What is the initial treatment for coronary vasospasm?

Initial Treatment for Coronary Vasospasm

Calcium channel blockers (CCBs) are the first-line treatment for coronary vasospasm, with high doses often required (up to 480 mg/day verapamil, 260 mg/day diltiazem, or 120 mg/day nifedipine), while short-acting nitrates should be provided for acute symptom relief. 1

Immediate Management of Acute Vasospastic Episodes

• Short-acting sublingual nitroglycerin (0.3-0.4 mg) or isosorbide dinitrate (5-10 mg) should be provided for immediate relief of acute vasospastic episodes 1, 2
• For episodes resistant to sublingual nitrates, sublingual nifedipine (5-10 mg) or intravenous nitrates (nitroglycerin or isosorbide dinitrate, 2-10 mg) can be administered 2
• During coronary angiography, if vasospasm is detected, intracoronary nitroglycerin (0.3 mg) should be directly infused into the affected coronary artery 1

Long-Term Pharmacological Management

First-Line Therapy

• Calcium channel blockers are the cornerstone of treatment for coronary vasospasm due to their effectiveness in alleviating signs and symptoms of coronary spasm 1
• High doses of CCBs are often required and should be titrated to maximum tolerated doses:
  • Verapamil: up to 480 mg/day
  • Diltiazem: up to 260 mg/day
  • Nifedipine: up to 120 mg/day 1
• Amlodipine (10 mg daily) has been shown to be effective in reducing anginal episodes in patients with vasospastic angina 3
• CCBs block the calcium ion influx into vascular smooth muscle cells, inhibiting coronary spasm 4

Combination Therapy

• In most patients, a combination therapy with long-acting nitrates and high doses of calcium channel blockers will result in improved symptoms, as CCBs alone achieve complete resolution in only 38% of patients 1
• For severe vasospastic angina, it may be necessary to use unusually high dosages of calcium antagonists or even a combination of non-dihydropyridine (such as diltiazem) with dihydropyridine calcium blockers (such as amlodipine) 1
• Nicorandil, a potassium channel activator, may be useful in patients with refractory vasospastic angina 1

Special Considerations

• Removal of precipitating factors such as smoking cessation is essential in the management of vasospastic angina 1
• Beta-blockers have theoretical adverse potential in vasospastic angina and their clinical effect is controversial 1
• Alpha-receptor blockers have been reported to be of benefit, especially in patients who are not responding completely to calcium channel blockers and nitrates 1
• Spontaneous remission of spasmodicity occurs in about half of western people following medical treatment for at least 1 year, making it acceptable to taper and discontinue treatment 6-12 months after angina has disappeared 1

Treatment of Refractory Vasospastic Angina

• For patients with refractory vasospastic angina not responding to conventional therapy, unconventional treatment methods may need to be considered 5
• Long-acting CCBs and nitrates are recommended in patients with coronary artery spasm (Class I recommendation) 1
• Immediate-release nifedipine should not be administered to patients with acute coronary syndromes in the absence of beta-blocker therapy (Class III: Harm) 1

Prognosis

• The prognosis of variant angina is usually excellent in patients who receive medical therapy, especially in patients with normal or near-normal coronary arteries 1
• The 5-year survival rate is approximately 89-97% overall 1
• Patients with coronary artery vasospasm superimposed on fixed obstructive coronary artery disease have a worse prognosis 1

Common Pitfalls and Caveats

• Avoid using beta-blockers as first-line therapy as they may theoretically worsen coronary vasospasm 1
• Do not undertreat with inadequate doses of calcium channel blockers; high doses are often required for effective control 1
• Be aware that immediate-release nifedipine should not be used without beta-blocker therapy in acute coronary syndromes 1
• Remember that nitrates are highly effective in abolishing acute vasospasm but are not as successful in preventing attacks of resting angina 1
• Monitor for potential side effects of high-dose calcium channel blockers, including peripheral edema 3