What is the treatment for unstable angina?

Treatment of Unstable Angina

The treatment of unstable angina requires immediate hospitalization, preferably in a coronary care unit, with administration of antiplatelet therapy (aspirin and clopidogrel), anticoagulation (unfractionated or low molecular weight heparin), anti-ischemic medications (beta-blockers, nitrates), and early invasive management for high-risk patients. 1

Initial Management

• Patients with unstable angina should be hospitalized immediately, preferably in a coronary care unit, for close monitoring and aggressive treatment 1
• Provide short-acting nitroglycerin for immediate symptom relief with proper usage instructions 1
• Administer aspirin 75-150 mg daily as it significantly reduces the risk of myocardial infarction, stroke, or death 1, 2
• Initiate clopidogrel with a 300 mg loading dose followed by 75 mg daily in conjunction with aspirin 3
• Start beta-blockers intravenously in hemodynamically stable patients, followed by oral maintenance therapy 1
• Begin anticoagulation with either unfractionated heparin (UFH) or low molecular weight heparin (LMWH) 2, 1
• Enoxaparin is preferable to UFH as an anticoagulant in patients with unstable angina/NSTEMI, unless coronary artery bypass grafting (CABG) is planned within 24 hours 2

Risk Stratification and Invasive Management

• High-risk patients are identified by recurrent ischemia, elevated troponin levels, hemodynamic instability, major arrhythmias, or early post-infarction unstable angina 1
• If non-cardiac surgery can be postponed safely, patients should be diagnosed and treated according to unstable angina management guidelines 2
• In the unlikely combination of a life-threatening clinical condition requiring urgent non-cardiac surgery and acute coronary syndrome, surgery should be given priority 2
• An early invasive strategy with routine coronary angiography within 48 hours followed by revascularization is recommended for intermediate to high-risk patients 2
• The TACTICS-TIMI 18 trial demonstrated that an early invasive strategy reduced death, myocardial infarction, or rehospitalization for acute coronary syndrome at 6 months (15.9% vs 19.4%) compared to a conservative strategy 2

Pharmacological Treatment

• Beta-blockers: Administer intravenously in hemodynamically stable patients, followed by oral maintenance therapy 1
• Nitrates: Use intravenous nitroglycerin for acute management, followed by long-acting nitrates for maintenance therapy 1
• Dual antiplatelet therapy: Continue aspirin 75-150 mg daily long-term and clopidogrel 75 mg daily for at least 12 months 1, 3
• Anticoagulation: Use either unfractionated heparin or low molecular weight heparin during the acute phase 2
• Statins: Initiate high-intensity statin therapy for all patients with unstable angina 1

Revascularization Options

• If percutaneous coronary intervention (PCI) is indicated, the use of bare metal stents or balloon angioplasty is recommended when non-cardiac surgery is planned soon after intervention 2
• For patients with significant left main disease, three-vessel disease (particularly with depressed left ventricular function), coronary artery bypass grafting (CABG) should be performed to improve prognosis and relieve symptoms 2
• The choice between PCI and CABG will depend on several factors including coronary anatomy, comorbidities, and patient preference 2

Long-term Management

• Continue aspirin 75-150 mg daily indefinitely 1
• Maintain beta-blocker therapy, particularly in post-MI patients 1
• Continue statin therapy for all patients with coronary disease 1
• Consider ACE inhibitors for patients with left ventricular dysfunction, hypertension, or diabetes 2

Common Pitfalls and Caveats

• Avoid immediate-release or short-acting dihydropyridine calcium antagonists as they may increase adverse cardiac events 1
• Be cautious with clopidogrel in patients who are CYP2C19 poor metabolizers, as they may have reduced antiplatelet effect 3
• Avoid concomitant use of clopidogrel with omeprazole or esomeprazole as they significantly reduce the antiplatelet activity 3
• Ensure proper nitrate dosing schedule with nitrate-free intervals to prevent tolerance 1
• Monitor for bleeding complications with dual antiplatelet therapy and anticoagulation 3