Initial Management of NSTEMI

Immediate Stabilization and Monitoring

The American College of Cardiology recommends administering aspirin 162-325 mg orally upon presentation, initiating anticoagulation with unfractionated heparin or enoxaparin, adding a P2Y12 inhibitor, and performing risk stratification to determine timing of invasive strategy within 24 hours 1, 2, 3
Patients with NSTEMI should be admitted to a monitored unit with continuous cardiac rhythm monitoring for at least 24 hours to detect arrhythmias and electrical instability 1, 3
Supplemental oxygen should be administered only if arterial oxygen saturation is <90% to avoid routine oxygen in normoxic patients 1, 3
Sublingual or intravenous nitroglycerin should be considered for ongoing ischemic chest pain, unless contraindicated by systolic blood pressure <90 mmHg, severe bradycardia or tachycardia, right ventricular infarction, or recent phosphodiesterase inhibitor use (within 24-48 hours) 1, 3
Beta-blocker therapy should be initiated to reduce myocardial oxygen demand by decreasing heart rate, blood pressure, and contractility 1, 3
Morphine sulfate intravenously should be considered for uncontrolled ischemic chest discomfort despite nitroglycerin, though use cautiously as it may delay P2Y12 inhibitor absorption 1

Aspirin is the cornerstone and must be given immediately, with a loading dose of 162-325 mg orally (non-enteric coated for faster absorption) 1, 2, 3
The maintenance dose of aspirin is 75-100 mg daily indefinitely 1, 2
A P2Y12 inhibitor, such as ticagrelor (180 mg loading dose, then 90 mg twice daily) or clopidogrel (300-600 mg loading dose, then 75 mg daily), should be added before diagnostic angiography (upstream administration) 1, 2, 3, 4, 5

Parenteral anticoagulation should be initiated immediately in all patients, with options including unfractionated heparin, enoxaparin, or fondaparinux 1, 4, 6, 7
For early invasive strategy, unfractionated heparin or enoxaparin should be used, while fondaparinux is preferred for conservative strategy due to lower bleeding risk 1, 4, 6, 7

Immediate risk stratification using GRACE or TIMI score should be performed to determine the timing of invasive strategy 1, 2, 9
Early invasive strategy (angiography within 12-24 hours) is mandatory for high-risk patients, including those with refractory angina, hemodynamic instability, electrical instability, elevated cardiac troponin with high-risk features, or high GRACE or TIMI risk score 1, 2, 9
Conservative strategy (selective invasive) may be considered for low-to-intermediate risk patients who are initially stabilized 1, 9

Eptifibatide or tirofiban may be added upstream (before angiography) in very high-risk patients, particularly if delay to catheterization is anticipated 4, 5, 6
Abciximab should not be given upstream, only use if PCI is imminent with no delay to angiography 4, 5, 6

Beta-blockers should be initiated within 24 hours unless contraindicated, and continued indefinitely for secondary prevention 2, 3
ACE inhibitors should be started within 24 hours for patients with heart failure, left ventricular dysfunction, hypertension, or diabetes, and ARBs should be used for ACE inhibitor-intolerant patients 1, 2, 3
Statins should be initiated with high-intensity statin therapy (atorvastatin 80 mg or rosuvastatin 40 mg) regardless of baseline LDL cholesterol 1, 2

NSAIDs (except aspirin) should be avoided during hospitalization due to increased mortality, reinfarction, hypertension, heart failure, and myocardial rupture risk 1, 3
Immediate-release dihydropyridine calcium channel blockers (nifedipine) should not be used without adequate beta-blockade 1, 3
Omeprazole and esomeprazole should be avoided with clopidogrel due to reduced antiplatelet effect; use other PPIs if gastroprotection is needed 4
Angiography should not be delayed in high-risk patients for "medical stabilization", as early invasive approach (within 24 hours) reduces ischemic events 9, 1, 2