What are the treatment approaches for angina?

Treatment Approaches for Angina

The cornerstone of angina treatment is a stepwise pharmacological approach starting with sublingual nitroglycerin for acute relief, followed by beta-blockers as first-line therapy, with calcium channel blockers or long-acting nitrates added as needed for symptom control. 1

Initial Management

Acute Symptom Relief

• Sublingual nitroglycerin (0.4 mg) should be provided to all patients for immediate relief of angina attacks and situational prophylaxis 1
  • Can be administered up to 3 doses at 3-5 minute intervals until pain is relieved 2
  • If patients do not respond to sublingual preparations, buccal preparations should be considered as they are more effective 1

Risk Factor Modification

• All patients should receive:
  • Aspirin 75-300 mg daily (or clopidogrel 75 mg daily if aspirin is contraindicated) 1
  • Statin therapy for LDL cholesterol reduction 1
  • Smoking cessation counseling (if applicable) 1
  • Blood pressure control according to guidelines 1
  • Weight reduction if BMI is elevated 1

Stepwise Pharmacological Therapy

First-Line Therapy

• Beta-blockers should be initiated and titrated to full dose 1
  • Provides 24-hour protection against ischemia
  • Particularly beneficial in patients with prior MI 1
  • Patients should be warned not to stop beta-blockers suddenly; they should be tapered over four weeks 1

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

• Calcium channel blockers (long-acting) 1
  • Particularly effective for vasospastic angina in high doses (up to 480 mg/day verapamil, up to 260 mg/day diltiazem, up to 120 mg/day nifedipine) 1
  • Amlodipine has demonstrated efficacy in exercise-induced angina at doses of 5-10 mg daily 3

OR

• Long-acting nitrates 1
  • Must be used with a nitrate-free interval (10-12 hours, typically overnight) to avoid tolerance 1, 2, 4
  • Nitrate patches should be used in dosages of at least 10 mg 1

OR

• Nicorandil (where available) 1
  • Particularly useful for vasospastic angina 1, 2

Third-Line Therapy (if symptoms persist)

• Combination therapy: Add calcium channel blocker to beta-blocker 1

  • If this combination is unsuccessful, substitute the calcium channel blocker with a long-acting nitrate or nicorandil 1

• Ranolazine (750-1000 mg twice daily) can be considered as add-on therapy 5, 6

  • Demonstrated efficacy in reducing angina frequency and nitroglycerin use when added to standard therapy 5
  • Particularly useful when added to maximum doses of other anti-anginal agents 5

Special Considerations

Vasospastic Angina

• Calcium channel blockers are the mainstay of treatment 1, 7
  • High doses may be required (as noted above)
  • Complete resolution of symptoms occurs in only 38% of patients 1
• Long-acting nitrates should be added if calcium channel blockers alone are insufficient 1, 7
• Consider discontinuing treatment after 6-12 months if angina has disappeared, as spontaneous remission occurs in about half of patients 1

Refractory Angina

• If patients are not adequately controlled by maximal therapeutic doses of two drugs, the remaining evidence-based therapeutic options are limited 1
• If a third drug is introduced, its effect should be monitored and discontinued if ineffective 1
• Consider referral for evaluation for revascularization 1

Common Pitfalls and Caveats

1. Nitrate tolerance: All nitrates must be used with a nitrate-free interval to maintain efficacy 1, 2, 4

2. Poor adherence: Always consider medication adherence when drug therapy is unsuccessful 1

3. Inappropriate dosing: Optimize the dose of one drug before adding another 1

4. Abrupt discontinuation: Beta-blockers should never be stopped suddenly due to risk of rebound angina 1

5. Overlooking prophylaxis: Many patients are unaware of the prophylactic use of sublingual nitroglycerin before engaging in activities that might trigger angina 8

6. Gender differences: Treatment effects on angina frequency and exercise tolerance may be considerably smaller in women than in men 5