Treatment for Prinzmetal's Angina
Calcium channel blockers and nitrates are the first-line therapies for Prinzmetal's angina, with calcium channel blockers preventing spasm in approximately 90% of patients. 1, 2
First-Line Medical Therapy
- Calcium channel blockers are the cornerstone of treatment, with amlodipine, nifedipine, diltiazem, and verapamil all being highly effective options. 1, 3, 4
- Amlodipine is FDA-approved specifically for confirmed or suspected vasospastic angina and may be used as monotherapy or in combination with other antianginal agents. 3
- Nitrates (nitroglycerin and isosorbide dinitrate) effectively relieve coronary artery vasospasm and should be used alongside calcium channel blockers. 1, 5
- Long-acting nitrates provide prophylactic benefit, while sublingual nitroglycerin treats acute attacks. 5, 6
Critical Medications to Avoid
- Beta-blockers are contraindicated in Prinzmetal's angina because they cause unopposed alpha-adrenergic vasoconstriction, which precipitates and worsens coronary spasm. 1, 2, 7
- Large doses of aspirin are contraindicated in pure vasospastic angina without underlying atherosclerotic disease. 2, 7
Essential Non-Pharmacologic Management
- Smoking cessation is mandatory, as smoking is a significant risk factor for Prinzmetal's angina. 1
- Avoid triggers including emotional stress, cold exposure, and hyperventilation, as attacks often occur in early morning hours. 2
Second-Line and Refractory Cases
- For patients not responding completely to calcium channel blockers and nitrates, alpha-receptor blockers have been reported to be beneficial. 1
- Combination therapy using nitrates plus calcium channel blockers is needed in some patients who fail monotherapy. 5
- Patients with coronary artery vasospasm superimposed on fixed obstructive coronary artery disease require more aggressive therapy and have a worse prognosis. 1
Monitoring Requirements
- Monitor for resolution of anginal episodes and ST-segment changes on ECG to assess treatment efficacy. 1
- Long-term therapy is necessary despite symptom-free intervals, as Prinzmetal's angina often occurs in clusters with prolonged asymptomatic periods. 1
- Maintain vasodilator therapy throughout the perioperative period without interruption if surgery is required. 2
Common Pitfalls
- Do not use exercise stress testing for diagnosis or risk stratification, as it shows unpredictable and non-reproducible results in Prinzmetal's angina. 2, 8, 7
- Do not assume a normal resting ECG excludes active disease, as the ECG may be completely normal between episodes. 2, 8
- Recognize that 58% of Prinzmetal angina patients have underlying obstructive coronary disease, which dramatically alters risk assessment and treatment approach. 2