Medical Lecture Note: Summary of Management of Acute Coronary Syndrome (ACS)

Initial assessment:

Consider the diagnosis: women, the elderly, and patients with diabetes may have atypical presentations.
Obtain 12 lead ECG within 10 minutes of arrival; repeat every 10 minutes if initial ECG nondiagnostic but clinical suspicion remains high (initial ECG often NOT diagnostic).

1. STEMI: ST segment elevations of 1 mm (0.1 mV) in 2 anatomically contiguous leads or 2 mm (0.2mV) in 2 contiguous precordial leads, OR new left bundle branch block and presentation consistent with ACS. If ECG suspicious but not diagnostic, consult cardiology 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.
Provide oxygen; attach cardiac and oxygen saturation monitors; establish IV access.
Treat sustained ventricular arrhythmia rapidly according to ACLS protocols.
Give aspirin 325 mg (non-enteric coated), to be chewed and swallowed (unless aortic dissection is being considered). If oral administration 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, coagulation studies, hematocrit / hemoglobin.
Treat left heart failure:

give afterload reducing agent (eg, nitroglycerin sublingual tablet and/or IV drip at 40 mcg/minute provided no phosphodiesterase inhibitors [eg, for erectile dysfunction]);
titrate drip up quickly based on response;
give loop diuretic (eg, furosemide 80 mg IV).

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 three 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
Give beta blocker (eg, metoprolol 25 mg orally) IF no signs of heart failure (or high risk for heart failure), hemodynamic compromise, bradycardia, or severe reactive airway disease. If hypertensive, may initiate beta blocker IV instead (eg, metoprolol 5 mg intravenous every 5 minutes times three doese as tolerated).
Give morphine sulfate (2 to 4 mg slow IV push every 5 to 15 minutes) for persistent discomfort or anxiety
Start 80 mg of atorvastatin as early as possible, and preferably before PCI, in patients not on statin

Acute management STEMI:

Select reperfusion strategy: Primary percutaneous coronary intervention (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.
Treat with fibrinolysis if PCI unavailable within 90-120 minutes, symptoms <12 hours, and no contraindications.
Give antiplatelet therapy (in addition to aspirin) to all patients:

1. Prasugrel: For patients undergoing primary PCI and NOT at high risk of bleeding (age <75 years, weight >60 kilograms, no stroke or TIA), give prasugrel 60 mg
2. Clopidogrel: For patients undergoing primary PCI who are not candidates for prasugrel due to a high risk of bleeding, give clopidogrel 600 mg. (Some patients, such as those with recent GI bleed or head trauma, may not be candidates for either). For patients undergoing fibrinolysis or no reperfusion therapy, give clopidogrel loading dose of 300 mg if age less than 75 years; if age 75 years or older, give 75 mg daily dose only.
3. Glycoprotein IIb/IIIa inhibitor (GPIIb/IIIa): If PCI is planned give GPIIb/IIIa in consultation with cardiology. Patients who receive bivalirudin should not receive GPIIb/IIIa.

1. Unfractionated heparin (UFH): For patients undergoing primary PCI who are receiving a GP IIb/IIIa inhibitor, we suggest an IV bolus of 50 to 70 units/kg (target activated clotting time >200 seconds) up to a maximum of 4000 units. For those patients not receiving a GP IIb/IIIa inhibitor, we suggest an intravenous bolus of 60 to 100 units/kg up to a maximum of 4000 units (give after fibrinolytic therapy).
2. Bivalirudin is an acceptable alternative to heparin plus GP IIb/IIIa in patients undergoing primary PCI. Initial bolus of 0.75 mg/kg IV followed by IV infusion of 1.75 mg/kg per hour; can be discontinued after PCI.
3. Enoxaparin: For patients not managed with PCI and <75 years and whose serum creatinine is <2.5 mg/dL [220 micromol/L] in men and <2.0 mg/dL [175 micromol/L] in women, give a loading dose of 30 mg IV bolus and 1 mg/kg subcutaneously every 12 hours. The creatinine clearance should be used to determine the timing of subsequent doses. UFH is preferred in patients with dialysis dependent renal failure.

Acute management of unstable angina or non-STEMI:

1. Thienopyridine: If the patient is undergoing same day PCI, give clopidogrel 600 mg; for patients undergoing early PCI in whom thienopyridine is withheld before PCI AND who are not at high risk of bleeding (age <75 years, weight ≥60 kilograms, no history of stroke or TIA) give prasugrel 60 mg instead of clopidogrel
2. GP IIb/IIIa inhibitor (either eptifibatide or tirofiban) may be added to or in place of clopidogrel in some circumstances (eg, high risk patient). Abciximab is contraindicated in patients not referred for cardiac catheterization.

1. UFH is preferred, particularly for emergent PCI; give an IV bolus of 50 to 60 units/kg followed by 12 units/kg per hour IV (goal aPTT time of 1.5 to 2 times control or approximately 50 to 75 seconds)
2. Enoxaparin is an alternative to UFH for patients not undergoing early PCI: Give as described in the STEMI section above, using the regimen for patients with STEMI who receive fibrinolytics
3. Fondaparinux is an alternative to enoxaparin in patients with NSTEMI at increased risk of bleeding being managed without PCI or fibrinolysis. The dose is 2.5 mg subcutaneously.
4. Bivalirudin is an acceptable alternative to UFH in patients going for PCI. It is given as an IV bolus of 0.1 mg/kg and an infusion of 0.25 mg/kg per hour before angiography. If used, bivalirudin is combined with oral clopidogrel 600 mg.

Other 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.

References: UTD

Medical Lecture Note