How to manage stable angina?

Management of Stable Angina

Beta-blockers should be the first-line therapy for stable angina, followed by calcium channel blockers or long-acting nitrates if beta-blockers are ineffective or contraindicated, with short-acting nitroglycerin prescribed to all patients for immediate symptom relief. 1

Pharmacological Management Algorithm

First-Line Therapy

• Provide short-acting nitroglycerin for immediate symptom relief and situational prophylaxis, with proper instructions on usage 1
• Start with a beta-blocker (e.g., metoprolol, atenolol, bisoprolol) titrated to full dose, considering 24-hour protection against ischemia 1
• Beta-blockers are superior to calcium channel blockers in reducing exercise-induced ischemia as demonstrated in the TIBBS study 1

Second-Line Therapy (if beta-blockers are ineffective or contraindicated)

• Try monotherapy with a calcium channel blocker (long-acting) 1
• Alternative options include long-acting nitrates or nicorandil 1
• Consider sinus node inhibitors (e.g., ivabradine) in patients who cannot tolerate beta-blockers 1

Combination Therapy

• If beta-blocker monotherapy is insufficient, add a dihydropyridine calcium channel blocker 1
• If calcium channel blocker monotherapy or combination therapy is unsuccessful, substitute with a long-acting nitrate or nicorandil 1
• Be careful to avoid nitrate tolerance by ensuring a nitrate-free interval 1

Third-Line Therapy

• Consider metabolic agents (e.g., ranolazine, trimetazidine) as add-on therapy when conventional drugs are not tolerated 1, 2
• Ranolazine has proven efficacy in reducing angina frequency and nitroglycerin use when added to standard therapy 2, 3

Medications for Prognostic Benefit

In addition to symptom control, these medications should be prescribed to improve prognosis:

• Aspirin 75-150 mg daily (unless contraindicated) 1
• Clopidogrel 75 mg daily as an alternative if aspirin is contraindicated 1
• Statin therapy for all patients with coronary disease 1
• ACE inhibitor therapy in patients with:
  • Hypertension
  • Heart failure
  • Left ventricular dysfunction
  • Prior myocardial infarction with LV dysfunction
  • Diabetes 1
  • Consider in all patients with proven coronary disease 1

Special Considerations

Vasospastic Angina Management

• Remove precipitating factors (e.g., smoking cessation) 1
• High-dose calcium channel blockers are the mainstay of treatment (up to 480 mg/day verapamil, up to 260 mg/day diltiazem, up to 120 mg/day nifedipine) 1
• Add long-acting nitrates if symptoms persist 1
• Consider nicorandil in refractory cases 1

Proper Use of Short-Acting Nitrates

• All patients should be prescribed sublingual nitroglycerin for immediate relief 1
• Patients should be properly educated on correct usage 4
• Can be used prophylactically before activities known to trigger angina 4
• If angina does not respond to nitroglycerin, patients should seek emergency care as this may indicate myocardial infarction 1

Avoiding Nitrate Tolerance

• Ensure a daily nitrate-free interval when using long-acting nitrates 1, 5
• Remove transdermal patches at night to achieve nitrate-free periods 1
• Consider pentaerythritol tetranitrate (PETN) which may have less tendency to develop tolerance 5

When to Consider Revascularization

• When symptoms are not adequately controlled with optimal medical therapy (two or more anti-anginal drugs at optimal doses) 1
• For high-risk patients with:
  • Left main coronary artery stenosis
  • Three-vessel disease
  • Two-vessel disease with proximal left anterior descending artery involvement
  • Especially if left ventricular function is impaired 1, 6

Common Pitfalls to Avoid

• Using three anti-anginal drugs simultaneously may provide less symptomatic protection than two drugs; optimize dosing of one drug before adding another 1
• Immediate-release or short-acting dihydropyridine calcium antagonists should be avoided as they can increase adverse cardiac events 1
• Poor medication adherence is a common cause of treatment failure and should always be assessed 1
• Nitrate tolerance can develop with continuous therapy; ensure proper dosing schedule with nitrate-free intervals 1, 5
• Overlooking patient education about proper use of sublingual nitroglycerin 4

Remember that treatment should be tailored based on individual patient characteristics, comorbidities, and response to therapy, with the goal of reducing mortality, preventing myocardial infarction, and eliminating angina symptoms to improve quality of life 7.