(See also Overview of Coronary Artery Disease Overview of Coronary Artery Disease Coronary artery disease (CAD) involves impairment of blood flow through the coronary arteries, most commonly by atheromas. Clinical presentations include silent ischemia, angina pectoris, acute... read more .)
Many patients with variant angina also have significant fixed obstruction of at least one major coronary artery. Patients with mild or no fixed obstructions have better long-term outcomes than patients with associated severe fixed obstructions.
Symptoms and Signs of Variant 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.
Diagnosis of Variant Angina
Provocative testing with ergonovine or acetylcholine during angiography
Diagnosis of variant angina is suspected if ST-segment elevation occurs during the attack. Between anginal attacks, the ECG may be normal or show a stable abnormal pattern.
Confirmation is by provocative testing with ergonovine or acetylcholine, which may precipitate coronary artery spasm. Coronary artery spasm is identified by finding significant ST-segment elevation on ECG or by observation of a reversible spasm during cardiac catheterization. Testing is done most commonly in a cardiac catheterization laboratory.
Treatment of Variant Angina
Calcium channel blockers
Average survival at 5 years is 89 to 97%, but mortality risk is greater for patients with both variant angina and atherosclerotic coronary artery obstruction. Risk increases with increasing obstruction.
Usually, sublingual nitroglycerin promptly relieves variant angina. Calcium channel blockers may effectively prevent symptoms. Theoretically, beta-blockers may exacerbate spasm by allowing unopposed alpha-adrenergic vasoconstriction, but this effect has not been proven clinically.
Oral drugs most commonly used are calcium channel blockers:
Sustained-release diltiazem 120 to 540 mg once a day
Sustained-release verapamil 120 to 480 mg once a day (dose must be reduced in patients with renal or hepatic dysfunction)
Amlodipine 5 to 10 mg once a day (dose must be reduced in elderly patients and in patients with hepatic dysfunction)
Although all these drugs relieve symptoms, they do not appear to alter prognosis.