Staccato left anterior descending artery occlusion: a recognizable subset of unstable angina.

Twenty-four of 96 patients with unstable angina exhibited transient ST-T abnormalities in anterior electrocardiographic leads at rest combined with severe subtotal stenosis (80% to 95% narrowing) of the proximal left anterior descending artery (LAD). This entity is termed staccato LAD occlusion to signify the probable pathophysiology responsible for the patients' repeated episodes of ischemic cardiac angina. Although staccato LAD occlusion represents a minority of patients hospitalized with unstable angina, it includes most who suffer cardiac complications. Among patients treated medically, 10 of 16 with staccato LAD occlusion developed anterior myocardial infarction, whereas cardiac complications occurred in only three of the remaining 50 patients with unstable angina during the 4-month follow-up period (p less than 0.001). Medical treatment of staccato LAD occlusion should be directed primarily against coronary occlusion. Considering the high risk of myocardial infarction, until reliable methods for preventing the threatened occlusion are demonstrated, urgent coronary bypass surgery seems warranted for these patients.