The diagnosis of
coronary artery spasm is confirmed by angiography, for example, change in caliber of the coronary arteries plus evidence of
ischemia. The prevalence and contribution of
coronary artery spasm in the individual patient with symptoms of
ischemic heart disease is not known and depends on how the condition is defined. The prognosis of patients with
coronary artery spasm appears to depend on the presence or absence of severe
coronary atherosclerosis, that is, those with severe disease have a worse prognosis.
Nitrates should be used to initiate
therapy in all patients with this problem. Intravenous
nitrates have proven useful in patients whose symptoms are difficult to control and who require hospitalization. beta blockers used alone may be detrimental in patients with
coronary artery spasm, but studies supporting the detrimental effects are few. The combination of
nitrates, beta blockers and
nifedipine has proved effective
therapy for many patients with recurrent
angina at rest, possibly related to
coronary artery spasm. Several open-label and double-blind placebo control trials have shown that all of the
calcium antagonists are effective short-term agents for patients with proven
coronary artery spasm. When
nifedipine was compared with
isosorbide dinitrate in a randomized crossover, double-blind trial in patients with
coronary artery spasm, both drugs were shown to be efficacious and neither was superior. The traditional alpha-blocking agents have not been shown to be an effective
therapy, but a recent study of
prazosin, a selective alpha blocker, revealed excellent results in patients whose conditions were resistant to
therapy with traditional
calcium blockers, beta blockers and, in 1 case,
phenoxybenzamine.(ABSTRACT TRUNCATED AT 250 WORDS)