is planned or possible. Class I, Level A (European Society of Cardiology) 26.

  • Unfractionated heparin (UFH): 70–100 U/kg IV bolus (reduce to 50–70 U/kg if a GP IIb/IIIa inhibitor is used concurrently). Class I, Level A (European Society of Cardiology) 26.
  • Bivalirudin: 0.75 mg/kg IV bolus followed by continuous infusion of 1.75 mg/kg/h during the procedure. Class I, Level A (European Society of Cardiology) 26.

Continuation of Existing Anticoagulation in NSTEMI

• NSTEMI patients already receiving anticoagulation before hospital arrival should continue the same agent throughout the angiography procedure. Class I, Level B (American College of Cardiology) 24.