Increased plasma plasminogen activator inhibitor activity after coronary spasm.

To examine whether ischemic attack induced by coronary spasm changes fibrinolytic activity, we examined plasma levels of tissue-plasminogen activator antigen and plasminogen activator inhibitor activity before and after hyperventilation test in patients with variant angina and in control subjects. In 12 patients with variant angina, ischemic attack associated with ST-segment elevation on the electrocardiogram was induced by hyperventilation and plasma plasminogen activator inhibitor activity levels increased significantly 15 min after the attacks (pre, 5.1 +/- 0.8; immediately after, 5.8 +/- 1.1; and 15 min after, 7.2 +/- 0.9 IU/ml, P < 0.01). In 12 control subjects, plasminogen activator inhibitor activity levels did not change. Plasma tissue-plasminogen activator antigen levels did not change in both two groups. We conclude that coronary artery spasm increases plasma plasminogen activator inhibitor activity and that it may thereby lead to the coronary thrombus formation.