What is the recommended management for angina?

Management of Angina

All patients with angina should receive aspirin 75-300 mg daily and sublingual nitroglycerin for acute symptom relief, with beta-blockers as first-line regular therapy for symptom control, titrated to full dose unless contraindicated. 1, 2

Immediate Symptomatic Relief

• Sublingual nitroglycerin (0.3-0.4 mg) should be taken in response to pain and prophylactically before activities that trigger angina 1, 2
• If sublingual preparations fail, buccal nitroglycerin should be considered as it is more effective than sublingual formulations 1
• Patients can repeat nitroglycerin every 3-5 minutes if pain persists 3

Prognostic (Mortality-Reducing) Medications

These medications improve survival and must be prescribed to all eligible patients:

• Aspirin 75-300 mg daily reduces subsequent vascular events and should be given to all patients 1, 2
• Statins should be prescribed to all patients with documented coronary artery disease to reduce adverse ischemic events 2
• ACE inhibitors should be used in patients with hypertension, heart failure, left ventricular dysfunction, prior myocardial infarction, or diabetes 2

First-Line Regular Symptomatic Treatment

• Beta-blockers are first-line therapy for regular symptom control due to their effects on heart rate, contractility, and mortality benefits 1, 2
• Beta-blockers should be titrated to full therapeutic doses for maintenance therapy 2
• Critical warning: Patients must not stop beta-blockers suddenly as this can cause severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias 1, 4
• When discontinuation is necessary, beta-blockers must be tapered over 4 weeks (or 1-2 weeks per FDA labeling) 1, 4
• Patients should be warned not to allow prescriptions to run out 1

Second-Line Regular Symptomatic Treatment

If beta-blockers alone are insufficient or contraindicated:

• Add a long-acting dihydropyridine calcium channel blocker (such as amlodipine) to beta-blocker therapy 2
• Long-acting calcium channel blockers should be used when beta-blockers are contraindicated or ineffective 2
• Never use short-acting dihydropyridine calcium antagonists without concurrent beta-blocker therapy due to increased risk of adverse cardiac events 2
• Long-acting nitrates can be used as an alternative to calcium channel blockers when beta-blockers are contraindicated 2

Nitrate Therapy Considerations

• All nitrates (oral and patches) must be used with a nitrate-free interval to avoid tolerance 1, 2
• Nitrate patches should be dosed at least 10 mg 1
• A simple method is removing the patch at bedtime and reapplying in the morning, providing a patch-free period when most patients experience few attacks 5
• Continuous 24-hour nitrate therapy leads to tolerance in most patients with stable angina 5

Treatment Algorithm for Inadequate Control

• If symptoms persist despite maximal doses of beta-blocker monotherapy, add a dihydropyridine calcium channel blocker 2
• If patients are not adequately controlled by maximal therapeutic doses of two drugs, refer to cardiology rather than adding a third drug 1, 2
• If a third drug is introduced, monitor its effect closely and discontinue if ineffective 1
• If a patient cannot tolerate a beta-blocker or verapamil, use the cheapest drug that controls symptoms and ensures compliance 1

Referral Indications

All patients with clinically certain angina should be referred to identify whether they would benefit from prognostic investigation and treatment 1, 2

Specific referral triggers:

• Symptoms uncontrolled despite full doses of two drugs 1, 2
• Uncertain diagnosis requiring clarification 1
• Pain on minimal exertion 1
• Patients with uncontrolled symptoms should be referred for angiography, not exercise testing 1

Referral decisions are influenced by clinical factors (pain severity, age), comorbidity, risk factors, patient preference, and threat to employment or lifestyle 1

Medications to Avoid

• Dipyridamole is not recommended as it can enhance exercise-induced myocardial ischemia 2
• Chelation therapy is not recommended due to lack of evidence 2
• Short-acting dihydropyridine calcium antagonists should be avoided unless combined with beta-blockers 2

Common Pitfalls

• Beta-blockers may mask tachycardia from hypoglycemia in diabetic patients, though dizziness and sweating remain 4
• In pheochromocytoma, beta-blockers must only be given after alpha-blocker initiation to avoid paradoxical hypertension 4
• Beta-blockers may mask hyperthyroidism signs; avoid abrupt withdrawal which can precipitate thyroid storm 4
• Metoprolol exhibits several-fold higher plasma concentrations in poor CYP2D6 metabolizers (8% of Caucasians), decreasing cardioselectivity 4
• Patients with bronchospastic disease generally should not receive beta-blockers, but if necessary, use the lowest possible dose with readily available bronchodilators 4