What is the approach to treating stable angina?

Approach to Stable Angina Treatment

The treatment of stable angina requires two parallel strategies: prognostic therapy (aspirin, statins, ACE inhibitors) to prevent MI and death, followed by symptomatic therapy starting with beta-blockers as first-line, then adding calcium channel blockers or other agents as needed for symptom control. 1, 2

Step 1: Immediate Prognostic Therapy (Prevents Death and MI)

These medications do not relieve symptoms but are mandatory because they reduce mortality and cardiovascular events 1, 2:

• Aspirin 75-325 mg daily for all patients without contraindications—this is non-negotiable as it reduces vascular events 1, 3, 2
• Statin therapy regardless of baseline cholesterol, targeting LDL-C <70 mg/dL when possible 2, 4
• ACE inhibitors for patients with coexisting hypertension, heart failure, LV dysfunction, prior MI, or diabetes 3, 2, 4

Critical distinction: These prognostic medications and symptomatic antianginal drugs are fundamentally different—no antianginal drug has been proven to reduce cardiovascular mortality or MI rates 1, 3

Step 2: First-Line Symptomatic Therapy

• Beta-blockers are the preferred initial antianginal agent due to mortality benefits in post-MI patients and proven efficacy in symptom control 3, 2, 4
• Target doses: bisoprolol 10 mg once daily, metoprolol 200 mg once daily, or atenolol 100 mg daily 3, 4
• Optimize the dose of one beta-blocker before adding another agent 4
• Sublingual nitroglycerin should be prescribed for all patients for immediate symptom relief and situational prophylaxis 4, 5

Step 3: Second-Line Therapy (If Beta-Blockers Fail or Are Contraindicated)

• Add or substitute with calcium channel blockers if beta-blockers are contraindicated, not tolerated, or symptoms persist despite optimal dosing 3, 4
• Long-acting dihydropyridines (amlodipine) or non-dihydropyridines (diltiazem, verapamil) are equally effective 3, 6
• Long-acting nitrates are considered third-line because a nitrate-free interval is required to avoid tolerance 4, 6

Step 4: Third-Line Add-On Therapy

If symptoms persist despite two antianginal drugs 4:

• Ranolazine 500-1000 mg twice daily can be added to existing therapy—proven effective in the CARISA and ERICA trials when added to beta-blockers or calcium channel blockers 5
• Ivabradine for patients with heart failure and reduced ejection fraction (LVEF <40%) 4
• Nicorandil as add-on therapy, though safety data in heart failure is uncertain 4

Step 5: Revascularization

• Consider coronary arteriography when symptoms are not satisfactorily controlled by medical treatment with two antianginal drugs 4
• PCI is effective for anatomically suitable lesions in patients with persistent symptoms 3, 4
• CABG is indicated for significant stenosis (≥50% left main, proximal three-vessel disease) and reduces mortality in specific subgroups: left main stenosis, proximal LAD stenosis, or three-vessel disease with impaired LV function 1, 3, 4

Mandatory Lifestyle Modifications

• Smoking cessation is mandatory—it directly impacts mortality 2
• Aerobic physical activity 150-300 minutes per week at moderate intensity 2
• Mediterranean diet emphasizing vegetables, fruit, fish, and poultry 2
• Weight management and strict diabetic control 4

Critical Pitfalls to Avoid

• Never combine verapamil or diltiazem with beta-blockers in heart failure patients—negative inotropic effects 4
• Avoid immediate-release or short-acting dihydropyridine calcium antagonists—they can increase adverse cardiac events 4
• Do not use three antianginal drugs simultaneously—may provide less symptomatic protection than two drugs 4
• Beta-blockers are absolutely contraindicated in vasospastic angina (Prinzmetal's)—they cause unopposed alpha-mediated vasoconstriction, worsening coronary spasm 3
• Avoid combining ivabradine with non-dihydropyridine CCBs or strong CYP3A4 inhibitors 4
• Poor medication adherence is a common cause of treatment failure and should always be assessed 4

Special Considerations

• Up to 40% of patients may have microvascular angina rather than obstructive epicardial disease, explaining why ischemia can persist after successful revascularization 1, 2
• For vasospastic angina, calcium channel blockers are the gold standard first-line therapy (verapamil 240-480 mg/day, diltiazem 180-360 mg/day, or nifedipine 60-120 mg/day) 3
• Diabetes is not a contraindication for beta-blockers—diabetic patients benefit equally or more from their use 4
• An angina attack that does not respond to short-acting nitroglycerin should be regarded as a possible myocardial infarction 4