Management of STEMI or NSTEACS

STEMI 또는 NSTEMI에서 아스피린 이외에 추가하는 항혈소판약제는 ticagrelor loading dose 180 mg입니다. CAG/PCI 후에는 prasugrel 60 mg을 사용할 수 있습니다. 출혈 경향을 보이는 경우와 STEMI에서 fibinolytic Tx를 하는 경우는 clopidogrel을 사용하고, prior stroke or TIA, 75세 이상, weight < 60 kg의 경우는 prasugrel 금기 (절대적, 상대적)입니다.

​

Acute management STEMI:

Give oral antiplatelet therapy (in addition to aspirin) to all patients:

1. Patients treated with fibrinolytic therapy: Give clopidogrel loading dose 300 mg if age 75 years or less; if age over 75 years, give loading dose of 75 mg.

2. Patients treated with no reperfusion therapy: Give ticagrelor loading dose 180 mg.

3. Patients treated with primary PCI: Give ticagrelor loading dose of 180 mg or prasugrel loading dose of 60 mg (if no contraindications: prior stroke or TIA, or relative contraindications for prasugrel such as those age 75 years or older, weight less than 60 kg). For patients at high risk of bleeding or those for whom prasugrel or ticagrelor cannot be used, we give clopidogrel 600 mg.

Acute management of unstable angina or non-STEMI:

Give antiplatelet therapy (in addition to aspirin) to all patients:

1. Patients not treated with an invasive approach: Give ticagrelor loading dose 180 mg. For these patients who are at very high risk (eg, recurrent ischemic discomfort, dynamic ECG changes, or hemodynamic instability), consider adding a GP IIb/IIIa inhibitor (either eptifibatide or tirofiban).

2. For patients managed with an invasive approach: Give ticagrelor loading dose of 180 mg at presentation. Prasugrel loading dose of 60 mg may be used as an alternative if given after diagnostic coronary angiography.

For patients age 75 years or older, who weigh less than 60 kg, or with past stroke or TIA, ticagrelor or clopidogrel are preferred to prasugrel. Clopidogrel may be given in a dose of 300 to 600 mg, but we prefer 600 mg. For patients otherwise at high risk for bleeding due to prior hemorrhagic stroke, ongoing bleeding, bleeding diathesis, or clinically relevant anemia or thrombocytopenia, clopidogrel 300 to 600 mg is an option.

For patients treated with an invasive approach and who receive bivalirudin, we do not recommend routinely giving a GP IIb/IIIa inhibitor; for those patients treated with heparin and who are troponin-positive, we suggest adding a GP IIb/IIIa inhibitor (either abciximab or eptifibatide) given after diagnostic angiography. For those undergoing an invasive approach who are at very high risk (eg, recurrent ischemic discomfort, dynamic ECG changes, or hemodynamic instability), we consider adding a GP IIb/IIIa inhibitor prior to diagnostic angiography (either eptifibatide or tirofiban) or after diagnostic angiography (abciximab or eptifibatide). Refer to text for dosing.

​

​

Rapid overview: Management of ST-elevation myocardial infarction (STEMI) or non-ST-elevation acute coronary syndrome (NSTEACS)

Initial assessment:

Consider the diagnosis in patients with chest discomfort, shortness of breath, or other suggestive symptoms. Women, older adults, and patients with diabetes may have "atypical" presentations.

Obtain 12-lead ECG within 10 minutes of arrival; repeat every 10 to 15 minutes if initial ECG is nondiagnostic but clinical suspicion remains high (initial ECG often NOT diagnostic).

1. STEMI: ST segment elevations ≥1 mm (0.1 mV) in two anatomically contiguous leads or ≥2 mm (0.2 mV) in leads V2 and V3 OR new left bundle branch block and presentation consistent with ACS. If ECG suspicious but not diagnostic, consult cardiologist early.

2. Non-STEMI or unstable angina: ST segment depressions or deep T wave inversions without Q waves or possibly no ECG changes.

Obtain emergent cardiology consultation for ACS patients with cardiogenic shock, left heart failure, or sustained ventricular tachyarrhythmia.

Initial interventions:

Assess and stabilize airway, breathing, and circulation.

Attach cardiac and oxygen saturation monitors; provide supplemental oxygen as needed to maintain O2 saturation >90%. Establish IV access.

Treat sustained ventricular arrhythmia rapidly according to ACLS protocols.

Give aspirin 325 mg (nonenteric coated) to be chewed and swallowed (unless aortic dissection is being considered). If oral administration is not feasible, give as rectal suppository.

Perform focused history and examination: Look for signs of hemodynamic compromise and left heart failure; determine baseline neurologic function, particularly if fibrinolytic therapy is to be given.

Obtain blood for cardiac biomarkers (troponin preferred), electrolytes, hematocrit/hemoglobin. Perform coagulation studies for patients taking anticoagulants or as otherwise indicated (eg, known coagulopathy).

Give three sublingual nitroglycerin tablets (0.4 mg) one at a time, spaced five minutes apart, or one aerosol spray under tongue every 5 minutes for 3 doses IF patient has persistent chest discomfort, hypertension, or signs of heart failure AND there is no sign of hemodynamic compromise (eg, right ventricular infarction) and no use of phosphodiesterase inhibitors (eg, for erectile dysfunction); add IV nitroglycerin for persistent symptoms.

Treat left heart failure if present: Give afterload-reducing agent (eg, nitroglycerin sublingual tablet and/or IV drip at 40 mcg/minute provided no hypotension and no phosphodiesterase inhibitors [eg, for erectile dysfunction]; titrate drip up quickly based on response); give loop diuretic (eg, intravenous furosemide); administer noninvasive positive pressure ventilation (eg, BLPAP) to appropriate patients.

Give beta blocker (eg, metoprolol tartrate 25 mg orally) IF no signs of heart failure and not at high risk for heart failure and no signs of hemodynamic compromise, bradycardia, or severe reactive airway disease. If hypertensive, may initiate beta blocker IV instead (eg, metoprolol tartrate 5 mg intravenous every 5 minutes for 3 doses as tolerated).

Give morphine sulfate (2 to 4 mg slow IV push every 5 to 15 minutes) for unacceptable, persistent discomfort or anxiety related to myocardial ischemia.

Start 80 mg of atorvastatin as early as possible and preferably before PCI in patients not on statin. If patient is taking a low- to moderate-intensity statin, switch to atorvastatin 80 mg.

Acute management STEMI:

Select reperfusion strategy: Primary PCI strongly preferred, especially for patients with cardiogenic shock, heart failure, late presentation, or contraindications to fibrinolysis. Activate cardiac catheterization team as indicated. For patients with symptoms of >12 hours, fibrinolytic therapy is not indicated, but emergent PCI may be considered, particularly for patients with evidence of ongoing ischemia or those at high risk of death.

Treat with fibrinolysis if PCI unavailable within 120 minutes of first medical contact, symptoms <12 hours, and no contraindications.*

Give oral antiplatelet therapy (in addition to aspirin) to all patients:

1. Patients treated with fibrinolytic therapy: Give clopidogrel loading dose 300 mg if age 75 years or less; if age over 75 years, give loading dose of 75 mg.

2. Patients treated with no reperfusion therapy: Give ticagrelor loading dose 180 mg.

3. Patients treated with primary PCI: Give ticagrelor loading dose of 180 mg or prasugrel loading dose of 60 mg (if no contraindications: prior stroke or TIA, or relative contraindications for prasugrel such as those age 75 years or older, weight less than 60 kg). For patients at high risk of bleeding or those for whom prasugrel or ticagrelor cannot be used, we give clopidogrel 600 mg.

Give anticoagulant therapy to all patients:

1. For patients treated with primary PCI, we prefer UFH to bivalirudin. This recommendation assumes that patients will receive a potent oral antiplatelet agent (ticagrelor or prasugrel), which we prefer to clopidogrel. For those patients who receive clopidogrel, we prefer bivalirudin.

Dosing of UFH: An initial IV bolus of 50 to 70 units/kg up to a maximum of 5000 units. Additional heparin may be given in the catheterization laboratory based on the results of ACT monitoring. Dosing of bivalirudin: Initial bolus of 0.75 mg/kg IV followed by IV infusion of 1.75 mg/kg per hour; can be discontinued after PCI.

2. For patients treated with fibrinolysis, we prefer enoxaparin for patients not at high bleeding risk or fondaparinux for those at high bleeding risk. For those patients in whom PCI is possible or likely after fibrinolytic therapy, UFH is reasonable.

Dosing of enoxaparin Patients <75 years: Loading dose of 30 mg IV bolus followed by 1 mg/kg subcutaneously every 12 hours; maximum of 100 mg for the first two subcutaneous doses. The first subcutaneous dose should be administered with the IV bolus. Dose adjustment for renal impairment (CrCl <30 mL/minute)*: Loading dose of 30 mg IV followed by 1 mg/kg subcutaneously every 24 hours. The first subcutaneous dose should be administered with the IV bolus. Patients ≥75 years: No IV loading dose. Administer 0.75 mg/kg subcutaneously every 12 hours; maximum of 75 mg for the first two doses. Dose adjustment for renal impairment (CrCl <30 mL/minute)*: No IV loading dose. Administer 1 mg/kg subcutaneously every 24 hours. Supplemental IV bolus dose for patients who will receive PCI after >1 dose of therapeutic enoxaparin: 0.3 mg/kg if last enoxaparin dose was given 8 to 12 hours earlier; no supplemental IV dose if last enoxaparin dose was within 8 hours; use UFH if last enoxaparin dose was more than 12 hours ago. Dosing of UFH: IV bolus of 60 to 100 units/kg to a maximum of 4000 units, followed by an IV infusion of 12 units/kg per hour (maximum 1000 units per hour) adjusted to achieve a goal aPTT of approximately 50 to 70 seconds (1.5 to 2 times control). Dosing of fondaparinux: 2.5 mg intravenously, followed by 2.5 mg subcutaneously every 24 hours. This drug should be avoided in CrCl <30 mL/minute.

3. For patients not receiving reperfusion therapy, we use enoxaparin or UFH.

Dosing of enoxaparin: Dose same as for patients treated with fibrinolysis (refer to section 2 above). Dosing of UFH: IV bolus of 50 to 70 units/kg to a maximum of 5000 units, followed by an IV infusion of 12 units/kg per hour adjusted to achieve a goal aPTT of approximately 50 to 70 seconds (1.5 to 2 times control).

Acute management of unstable angina or non-STEMI:

Give antiplatelet therapy (in addition to aspirin) to all patients:

1. Patients not treated with an invasive approach: Give ticagrelor loading dose 180 mg. For these patients who are at very high risk (eg, recurrent ischemic discomfort, dynamic ECG changes, or hemodynamic instability), consider adding a GP IIb/IIIa inhibitor (either eptifibatide or tirofiban).

2. For patients managed with an invasive approach: Give ticagrelor loading dose of 180 mg at presentation. Prasugrel loading dose of 60 mg may be used as an alternative if given after diagnostic coronary angiography.

For patients age 75 years or older, who weigh less than 60 kg, or with past stroke or TIA, ticagrelor or clopidogrel are preferred to prasugrel. Clopidogrel may be given in a dose of 300 to 600 mg, but we prefer 600 mg. For patients otherwise at high risk for bleeding due to prior hemorrhagic stroke, ongoing bleeding, bleeding diathesis, or clinically relevant anemia or thrombocytopenia, clopidogrel 300 to 600 mg is an option.

For patients treated with an invasive approach and who receive bivalirudin, we do not recommend routinely giving a GP IIb/IIIa inhibitor; for those patients treated with heparin and who are troponin-positive, we suggest adding a GP IIb/IIIa inhibitor (either abciximab or eptifibatide) given after diagnostic angiography. For those undergoing an invasive approach who are at very high risk (eg, recurrent ischemic discomfort, dynamic ECG changes, or hemodynamic instability), we consider adding a GP IIb/IIIa inhibitor prior to diagnostic angiography (either eptifibatide or tirofiban) or after diagnostic angiography (abciximab or eptifibatide). Refer to text for dosing.

Give anticoagulant therapy in all patients:

1. For patients undergoing urgent catheterization (within four hours) or those managed with an early invasive strategy (angiography within 4 to 48 hours), we use either heparin or bivalirudin. We prefer initiation of heparin in the emergency department and a switch to bivalirudin in the catheterization laboratory.

Dosing of UFH: IV bolus of 60 to 70 units/kg to a maximum of 5000 units, followed by an IV infusion of 12 units/kg per hour adjusted to achieve a goal aPTT of approximately 50 to 70 seconds (1.5 to 2 times control). Dose of bivalirudin: If bivalirudin is given in the emergency department, IV bolus of 0.1 mg/kg and an infusion of 0.25 mg/kg per hour before angiography. If PCI is performed, an additional 0.5 mg/kg bolus is given and the infusion rate is increased to 1.75 mg/kg per hour.

2. For patients receiving a noninvasive approach, we recommend either fondaparinux or enoxaparin.

Enoxaparin is an alternative to UFH for patients not undergoing an early invasive approach. No loading dose is necessary. Dosing is 1 mg/kg subcutaneously every 12 hours. Dose adjustment for renal impairment (CrCl <30 mL/minute)*: 1 mg/kg subcutaneously every 24 hours. Fondaparinux: 2.5 mg subcutaneously every 24 hours. This drug should be avoided in patients with a CrCl <30 mL/minute.

Other important considerations:

Cocaine-related ACS: Give benzodiazepines (eg, lorazepam 2 to 4 mg IV every 15 minutes or so) as needed to alleviate symptoms; do NOT give beta blockers.

Stop NSAID therapy if possible.

Correct any electrolyte abnormalities, especially hypokalemia and hypomagnesemia, which often occur together.

ECG: electrocardiogram; ST: ST-segment; IV: intravenous; ACLS: advanced cardiac life support; BLPAP: bilevel positive airway pressure; PCI: percutaneous coronary intervention; TIA: transient ischemic attack; UFH: unfractionated heparin; ACT: activated clotting time; CrCl: creatinine clearance estimated using Cockcroft-Gault equation (a calculator is available in UpToDate); aPTT: activated partial thromboplastin time; GP: glycoprotein; NSAID: nonsteroidal antiinflammatory drug.

* Repeated doses of low molecular weight heparin in patients with renal insufficiency may lead to accumulation and increased risk of bleeding to varying degrees. By contrast, UFH is not dependent primarily upon renal function for clearance and may be a preferred option for patients with CrCl <20 mL/minute, kidney failure, or receiving dialysis.

​

REF. UpToDate 2020.08.30