What is the treatment for unstable angina?

Treatment of Unstable Angina

The initial treatment of unstable angina should include short-acting beta-selective blockers without intrinsic sympathomimetic activity, usually administered intravenously, along with nitrates for symptom control, aspirin, and anticoagulation with heparin. 1

Initial Management

• Patients with unstable angina should be hospitalized, preferably in a coronary care unit, for close monitoring and aggressive treatment 1
• Provide short-acting nitroglycerin for immediate symptom relief with appropriate instructions on proper use 1
• Administer aspirin 75-150 mg daily as it significantly reduces the risk of myocardial infarction, stroke, or death (risk reduction of 5.5% in unstable angina) 1
• Start intravenous beta-selective blockers without intrinsic sympathomimetic activity, with oral beta-blockers substituted later during hospitalization 1
• Initiate anticoagulation with heparin (unfractionated or low molecular weight) 1

Pharmacological Treatment

First-Line Medications

• Beta-blockers: Should be administered initially intravenously in hemodynamically stable patients, followed by oral maintenance therapy 1
• Nitrates: Intravenous nitroglycerin for acute management, followed by long-acting nitrates for maintenance therapy 1
• Aspirin: 75-150 mg daily, should be continued long-term (at least 18 months) 1
• Heparin: Either unfractionated heparin (bolus of 5,000 U followed by infusion of 1,000 U/h titrated to maintain APTT of approximately 2 times control) or low molecular weight heparin 1, 2

Additional Medications

• Calcium channel blockers: If beta-blockers are contraindicated or not tolerated, non-dihydropyridine calcium channel blockers (verapamil or diltiazem) may be substituted, but not if there is left ventricular dysfunction 1
• ACE inhibitors: Should be added if the patient has an anterior MI, persistent hypertension, evidence of left ventricular dysfunction, heart failure, or diabetes mellitus 1
• Statins: All patients with coronary disease should receive statin therapy 1
• GP IIb/IIIa receptor blockers: Consider in high-risk patients, particularly those undergoing percutaneous coronary intervention 1, 2

Risk Stratification and Further Management

• High-risk patients include those with recurrent ischemia, elevated troponin levels, hemodynamic instability, major arrhythmias, or early post-infarction unstable angina 1
• For high-risk patients, early coronary angiography (within initial hospitalization) should be performed 1
• If symptoms persist despite optimal medical therapy, coronary angiography followed by appropriate revascularization (PCI or CABG) is indicated 1

Long-term Management

• Continue aspirin 75 mg daily long-term 1
• Maintain beta-blocker therapy, particularly in post-MI patients 1
• Continue statin therapy for all patients with coronary disease 1
• ACE inhibitor therapy for patients with hypertension, heart failure, LV dysfunction, prior MI with LV dysfunction, or diabetes 1
• Consider clopidogrel as an alternative antiplatelet agent in patients who cannot take aspirin 1

Common Pitfalls and Caveats

• Avoid immediate-release or short-acting dihydropyridine calcium antagonists as they may increase adverse cardiac events 1
• In patients with elevated diastolic blood pressure and acute coronary syndrome, blood pressure should be lowered slowly, with caution to avoid falls of DBP below 60 mmHg 1
• An attack of angina that does not respond to short-acting nitroglycerin should be regarded as a possible myocardial infarction 1
• Avoid nitrate tolerance by ensuring a daily "nitrate-free" interval when using long-acting nitrates 1
• Thrombolytic agents are not recommended for routine treatment of unstable angina without objective evidence of ongoing ischemia 3

By following this evidence-based approach to the management of unstable angina, clinicians can effectively reduce symptoms, prevent progression to myocardial infarction, and improve overall outcomes for patients with this serious condition.