What is the initial management strategy for a patient with chronic stable angina in the outpatient department (OPD), including recommended drug dosages?

Management of Chronic Stable Angina in the Outpatient Setting

All patients with chronic stable angina require a dual-strategy approach: medications for symptom relief (antianginal drugs) combined with medications for event prevention (antiplatelet agents, statins, and ACE inhibitors), alongside aggressive lifestyle modification. 1

Medications for Event Prevention (Priority #1: Reduce Mortality)

These medications must be initiated in all patients unless contraindicated, as they directly reduce cardiovascular death and myocardial infarction:

Antiplatelet Therapy

• Aspirin 75-100 mg once daily is mandatory for all patients with chronic stable angina, particularly those with prior MI or revascularization 1, 2
• Clopidogrel 75 mg once daily is the alternative for aspirin-intolerant patients 1
• If the patient has undergone PCI with stenting, dual antiplatelet therapy (aspirin + clopidogrel) is required for 6 months 1

Lipid-Lowering Therapy

• Statins are mandatory in all patients with chronic stable angina, regardless of baseline cholesterol levels, due to proven mortality reduction 1, 2
• Add ezetimibe if LDL goals are not achieved with maximum tolerated statin dose 1
• For very high-risk patients not reaching goals on statin plus ezetimibe, consider adding a PCSK9 inhibitor 3

ACE Inhibitors

• ACE inhibitors are recommended for patients with hypertension, diabetes, heart failure, LV dysfunction, or prior MI 1, 2, 3
• Dosing examples: ramipril 10 mg daily (from HOPE trial) or perindopril (from EUROPA trial) 1
• These provide vasculoprotective effects beyond blood pressure reduction 1

Proton Pump Inhibitors

• Add a PPI for patients at high risk of gastrointestinal bleeding who are receiving aspirin, dual antiplatelet therapy, or oral anticoagulation 1

Medications for Symptom Relief (Antianginal Therapy)

Immediate Relief

• Sublingual nitroglycerin (short-acting nitrate) must be prescribed to all patients for immediate relief of angina episodes and situational prophylaxis 1, 2
• Critical pitfall: An angina attack that does not respond to sublingual nitroglycerin should be treated as a possible myocardial infarction 2

First-Line Antianginal Therapy

Beta-blockers are the preferred initial antianginal agent due to mortality benefits in post-MI patients and proven symptom control 1, 2:

• Bisoprolol 10 mg once daily, OR
• Metoprolol CR 200 mg once daily, OR
• Atenolol 100 mg once daily 2

Important: Diabetes is NOT a contraindication to beta-blockers; diabetic patients benefit equally or more 1, 2

Second-Line Antianginal Therapy (When Beta-Blockers Fail or Are Contraindicated)

If beta-blockers are contraindicated, not tolerated, or symptoms persist despite optimal dosing:

• Calcium channel blockers (CCBs) are the next choice 1, 2:

  • Amlodipine 5-10 mg once daily (dihydropyridine CCB), OR
  • Diltiazem CD 180-360 mg once daily (non-dihydropyridine CCB)

• Long-acting nitrates are considered third-line because a nitrate-free interval is required to avoid tolerance 2, 4

Critical pitfall: Avoid combining verapamil or diltiazem with beta-blockers in patients with heart failure due to negative inotropic effects 2

Critical pitfall: Immediate-release or short-acting dihydropyridine calcium antagonists should be avoided as they can increase adverse cardiac events 2

Third-Line Add-On Therapy (Refractory Symptoms)

If symptoms persist despite two antianginal drugs at optimal doses:

• Ranolazine 500 mg twice daily initially, then increase to 1000 mg twice daily as add-on therapy 2, 5

  • Ranolazine reduces angina frequency and nitroglycerin use when added to existing therapy 5
  • Particularly effective for microvascular angina 2

• Nicorandil may be considered as add-on therapy, though safety data in heart failure is uncertain 2

Critical pitfall: Using three antianginal drugs simultaneously may provide less symptomatic protection than two drugs 2

Critical pitfall: Do not combine ivabradine with non-dihydropyridine CCBs or strong CYP3A4 inhibitors 1, 2

Lifestyle Modifications (Essential Component)

• Exercise-based cardiac rehabilitation is mandatory and significantly reduces cardiovascular mortality while improving risk factor control 1, 3
• Aerobic physical activity: 150-300 minutes per week of moderate intensity OR 75-150 minutes per week of vigorous intensity 1
• Smoking cessation is strongly advised 1, 2
• Weight management and diabetic control are essential 2
• Annual influenza vaccination, especially in elderly patients 1, 3

When to Consider Revascularization

Coronary angiography with FFR/iFR guidance should be pursued when:

• Angina persists despite treatment with two antianginal drugs at optimal doses 2
• High-risk features are present (left main disease, three-vessel disease, proximal LAD stenosis, or impaired LV function) 2, 4
• Symptoms are inadequately responding to medical treatment and significantly limit lifestyle 1, 2

Follow-Up Strategy

• Review patient response to medical therapies at 2-4 weeks after drug initiation 1
• Clinical follow-up every 4-12 months to assess symptom control, medication adherence, risk factor modification, and functional status 1, 3
• Patient education about the disease, risk factors, and treatment strategy is essential for long-term adherence 1, 3

Common Pitfalls to Avoid

• Poor medication adherence is a common cause of treatment failure and should always be assessed 2
• Nitrates are contraindicated in patients with hypertrophic obstructive cardiomyopathy or those taking phosphodiesterase inhibitors 1
• Optimize one drug's dosing before adding another; avoid polypharmacy without adequate dose titration 2
• Do not combine nicorandil with nitrates as it lacks additional efficacy 2