Vasospastic Angina

Symptoms are anginal discomfort occurring mainly during rest, often at night, and only rarely and inconsistently during exertion (unless significant coronary artery obstruction is also present). Attacks tend to occur regularly at certain times of day.

• Diagnostic criteria

• Provocative testing with ergonovine or acetylcholine during angiography

Diagnosis of vasospastic angina is suspected if ST-segment elevation occurs during an attack. Between anginal attacks, the ECG may be normal or show a stable abnormal pattern.

Definitive diagnosis requires (1, 2):

• Nitrate-responsive angina during a spontaneous episode

• ECG changes during a spontaneous episode

• Epicardial coronary artery spasm with near-total constriction either spontaneously or in response to provocative testing

ECG Changes in Vasospastic Angina

Image

This image shows ST-segment elevation in the inferior leads (II, III, aVF) consistent with an acute vasospasm of the right coronary artery.

Susmit/stock.adobe.com

Confirmation is by provocative testing with ergonovine, acetylcholine, or hyperventilation, which may precipitate coronary artery spasm. Coronary artery spasm is identified by finding significant ST-segment elevation on ECG and/or by observation of a reversible spasm during cardiac catheterization. Testing is performed most commonly in a cardiac catheterization laboratory.

• Trigger avoidance

• Sublingual nitroglycerin acutely

• Risk factor management as appropriate (aspirin or statin, smoking cessation, glycemic control, weight loss, physical activity)

• Calcium channel blockers

• Sometimes long-acting nitrates or nicorandil

Smoking is a common trigger for vasospasm and should be avoided, as should sympathomimetics such as cocaine and methamphetamine (1). Beta-blockers may exacerbate spasm by allowing unopposed alpha-adrenergic vasoconstriction and are not recommended for use for vasospastic angina (2).

Usually, sublingual nitroglycerin promptly relieves vasospastic angina.

For patients with coexisting atherosclerotic disease, risk factor management, including antiplatelet therapy, lipid control, smoking cessation, glycemic control, weight loss, dietary changes, and physical activity, is important.

Non-dihydropyridine, long-acting calcium channel blockers (diltiazem and verapamil) may effectively prevent symptoms and are recommended as first-line therapy (3). Long-acting nitrates are a second-line option, followed by substitution of nicorandil for the long-acting nitrate (3).

Although all these medications relieve symptoms, they do not appear to alter prognosis. Average survival at 5 years is approximately 95% if concomitant obstructive coronary artery disease is absent or present in only one vessel, and it is approximately 80% for patients with multivessel obstructive coronary artery disease. Mortality risk is greater for patients with both vasospastic angina and atherosclerotic coronary artery obstruction (4, 5).