What is the ongoing medical management of angina?

Ongoing Medical Management of Angina

The ongoing medical management of angina requires two distinct therapeutic strategies: aspirin 75 mg daily, statin therapy, and ACE inhibitors (if indicated) to prevent cardiovascular events and reduce mortality, combined with beta-blockers as first-line symptomatic therapy, with short-acting nitrates for all patients for immediate relief. 1, 2

Dual Treatment Goals

Pharmacological therapy for chronic stable angina has two fundamentally different objectives that cannot be achieved with the same medications 3:

• Prognostic therapy (preventing MI and death): aspirin, statins, and ACE inhibitors do not alleviate symptoms 3
• Symptomatic therapy (reducing angina and improving quality of life): antianginal drugs do not improve survival 3

Medications for Prognostic Benefit (Disease Modification)

These medications reduce cardiovascular events and mortality but do not relieve anginal symptoms:

• Aspirin 75-150 mg daily should be prescribed to all patients unless contraindicated 1, 2
• Statin therapy is mandatory for all patients with coronary disease regardless of cholesterol levels 1, 2
• ACE inhibitors are recommended for patients with coexisting hypertension, heart failure, LV dysfunction, prior MI with LV dysfunction, or diabetes 1, 2

First-Line Symptomatic Therapy

Beta-blockers are the initial antianginal agent of choice 1, 2, 4:

• Start with metoprolol 200 mg once daily, bisoprolol 10 mg once daily, or atenolol 100 mg daily as target doses 1
• Beta-blockers reduce heart rate, myocardial contractility, and oxygen demand 5
• They are superior to calcium channel blockers in reducing exercise-induced ischemia 2
• Critical warning: Never abruptly discontinue beta-blockers in patients with coronary artery disease, as this can precipitate severe exacerbation of angina, MI, and ventricular arrhythmias 5
• When discontinuing, taper gradually over 1-2 weeks 5

Short-Acting Nitrates for All Patients

• Sublingual nitroglycerin must be prescribed to every patient for immediate symptom relief and situational prophylaxis 1, 2
• Patients should sit during first use to prevent hypotension 1
• If angina does not respond to nitroglycerin, patients must seek emergency care immediately as this may indicate myocardial infarction 2

Second-Line Symptomatic Options

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

• Calcium channel blockers are the next option 1, 2, 4

  • Long-acting dihydropyridines (amlodipine 5-10 mg daily) or non-dihydropyridines are equally effective 6, 4
  • Amlodipine has demonstrated reduction in hospitalizations for angina and revascularization procedures in documented CAD 6
  • Avoid immediate-release or short-acting dihydropyridine calcium antagonists as they can increase adverse cardiac events 2

• Long-acting nitrates are considered third-line therapy 4

  • Require nitrate-free intervals to prevent tolerance 2, 4
  • Can be combined synergistically with beta-blockers to block reflex tachycardia 3

Combination Therapy Strategy

Double or triple therapy is often needed to control symptoms effectively 3:

• Combinations should have additive or synergistic effects 3
• Optimize dosing of one drug before adding another - using three antianginal drugs simultaneously may provide less symptomatic protection than two optimally dosed drugs 2
• Nitrates combined with beta-blockers provide synergistic anti-ischemic effects by blocking reflex tachycardia 3

Alternative Agents

For patients with contraindications or inadequate response to first-line therapy, second-choice medications include ivabradine, nicorandil, ranolazine, and trimetazidine 3:

• No direct comparisons have demonstrated superiority of first-choice over second-choice agents 3
• Meta-analyses show all antianginal drugs have similar efficacy in reducing symptoms 3

Special Consideration: Vasospastic Angina

• High-dose calcium channel blockers are the mainstay (up to 480 mg/day verapamil, 260 mg/day diltiazem, or 120 mg/day nifedipine) 2

Essential Lifestyle Modifications

Risk factor modification must accompany pharmacological therapy 1:

• Smoking cessation
• Mediterranean diet
• Regular physical activity
• Weight reduction
• Strict diabetic control 1

When to Consider Revascularization

• Symptoms not adequately controlled with optimal medical therapy (two or more antianginal drugs at optimal doses) 2
• High-risk anatomical features: left main stenosis ≥50%, proximal three-vessel disease, or proximal LAD stenosis 1
• Left ventricular dysfunction 2

Critical Pitfalls to Avoid

• Poor medication adherence is a common cause of treatment failure and must always be assessed 2
• Never use three antianginal drugs before optimizing two 2
• Avoid abrupt beta-blocker discontinuation 5
• Ensure nitrate-free intervals to prevent tolerance 2
• Avoid short-acting dihydropyridines 2

Important Pathophysiology Note

Up to 40% of patients with angina may have microvascular angina (coronary microvascular dysfunction) rather than obstructive epicardial disease 3:

• This explains why myocardial ischemia can persist after successful revascularization 3
• Treatment approach remains the same but helps explain refractory symptoms in some patients 3