There were numerous reports for clinical characteristics and prognosis of patients with variant angina (VA) but little information is available for patients with VA who presented as acute myocardial infarction (AMI). The purpose of this study is to determine the clinical and angiographic predictors for initial development of AMI in patients with VA and prognosis of patients with VA who presented as AMI.

The study group comprised 166 patients with VA:forty one (25%) of whom presented as AMI (Group A;Male 32, mean age 50 years) and 125 presented as typical VA or unstable angina (Group B;Male 73, mean age 54 years). The diagnosis of VA was made by spontaneous spasm and ergonovine or acetylcholine (only Group B) provocation.

1)Male gender (78% vs. 58%, p<0.05), smoking (74% vs. 53%, p<0.05), and disease duration (18±5 vs. 7±1 month, p<0.0001), and ST-segment elevation during chest pain (71% vs. 23%, p<0.05) were significantly higher in group A than in Group B. 2)Prevalence of fixed stenosis of 50% or greater was higher in Group A than in group B (12% vs. 2%, p<0.05) and the percent stenosis after nitroglycerin injection was also greater in group A than in group B (43±5% vs. 28±2, p<0.01), but the disease activity such as frequency of resting angina, spontaneous spasm, and multivessel spasm were not different between two groups. 3)During clinical follow-up at a mean duration of 2.7 years, three patient (2%) in group B died of a cardiac cause. Non-fatal MI occurred 1 (2%) and 3 patients (2%) in group A and B, respectively.

Our data show that male gender, smoking, duration of disease, ST-segment elevation during chest pain, and a fixed stenosis of 50% or greater are predictors for initial development of AMI in patients with VA. The prognosis in group A is excellent and this may be associated with less severe atherosclerotic disease and a high rate of medication with calcium channel blocker or nitrate compared with those in previous studies.